'*!.: I Mafiyland Geological Survey .ii'iiii'iii.'' m The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004627679 Cornell University Library QE 665.M38M6 Middle and Upper Devonian| ^^^^^ 3 1924 004 627 679 MARYLAND GEOLOGICAL SURVEY MIDDLE AND UPPER DEVONIAN TEXT BALTIMORE THE lOHNS HOPKINS PRESS 1913 S ^.^n2L,'=l^ /<^UJ-i^ BALTIMORE, TSa.f J. a. A. COMMISSION PHILLIPS LEE GOLDSBOEOUGH, . . . Peesident. GOVEENOB OF MABTLAND. EMEESOlSr C. HARRINGTON, COMPTKOLLEE OF MARYLAND. IRA REMSEN, Executive Officer. PRESIDENT OF JOHNS HOPKINS UNIVERSITY. E. W. SILVESTER, Secretahy. PRESIDENT OF MARYLAND AGRICULTURAL COLLEGE. SCIENTIFIC STAFF WM. BULLOCK CLAEK, State Geologist. SUPEIUNTENDENT OF THE SURVEY. EDWARD B. MATHEWS, . . Assistant State Geologist. CHARLES K. SWARTZ, Geologist. EDWARD W. BERRY, Geologist. J. T. SINGEWALD, JR., Geologist. LETTER OF TRANSMITTAL To His Excellency Phillips Lee Goldsborough, Governor of Maryland and President of the Geological Survey Com- mission, Sir: — I have the honor to present herewith the sixth volume of a series of reports dealing with the systematic geology and paleontology of Mary- land. The preceding volumes have dealt with the Lower Devonian, Lower Cretaceous, Eocene, Miocene, and Pliocene and Pleistocene deposits and the remains of animal and plant life which they contain. The present volume treats of the Middle and Upper Devonian deposits and their con- tained life, a knowledge of which is very important from an educational and scientific standpoint. I am, Very respectfully, WM. BULLOCK CLAEK, State Geologist. Johns Hopkins UNivEKSiTr, Baltimobe, January, 1913. CONTENTS PAGE THE MIDDLE DEVONIAN DEPOSITS OF MARYLAND. By Chakles S. Pbossee, E. M. Kindle, and Charles K. Swartz 23 introdtjctoby 25 general distribution 26 european equivalents 27 development of the classification in new york 32 adoption of bomney formation 40 Stbatigraphic and Paleontologic Characteristics 47 the romney formation 47 Introduction 47 Subdivisions 48 The Onondaga Shale Member 48 Character and Thickness 48 Fauna 40 Romney-Oriskany Boundary 40 The Marcellus Black Shale Member 40 Character and Thickness 49 Fauna 50 Onondaga-Marcellus Boundary 50 The Hamilton Member 50 Character and Thickness 50 Fauna 51 Hamilton-Jennings Boundary 51 Distribution of the Romney Formation 51 Exposures of Onondaga Member 53 Exposures at 21st Bridge 53 Exposure at Queens Point 54 Exposure at Williams Road 54 Exposure East of Oldtown 56 Exposure at Tonoloway 58 Exposure at Hancock 58 Exposure at Berkeley Springs, West Virginia ... 59 Exposures of Marcellus and Hamilton Members 50 Exposure at 21st Bridge 59 Exposures in Braddock and Jennings Runs 63 Exposures near Cumberland 65 Exposures at Wolfe Mill 67 Exposures on Williams Road 69 Exposure at Gilpin 72 Exposures of Southern Allegany County 75 14 CONTENTS PAGE Exposures West of Tonoloway Ridge 77 Exposure at Tonoloway 80 Exposure near Hancock 81 Exposure at Millstone 83 Exposure at Warren Point 83 Exposure at Ernstville 85 Exposure at McCoys Ferry 86 COBEELATION OF THE MIDDLE De^'ONIAN 88 ONONDAGA MEMBER 88 MARCELLTJS MEMBEE 97 HAMILTON MEMBEE ^S GEOLOCICAL DISTRIBUTION OF SPECIES 103 RELATIONS OF THE FAUNAS TO THE SEDIMENTS 109 SYSTEMATIC PALEONTOLOGY, MIDDLE DEVONIAN 115 Coelenterata. Charles S. Prosser 119 Vermes. Edward M. Kindle 122 Molluscoidea 123 Bryozoa. E. O. Ulrich and R. S. Bassler 123 BracMopoda. Charles S. Prosser and Edward M. Kindle 124 MoUusca 214 Pelecypoda. Charles S. Prosser and Edward M. Kindle 214 Gastropoda. Charles S. Prosser and Edward M. Kindle 280 Cephalopoda. Charles S. Prosser and Edward M. Kindle 307 Arthropoda 326 Trilobaia. Charles S. Prosser and Edward M. Kindle 326 Ostracoda. Charles S. Prosser and Edward M. Kindle 335 THE UPPER DEVONIAN DEPOSITS OF MARYLAND. By Charles S. PEOSSEE AND Chaeles K. Swartz 339 Introductory 341 Steatigeaphic and Paleontologic Characteristics 347 the jennings formation 347 Introductory 347 Distribution of the Jennings Formation 353 Exposures in Washington County 354 Exposure Bast of Millstone 3,154 Exposure between Tonoloway Ridge and Sideling Hill 356 Exposures in Allegany County 359 Exposure West of Sideling Creek 359 Exposure Northwest of Little Orleans 359 Exposure on Green Ridge 360 Exposure on National Road on Polish Mountain 362 Exposure on Williams Road on Polish Mountain 367 Exposure East of Cumberland 37O Exposure on Jennings Run 371 Exposure on Braddock Run 376 Exposures in Garrett County 377 Exposure in Savage River Valley 377 Exposure on National Road 378 CONTENTS 15 PAGE Exposure on Salisbury Road 382 Exposure on Pea Ridge 383 Exposure on Green Glade Run 386 Exposure on I^ess Lick Road to Altamont 387 Exposure North of Deer Park 391 Exposure Northeast of Oakland 393 Exposure on Trout Run 306 Exposure on Cherry Creek 397 Exposure at Red House 398 THE CATSKILL FOEMATION 309 Introductory 399 Distribution, of the GatskiU Formation 401 Exposures in Allegany County 401 Exposure on Jennings Run 401 Exposure on Braddock Run 403 Exposures in Garrett County 404 Exposure at Frankville and Crabtree 404 Exposure on National Road West of Frostburg 406 Exposure on Road over 4-Mile Ridge 408 Correlation of the Uppper Devonian. By C. K. Swartz 410 jennings formation 410 Introductory 410 Nature of the Problem 410 Method of Solution 410 Lithological and Faunal Subdivisions 411 Genesee Black Shale Member 411 Character and Thickness 411 Fauna 412 Romney-Genesee Boundary 412 Woodmont Shale Member 412 Character and Thickness 412 Subdivisions 413 Beds containing the Naples Fauna 413 Beds containing the Ithaca Fauna 414 Genesee-Woodmont Boundary 414 Parkhead Sandstone Member ". 415 Character and Thickness 415 Fauna 415 Subdivisions 416 Woodmont-Parkhead Boundary 417 Chemung Sandstone Member 417 Character and Thickness 417 Fauna 418 Subdivisions 418 Chemung-Parkhead Boundary 421 Catskill-Chemung Boundary 422 IQ CONTENTS PAGE ,, ,, , 423 Correlation with New York ^^^ Genesee Shale Member Woodmont Shale Member Parkhead Sandstone Member Chemung Member Correlation with Pennsylvania _ 4oo catskill formation geological disteibtjtion of species _ Local Sections of the Upper Devonian. By C. K. Swabtz 4^^ the jennings formation Sections east of Wills Mountain ^^^ I, Section Bast of Millstone **•'' II, Section along Yellow Spring Run 452 III, Section East of Berkeley Springs 454 IV, Section on National Road East of Hancock. . . 458 V, Section on Hancock-Harrisonville Road 402 VI, Section in Thompson Township, Fulton County, Pennsylvania 463 VII, Section Bast of Woodmont Station 468 VIII, Section on National Road West of Tonolo- ■way Ridge ^''^ IX, Section near Mann, Pennsylvania 474 X, Section on Sideling Hill Creek 479 XI, Section on Fifteen-Mile Creek 480 XII, Section near Little Orleans 482 XIII, Section on Western Maryland Railroad 2 Miles West of Pawpaw 489 XIV, Section at Town Creek 494 XV, Section 2 Miles North of the Mouth of Town Creek 502 XVI, Section on National Road West of Green Ridge 504 XVII, Section on Williams Road, Polish Mountain 507 XVIII, Section on National Road, Polish Moun- tain 512 XIX, Section near Round, West Virginia 516 XX, Section on Williams Road East of Cumber- land 516 Sections West of Wills Mountain 519 XXI, Section at Ellerslie, Pennsylvania 519 XXII, Section on Jennings Run Road 523 XXIII, Section near Allegany Grove 523 XXIV, Section near Keyser, West Virginia 528 XXV, Section on Middle Fork 530 SYSTEMATIC PALEONTOLOGY, UPPER DEVONIAN 535 Goelenterata. John M. Clarke and Charles K. Swartz 539 Echinodermata. John M. Clarke and Charles K. Swartz 543 CONTENTS 17 PAGE Yermes. John M. Clarke and Charles K. Swartz 544 Molluscoidea 546 BracMopoda. John M. Clarke and Charles K. Swartz 546 MoUusca 606 Pelecypoda. John M. Clarke and Charles K. Swartz 606 Oastropoda. John M. Clarke and Charles K. Swartz 661 Cephalopoda. John M. Clarke and Charles K. Swartz 690 Arthropoda 699 TriloMta. John M. Clarke and Charles K. Swartz 699 Verteirata 700 Pisces. Charles K. Swartz 700 GENERAL INDEX 703 PALEONTOLOGICAL INDEX 709 ILLUSTRATIONS PLATE FACING PAGE I. Fig. 1. — View from Sideling Hill showing Town Hill in background 48 Fig. 2. — ^View showing the Marcellus and Hamilton members of the Romney formation at 21st Bridge 48 II. Fig. 1. — ^View showing bending of Romney shale, due to creep, in cut of Western Maryland Railroad west of Tonoloway 64 Fig. 2. — ^View showing the Lower Romney sandstone on Chesa- peake and Ohio Canal near Tonoloway 64 III. Fig. 1. — ^View showing Jennings topography near Little Orleans. . . 384 Fig. 2. — View showing rectilinear jointing in the sandy shale of the Jennings formation near Stotlers Crossroads 384 IV. Fig. 1. — View showing the Woodmont shales on Town Creek, east of Gilpin 400 Fig. 2. — ^View showing the contact of the Genesee and Woodmont west of Corriganville 400 V. Fig. 1. — View showing the Catskill formation on Jennings Run Road, 1 mile east of Barrellville 416. Fig. 2. — View showing the lower part of the Catskill formation on Jennings Run 416 VI. Columnar sections in pocket at end of volume. MIDDLE DEVONIAN PALEONTOLOGY VII. Coelenterata-Anthozoa, Vermes-Chaetopoda and Molluscoidea- Bryozoa In Atlas VIII-XX. MoUuscoidea-Brachiopoda In Atlas XXI. MoUuscoidea-Brachiopoda and Mollusca-Pelecypoda In Atlas XXII-XXXIV. Mollusca-Pelecypoda In Atlas XXXV-XXXVII. Mollusca-Gastropoda In Atlas XXXVIII. Mollusca-Gastropoda and Cephalopoda In Atlas XXXIX-XLI. MoUusca-Cephalopoda In Atlas XLII-XLIII. Mollusca-Cephalopoda and Arthropoda-Trilobita In Atlas XLIV. Arthropoda-Trilobita and Ostracoda In Atlas UPPER DEVONIAN PALEONTOLOGY XLV. Coelenterata-Anthozoa In Atlas XLVI. Echinodermata-Asteroidea In Atlas XLVII-LVIII. MoUuscoidea-Brachiopoda In Atlas LIX. MoUuscoidea-Brachiopoda and Mollusca-Pelecypoda In Atlas LX-LXVI. Mollusca-Pelecypoda In Atlas LXVII-LXX. Mollusca-Gastropoda In Atlas LXXI. Mollusca-Gastropoda and Cephalopoda In Atlas LXXII. Mollusca-Cephalopoda and Arthropoda-Trilobita ! . . In Atlas LXXIII. Vertebrata-Pisces In Atlas 20 ILLUSTRATIONS FIGUEE PAGE 1. Diagram showing suggested relations between the Upper Devonian of Maryland and New York *. 97 2. Diagram showing the correlation of Marine Upper Devonian of Mary- land and Pennsylvania , 437 PREFACE The present volume is the sixth of a series of reports dealing with the systematic geology and paleontology of Maryland, the Lower Devonian, Lower Cretaceous, Eocene, Miocene, and Pliocene and Pleistocene de- posits having already been fully described. The present volume is devoted to a consideration of the Middle and Upper Devonian deposits and their contained faunas, the Lower Devonian geology and its life having been fully treated in a companion volume devoted to that subject. The discussion of the Middle and Upper Devonian is the combined result of the work of a number of individuals, many of them experts in special fields of research. The general stratigraphic description of the Middle and Upper De- vonian has been the work of Prof. Charles S. Prosser, of Ohio State Uni- versity, who has also contributed the discussion of the faunas of the Middle Devonian. The Upper Devonian faunas are described by Dr. John M. Clarke, Director of New York Geological Survey, and Dr. Charles K. Swartz, of the Johns Hopkins University. Dr. Edward M. Kindle, formerly of the U. S. Geological Survey, has contributed a chapter on the stratigraphy and fauna of the Onondaga horizon of the Middle Devonian. The limited Bryozoan and Ostracod faunas are contributed, as in previous volumes, by Drs. E. 0. Ulrich and E. S. Bassler, of the U. S. Geological Survey and U. S. ^^ational Museum respectively. Dr. C. K. Swartz, of the Johns Hopkins University, has furnished a chapter on the correlation of the Onondaga and Marcellus members of the Eomney formation, and has contributed a large amount of material for the stratigraphic and paleontologic chapters. 23 PREFACE The Maryland Geological Survey has enjoyed the cooperation of the U. S. Geological Survey as in previous volumes. It is indebted to this organization for the use of drawings illustrating Dr. Kindle's contribution. Special acknowledgment is due to Dr. John M. Clarke for the loan of many drawings first used in the classic volumes of the JSTew York Geological Survey. THE MIDDLE DEVONIAN DEPOSITS OF MARYLAND BY CHARLES S. PROSSER EDWARD M. KINDLE AND CHARLES K. SWARTZ THE MIDDLE DEVONIAN DEPOSITS ,0F MARYLAND BY CHARLES S. PROSSER, E. M. KINDLE, AND C. K. SWARTZ INTEODUCTOEY' The Paleozoic time divisions — Cambrian, Ordovician, Silurian, De- vonian, Carboniferous and Permian — ^which are called periods by the International Congress of Geologists and the United States Geological Survey and eras in Dana's Manual of Geology'' were frequently divided in a general way into lower, middle, and upper divisions while the terms earlier and later were sometimes used. In 1894, Prof. Henry S. Williams proposed that this two- or three-fold division should be designated by prefixing the syllables Eo (dawn), Meso (middle), and Neo (new) to the name of the period." Later, the syllable Paleo (ancient), has been substituted by some authors for Eo.* The Devonian formations were distributed by Professor Williams under these three divisions in the following manner : The Eodevonian contained the Oriskany sandstone, Cauda galli (Esopus) and Schoharie grits and Comiferous or Onondaga ' Contributed by Charles S. Prosser. ^ In general the taxonomic terms of the International Congress of Geologists will be used in this report. Frequently, however, the term ieds is used instead of stage, as Hamilton, Portage, or Chemung heds, a term of similar taxonomic value used by Messrs. Clarke and Schuchert in their descriptions of certain New York formations. ' Jour. Geology, Vol. II, p. 157, and see table on p. 155. ■■Clarke and Schuchert, Science, N. S., Vol. X, Dec. 15, 1899, p. 876; and Am. Geologist, Vol. XXV, 1900, p. 118. The International Congress of Geologists at the Paris meeting of 1900 adopted the prefix Paleo, but stated that Eo may be used to shorten too long a name (Comptes Rendus, 8th Session, 1901, pp. 153, 198). 26 The Middle Devonian Deposits of Maryland limestone ; the Meso devonian, the Marcellus shale and Hamilton forma- tion, and the Neodevonian the Tully limestone, Genesee shale, Portage and Chemnng formations together with the Catskill formation which in eastern ISTew York and northeastern Pennsylvania replaces the greater part of the Chemung and Portage formations. Eeeently Dr. J. M. Cleake and Prof. Charles Schuchert have trans- ferred the Lower Helderberg to the Devonian and rearranged the list of formations for the Lower Devonian and Middle Devonian. In their classification the Lower Devonian consists of the Lower Helderberg limestones or Helderberg and the Oriskany sandstone ; while the Esopus and Schoharie grits and Onondaga limestone were referred to the Middle Devonian.^ General Distribution Eocks of Middle Devonian age have a considerable distribution, aside from that of the eastern United States and Canada, for they have been identified and described in Nevada; the dolomite of Manitoba con- tains the European species Siring ocephalus iurtim; Spirifer mucronatus has been found upon the banks of the Albany Eiver south of Hudson Bay ; the fauna of the Hamilton shales occurs in the Mackenzie Valley from the Clear Water Eiver to the Arctic Ocean, while it is also reported from the Porcupine Eiver, a western tributary of the Yukon in Alaska and perhaps also on Kouiou Island in the southern part of that territory. In the Brazilian province of Para, in the Erere district, are beds which Katzer refers to the base of the Middle Devonian. Dr. John M. Clarke has stated regarding the fauna of the Erere sandstone that it " is remarkably free from species or representatives of subgeneric groups prevailing elsewhere in early Devonian faunas and equally devoid of types which elsewhere pass upward into the later faunas ; in other words, it is with all its resemblance to the Hamilton, a more typical and better defined Middle Devonian fauna than that." " ^ Science, N. S., Vol. X, 1899, p. 876. ''Archives do Museu Nacional do Rio de Janeiro, Vol. 10, 1899. Author's English edition, 1900, p. 90. Maryland Geological Survey 27 Later Prof. Sehiiehert reviewed the -works on the " Geology of the lower Amazon region " and stated that the Erere fauna " seems to hold the horizon of the American Onondaga, hardly that of the Hamilton, and certainly there is nothing in it that indicates the Genesee fauna." ^ Dr. Steinmajin reported Middle Devonian from Bolivia, east of Lake Titicaca," which is also accepted by Dr. Freeh, and Prof. Cleland from the Jachel Eiver in Central Argentina." On the Eastern Continent Middle Devonian rocks occur in England in northern and southern Devonshire, in northern France and southern Belgium, in the region of the Vosges, the Central Plateau and the Montagne-lSToire of France, in the Pyrenees and Spain. In central and eastern Europe they occur in the Eifel, Kheinland (Nassau), Hartz, Thuringia, Bohemia,, Galicia, Russian Poland, the Carnic Alps and on the Bosphorus. These rocks also cover a large area of eastern Eussia and the western slope of the Urals extending to the border of Finland on the north. In Asia Middle Devonian rocks occur in Armenia, Siberia, China and on the south side of the Tian-Shan Mountains in Central Asia. In Australasia in New South Wales, Victoria and Tasmania and also in Africa in the Sahara.' EuEOPEAN- Equivalents The early attempts at correlating the Devonian rocks of the United States with those of Europe dealt only with the formations found in New York which in fact has generally been the custom down to the present time. In 1843 Conrad published the statement that " the Ithaca group, Chemung group, and the Old Eed Sandstone near Blossburg, in Pennsyl- '■ Jour. Geol., Vol. XIV, 1906, p. 738. Also see p. 734 where Schuchert states that " while he would refer it [the BrerS fauna] to a horizon about that of the Onondaga (Corniferous), he holds that it has no close faunistic relationship with it." ^ Am. Nat., Vol. 25, p. 856. » Bull. U. S. Geol. Surv., No. 206, 1903, p. 19. * For this account of the distribution of the Middle Devonian the writer is largely indebted to de Lapparent's Trait6 de GSologie, Freeh's Lethaea palaeo- zoica and Kayser's Lehrbuch der geologlschen Formationskunde. 28 The Middle Devonian Deposits of Maryland vania, constitute the equivalents of the Devonian system as developed in Europe " and contain a number of fossils characteristic of European De- vonian strata/ The same year Vanuxem stated that the last three groups of the " Erie Division," viz., the Portage, Ithaca and Chemung "appear to correspond with the Devonian system of Mr. Phillips."' The following year Prof. Hall gave the base as somewhat lower when he stated that the Devonian system appears " to correspond to the Chemung and Portage groups, and also to include a portion of the Hamilton."' In 1847 Professor Hall stated that " With the Schoharie grit, commences a series of strata containing fossils as distinct from those of the pre- ceding formations, as these are from the lower division. We here, for the iirst time, recognize several species that are regarded as Devonian forms ; and if zoological characters are to be paramount, we are compelled to unite all the succeeding strata as of Devonian age." ' Finally, in 1859, he raised the question whether even the Oriskany sandstone might not be considered as of Devonian age. For he wrote as follows concerning " the line of demarcation for the Silurian and Devonian systems. Shall the advent of the Oriskany sandstone, with its Spirifer of dichotomizing costas, be the division ? Or shall we look for some more marked and more readily defined and recognized feature for the distinction between what are regarded as two great geological systems ? " ' So far as the writer is aware de Yerneuil, in 1847, was the first geologist to definitely correlate the younger formations of the N"ew York System with subdivisions of the Devonian system of Europe. He made the base of the Oriskany sandstone the dividing line between the Devonian and Silurian systems ; ° correlated the Hamilton, TuUy, G-enesee, Portage and Chemung with the formations of the Eifel and Devonshire, and the ^ Jour. Acad. Nat. Sci., Philadelphia, Vol. VIII, p. 232. ' Geology New York, Pt. Ill, p. 171. ' lUa., Pt. IV, p. 20. * Palseontology of New York, Vol. I, p. xvii. » Ibid., Vol. Ill, Pt. I, p. 42. "Bulletin SoclgtS G6ologique de France, 2d ser.. Vol. IV, p. 677; also Am. Jour. Science, 2d ser.. Vol. V, 1848, p. 367. On the parallelism of the Palseozoic deposits of North America with those of Europe, translated by James Hall. Maryland Geological Survey 39 Mareellus with the shales of Wissenbach in N'assau, as is proved by their GoniatiteSj so analogous in form/ In recent years several geologists have considered the correlation of the American Middle Devonian with European rocks of equivalent age, of which the following are the most important. In 1889 Prof. H. S. Williams apparently correlated in a general way the American Middle Devonian with " the Ilf racombe [England] beds of Phillips, the Givetian limestone of Belgium, [and] the Stringocephalien shales or limestones of the Eifel and Hartz regions.'" In 1888 Prof. Williams examined in the field typical sections of the Devonian rocks of Devonshire, England, and later stated that " It appears probable that the limestones of South Devonshire represent the general interval be^tween the close of our Comiferous [Onondaga,] and the early part of our Chemung formations."' Professor fienevier, in 1896, classed the Hamilton flags and Mareellus shales together and regarded them as having been deposited during the same general period of time as the Tentaculite slates (lower part) of Thuringia, Hesse, Is'assau, and Bohemia; the Wissenbach or Orthoceras slates of Nassau; the Lenne slates (in part) of southern Westphalia and the schists with Phacops potieri of Brittany; all of which were correlated with the Couvinian age or stage, which he gave as the lower one of the Middle Devonian or Eifelian epoch or series.* Dr. Freeh draws the line between the Ix)wer Devonian and the Middle Devonian of New York at the top of the Upper Oriskany sandstone and considers the Middle Devonian as composed of the Ulsterian and Erian series, in the latter of which are the Mareellus shales, Hamilton beds and Stringocephalvs beds of Canada.' At an earlier date Dr. Erech in his summary of the important occurrences of the Devonian gave the ^Ibid., p. 678; and Am. Jour. Sci., ibid., pp. 367, 368. "CongrSs Gfiologique International. Compte Rendu, 4me. session, Londres, 1888, 1891. Appendix A, p. 142. Also issued as : Report of the Sub-Committee on the Upper Paleozoic (Devonic) by H. S. Williams, C, 1889, p. 22. ' Am. Jour. Sci., 3d ser.. Vol. XXXIX, 1890, p. 36. * Chronographe gfiologique. 2de 6dit. des Tableaux des Terrains sfidimen- taires. Compte-rendu du CongrSs Gfiologique International, Sixi§me session, Aoflt, 1894, Zurich; Lausanne, Mars, 1897. " Lethffia geognostica, I Th. Lethsea palseozoica, 2 Bd., 4 Lief., 1902, p. 690. 30 The Middle Devonian Deposits of Maryland Marcellus shale and Hamilton group as forming the upper part of the Middle Devonian and correlated them as beginning in the time of the upper part of the Calceola sandalina stage and continuing through that of the Stringocephalus lurtini of Rheinland/ In this same table the Marcellus and Hamilton considered together are correlated with the upper part of the Eifelian {Calceola, shales of Couvin) together with the entire Givetian (which is composed in ascending order of the red sand- stone and conglomerate of Vicht and Stringoceplialus limestone of Givet) of Belgium. While they are given as equivalent in England to the llfracombe beds, vdth probably additional ones below and above, of ISTorth Devon; and to the upper part of the Calceola shales of Hope's Nose and Ogwell House succeeded by the diabase and scale stone of the Ash- prington series and the Stringocephdliis limestone of South Devon. In another part of the work Dr. Freeh in comparing the North Amer- ican and Rhenish Devonian said : In the Comiferous [Onondaga] lime- stone the faunal diversity is less sharply defined than in the lower formations; but in this case as in the higher Hamilton group still dis- tinctly perceptible. The latter is often developed in the form of sandy marl and caJcareous sand and the peculiar faunal similarity with the Ehenish Lower Devonian partly rests upon this harmony in facies. But on the other hand, the marl (Moscow shale), for example, where it forms on Cayuga Lake the greater part of the Hamilton, has a perfect agree- ment in facies with the Calceola marl and likewise the Encrinal lime- stone reminds one of a similar interstratified limestone The fauna of the American Middle Devonian, whose chief representatives the Hamil- ton group contains, is notwithstanding some corresponding features yet on the whole so different, that one must assume the existence of a special sea province also in Middle Devonian time differing from the Rhenish." .... Finally at the close of this section is the statement that the Mar- cellus shale corresponds to the lower part of the stage of the Maeneceras terebratum' of Rheinland which Dr. Erech puts in the stage of the Stringocephalus lurtini. ^IMd., 2 Bd., 1 Lief., 1897, Tab. XIX, op. p. 256. "Jftid., pp. 214,215. 'Ibid., p. 216. Maryland Geological Survey 31 De Lapparent considered the Middle Devonian of North America as composed of tlie Comiferous (Onondaga) limestone, Marcellus shale and Hamilton beds." The Marcellus shale he correlated with the upper part of the Eifelian stage and lower part of the Givetian while the Hamilton beds represent the remaining and greater part of the latter stage. He also gave the lower Marcellus shale as representing the upper part of the shales of Ogwell House and then the remaining portion together with the Hamilton beds as synchronous with the Ilfracombe or Plymouth beds of Devonshire, England." Professor Kayser in the table of the Devonian formations of New York in the second edition of his Formationskunde gave the Middle Devonian as composed of the Marcellus shale and Hamilton beds ; * but in the text he said : The American geologists generally still classify the Onondaga limestone as Lower Devonian; according to European ex- perience one would rather be inclined to classify it entirely or mostly as Middle Devonian. The great similarity of the characteristic Spirifer acuminatus with our S. cultrijiigatus argues for this classification." Eegarding the classification oi the Hamilton he wrote : Although the Hamilton shale locally might represent the entire Middle Devonian yet on the whole it corresponds to the upper division. This is surely shown by the frequent overlying beds of the Tully limestone and Genesee shale, the first of which contains the Brachiopod fauna of our Iberg limestone (Rhynchonella venusiula-cuboides, ete.).° The third edition of this standard reference work, however, gives the Middle Devonian as composed of the Schoharie grit, Onondaga limestone, Marcellus shale and Hamilton beds ° which differs from the classification of the Middle Devonian of New York by Clarke in the exclusion of the Esopus grit. • Traite Geol., 4th ed., 1900, p. 857. ^ lUd., p. 869. ^ Lehr. d. geol. Formationskunde, 1902, p. 150. *I6id., p. 151. "J&iti., p. 151. "lUd., 1908, p. 172. 33 The Middle Devonian Deposits of Maryland Finally Kayser has given the correlation of the Middle Devonian of Europe and ISTorth America in the following table : Sheinland Selgium Bohemia North America Stringocephalus limestone, Wissenbach and H G3 G' Gi and Hamilton beds Marcellus beds Onondaga limestone Calceola shales Lenne slates Mnenlan limestone and Schoharie sandstone Dr. Hermaiin Credner gives the Middle Devonian of ISTew York as composed in ascending order of the Upper Helderherg (Onondaga), Marcellus shale and Hamilton sandstone, shale and limestone. The Upper Helderherg he correlates with the Eifelian and stage of the Calceola sandalina and the Marcellus and Hamilton with the Givetian and stage of the Stringocephalus iurtinu Sir Archibald Geilde considers the Middle Devonian of New York as composed of the Marcellus and Hamilton groups ; ' while the same divi- sion in Europe he gives as composed of the Eifelian and Givetian with which he correlates the Marcellus and Hamilton.* Development of the Classification in New York The Geological Survey of New York was organized in 1836 and the annual reports contained the preliminary names of the formations which now compose the Devonian and other systems of rocks represented in that state." The correlation for the different districts, however, had been more fully perfected when the final reports were published and in these we find, substantially, the list of names which have become classic in the Paleozoic geology of North America. Dr. Emmons' report on the Sec- ond District, which covered northeastern New York, was published in ^Ibid., p. 179. ' Elemente d. Geologie, 9th ed., 1902, p. 447. = Text-Book of Geology, 4th ed.. Vol. II, 1903, p. 997. * IMd., " The Geological Record," opposite p. 861. " See especially the 3d and 4th An. Repts., Fourth Geol. Dist. (Assemhly Doc. No. 275, 1839, and ibid., No. 50, 1840), and 4th An. Rept, Third Geol. Dist. (Assemhly Doc. No. 50, 1840). Maryland Geological Survey 33 1842 and the name " New York Transition System " was used for the " series which fill up the space between the Primary and the Old Eed System." * This system was divided by Dr. Emmons into four groups which, arranged in ascending order, he characterized as follows : " Cham- plain group, at the base of the Transition system; Ontario group, com- prehending the rocks which lie upon its southern border for about 15 or 20 miles; the Helderberg series; and lastly, the Erie group, which completes the whole series of the system, extending up to the old red sandstone." ' The limits of these groups are not clearly indicated in this part of the report; but it appears probable that the upper limit of the Helderberg group was placed at the top of the Upper Helderberg or Onondaga limestone and that the Erie group included the rocks from the base of the Marcellus shales to the top of the Chemung. At the close of the report is given a " Tabular view of the sedimentary rocks of New York'" in which appears the "New York system" composed of the four groups named in the earlier part of the report, while the limits of the Helderberg and Brie groups are clearly shown to he as above stated. The Devonian rocks of New York, however, are most typically developed in the central and western parts of the state which formed the Third and Fourth Geological Districts. The final report of the Third District by Lardner Vanuxem, which covered central New York, also appeared in 1842 and in this the classification of Dr. Emmons, though somewhat modified, was adopted.' All the sedimentary rocks of the district, with the exception of the Quaternary and some beds referred to the Taconic system, were given under the " New York System " which was composed of five divisions named in ascending order the Champlain, Ontario, Helderberg, Erie, and Catskill. The Helderberg division included all the rocks from the base of the " Onondaga salt group " to the top of the " Corniferous limestone " ; while the Erie division contained the Marcellus '■ Geology New York, Ft. II, p. 99. 'Ihid., p. 100. = I&i..^... lilMlM iiirfinr- vM^^ « -'»>^- '"''^'^'^^^^:.j:..' ^Z'. .:. :'-*■■::■■■ - ■ ^.r-*^-"'- ■:- H^ /^*^'^^^- *-;'*r"'"^ .3t '.":.'/--. ■^ ^ESi'«:»<.;', ■ , :- . -■. i^^ A. ■.■■'^^:. /.,.,, -i'^: !; ■ . ' ■ ■ ^■vtr vv Fig. I. — ^viEw from sideling hill showing town hill in background. Fig. 2.- -VIEW SHOWING THE MARCELLUS AND HAMILTON MEMBERS OF THE ROMNEY FORMATION AT 2IST BRIDGE. Maryland Geological Survey 49 purity. They play a less important role in the Maryland sections than in Pennsylvania, the dark and drab shale almost, if not entirely, supplant- ing them locally. The thickness of this member varies from 100 to 150 feet. Fauna. — The Onondaga member contains numerous species many of which are found in the Marcellus and Hamilton of New York. Associated with them, however, are some which are restricted to the Onondaga of New York, including Anoplotheca aawtiplicaia, which is probably the most com- mon member of the fauna, and several trilobites. . Eomney-Oriskany Boundaky. — Unconformable relations between the shale of the Onondaga member and the Oriskany sandstone are strongly suggested by the extremely abrupt and complete change in the character of the sediments at the top of the Oriskany sandstone. The lithologic change is from a coarse sand to a very fine-textured shale. The faunal change is equally abrupt. The unconformity which appears to exist be- tween the Oriskany and the Onondaga shale member is to be correlated with the well-known one at the base of the limestone of Onondaga age in western New York, Indiana, and Kentucky. Eowe has shown that a conglomerate develops locally at the base of the Eomney as in the section at Warren Point, Pennsylvania, affording additional evidence of this unconformity. Again, the thickness of the Oriskany decreases from 417 feet at Tonoloway to 53 feet at Warren Point, but 15 miles northeast of the former place suggesting erosion of the Oriskany. Marcellus Black Shale Meniber Character and Thickness. — The Marcellus member of the Eomney formation in Allegany County is composed principally of fissile black shale some of which weathers to a yellowish or buff color on long exposure. In comparatively fresh exposures, however, as in the railroad cuts at 21st Bridge the shales are either black or rusty brown after some weathering. The black shales are shown to best advantage in these cuts although, on the Williams Eoad, 3% miles southeast of Cumberland, is, perhaps, the most nearly complete exposure of this division with an approximate thick- ness of 500 feet. In the lower part of some exposures are bands or nodules 4 50 The Middle Devonian Deposits of Maryland of very dark colored thin limestone. The lithologieal characters of these shales agree closely with those of typical exposures of the Marcellus shales in New York state. Fauna. — This member contains a meager fauna comprising but few species and individuals. The most abundant forms are Liorhynclius limi- tare, L. mysia, and Styliolina ■jisswrella, which are common in the Mar- cellus formation of New York. Onondaga-Maecellus Boundaey. — The contrast between the lithology of the Onondaga and Marcellus shale members of the Eomney is generally well marked except near the zone of transition between the two. Black bituminous shales are sometimes conspicuous elements of the lower mem- ber but almost invariably form a subordinate part of the beds and are less frequently fissile than those of the overlying Marcellus. Carbonaceous shales comprise a large part if not the whole of the Marcellus member in most sections and are highly fissile. The intergrading of the two types of sediment will, however, always make it difficult in many sections to decide upon a precise plane of separation. This intergrading is of much the same character as that between the Marcellus and Hamilton in New York. In some sections, as at 31st Bridge on the Potomac Eiver, a band of argillaceous limestone terminates the Onondaga shale member. Hamilton Member Character and Thickness. — This member of the Eomney formation has an approximate thickness of 1000 feet and is composed of shales and sandstones. In recent exposures the shales, generally bluish or bluish- gray in color, vary in composition from rather coarse arenaceous to those that are fine and argillaceous. The sandstones, which on fresh surface are generally blue or gray in color, are not very coarse in texture and the layers are often less thaa a foot thick. All of these rocks, however, on long exposure usually present along the highway a slightly greenish or yellowish-gray tint. Two or more prominent sandstone zones varying in thickness from about 30 to 75 feet occur in this member of the formation. The lower one is from 850 to 1050 feet above the base of the formation, in the sections east of Wills Mountain, while the upper zone is at or near the Maryland Geological Sukvey 51 top of the formation. Both of these sandstone zones are clearly shown in the sections on the Williams Road and at Tonoloway Station, opposite Great Cacapon, and the upper one at Gilpin and above Corriganville. A conglomerate is found about 175 feet below the top of the Hamilton in the sections east of Hancock. In the vicinity of Millstone it becomes con- spicuous and forms well defined ridges. Fauna. — The shales in many localities are very fossilif erous, especially those between the two sandstone zones, and contain numerous specimen? of such characteristic species of the iN'ew York Hamilton as Spirifer rmwronatus (Conrad), iS. granulosus (Conrad), Athyris spirifer aides (Eaton), Tropidoleptus carinaius (Conrad), Chonetes coronatus (Con- rad), Phacops rana (Green), and other species. On account of the presence of numerous Hamilton species together with a lithologic simil- arity and approximate stratigraphic position this division of the Eomney formation is regarded as equivalent to the Hamilton stage of New York. Eomney-Jennings Boundary. — The boundary between the Hamilton member of the Eomney and the Jennings formation is discussed on a subsequent page to which the reader is referred. DISTRIBUTION OF THE ROMNEY FORMATION The Eomney formation in M.aryland is confined to Allegany and Washington counties in the Eidge District of the Greater Appalachian Valley, the larger area occurring in Allegany County. The western area enters this county from Pennsylvania at Bllerslie and, skirting the foot hills of the Allegany Front, crosses to the Potomac Eiver and then extends southwest to the bend in the river at Keyser. In the region between Shriver Eidge and Green Eidge are several areas, mostly narrow, their outline due to the repeated folding of that section. The first one is a V-shaped area the western arm of which passes through the eastern part of Cumberland, the point extending into Pennsylvania, and the eastern arm lying mainly to the east of Evitts Creek and west of Nicholas Moun- tain extends south, crossing the Potomac Eiver at North Branch where it enters West Virginia. In the valley between Nicholas and Collier moun- 53 The Middle Devonian Deposits of Maryland tains is a narrow belt which extends two-thirds of the distance across the state and in the smaller valley to the east of Collier Mountain is a narrower area with less than half the length of the one just described. Immediately to the east is a belt of Oriskany sandstone and then the largest continuous area of Eomney in the county is reached which extends for 8 miles along the Potomac Eiver and may be called the Oldtown area from the village of that name in the Potomac valley about two-thirds of the distance across the area. In its western part the uplift of Warrior Mountain brings up the Oriskany sandstone and Helderberg limestones while the similar uplift of Stratford Ridge in its eastern part exposes the Oriskany. About half-way across the county the area greatly decreases in breadth and skirting the eastern side of Warrior Mountain and Iron Ore Ridge enters Pennsylvania to the northeast of Flintstone where it is about three-fourths of a mile in breadth. The most western area in Washington County extends as a narrow belt from the northeast to the southwest just west of Tonoloway Ridge and may be called the Tonoloway area. It crosses the Potomac Eiver into ' West Virginia a short distance west of Great Cacapon. Further east in the Hancock area, is a belt about one-half mile in width, upon which Hancock is situated, which crosses the county in a direction parallel to the one just described. The largest area in the county enters it to the southwest of Warren Point, Pennsylvania, makes a horseshoe curve about Elbow Eidge, returns into Pennsylvania crossing Licking Creek, and then turns and recrosses Washington County from the north- east to the southwest reaching the Potomac River at the mouth of Licking Creek. Since this area crosses Licking Creek several times it may be termed the Licking Creek area. To the southeast is the Emstville-McCoys area which begins at Emstville and extends eastward to the uplift of Forth Mountain. The lower shales are shown in Emstville, and at Mc- Coys Ferry are exposures of the Hamilton beds containing an excellent representation of the Hamilton fauna. This area is the farthest east that the Eomney formation is known in Maryland. In Garrett County the Eomney formation is not known to reach the surface, although there is a considerable area of the overlying Jennings. Makyland Geological Survey 53 Exposures of Onondaga Member Exposure at 21st Bridge. — There is probably no locality in Mary- land where the relations of the Onondaga, Marcellus, and Hamilton mem- bers of the Eomney can be seen to better advantage than at 21st Bridge, 1 mile east of Keyser. The three cuts adjacent to the intersection of the Baltimore and Ohio and Western Maryland railroads, together expose nearly all of the two basal members and a portion of the Hamilton. The lower portion of the Onondaga and the basal Oriskany sandstone are well exposed in the west cut where the section shows the following beds: Feet Drab, rather hard, slightly sandy shale with some calcareous concretions and bands 45 Lead-gray, fissile soft shale, Orhiculoidea abundant w 40 Oriskany sandstone 30 The highest beds of the Onondaga do not appear in the west cut but are exposed in the east cut of the Western Maryland Eailroad at 21st Bridge. These highest beds include at the top about 8 feet of dark argillaceous limestone in strata 6 to 20 inches thick, interbedded with dark shale. They were estimated by Prosser to lie about 168 feet above the base of the Eomney, giving a total thickness of about 170 feet for the Onondaga. This limestone holds Agoniatites expansus suggesting that it may represent a horizon near that of the " Agoniatite limestone " fauna of New York which, according to J. M. Clarke,^ was introduced into western New York before the cessation of Onondaga limestone depo- sition. With the exception of A. expansus, however, the fauna of this zone bears little resemblance to the assemblage recorded from the " Ago- niatite limestone " of New York. The following species have been recognized in a collection made by Swartz from a bed about 100 feet above the base of the Eomney in a section ascending the hill east of the river one-half mile south of 21st Bridge : Pholidops cf. areolata Dalmanella lenticularis Goniophora sp. undet. Panenka sp. undet. Agoniatites expansus. Phacops cristata ' Bull. New York State Mus., No. 49, 1901, p. 137. 54 The Mibole Devonian Deposits of Maryland A portion of the Marcellus shale is exposed above these limestone beds in the eastern part of this cut. In the Baltimore and Ohio Eailroad cut at Twenty-first Bridge nearly the whole of the Marcellus is exposed. The lower part of the beds at the south end of the cut contain in certain strata a great profusion of the flattened shells of Liorhynclvus Umitare which seem to occupy the strata in which they occur almost to the exclu- sion of other fossils. The southern half of the Baltimore and Ohio Eailroad cut is nearly all in the highly inclined, soft bluish-black Mar- cellus shales which appear to be nearly barren except for the Liorhynclius Umitare beds in the lower part. The development of minor crumpling and folding in these beds makes it difficult to estimate their thickness. There appears to be more than 100 feet of these nearly barren dark shales between the Onondaga shale and the beds holding the Hamilton fauna. In the northern half of the Baltimore and Ohio Eailroad cut about 75 feet of gray argillaceous and sandy shales are exposed. These contain a rich Hamilton fauna with such characteristic species as Tro- pidoleptus carinobtus and Spirifer mucronatus. The comparatively poor exposure of the Onondaga shale one-third mile west of Twenty-first Bridge, near Eosedale switch, affords a richer fauna in the lower beds than the cut at Twenty-first Bridge. The most abund- ant species at this point are Anoplotheca acutipUcata and Orbiculoidea media. Exposure at Queens Point, opposite Keyser, West Virginia. — The most westerly exposure of the Onondaga shale in the state occurs opposite Keyser, W. Va., at the foot of the Queens Point cliffs. Only a few feet of drab shales can be seen here. The fossils noted here include Fholidops sp. undet., Bollia ungula and some goniatite and trilobite fragments. West of this point the structure brings to the surface nothing older than the Upper Devonian. Exposure on the Williams Road 31/2 miles east of Gumlerland. — This section affords a nearly continuous exposure of the beds from the Oris- kany sandstone to the Parkhead member of the Jennings, and affords a clear conception of the essential characteristics of the different divisions of the Eomney. The Hamilton beds are described by Prosser in a subse- Maryland Geological Survey 55 quent chapter. Minor folding makes the Onondaga member appear thicker than it is/ The section begins at the Romney-Oriskany contact at the foot of Nicholas Mountain, east of Mt. Hermon Church, and extends westward on the old Williams Eoad. ROMNET FOKMATION Hamilton Member i, ^ rr, ^ , Feet. Total. No. 10. Soft drab shale weathering to small many-sided frag- ments 250+ 1097 No. 9. Gray sandstone with Hamilton fossils Tropidoleptus carinatus, etc 35 347 No. 8. Drab shale weathering in lumpy fragments 150 812 Marcellus Meviber No. 7. Black to drab fissile clay shale grading into next division. 360 662 No. 6. Road leading north, drab or buff blocky shale, a con- cretionary limestone 9 inches thick is found just below top of this unit. The shale contains: Strophalosia truncata (c), Liorhyn- chus Umitare (c), LiorhynchVrS cf. mysia (a), BucMola retrostriata (r) 45 302 No. 5. Fissile black shale. StylioUna flssurella ahundunt 100 257 Thickness, Marcellus member 505 Onondaga Memier No. 4. Green and drab shale. Repetition of bed No. 2 in part. .. . 102 157 No. 3. Fissile black shale weathering gray. Repetition of bed at base of Onondaga. Pholidops cf. areolata (r), AnoplotUeca acuti- pUcata large individuals (c), Agoniatites cf. expansus (r) 55 55 No. 2. Green and drab colored clay shale weathering in one band 10 feet thick to reddish. Minor folding. Chonetes mucronatus (a,) , Chonetes rugosa n. sp. (c), Pholidostrophia pennsylvanica n. sp. (r), Anoplotheca acutiplicata (r), Anoplotheca Camilla (r), Ambo- coelia um,bonata (a), Nucleospira cf. concinna (r), Reticularia cf. pmbriata (r), Nuculites modulatus n. sp. (r), Paleoneilo cf. con- stricta (r), Liopteria laevis (r), Orammysia sp. (r), EutUydesma? sp. (r), Modiom,orpha subalata (r), Naticopsis sp. (c), Loxonema hamiltonae (r), Euom,phalus sp. (r), Ooniatites sp. (r), Bactrites aciculus (c),Bollia ungula (c), Bollia obesa (r) 160 No. 1. Lead gray to black clay shale. Orbiculoidea lodiensis var. media (a), Anoplotheca acutiplicata (a), Bactrites aciculus (c), Enchostoma f sp 55 Thickness, Onondaga member 157 Oriskany-Romney contact ' The original measurements of the author did not allow for this feature. He is indebted to Dr. C. K. Swartz who first called his attention to this fact, and who has revised his estimates of the thickness of the lower beds. 56 The Middle Dea'Onian Deposits of Maryland Obiskany Fokmation Buff or brownish rather coarse sandstone with numerous fossils. The fossils were collected from the various beds of the above section. The lowest division contains a profusion of individuals but a very limited number of species. The succeeding bed contains a much more varied fauna and contains many species diagnostic of the Onondaga. The highest fauna which shows definite affinities with the Onondaga is in the succeed- ing bed which, however, is probably a repetition of the lowest unit de- scribed. The black fissile shale occurring 157 to 357 feet above the base is probably to be referred to the Marcellus ■whfle the overlying bed 45 feet thick contains a well defined Marcellus fauna.' In this as in many other sections no very sharp line can be drawn between the sediments holding the Onondaga and the Marcellus faunas, the one grading into the other. Taken as a whole, however, the upper, or Marcellus, shales are decidedly blacker and comparatively freer from light- colored shales than is the lower series in which green and drab-colored shales predominate. The Tropidoleptus carinatus fauna characteristic of the Hamilton was found in a bed of gray sandstone which lies not far above the base of that member. Exposure east of Oldtown. — One mile east of Oldtown, a cut in the Western Maryland Railroad affords an excellent section of the Onondaga and Marcellus shales. The Hamilton member and its fauna is also ex- posed a short distance east of this cut. The section exposed here follows : RoMNEY Formation Hamttton Member ^^^^ ^^^^ No. 13. Hard drab sandy shale: Lingula sp. undet., Spirifer mucronatus, Amtocoelia umlonata. Stropheodonta perplana, Tro- pidoleptus carinatus 400-)- 1060 No. 12. Gray fine-grained sandstone, weathering to shaly beds . . 50 660 No. 11. Drab and dark steel-gray hard shale, and covered, thick- ness very uncertain, Hamilton ? (Duplication by local folding) 250± 610 No. 10. Hard sandy drab shale with three or four thin bands holding Aulopora sp. at east end of cut 40 360 'Prosser has included all the beds above the base of the black shale, which occur 302 to 662 feet above the base of the section, in the Hamilton. The author would place the Marcellus-Hamilton boundary about 350 feet higher than the horizon selected by Prosser (662 feet above the base of the section). Maryland Geological Survey 57 Marcellus Member y^^t ^otai. No. 9. Hard fissile black shale with some thin hands of blue lime- stone full of Amhocoelia virginiana. (Local folding within, this ter- rane makes impossible any close or precise estimate of thickness) . . 100± 320 No. 8. Band of black limestone concretions 1 220.5 No. 7. Hard fissile black shale Styliolina fissurella nearly barren 115 219.5 Onondaga Member No. 6. Dark gray impure limestone in % to 1 inch bands inter- bedded with black bituminous shale, Strophatosia truncata and Cen- tronella of. ovata abundant in some bands of limestone 15 104.5 No. 5. Dark lead-gray to blackish shale 40 89.5 No. 4. Lead-gray blocky shale slightly calcareous with numerous goniatites and pelecypods in certain bands 6 49.5 No. 3. Dark lead-gray blocky shale with some' slightly calcareous bands: Dalmanella lenticularis, Modiomorpha sutalata, Panenka alternata, Panenka of. dichotoma, Panenka obsolescens n. sp., Panenka cf. muUiradiata, Agoniatites expansus, Phacops cristata var. pipa 30 43.6 No. 2. Soft dark gray to black argillaceous shale 12 13.5 No. 1. Fissile soft black shale with well rounded sand grains rather common 1.5 1.5 Ortskany Pokmation Drab or brownish soft shaly sandstone 1 Gray very hard coarse sandstone with Oriskany fossils, dipping east 12 The strata of this section which are assigned to the Onondaga shale include beds 1 to 6, a total thickness of about 105 feet. In the lower part of the shale below division 3 fossils are scarce with the exception of Anoplotheca acutiplicata which is a common species at this horizon. The next higher bed, 3 of the section, contains a rich fauna as shown by the foregoing list. The succeeding division of the section appears to contain few fossils and none were collected from it. The 15 feet of dark bituminous limestone at the top of the Onondaga contain in some bands great numbers of minute brachiopods. The two species Centronella cf. ovata and Strophalosia iruncata comprise a large proportion of the material of some of these bands. The next 100 feet of these shales represent the Marcellus. The only- fossil observed in them is Styliolina fissurella which occurs in abundance in certain beds in the upper part. 58 The Middle Devonian Deposits of Maeyland The next 100 feet of the fissile black shales, 9 of the section, appears to be barren except for some thin bands of blue limestone which are crowded with the minute shells of a variety of Ambocoelia virginiana. The lowest Hamilton fauna observed appears in some hard sandy beds about 250 yards east of the end of the cut. Exposure at Tonoloway. — At Tonoloway, opposite Great Cacapon, W. Va., nearly the whole of the Devonian below the Parkhead member of the Jennings is exposed with the exception of the Marcellus shale which is almost entirely concealed in the bottom of a small valley which reaches the Potomac along the strike of the beds of this portion of the section. At the base of the Marcellus shale and immediately above the Oriskany sandstone about 60 feet of interbedded greenish-drab and black blocky shale is exposed representing the Onondaga shale. The following fauna was found in these beds : Strophalosia truncata r Rhipidomella vanuxemi : c Ambocoelia umbonata c Nucleospira concinna c Dalmanella lenticularis c AnopUa cf. nuclenta r Leptaenisca austraUs r Styliolina fissurella a PJiacops cristata r Bollia ungula c BoUia obesa r Craterillina sp. Polygnathus sp. uudet r Four hundred feet or more above this fauna the typical Hamilton fauna appears in this section. Exposure at Hancock. — At Hancock the Onondaga fauna was found on the hill northwest of town, just east of the old sand quarry, in green blocky clay shale. About 60 feet above the Oriskany sandstone at this locality the following fossils were secured : Ambocoelia umbonata r Styliolina fissurella a Phacops sp. undet. Maryland Geological Survey 59 Typical thin, papery black shales of the Marcellus type are exposed in the shale quarry about 50 feet above this fauna. The Marcellus shale here, as in most of the Alleghany sections, is largely concealed in the slopes of a valley which occupies the easily eroded beds of the Marcellus horizon. They appear to have a thickness of 400 feet or more at Hancock. Exposure at Berkeley Springs, West Virginia,. — A good section of the Onondaga member occurs about 1% miles south of Berkeley Springs, W. Va., where the wagon road cuttings expose the Oriskany sandstone and the lower portion of the Romney, including most of the shales holding the Onondaga fauna. The following section was noted here : Romney Formation Marcellus Memher ^^^^ T„j^j_ No. 5. Fissile black shale, and covered 250 333 Onondaga Mevtber No. 4. Covered 35 83 No. 3. Black blocky argillaceous shale, full of fossils: Ghonetes sp. (r), Amhocoelia umbonata (a). Nucleosvira concinna (c). Anoplea nucleata (c), Dalmanella lenticularis (a), Leptaenisca australis n. sp. (c), PfiolidostropMa pennsylvanica n. sp. (r), Nucula of. coriuliformis (r), Cypricardinia f sp. (r), StylioUna fissurella (a), Phacops cristata (c), Gyphaspis cf. stephanophora (r) , Leperditia ? cf. suhrotunda (r) 20 48 No. 2. Drab shale, weathering cherry red in places; fossils scarce: Craniella hamiltoniae, LeptostropMa perplana, Ambocoelia umbonata 18 28 No. 1. Cream or light putty-colored clay shale, with some bufiBsh layers 10 10 Obiskany Formation Buffish-brown sandstone, crumbling to sand. The Marcellus in the section is imperfectly exposed and no fossils were observed in it. Exposures of Marcellus and Hamilton Members Exposure at 21st Bridge. — The best locality at which to study the Romney formation in its western area in Maryland is near its southern 60 The Middle Devonian Deposits of Maryland end in the railway cuts directly north of the Slst Bridge station on the Baltimore and Ohio E. E. This locality is 1% miles northeast of Monster Eock and the Oriskany sandstone and Helderberg limestones are well shown in the Baltimore and Ohio E. E. cut on the West Virginia side of the river. On the Maryland side of the river just above the railway bridge is a contact of the Oriskany sandstone and Eomney formation. In the ridge to the east of the West Virginia Central E. E. cut the folded Oriskany sandstone is nicely shown. The sections of. the Onondaga member in this vicinity are described by Kindle on a preceding page. In the West Virginia Central E. E. cut to the west of the river the black shale and blackish limestones at the top of the Onondaga member are exposed. The rocks dip steeply down to the cut of the Baltimore and Ohio E. E. which is directly below and only a short distance north of the 21st Bridge. At the southern end of the latter cut are thin, argillaceous, black shales, weathering to a rusty brown or iron color, which are somewhat above the limestones in the West Virginia Central E. E. cut. In some of the layers which are a little more arenaceous and tougher than most o'f the shales Liorhynchus limitare (Vanuxem) occurs abundantly, associated with an occasional other fossil. Some of the specimens of Liorhynchus are very perfect representatives of the species. Many of them, however, in the thin black shales are greatly crushed so that they are as flat as those occurring in the fissile black shales of New York, which they closely resemble, while some of the specimens from the coarser shales are gib- bous retaining the normal form of the species. From these shales the following species were obtained : Camarotoechia prolifica Hall ( ?) (poorly preserved specimens), Liorhynchus limitare (Vanuxem), Tropi- doleptus carincdus (Conrad), Brachiopod sp. (specimens that seem to have a pustulose or punctate structure, something like Spirifer fimhriatus but there is no fold or sinus and rather coarse plications cover the entire surface), Nuculites triqueter Conrad ( ?) (very imperfectly preserved). The shales here and there contain small somewhat calcareous concre- tions in which are numerous specimens of Liorhynchus limitare (Van- uxem) while some of the concretions are larger and more calcareous. Prom the range of the species it will be seen that the fauna is similar Maryland Geological Sdevey 61 to that of the Marcellus shales in New York. The lithologic character of the shale both before and after weathering agrees perfectly with much of the New York Marcellus. The correlation of these black fissile shales with the Marcellus shale of New York appears to the writer very probable ; a conclusion which is supported by various other sections in the lower part of the Eomney formation in Allegany and Washington counties as well as in the typical region of the formation near Eomney, West Virginia, which was carefully examined in connection with this work. Succeeding the fine black shales are rather coarser ones changing to thin sandstones or very arenaceous shales. Some of the shales in this zone are very thin and argillaceous and weather to a rusty color like the Marcellus. Other layers are more arenaceous, and vary to thin yellowish-green sandstones in which scarcely any fossils were found. At one place they form a sandstone stratum several feet in thickness composed of fairly thick layers. Fossils occur but infrequently in the lower part of this zone ; but increase in abundance in the higher rocks. The following species were collected in this part of the cut: Lingula clarhi Prosser, Stropheodonta sp., Chonetes mucronatus Hall, Chonetes scitulus Hall, Chonetes setiger (Hall), Chonetes lepidus Hall, Camarotoechia pro- lifica Hall (imperfect specimen), Liorhynchus sp., Tropidoleptiis cai-i- natixs (Conrad) (very abundant in thin layers of these shales), Spirifer mucronatus (Conrad), Nucula hellistriata (Conrad), NucuUtes triqueter Conrad, Leda rostellata (Conrad), Cimitaria, (?)' sp., Pleurotomaria sp. (apex of a specimen, internal impression), Bellerophon sp. This zone shows the transition from the Marcellus to the Hamilton shales and it will be seen that there is not a sharp line of division between them but a gradual change from the fissile black shales of the Marcellus containing Liorhynchus limitare (Vanuxem) to the bluish, coarser and fairly arenaceous shales which contain abundant specimens of some of the characteristic Hamilton species. This fauna is especially well preserved in the next higher zone near the northern end of the cut where the fine shales are so badly crumpled that no attempt was made to estimate their thickness although it would be interesting if this could be accurately determined. At the northern end of the cut are rather thin bluish shales, weathering to a rusty color, which contain numerous fossils. In thicker. 62 The Middle Devonian Deposits of Maryland bluish, slightly arenaceous and coarser shales, very near the northern end of the cut, fossils are abundant, especially Tropidoleptus carinatus (Con- rad) numerous large and beautifully preserved specimens of which were collected. Some of the other most abundant species are Spirifer mucro- natus (Conrad), Gkonetes coronatus (Conrad), Chonetes setiger (Hall), Chonetes mucronatm Hall, and Palaeoneilo constricta (Conrad). The complete fauna of this zone is as follows : Spiropliyion sp., Lmgida ligea (?) Kail, Stropheodonta (Leptostrophia) perplcma (Conxsid), StropJieo- donta (DouvilUna) inaequistriata (?) (Conrad), Orthothetes variabilis Prosser, Chonetes mucronatus Hall, Chonetes coronatus (Conrad), Chon- etes scitulvs Hall, Chonetes setiger (Hall), Chonetes lepidus Hall, Chon- etes Tnarylandicus Prosser, Camarotoechia prolifica ( ?) Hall, Tropido^ leptus carinatus (Conrad) (numerous large and beautifully preserved specimens), Spirifer mucronatus (Conrad), Spirifer granulosus (Con- rad) (pustules nicely preserved), Spirifer angustus Hall, Athyris spiri- fer oides (Eaton), Grammysia circularis (?) Hall (imperfectly preserved specimen), Nucuia hellistriata (Conrad), Nuculites triqueter Conrad, Palaeoneilo constricta (Conrad), Palaeoneilo emarginata. (Conrad), Palaeoneilo tenuistriata (.?) Hall, Mytilarca (Plethomytilus) oviformis (Conrad), Actinopteria decussata ( ?) Hall (the concentric lines are not as strong as in most of the specimens of this species), Aviculopecten ( ?) sp., Aviculopecten princeps (?) (Conrad), Cypricardelloi hellistriata (Conrad), Cypricardinia indenta (Conrad), Bellerophon sp., Gyrtolites (Cyrtonella) mitella (?) Hall, Phacops rana (Green), Crinoid stems. It will be seen from the above list that this fauna is characteristic of the Hamilton stage in New York, while the shales themselves, in litho- logical characters are not different from many of the fossiliferous Ham- ilton shales of that state. The exposures in this cut furnish an excellent illustration of the upper Marcellus shales, and the lower part of the fossil- iferous Hamilton shales. The black, fissile shales at the southern end con- taining specimens of Liorhynchus limitare (Vanuxem) are very similar to typical outcrops of the Marcellus shale in New York, even to the rusty color when weathered and the calcareous concretions. Again, the succeeding zone of more arenaceous shales with some thin sandstones in which fossils occur rather infrequently is similar to the lower part of the Hamilton Maryland Geological Survey 63 stage, especially as it occurs in eastern New York. Then the northern part of the cut in which both the thin and coarser shales contain abund- ant specimens of characteristic Hamilton fossils is very similar to typical fossiliferous Hamilton shales of New York. This is an excellent locality for collecting fossils and is one of the best, in the lower Eomney shales, to be found in the county. Exposures in BraddocJc and Jennings Rvns. — As already stated, the best outcrops of the Eomney shales in the western belt are in the railroad cuts at 21st Bridge ; but in the northern part of the county Braddock and Jennings runs have cut gorges through the Alleghany Front in which the Devonian and Carboniferous formations are, generally, fairly well shown. To the south of Braddock Run is the line of the Georges Creek and Cum- berland Eailroad along which are frequent cuts affording exposures of the rocks. The greater part of the cut directly east of the Winchester Pike crossing is through the Oriskany sandstone; but at its western end are black, fissile, argillaceoiis shales which belong in the Onondaga or Mar- cellus member. These shales are very fissile at the top and black on fresh exposure but weather to a drab color and turn readily into soil. The remainder of the Eomney is covered but in the first cut west of Winchester Pike station the rocks are in the Jennings formation with an average dip of 80°. The contact of the Eomney and Jennings is concealed. It cannot be far from the Winchester Eoad. The Eomney would appear to have a thick- ness of about 600 feet in this section. In the Jennings Eun section nearly all the Eomney is covered; but by the side of the highway a short distance west of Corriganville the upper part of the formation is shown. Although there are no outcrops of the lower shale at this locality, about 9 miles farther northeast in the continuation of this belt Professor Steven- son reported it as " well exposed in a bluff " perhaps a mile south of Hynd- man, Bedford County, Pa.,^ and also on the County Eoad north of this town where he stated that " Both the black and the yellow shales of the Mareellus are shown." ' As already stated the upper part of the formation is clearly shown in the ledges by the side of the highway one-half mile west 1 V, p. 99. = Ibid., p. 105. 64 The Middle Devoitian Deposits of Maetland of Corriganville where 147 feet of the Romney is exposed above which about 30 feet is covered when the black, fissile shales of the Genesee appear conspicuously and these in turn are succeeded by the shales and sandstones of the Woodmont; This is, probably, one of the best localities in western Maryland for studying the change from the Eomney to the Jennings and then the transition from the Genesee shale to the Woodmont member of the Jennings formation. The actual contact of the Romney and Jennings formations occurs in the covered zone of 30 feet though the greater part of it belongs in the Genesee shale as indicated by its thickness in other ex- posures in Allegany County. The section at this locality is about as follows : ' Total Thick- thick- ness, ness. Beginning at the eastern end of the road cut there are bluish, arenaceous shales with some layers of thin sandstone, the latter more conspicuous in the lower part of the exposure. The rocks weather to a yellowish-green and are much Iron-stalned. The upper part of this zone is more argillaceous, composed mostly of thin shales and this portion is near the middle of the Hamilton cut. Certain layers are fossiliferous, Spirifer mucronatus (Con- rad) and other Hamilton species occurring. The strike is about N. 35° B. and the dip 78° westward 80 80 The succeeding zone consists of shales alternating with sand- stones; one stratum of which reaches a thickness of 11 inches; but in this locality the individual sandstone strata do not reach so great a thickness as in some other exposures in western Mary- land. Still the zone of sandstones which is generally found near the top of the Romney formation is clearly represented 38 118 The upper 29 feet of the Romney formation, so far as shown in this cut, consists of thin, argillaceous shales in which Spirifer mucronatus (Conrad) and Tropidoleptus carinatus (Conrad) occur at the very top of the exposure 29 147 Covered zone 30 177 Black fissile shale of the Genesee in the base of the Jennings formation 73 250 Bluish thin shales alternating with sandstones of similar color. One massive stratum with a thickness of 2 feet, 8 inches, is succeeded by greenish shales alternating with thin sandstones. These rocks which form the western part of the cut, the upper portion of which is in the field at a distance of several feet from the highway, are in the Woodmont member of the Jennings forma- tioP 230 480 * All the sections in this chapter are described in reverse order, i. e., from the bottom upward. MARYLAND GEOLOGICAL SURVEY. MIDDLE AND UPPER DEVONIAN, PLATE 11. Fig. I. — VIEW showing bending of eomney shale due to creep in cut of western MARYLAND RAILROAD WEST OF TONOLOWAY. Fig. -VIEW SHOWING THE LOWER ROMNEY SANDSTONE ON CHESAPEAKE & OHIO CANAL NEAR TONOLOWAY. Maryland Geological Survey 65 From the upper part of the Romney formation at this locality the following fossils were collected: Stropheodonta (Leptostrophia) per- plana (Conrad), Stropheodonta demissa (Conrad), Choneies mucronatiis Hall, Chonetes coronatus (Conrad), Chonetes setiger (Hall), Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Ambocoelia um- bonata (Conrad), Nucula corbuliformis Hall, Leda rostellaia (?) (Con- rad), Pleurotomaria (Trepospira) rotalia Hall (?), Crinoid stems and segments. For the remainder of the distance to the Pennsylvania line the Romney shales are mostly concealed. Exposures near Cumierland. — On the western arm of the V-shaped area of this formation in the vicinity of Cumberland are various exposures, although none of them can be said to afford an opportunity for advan- tageous study of the fauna or other characters. There are exposures to the north of the city along the ISTational Eoad, beginning opposite Bell- vue Street where the shales are fairly fossiliferous. To the east is MeKaig's Hill, composed of the higher and harder Eomney shales both of which localities were briefly described by Dr. George H. Williams,' who also mentioned a slight depression, in going west from this locality toward the Bedford Eoad, occupied by the Marcellus shales.^ On the Williams Eoad to the southeast of Cumberland, just beyond the edge of the city, are outcrops of shales by the roadside which on the weathered surfaces have a somewhat olive tint and in this particular they differ from those of the Hamilton in northeastern Pennsylvania and New York, where they may change on weathering from a blackish or bluish color to a brownish tint. These shales are fossiliferous and specimens of Tropidoleptus carinatus (Conrad), Spirifer mucronatus (Conrad), Palaeoneilo emarginata (Conrad), Rhipidomella vanuxemi Hall, and other species were seen. The following list was obtained from outcrops on Williams Eoad about one-fourth mile east of Queen City hotel: LingulanudaUall (?), Stropheodonta (Leptostrophia) perplana (Conrad), Schuchertella variabilis Prosser, Choneies mucronatus Hall, 1 Johns Hopkins Univ. Cir., Vol. XI, No. 94, 1891, p. 26. ''/6i(t., p. 27. 5 66 The Middle Devonian Deposits of Maryland Chonetes coronatibs (Conrad), Productella cf. spinulicosta Hall, RMpi- domella vanuxemi Hall, Camarotoechia sp., Tropidoleptus carmatus (Conrad), Spirifer mucronatus (Conrad), Spirifer audaculus (Conrad), Ambocoelia itmbonaia (Conrad), iVwcw?a bellistriata (Conrad), Nuculites ohlongatus Conrad, Palaeoneilo constricta (Conrad), Palaeoneilo fecunda Hall, Palaeoneilo emarginata (Conrad), Liopteria cf. conradi Hall, Mo- diella pygmaea (Conrad), Aviculopecten princeps (Conrad), Cypricar- della hellistriata (Conrad), Palanosolen minutus Prosser, Pleurotomarm itys Hall ( ?), Bellerophon sp., Homalonotus dehayi (Green). About three-fourths of a mile east of the Queen City hotel the following species were collected: Stropheodonta (Leptostrophia) perplana (Con- rad) , Rhipidomella vanuxemi Hall, Bhipidomella hucosia Hall, Tropido- leptus carinatus (Conrad), Sprifer rmwronatus (Conrad), Palaeoneilo emarginata (Conrad), Cypricardella tenuistriata (Hall), Crinoid seg- ments. Farther up the road are exposures of the Genesee and Woodmont shales of the Jennings formation. The stratigraphic order of this section is complicated by faulting and folding as determined by Dr. E. B. Eowe. A layer of slightly arenaceous shale on the National Koad half way up the hill northeast of Cumberland furnished the following species: Chonetes mucronatus (Conrad), Chonetes sdtulus Hall, Chonetes setiger (Hall), Camarotoechia prolifica Hall, Spirifer mucronatus (Conrad), Vitulina pustulosa Hall, Nuculites ohlongatus Conrad, Palaeoneilo con- stricta (Conrad), Pleurotomcma itys (?) Hall (broken specimens). Eather heavy arenaceous shales on the National Eoad near the top of the hill and opposite Cemetery northeast of Cumberland gave the follow- ing list: Schuchertella sp., Chonetes sdtulus Hall, Chonetes setiger (Hall), Chonetes lepidus Hall, Atrypa reticularis (linne), Cyrtina ham- iltonensis Hall, Spirifer gramdosus (Conrad), Grammy sia lisulcata (Conrad), Pterinea flabellum (Conrad), Modiomorpha concentrica (Conrad). The shales and sazidstones on the Oldtown Eoad, east of Maryland Avenue, Cumberland, have furnished the following list : Lingula nuda Hall ( ?), Schuchertella sp., Chonetes mucronatus Hall, Chonetes sdtulus Maryland Geological Survey 67 Hall, Chonetes setiger (Hall), Tropidoleptus carinatus (Conrad), Cyr- tina hamiltonensis Hall, Spirifer mucronatus (Conrad), Spirifer granu- losus (Conrad), Amhocoelia umbonata (Conrad), Vitulina pustulosa Hall, Tellinopsis suhemargmata (Conrad), Nucula corbuliformis Hall, Nucvla bellistriata (Conrad), Nuculites oilongatus Conrad, Ptermea flabellum (Conrad), Paracyclas lirata Conrad, Pleurotomaria (Bem- hexia) sulcomarginata Conrad, Orthoceras hehryx Hall (?), Orthoceras constrictum Vanuxem. On the south side of the Potomac Eiver, about 3 miles south of Cum- berland and on the east side of Knobly Mountain, the following species were collected: Chonetes ef. scitidus Hall (these specimens are larger than those figured but they have the outline and the large number of strise), Chonetes setiger ( ?) Hall, Chonetes lepidus Hall, Spirifer mucro- natus (Conrad), Prothyris lanceolata Hall, Tellinopsis suhemarginata (Conrad), Nucula coriuliformis Hall, Nuculites triquster Conrad, Pa- laeoneilo cf. plana Hall, Palaeoneilo clarJcei Prosser, Modiella pygmaea (Conrad), Paracyclas lirata Conrad, Pleurotomaria (Bembexia) sulco- marginata Conrad, Orthoceras constrictum. Vanuxem, Orthoceras emacer- atum (?) Hall, Spyroceras crotalum (Hall), Spyroceras nuntium Hall. Four miles south of Cumberland on the West Virginia side of the Potomac Eiver opposite Madder's Island, the following species were obtained : Chonetes cf . scitidus Hall (large specimens similar to those from south bank Potomac Eiver, 3 miles south of Cumberland), Cama- rotoechia prolifica Hall, Spirifer mucronatus (Conxad), Ambocoelia umbonata (Conrad), Nucula corbuliformis Hall, Nuculites oblongatus Conrad, Nuculites triqueter Conrad, Modiella pygmaea (Conrad), Pleuro- tomaria (Bembexia) sulcomarginata Conrad, Cycloruema hamiltoniae Hall, Loxonema sp. (fragment of internal impression) . Exposure at Wolfe Mill— Below Wolfe Mill or Polks Mill along the eastern bank of Evitts Creek are exposures of the rather coarse, bluish, calcareous Hamilton shales. This locality which is on the National Eoad about 3 miles northeast of Cumberland, is a well-known collecting place of the Cumberland geologists, and the late Eobert H. Gordon and others have obtained very good specimens of Hamilton fossils. To 68 The Middle Devonian Deposits of Maryland the south of the. road on the creek bank the rocks are bluish and in quite firnij coarse layers. There is a steep dip toward the creek between 55° and 57% N., 40° W. To the north of the pike along the road to the mill the rocks are weathered to a greater extent, having a brownish tint and containing in layers numerous specimens of Hamilton species. The coarse blue shales on the creek bank and the brownish ones along the mill road agree in lithologic characters with the coarser shales of the Hamilton stage in New York. The following list gives a fair idea of the fauna of this locality which would undoubtedly be increased by further search : Stereo- lasma rectum Hall, cf. Amplexus hamiltoniae Hall, Cystiphyllum ameri- canum ( ?) Milne-Edwards and Haime, Bhopalonaria tenuis Ulrich and Bassler, Monticulipora ( ?) ma/rylanciensis Ulrich and Bassler, lAngulella ( ?) paliformis Hall, Lingula delia ( ?) Hall, Lingula, ligea ( ?) Hall, Lingula cf. compta Hall and Clarke, Orbiculoidea lodiensis (Vanuxem), var. media Hall, Craniella hamiltoniae Hall, Stropheodonta (Leptostro- phia) perplana (Conrad), Stropheodonta demissa (Conrad), Stropheo- donta (DouviUina) inaequistriata (Conrnd) , Stropheodonta concavaHsLll, Chonetes mucronatus Hall, Chonetes coronatus (Conrad), Chonetes setiger ( ?) (Hall), Ohonetes lepidus Hall, Chonetes vicinus (Castelnau), Stiophalosia truncata (Hall) , Rhipidomella vanuxemi Hall, RMpidomella penelope Hall, Liorhynchus lama (Billings), Tropidoleptus carinatus (Conrad), Atrypa reticularis (Linne), Gyrtina hamiltonensis Hall, 8pi- rifer mucronatus (Conrad), Spirifer granulosus (Conrad), Spirifer audaculus (Conrad), Spirifer angwtus (?) Hall, Spirifer (Beticularia) fimbriatus (Conrad), Ambocoelia umbonata (Conrad), Ambocoelia vir- giniana Prosser, Anoplotheca (Coelospira) acutiplicata (Conrad), Vitu- lina pustulosa Hall, Athyris spiriferoides (Eaton), Orthonota ( ?) parvula Hall, TeUinopsis suhemarginata (Conrad), Buchiola halli Clarke, Nu£ula corbuliformis Hall, Nucula bellistriata (Conrad), Nucula lirata (Con- rad), Nuculites oUongatus Conrad, Nuculites triqueter Conrad, Palaeo- neilo constricta (Conrad), Palaeoneilo pZana Hall, Palaeoneilo maxima (?) (Conrad), Palaeoneilo perplana var. grabaui Prosser, Palaeo- neilo emarginata (Conrad), Palaeoneilo tenuistriata (?) Hall, Parallel- odon hamiltoniae (Hall), Pterinea flabellum (Conrad), Leptodesma Maryland Geoi.ogtcal Survey 69 rogersi Hall, Mytilarca {Plethomytilus) oviformis (Conrad), Actinop- teria decussata Hall, Modiella pygmaea (Conrad), Avicvlofecten sp., Modiomorpha concentrica (Conrad), Modiomorpha subalata (Conrad), Modiomorpha mytiloides (?) (Conrad), Cypricardella bellisiriata (Con- rad), Cypricardinia- indenta (Conrad), Paracydas lirata (?) Conrad (small imperfect specimen), Paracydas tenuis Hall, Pleurotomaria sp., Pleurotomaria capillaria Conrad, Bellerophon hrevilmeatus ( ?) Conrad, Bellerophon (Bucanopsis) leda Hall, Loxonema hamiltoniae Hall, Plor iyceras sp., Platyceras cf . symmetricum Hall, Diaphorostoma lineatum ( ?) Conrad, Styliolina fissurella (Hall), Coleolus tenuicinctus Hall, Ortho- ceras suiulatum ( ?) Hall, Orthoceras constrictum ( ?) Vanuxem, Ortho- ceras cf. eodle Hall, Phacops rana (Green), Dalmanites (Cryphaeus) ioothi (Green). Exposure on Williams Road. — The best continuous exposure of the Eom- ney formation in the vicinity of Cumberland is on the Williams Eoad about 3y2 miles southeast of the central part of the city. The exposures are by the side of the road and are badly weathered, while the road itself winds to a considerable extent making the estimate of thickness somewhat unreliable, still it is probably upon the whole the best section in the vicinity of the city for the purpose of obtaining a general idea of the nature of the formation. Its base is on the western slope of Nicholas Mountain not far east of Mt. Hermon Church and a road which turns to the north. The section was divided into a number of zones which were ex- amined quite diligently for fossils and the lithological characters were also noted with care. The thickness of the zones was estimated but as the road is not at right angles to the strike, frequent determinations of the dip were difficult to make and the estimates are to be regarded as only an approximation. The Oriskany sandstone Is fairly well shown on the western side of this mountain, a section of which was given hy Dr. O'Harra in his report on Allegany County. The top, consisting of ahout 16 feet of much decomposed yellowish sandstone contain- ing many fossils is clearly shown and this is capped by 2 inches of coarse, blackish, non-fossiliferous sandstone. By the side of the highway the contact between the Oriskany sandstone and the dark Onondaga shales at the base of the Romney is well shown. Total Thick- thick- ness, ness. 70 The Middle Devonian Deposits of Maktland Total Thick- thick- ness, ness. The section of the Onondaga shale member at this place is de- scribed by Kindle, to whose account the reader is referred. The upper beds of the Onondaga are mainly yellowish to bufC very argillaceous shales as shown in the weathered outcrops. This zone contains but few fossils. The overlying beds are of Marcellus age 62 Fine, argillaceous shales of a blackish to bluish-black color which in the lower part weather to a slightly purplish tint. There are very few fossils in the zone; but near its center a poorly preserved specimen, apparently a LiorJiynchtis Umitare (Van- uxem), was found. A dip of 68° W. was measured on some of these shales 98 98 From the top of the bluish-black shales almost to the road turn- ing north. The zone is composed of yellowish to buff very argilla- ceous shales. There are occasional bands of rather blackish shales which are quite conspicuous In the mass of lighter colored ones. . . 62 160 Black, fissile, argillaceous shales at the side of the road turning north. The dip changes at this point and, possibly, this zone is not a continuation of the section 23 183 About 60 feet is covered opposite the Mt. Hermon Church 60 243 Fine, argillaceous shales, of bluish-gray color, which split into thin pieces. These shales with a thickness of about 208 feet have the lithologic appearance of the Hamilton but fossils are rare 208 451 Covered 78 529 Fine, yellowish-gray argillaceous shales. No fossils found 164 693 Bluish, arenaceous shales at the base changing into thin bedded to fairly massive, gray sandstones at the top of the zone. Both shales and sandstones are fossiliferous. This is the lower sand- stone zone 75 768 Yellowish to greenish-gray argillaceous shales which crumble into small pieces and when weathered are greatly iron stained. They contain some fossils, as for example, specimens of Spirifer, Ghonetes, and Orthoceras 87 855 Covered 36 891 Principally shales which weather to a yellowish or brownish color; and, apparently, before weathering vary from a light gray to a yellowish-green. There are some fossils but, as in all the Hamilton zones of this section, it is not a favorable locality for collecting 295 1186 Thin bedded greenish to yellowish-gray sandstones. This zone occurs near the top of the first hill southwest of Mt. Hermon Church and it is near the top of the Hamilton stage. This is the upper sandstone none 30 1216 BufC, argillaceous shales on the crest of the hill with a thick- ness of about 65 feet. This zone forms the top of the Romney formation which then has a thickness of 1438 feet as measured on Maryland Geological Sdevey 71 Total Thick- thick- the "Williams Road.' Succeeding the shales is a narrow covered zone on the highway and then an exposure of about 75 feet of argillaceous shale weathered to a brownish tint is reached which is in the Genesee at the base of the Jennings formation. This is followed by the greenish argillaceous shales with thin sand- stones of the Woodmont member of the Jennings which continue down the western slope of the hill 65 1281 The following species were collected from the Hamilton beds of the above section: Lingulella (?) pdiformis Hall, Lingula cf. nuda Hall, PhoKdops hamdltomae Hall (?) , Stropheodonta (Leptostrophia) perplana (Conrad), Schuchertella variabilis Prosser, Chonetes mucronatus Hall, Chonetes coronatus (Conrad), Choneies scitulus Hall (?), Chonetes setiger (Hall), Chonetes lepidus Hall, Bhipidomella cyclas Hall (?), Orthis sp. (small forms), Camarotoechia congregata (Conrad), Camaro- toechia prolifica Hall, Liorhynchus laura (Billings), Tropidoleptus cari- natus (Conrad), Spirifer mucronatus (Conrad), Spvrifer audaculus (?) (Conrad), Amhocoelia umbonata (Conrad), Anoplolheca (Coelospira) acutiplicata (Conrad), Vitulina pustulosa Hall ( ?), Phthonia sectifrons (Conrad), Grammysia arcuata (Conrad), Tellinopsis subemarginata (Conrad), Nuculites triqueter Conrad, Palaeoneilo constricta (Conrad), Modiella pygmaea (Conrad), Modiomorpha concenirica (Conrad) (?), Cyclonema liratum Hall var. grabaui Prosser, Homalonotus dehayi (Green). In general, it may be said, on comparing the rocks of the Williams Eoad section with the one at 31st Bridge that they are weathered to a much greater extent and a considerable part are much more yellowish. The limestones of the Onondaga shales were not found on the Williams Eoad nor as many specimens of Liorhynchus limitare (Vanuxem) as in the Baltimore and Ohio E. E. cut at 31st Bridge. Again, the very fossiliferous zone of the Hamilton as exposed in the cut near the 21st Bridge was not recognized while the sandstones of the upper part of the Williams Eoad are not shown in the southwestern section which, possibly, does not extend as high in the Eomney formation. '■ Dr. Swartz's estimate of 157 feet for the thickness of the Onondaga member is used in this estimate of the thickness of the Romney formation. 72 The Middle Devonian Deposits of Maryland Exposure at Gilpin. — This section is in the northern part of the county on the JSTational Eoad and Flintstone Creek to the southeast of Flint- stone. At the eastern end of the gap cut by Flintstone Creek through the northern end of Warrior Mountain is the top of the Oriskany sand- stone. The dip of the Upper Oriskany is 34° E. at this locality. The shales at the contact of the Oriskany and Eomney are not shown ; but in the field on the northern side of the road is an outcrop of quite black, thin, argillaceous shale with thin bedded sandstones some distance east of the Oriskany sandstone. There are occasional outcrops along the National Road to the east of the Oriskany sandstone and in the eastern part of Gilpin are outcrops of bluish-green shales which in layers are very fossiliferous. A fairly massive sandstone was also noted in this part of the section. On the bank of Flintstone Creek just south of and opposite Gilpin is a good exposure of the Hamilton shales in the upper part of the Eomney formation. They are bluish and arenaceous with an occasional layer of thin sandstone. The dip is 30° E. Thin layers of these shales contain abundant fossils as Spirifer mucronatus (Conrad), Tropidolepius carinatus (Conrad), Chonetes, and a few other species among which may be mentioned Pterinea fiabellum (Conrad). A 3-inch fossil band composed largely of Spirifer mucronatus (Conrad) occurs at the lower end of the outcrop. The shales crumble into rather irregular, angular, small blocks in a manner very similar to that of many of the thin bedded, arenaceous Hamilton shales in New York. The fauna of this locality is as follows: Stropheodonta {LeptostropUa) perplana (Conrad), Chonetes mucronatus Hall, Chonetes coronalus (Conrad), Chonetes scitulus Hall, Chonetes setiger (Hall), Chonetes lepidus Hall, Chonetes vicinus (Castel- nau) (?), Camarotoechia congregata (Conrad) (?), Tropidolepius cari- natus (Conrad), Atry pa reticularis (Linne), Spirifer mucronatus (Con- rad), Spirifer granulosus (Conrad), Spirifer ttdlius Hall, Amhocoelia umhonata (Conrad), Nucula bellistriata (Conrad), Nuculites oUongatus Conrad, Nuculites triqueter Conrad, Parallelodon hamiltoniae (Hall), Pterinea fiabellum (Comai) , Mytilarca (Plethomytilus) oviformis (Con- rad), (?) Modiomorpha sp., Modiomorpha concentrica (Conrad), Cyprir Maryland Geological Subvky 73 cardellalellistriata {Coniad) , PI eurotomai-ia (Bemhexia) sulcomarginata Conrad. On the National Eoad in Gilpin, 200 yaxds west of tlie bridge over Town Creek, the following species were collected in the arenaceous layers of the upper Eomney : Stropheodonia (LeptostropMa) perplana {Con- rad) , Schiichertella sp., Chonetes mucronatus Hall, Chonetes lepidus Hall, Tropidoleptus carinaius (Conrad), Spirifer mucronatus (Conrad), Am- iocoelia umbonata (Conrad), Paracyclas lirata Conrad, Cyrtolites (Cyr- tonella) mitella Hall. The lithological appearance and fauna of this zone are those of the typical 'New York Hamilton in which stage it clearly belongs. It is in the upper part of the Eomney formation. Although the exact contact of the Hamilton and Genesee shales is not shown, still the covered interval is not great and it is thought that the thickness of the Eomney formation along the National Eoad. through Gilpin is given quite accurately. The eastern ridge crossing the road in Gilpin was considered the upper sandstone of the Eomney which is about on the line of strike with the highest exposure of the formation shown on the bank of the creek. The rocks immediately succeeding this sandstone are covered but allowance was made for the shale at the top of the Eomney while the base of the formation is clearly marked at the western end of Gilpin by the Oriskany sandstone. There is, apparently, no folding in this distance and the direction is nearly at right angles to the strike so that the locality is favorable for measuring the thickness of the formation. The average dip of the exposures from the top of the Oriskany sandstone to the top of the Eomney formation is about 30°. The paced distance from the top of the Oriskany sandstone to the top of the lower sandstone near the corner of the road leading north in Gilpin is 3080 feet which gives a thickness of 1040 feet. The paced distance from the base to the point at which the top of the Eomney was drawn above the second sandstone, is 3180 feet which gives a thickness of 1590 feet for the formation. The same distance measured by the buggy wheel gave a hori- zontal distance of 3205 feet and a thickness of 1602 feet. An independent measurement at this locality by Eowe gave a thickness of 1605 feet for 74 The Middle Devonian Deposits of Maryland the Eomney formation. On account of the fairly definite limits of the formation at Gilpin, the absence of folds, and the direction nearly at right angles to the line of strike it is probable that this is as reliable an estimate of the thickness of the Eomney formation as has been obtained in Allegany County. This belt of the Eomney formation may be followed northeasterly across the eastern part of Bedford County, and in the northeastern part of it. Professor Stevenson gave two measurements of the thickness of the rocks representing this formation. On Yellow Creek to the north-- west of Hopewell he obtained 1756 feet, but the upper limit was uncertain and the lower portion difficult to measure,' from which is tO' be deducted 200 ± feet of Genesee shale,'' which was included in his Hamilton ' group, leaving 1556 feet for the thickness of the rocks equivalent to the Eomney. Somewhat farther northeast, near Saxton, he obtained 1587 feet for the total thickness of these shales,* which agrees very closely with our result in Gilpin. About 3 miles southwest of the Gilpin section by the side of the road turning northeast and crossing Warrior Mountain from Eush, are ex- posures of black argillaceous shales in which a few specijnens of goniatites were found and there are also quite large concretions of blackish lime- stone one of which is over 2 feet in diameter. These shales are in the Onondaga member of the Eomney formation, but the Hamilton part of the formation to the eastward is mostly covered. On the east side of the gap in Warrior Mountain, however, to the east of Eush, the following species were obtained : Chonetes mucronatus Hall, Spirifer mucro'mtus (Conrad), Spwifer audaculm (Conrad), Spi- rifer angustus Hall, Spinfer sculptilis var. murylandensis Prosser, Spirifer sp., Nucula coriuKformis Hall, Pterinea flahellum (Conrad), Nyassa arguta (?) Hall, Plewrotomaria {Bembexia) sulcomarginata Conrad, (?) Cyclonema hamiltoniae Hall (poorly preserved specimen), Homalonoius dekayi (Green). ' T', p. 226. '"lUd., p. 82. = 7&i(J., p. 81. '/6id., p. 82. Maryland Geological Survey 75 Exposures of Southern Allegany County. — The belt of Eomney, just described at Gilpin, when followed more than one-half the distance across the county to the south, becomes broader and because of repetition by fold- ing, the formation extends for 8 miles along its southern border. There are various exposures, still in most of them the rocks are badly weathered and the folding has made it well nigh impossible to form any satisfactory estimate regarding their thickness. Outcrops were studied at a number of localities, the most important of which will be somewhat briefly described. In the eastern part of the area in Town Creek Valley north of Strat- ford Ridge are exposures of coarse arenaceous shales by the side of the highway directly north of Mr. George Diefenbaugh's house. The shales are bluish and contain a good manv fossils among which are such charac- tertistic Hamilton species as Spvrifer mucronatus (Conrad), Tropido- leptus carvnatus (Conrad), Pterinea flabellum (Conrad), and other species. The complete list is as follows: Stropheodonta (Leptostrophia) perplana (Conrad), Chonetes mucronatus Hall, Chonetes lepidus (?) Hall, Tropidoleptus carinatus (Conrad), Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Amhocoelia umbonata (Conrad), Palaeo- neilo sp., Pterinea flabellum (Conrad), Actinopteria cf. boydi (Conrad),' Pleurotomaria (Bembexia) sulcomarginata Conrad. It will be seen that the fauna is a Hamilton one and the lithologic appearance of the shales is like that of numerous outcrops of arenaceous Hamilton shales in New York. Somewhat farther south by the side of the same road and south of Mr. Eufus Diefenbaugh's house are fine, black, argillaceous shales becom- ing brownish to chocolate colored on w'eathering. They contain good specimens of Styliolina flssurella (Hall) and lAorhynchus limitare (Vanuxem) though most of the latter specimens are very much crushed and the markings are nearly obliterated. These shales are fully as fissile and black as any of the Marcellus shales in New York in which stage they belong. * Although Hall mentions rarely finer intercalated rays for this species and none are shown in the figures, there is in the above specimen a finer ray betwefin the two coarser ones which are cancellated by concentric lines. 76 The Middle Devonian Deposits of Maryland Three miles northeast of Oldtown where the road to Green Eidge crosses the iron bridge over Town Creek, is an excellent outcrop of Hamilton shales shown in the highway cut on the western bank of the creek. The shales are rather coarse, somewhat arenaceous, bluish in color, some of them weathering to a buff and very fossiliferous, large numbers of Spirifer mucronatus (Conrad) occurring associated with other species. Some of the layers in the upper part of the exposure contain numerous specimens of Bpirophyton. The other most abundant species are Tropido- leptus cwrinatus (Conrad) and Chonetes. The number of species is not large but it is a magnificent locality for specimens of Spirifer mucronatus (Conrad). The complete list obtained at this locality is as follows: Stropheodonta (Leptostrophia) perplana (Conrad), Chondes mucro- natus Hall, Chonetes scitulus Hall (some of the large forms), Chonetes setiger (Hall), Chonetes lepidus Hall, Chonetes viciiius (Castelnau) (some of these specimens have very much the outline of the gibbous specimens figured in the New York report as Chonetes gibbosus which is a synonym of Chonetes defiectus = vicinus) , Camarotoechia congregata (Conrad), Eunella lincTclaeni Hall, Tropidoleptus carinatus (Conrad) (medium-sized specimens abundant in some of the blocks), Cyrtvna hamiltonensis Hall, Spirifer mucronatus (Conrad) (abundant and excel- lent specimens of the mucronate form; some of the layers of rock composed largely of shells of this species), Spirifer granulosus (Conrad), Ambocoelia umbonata (Conrad), Athyris spiriferoides (Eaton), (?) Meristella sp., NucuUies oblongatus Conrad (internal impression), Pterinea flabellum (Conrad), Actinopteria sp., Aviculopecten cf. princeps (small, imperfect specimen), Pleurotomaria (Bembexia) sulcomarginata Conrad, Bellerophon sp., Styliolina fissurella (Hall), Tentaculites bellidtis Hall, Homalonotus dekayi (Green). The fauna is that of the Hamilton and the appearance of the rocks is almost identical with that of similar shales in the Hamilton of New York, to which stage these shales belong. By the highway leading west from Oldtown and opposite the church, are outcrops of olive, argillaceous shales, with an occasional thicker mealy layer, which weather to a buff color and readily disintegrate into soil. Maryland Geological Survey 77 No fossils were found. On the eastern side of Big Spring Eun at the highway crossing some '6 miles northwest of Oldtown, are very smooth, black, argillaceous shales, agreeing in lithologic appeai'ance with the Marcellus shales. One layer is thicker and somewhat arenaceous. The dip is between 43° and 45° nearly S. E., and no fossils were found. This locality is near the southern end of Warrior Mountain and not far from the Oriskany sandstone which was brought up by that uplift. Farther up the run on its southern bank are bluish-black shales which, on weathering, break into rectangular pieces and become rusty brown in color. This outcrop occurs after crossing the axis of Warrior Mountain and on its western side with a dip of between 9° and 10° S. The rocks are probably in the lower part of the Hamilton stage. On the road east of Pine Hill, about 4 miles north of Oldtown, the fol- lowing species were collected by O'Harra: Stropheodonta (Leptostrophia) perplana (Conrad), Chonetes mucronatus Hall, Camarotoechia prolifica Hall, Eunella linchlaeni Hall, Tropidoleptus carinaius (Conrad), Cyrtina hamiltonensis Hall, Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Actinopieria decussata Hall, Bellerophon sp., Bellerophon brevilineatus Conrad (?), Cyrtolites (Cyrtonella) mitella Hall (?), Orthoceras hehryx Hall (?), Orthaceras cf. aulax Hall, Homalonotus dekayi (Green), Phacops rana (Green). The following specimens are in the Johns Hopkins University collec- tion from the Hamilton of western Maryland but without exact locality labels: Schuchertella sp., Camarotoechia congregata (Conrad), Camaro- toechia sappho Hall, Cyrtina hamiltonensis Hall, Spirifer audaculus (Conrad), Amhocoelia umhonata (Conrad), Nucula sp., Tancrediopsis clarkei Prosser, Modiomorpha concentrica (Conrad), Paracyclas lirata Conrad, PleurotomMria itys Hall (?), Bellerophon (Patellostium) patulus Hall (?), Macrochilus hamiltoniae Hall, Spyroceras crotalum (Hall), cf. Oomphoceras pingue Hall. Exposure West of Tonoloway Ridge. — In Washington County are several areas of Komney rocks, mainly narrow belts crossing the county in a direction about northeast to southwest from Pennsylvania to West Vir- ginia. The most western belt in the county is the one to the west of 78 The Middle Devonian Deposits oe Maeyland Tonoloway Eidge which crosses the western part of Hancock township from Pennsylvania to the Potomac Eiver in a direction about parallel with that of the ridge. The belt of lower country between Tonoloway Ridge and Sideling Hill is composed mainly of rocks belonging in the Eomney, Jennings, and Catskill formations. No. 1. The first exposure of Eomney shale in following the National Eoad west from Hancock occurs after crossing Tonoloway Ridge, about 3 miles West of the village. The outcrops of clearly argillaceous, sparingly fossiliferous shales, bufi to olive in color especially by the roadside, weather to a decidedly buff color and are often stained with reddish spots or streaks ; while at certain places they vary from very light gray to an almost whitish color. This exposure which belongs in the lower, fine, nearly unfossiliferous shales of the Hamilton, occurs by the bam where the road turns south. A little farther west is a second outcrop by the house in which the shales have about the same lithologic appearance. No fossils were found and on weathering these shales are decidedly buff in color and the edges of the breaks are clearly stained red from the iron which they contain. No. 2. On top of the ImoU to the west are olive, very argillaceous shales which when weathered have a decidedly buff to reddish color. Some of them have concentric reddish layers, the tint probably due to weather- ing and the presence of iron. Spirifer mucronatus (Conrad) was found. No. S. A little farther west on the road, about one-quarter mile west of Tonoloway Eidge, are somewhat arenaceous, gray to bluish-gray blocky shales which break into more rectangular pieces and contain numerous specimens of Spirifer mucronatus (Conrad) though with this exception fossils are not common. The following species were obtained : Chonetes coronatus (Conrad), Tropidoleptus carinatu^ (Conrad), PaZaeojieiZo mvia Hall ( ?), Tentaculites attenuatus Hall. On the National Eoad about one-half mile west of Tonoloway Eidge the following species were found : Schuchertella sp., Chonetes coronatus (Conrad), Chonetes scitulus Hall, Chonetes setiger (Hall), Chonetes lepidus Hall, Tropidoleptus carinatus (Conrad), Spirifer mucronatus (Conrad), Nucula bellistriata (Conrad), NucuUtes ohlongatus Conrad, Maryland Geological Survey 79 Palaeoneilo sp., Palaeon-eilo rowei Prosser, Leda rostellata (Conrad), Pterinea flabellum (CotxtslS.) , Phurotomaria (Bemiexia) sulcomarginata Conrad (?), Pleurotomaria (Trepospira) rotalia Hall (?), Diaphoros- toma lineatum (Conrad) ( ?), Tentaculites attenuatus Hall, Phacops rana (Green). A little higher more argillaceous and nearly olive shales occur in which there are more species, Chonetes being abundant. This zone is but a few feet in thickness when the shales again change to those that are nearly bluish-gray, containing about the same species. On the bank of the creek below the road are bluish-gray to gray shales which are decidedly argillaceous in composition, and when weathered more nearly buff in color though along the stream they are for the most part quite compact and bluish. Some of the layers show large, irregular, concretionary structure. These shales which are quite bluish and contain numerous small concretions, some of which are calcareous, are about in line with the weathered buff and red shales of the middle outcrop on the road above. A few specimens of Spirifer mucronatus (Conrad) were found in the shales on the bank of the creek but they are rare. A ledge of fairly massive, greenish-gray sandstone, as weathered, occurs by the side of the road which is near the top of the Eomney formation. It is supposed to be at about the same horizon as the sand- stones in Allegany County which occur near the top of the Eomney. The sandstone is quite compact, breaks into block-like pieces and has a dip of 60° N., 50° W. The rocks are pretty well covered along this part of the road which is to be regretted because the line of transition from the Eomney to the Jennings formation is thereby obscured. IsTo fossils were found but there is very little opportunity to hunt for them as the rocks are so highly inclined and the outcrops are so slight. After crossing a narrow covered area there are fissile, olive shales with an occasional thin sandstone, 3 or 3 inches in thickness. These shales stand at a high angle and only the loose pieces could be examined but in these were found fragments of Pterochaenia fragilis (Hall) and Goniatites. These rocks do not have the lithologie appearance of the Genesee shales of Allegany County, which appear to be wanting, and they were referred to the 80 The Middle Devonian Deposits of Maryland Woodmont member of the Jennings. There is no doubt but that they are above the Romney and in the basal portion of the Jennings formation. Exposure at Tonoloway. — A much better section of the Romney is shown in the cuts of the Western Maryland Railroad at Tonoloway Station. The lower part of this section is referred to the Onondaga by Kindle who describes it more fully on a preceding page. Total Thick- thick- ness, ness. No. 1. The contact of the Oriskany sandstone and Romney Is nearly in the rear of the Lockkeeper's house, but the shales for some little distance above the sandstone are covered. The layers of the lowest shales exposed are fairly thick, some of them varying from 1 to 2% inches. Some of them are drab in color and they contain the most fossils found in this zone. The number of species and specimens, however, is small. The lower shales are succeeded by those that are thinner, varying from bluish-black to black which in lithologic appearance resemble much more closely the usual Marcellus shale. Fossils are very rare but speci- mens of StylioUna fissurella (Hall) were found and a broken specimen, apparently, of Liorhynchus Umitare (Vanuxem). The dip varies from 45° to 70° or more, but now and then the thin shales are greatly contorted and crushed so that it is difficult to measure the thickness accurately. In general, the exposure ap- pears to agree better with the Onondaga and Marcellus than the Hamilton and it is thought that they represent those members of the Romney formation 328 328 No. 2. Succeeding these thin shales are bluish, somewhat irregular sandy shales which extend to Possum Hollow Run and are similar to the Hamilton beds containing Hamilton fossils and clearly belonging in that member of the Romney formation. The greater part of this zone is covered 479 807 No. 3. To the west of Possum Hollow Run are bluish Hamilton shales and some thin bedded sandstones. The rocks from the base of this zone to the western end of the section are excellently shown along the bank of the canal where they form a high steeply-dipping cliff. The dip, in general, is about 70° for the remaining part of the section 225 1032 No. 4. Lower sandstone zone, composed mainly of bluish, not very thick bedded sandstones, which is conspicuous on the bank of the canal 57 1089 No. 5. Following No. 4 are bluish-gray, arenaceous shales with an occasional thin sandstone stratum. These shales split into rather irregular pieces and in lithologic appearance closely re- semble the Hamilton arenaceous shales of New York. They are Maryland Geological Survey 81 Total Thick- thick- very fossUiferous and contain numerous specimens of Spirifer mucronatus (Conrad) and Tropidoleptus carinatus (Conrad) -while other species are common. It is a typical Hamilton fauna as will be seen from the following list: Ohonetes mucronatus Hall, Chonetes coronatus (Conrad), Ohonetes setiger (Hall), Spirifer mucronatus (Conrad), Prothyris lanceolate Hall, Paracyclas lirata Conrad, DiapUoro stoma lineatum (?) Conrad, Coleolus cf. tenui- cinctus Hall, Orthoceras iehryx ( ?) Hall 505 1594 No. 6. This zone consists of a massive, grayish to slightly greenish-gray sandstone which breaks into quite large, irregular blocks and dips at an angle of 70°. Fossils are very rare in this sandstone; but specimens of Spirifer were found by Dr. Rowe 59 1653 This sandstone appears to the writer to represent the one which occurs at numerous other localities in the upper part of the Rom- ney formation and the top of the sandstone is regarded as marking the upper limit of the Romney in this section. If this be true then the Romney formation has an approximate thickness of 1653 feet in the western part of Washington County which agrees closely with its thickness in Allegany County, 1590 feet, at Gilpin. No. 7. The remaining part of the section consists of thin, greenish shales alternating with thin bedded sandstones. The dips vary from 70° to 83° and the average of a number of readings is 75°. Succeeding the massive sandstone at the top of the Romney formation are thin greenish shales and there is no representation of the black Genesee shale. The layers of sandstone are thin, still there is a great deal of sandstone and it, possibly, forms nearly one-half of the thickness of the rocks. This zone is in the Jennings formation and, probably, all of it belongs in the Wood- mont member 1257 2910 Exposures near Hancock. — The Romney is exposed on the National Road just east of Hancock. The following descriptions of the various zones of the section beginning with N"o. 1, at the top of the Romney, are from Dr. Rowe's notes : „ ^ , Total Thick- thick- nesB. ness. No. 1. Cross and thin bedded light olive sandstone with little or no shale. Average dip 48°. Strike N. 25° E. Sandstone zone at the top of the Romney formation 55J 388 No. 2. Layer with numerous specimens of Camarotoechia J 332^ No. 3. Cross and thin bedded light olive sandstone with little or no shale 72 332 6 83 The Middle Devonian Deposits of Maryland Total Thick- thick- ness. nesB. No. 4. Bluish-gray shales with a band of calcareous sand- stone near the top. This zone is fossiliferous. Average dip 60° E. Strike N. 35° E 260 260 The shales in the small run at the east end of Hancock, just east of the Catholic Church furnished the following species: Orbi- culoidea sp., Stropheodonta {LeptostropMa) perplana (Conrad), Chonetes mucronatus Hall, Chonetes coronatus (Conrad), Cfio- netes scitulus Hall, Chonetes settger (Hall), Chonetes lepidus Hall, Gamarotoechia congregata- (Gonrsid) , Tropidoleptus carinatus (Con- rad), Cyrtina hamiltonensis Hall, Spirifer muoronatus (Conrad), Spirifer granulosus (Conrad), Spirifer. audaculus (Conrad), Spiri- fer tullius Hall, Amiocoelia urnbonata (Conrad), Orthonota un- dulata Conrad, Pleurotomaria capillaria Conrad, Bellerophon sp. The following species were collected by Dr. Eowe on the road from Hancock to Harrisonville about 2 miles north of Hancock in the southern part of Fulton County, Pa.: Stropheodonta (Leptostrophia) perplana (Conrad), Stropheodonta demissa (Conrad), Stropheodonta cf. concava Hall (small specimen), Schuchertella sp., Chonetes miicronatm Hall, Chonetes coronatus (Conrad), Chonetes scitulus Hall, Chonetes setiger (Hall), Camarotoechia congregata (Conrad), Tropidoleptus carinatus (Conrad), Cyrtina hamiltonensis Hall, Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Spirifer audaculus (Conrad), Spirifer tullius Hall, Grammysia cf. circularis Hall, Nucula corbuliformis Hall, Palaeoneilo rowei Prosser, Palaeoneilo marylandica Prosser, Parallelodon hamiltoniae (Hall), Pterinea flahellum (Conrad), Aviculopecten prin- ceps (Conrad), Modiomorpha concentrica (Conrad), Modiomorpha my- tiloides (Conrad) (?), Goniophora hamiltonensis Hall, Pholadella ra- diata (Conrad), Cypricardella tenuistriata (Hall), Paracyclas Ivrata Conrad, Pleurotomaria (Bembexia) sulcomarginata Conrad, Pleuroto- maria capillaria. ponrad, Cyclonema hamiltoniae Hall, Platyceras erectum Hall ( ?), Homalonotv^ dehayi (Green). The following species were collected in the cut on the Baltimore and Ohio Eailroad at Hancock station, on the West Virginia side of the Potomac Eiver: Stropheodonta {Leptostrophia) perplana (Conrad), Chonetes mucronatus Hall, Spirifer granulosus (Conrad), Spirifer auda- Maryland Geological Survey 83 culiis (Conrad), Ortlionota undulata Conrad, Pleurotomaria cdpillaria Conrad ( ?), Bellerophon sp. Exposure at Millstone. — At the western end of Millstone village is a bloeky sandstone on the upper layers of which are good specimens of Spirophyton velum (Vannxem). This sandstone is perhaps the one at the top of the Eomney formation and is brought up at this locality by a small anticlinal fold. Along the road east of this point are olive, thin, micaceous shales, alternating with thin olive sandstones which dip about 40° S., 10° E., and are in the lower part of the Jennings formation. To the west of the anticline, the rocks dip westerly and soon expose the olive shales and sandstones in the lower part of the Jennings formation. No fossils were found in the Jennings shales in the village although, probably, more careful search would reveal some. To the southeast of Millstone on the National Road about one-half mile west of Licking Creek are yellowish, very argillaceous shales, much spotted with red blotches from weathering, which contain Tropidoleptus carinatus (Conrad) in considerable abundance, Spirifer mucronatus (Conrad) and Chonetes; the complete list being as follows: Chonetes mucronatus Tlsll, Chonetes setiger (Hall), Tropidoleptus carinatus (Con- rad), Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Spi- rifer audacvlus C Conrad'), Bellerophon sp. A little farther west, a zone of quite heavy, massive sandstone crosses the road which before weathering is grayish in color but afterwards has a brownish tint. It is strongly arenaceous and breaks into rather small blocks. A few fossils are to be found in it such as Spirifer; hut they are rather infrequent. Some 8 feet of the rock is shown with a dip of 70° about N. For a few feet the rocks are covered, then coarse sandy shales appear and these in turn are followed' by finer shales and then a sandstone stratum 1 foot in thickness. This is probably an outcrop of the upper sandstone of the Eomney formation. Exposure at Warren Point. — This outcrop occurs at the southern end of the iron bridge crossing Licking Creek, just over the state line in Penn- sylvania, and a little more than. 1 mile southeast of Warren Point. In the cliff on the southern side of the creek, a short distance to the west. 84 The Middle Devonian Deposits of Maryland is the best exposure of the Helderberg formation in the Hancock region, showing the faunas of the Coeymans limestone, 'New Scotland beds and Beeraft limestone of New York. This region has been well described by Dr. Eowe and he has also described the section at the southern end of the bridge, which is an especially interesting one as it shows the con- tact of the Oriskany and Eomney with a conglomerate at the top of the Oriskany and another at the base of the Eomney, and called attention to its structural significance. A more detailed section of this locality follows : No. 1. On the bank at the eastern side of the bridge and along the side of the highway to the south the upper rocks of the Oriskany sandstone and the succeeding shales of the Eomney formation are shown. Begin- ning at the top of the section these shales as shown by the roadside are somewhat arenaceous, rather coarser than the lower ones, weather to a slightly greenish tint and are in the Onondaga member. There are some fossils here and the following species have been identified : Rhipidomella cyclas Hall (?), Ambocoelia umhonata (Conrad), Styliolina fissurella (Hall), Phacops rana (Green), Crinoid segments. No. 2. The lowest shales are argillaceous, weather to a slightly greenish tint and contain some quartz pebbles which were probably de- rived from the lower Oriskany conglomerate. No. S. Covered for some 3 to 3 inches ; Eomney-Oriskany contact. No. Jf. At the top of the Oriskany a layer of mainly rather coarse grained sandstone in which are some quartz pebbles. No. 5. A conglomerate layer, 2% inches in thickness, containing quite large, smooth, quartz pebbles some of which are V/2, inches in length and % of an inch in width. No. 6. Dark blue, arenaceous limestone in which are bands of grit containing some fair sized quartz pebbles, and conglomerate. Only the upper part of this zone, in which fairly abundant specimens of Oriskany fossils occur in layers, is shown on the eastern side of the bridge; but on the western side is a much better outcrop where between 14 and 15 feet is exposed. The grit and conglomerate layers are also better shown on the western side. Maryland Geological Suevey 85 No. 7. Below the grit of the previous zone is dark blue limestone containing quite large masses of blackish chert. During low water 4 feet, 3 inches of this zone is shown to the level of Licking Creek. The contact of the Oriskany and Eomney is also shown in the aban- doned quarry to the east of the bridge on the northern side of the creek. At the top of the Oriskany is a conglomeratic layer, with a thickness of 8 inches, in which are large and numerous quartz pebbles. Above this is a shaly layer containing a good many pebbles and this is regarded as a basal conglomerate of the Eomney formation. As has been already stated the conglomerate at the top of the Oriskany sandstone indicates shallow water and shore conditions which were prob- ably followed by a land area. This land area evidently continued for a time preceding the formation of the Onondaga shale, when a subsidence occurred and the basal conglomerate of the Eomney formation was deposited. The Warren Point conglomerates were discovered by Dr. Eowe who first called attention to the evidence of unconformity at this locality between the Oriskany and Eomney formations. Farther south- ward, in Virginia, Darion described an erosional unconformity between the Monterey (Oriskany) and Eomney formations, especially in the region to the west of Staunton." Exposure at Emstville. — By the roadside in Emstville, to the southeast of Licking Creek, are exposures of fine, blue shales which split irregularly and are quite arenaceous. They contain a considerable fauna composed of Phacops rana (Green), Chonetes coronatus (Conrad), and other species as listed below: Stereolasma rectum (Hall), EeUophyllum sp., Orbicur loidea lodiensis var. media Hall, CrameUa sp., Leptaena rhomboidalis (Wilckens), Chonetes coronatus (Conrad), Chonetes cf. scitidus Hall, Chonetes setiger (Hall) (?), Productella (?) schucherti Prosser, RUpi- domella cf. vanuxemi Hall, Bhipidomella cyclas Hall (?), Schizophoria striatula (Sdilotheim) {■?) , Amhocoelia umhonata (Conrad), AmSccoeKa praeumbona Hall ( ?), Nucleospira concinna Hall, Nucula coriuliformis Hall, Nuculites ohlongatus Conrad, Parallelodon hamiltoniae (Hall), ' Am. Geol., Vol. X, 1892, p. 16. 86 The Middle Devonian Deposits of Maryland Pleurotomaria (Bembexia) sulcomarginata Conrad, Pleurotomaria {Tre- pospira) rotalia Hall (?), Diaphorosioma lineatum (Conrad), Styliolina fissurella {Hell), Spy roceras crotalum (Hall), Spyroceras claa-Tcei Prosser, Phacops rana (Green), Dalma-nites niarylandioiis Prosser. Exposure at McCoys Ferry.— At McCoys Ferry to the west of the south- ern end of North Mountain and 4 miles southwest of Clear Spring is the most eastern outcrop of the Romney shales. The rocks are grayish and somewhat arenaceous and are exposed to best advantage by the side of the highway under the Western Maryland Eailroad bridge. These shales are very fossiliferous containing large numbers of Ghonetes, especially fine specimens of Chonetes coronatus (Conrad), Spmfer mucronatus (Con- rad), Tropidoleptus carinatus (Conrad), Cyrtina hamiltonensis Hall, and other species as follows: Stropheodonta (Leptostrophia) perplana (Conrad), Schuchertella variabilis Prosser, Chonetes mucronatus Hallj Ghonetes coronatus (Conrad), Chonetes setiger (Hall), Chonetes lepidus Hall, Chonetes vicinus (Castelnau), Tropidoleptus carinatus (Conrad), Cyrtina hamiltonensis Hall, Spirifer mucronatus (Conrad), Spirifer granulosus (Conrad), Spirifer audaculus (Conrad), Spirifer acuminatus (Conrad), Spirifer angustus Hall ( ?), Palaeoneilo ienuistriata Hall ( ?), Tentaculites attenuaius Hall. In this exposure the lithologj'- and fauna agree so closely with the typical Hamilton shales of New York that there seems to be no oppor- tunity for any question concerning the correctness of this correlation. In the immediate vicinity of McCoys Ferry, on the Chesapeake and Ohio Canal, is an interesting cliff of Tuscarora sandstone. There are exposures of blue, fairly arenaceous shales between the canal and the Western Maryland Eailroad southwest of McCoys Ferry. The rocks are less fossiliferous than those at the Ferry but certain layers contain a fair number of species of brachiopods while pelecypods are more abundant than in the preceding zone. These outcrops are probably higher in the Eomney formation than those at McCoys Ferry. The fauna is as follows: Chonetes scitulus Hall, Chonetes setiger (Hall), Chonetes vicinus (Castelnau), Tropidoleptus carinatus (Conrad), Spirifer mucro- natus (Conrad), Prothyris lanceolata Hall, Grammysia bisulcata (Con- Maryland Geological Survey 87 rad), Grammysia arcvata (Conrad), Nucula corbuliformis Hall, Nucu- lites ohlongatus Conrad, Nucidites triqueter Conrad, Nuculites grabaui Prosser, Palaeoneilo constricta (Conrad), Palaeoneilo emarginata (Con- rad), Falaeoneilo tenuistriata (Conrad), Leda diversa Hall, Nyassa ar- guta Hall ( ?), Aviculopecten piinceps (Conrad), Paracydas lirata Con- rad, Pleurotomaria {Trepospira) rotalia Hall (?), Diapliorostoma line- atum Conrad (?), TentacvMtes attenuatus Hall, Tentaculites bellulus Hall, var. potomacensis Prosser, Phacops rana (Green). On the road about one-fourth mile north of Green Spring Furnace the following species were collected: Chonetes mucronatus Hall, Oho- netes coronatus (Conrad), Chonetes, lepidus Hall, RMpidomella sp., Cyrtina liamiltonensis Hall, Tentaculites attenuatus Hall. 88 The Middle Devonian Deposits of Maryland COERELATIOF OF THE MIDDLE DEVOISTIAN Onondaga Member ' The earlier students of the Middle Devonian believed that the Onon- daga member and its equivalents were absent in Maryland and adjoining parts of Pennsylvania and West Virginia and referred the lower beds of the Romney to the Marcellus. Thus, Prosser, who made a critical study of the Eomney of Maryland, stated that the Onondaga is absent in Maryland and that the Marcellus rests upon the eroded surface of the Oriskany/ This was also the view of O'Harra/ who described the geology of Allegany County, and of Eowe* and Schuehert." Other students of the problem in adjoining areas arrived at the same conclusions." Kindle, who discusses the question elsewhere in this volume, has recently shown ' that the lower beds of the Eomney differ faunally from the overlying strata and has called them the Onondaga member of the Eomney forma- tion, which term has been adopted by the U. S. Geological Survey.' Before discussing the age of this member it will be helpful to review the conditions that exist in New York, which is the typical area. The Marcellus of New York was originally made to comprise the dark car- bonaceous shales lying between the Onondaga and Hamilton. It included two limestones, the lower of which is known as the Goniatite and the upper as the Stafford limestone. Eecently the Marcellus formation has ' Contributed by Charles K. Swartz. = Prosser, C. S., Jour. Geol., vol. Ix, 1900, p. 418, and discussion in ms. of Romney formation for present volume. = 0'Harra, C. C, Md. Geol. Survey, Geology of Allegany County, 1900, pp. 103, 160. * Rowe, R. B., Devonian of Md. Ms. in library of Johns Hopkins Univ. » Schuchert, Chas., Proc. U. S. Nat. Mus., vol. xxvi, 1903, p. 414. "Darton, N. H., Amer. Geol., vol. x, 1892, p. 16; Stevenson, J. J., 2d Geol. Survey Penn., vol. T2, 1882, pp. 81-83; Ulrich, E. O., and Schuchert, Chas., Bull. N. y. State Mus., No. 52, 1902, pp. 653-654. ' Bull. U. S. Geol. Survey, No. 508, 1912, pp. 35-38. » U. S. Geol. Survey, Pawpaw-Hancock Polio, 1912, field edition, p. 75. Maryland Geological Survey 89 been subdivided into three parts by Clarke and Luther; who have des- ignated them the Marcellus shale, the Stafford limestone, and the Cardiff shale, corresponding to the lower shale, the upper limestone, and the upper shale respectively. Clarke " has shown that the Onondaga and Marcellus do not represent strictly successive periods of time, but that the lower beds of the Marcellus were deposited contemporaneously with the upper beds of the Onondaga, limestone being formed to the west farther from the shore, while the clays were deposited simultaneously in the east nearer the shore. This was proved by tracing the Goniatite limestone westward until it finally merged with the upper bed of the Onondaga limestone due to the thin- ning and ultimate disappearance of the black shales which lie between it and the Onondaga, in central New York. In other words, the lower beds of the Marcellus and upper beds of the Onondaga are contem- poraneous and represent not two periods of time, but two phases of sediments deposited simultaneously but under different conditions. It thus becomes impossible to speak of Marcellus time as successive to Onon- daga time, precisely as it is impossible to distinguish Chemung from Catskill time. The Goniatite limestone, which is the important horizon-marker, is distinguished by the presence of numerous goniatites, particularly Ago- niatites expansus, which is its most diagnostic form. The latter species is sometimes said to occur both in the Onondaga and the Marcellus, but it is to be noted that these terms may signify only the same horizon. The Stafford limestone which occurs at a higher level in the Marcellus is characterized by the advent of numerous species of Hamilton afiBnities which mingle with those of earlier age. It thus becomes a suitable hori- zon for a formational division as proposed by Clarke. It would not be surprising to find that the shales replace succes- sively lower and lower limestone beds as we approach the shore line until a large part of the deposit of Onondaga time may be represented by shale. Such appears to be the case in Maryland. ' Bull. N. Y. State Mus., No. 63, 1902, p. 16. " Clarke, J. M., Bull. N. Y. State Mus., No. 49, 1901, pp. 115-138. 90 Ti-iE Middle Devonian Deposits of Maryland The correlation of these sediments will now be considered, discussing first their faunal and stratigraphic relations and then their age. The fauna of the Onondaga member is rich both in species and individuals in the Maryland area, contrasting strikingly in this respect with that of the overlying Marcellus. The accompanying table shows the species that have been observed in the Onondaga member in Maryland and adjoining parts of West Virginia, and indicates their range in the New York section. Four elements may be discriminated in this fauna, according to their habitat in the New York section, i. e., species found in black shale, in arenaceous shale, in the Marcellus limestones and in the Onondaga lime- stone. Four species, Liopteria Icevis, OrMculoidea, lodiensis, Btyliolina fissu- rella, and Bactntes aciculus, which are among the most common species of the fauna, are also common in the black shale of the Marcellus of New York. The three last species are frequent in the Genesee in which similar shale recurs. Since such carbonaceous muds are known to occur in different formations it is possible that these species are not so diagnostic of a particular horizon as of a definite kind of sediment. Endle, who holds this view, urges that they have little value for purposes of precise correlation. However, such weight as they possess is clearly in favor of the relation of the beds under consideration to the Marcellus shale of New York. A second element of the fauna consists of 12 species that are found in the arenaceous shale of the Hamilton, as well as in the Marcellus, none of which are known in New York in beds older than the Marcellus. They constitute 46 per cent of the species significant for purposes of correlation and strongly suggest the close faunal relation of these beds to the Mar- cellus. Eeference has already been made to the impure limestone occurring in the Marcellus of New York in which Agoniatites expansus and Badrites adoulatus are found, the former species occurring in such numbers that this bed has been called the Goniatite limestone. A very similar lime- MaeylXnd Geological Survey 91 Onondaga Species « I 1 ^ O a. 1 1 O en 3 i a S a o 60 a 9 S BRACHIOPODA Lingula cf. nada Hall + + + + + + + + + Orblculoidea lodlenses var media Hall Craniella hamiltoniae Hall Pholidops cf. areolata Hall Stropbeodonta (Leptostrophia) perplana (Con- rad) -\ Schuchertella variabilis Prosser Leptaenisca australis Kindle Chonetes mucronatns (Conrad) Chonetes rugosus Kindle . + + ? + H + 1- + + + . + . + . + . + + . + + + ? + + + + + + + + + + + + + + + + + + + + + + + + + + Strophalosia truncata (Hall) Dalmanella lenticularis (Vanuxem) Rhipidomella vanuxeml Hall Rhipldomella cyelas Hall ? Centronella cf. ovata Hall Spirifer (Retieularia) fimbriatus (Conrad) . . . Ndpleoanira concinna Hall Anoplotheca acutiplicata (Conrad) Anoplotheca Camilla (Hall) PELEOTPODA. Fanenka alternata Hall Panpnka cf dicbotoma Hall Panenka obsolescens Kindle Panenka cf. multiradiata Hall Nnpnla corbnliformis Hall .. . + i .. Nnculites triqueter Conrad Nnculites modulatns Kindle Palaeoneilo conatricta ? (Conrad) + + + + + + -r + + + + + ATlculopecten eqnilatera (Hall) Modiomorpha snbalata (Conrad) GASTROPODA Platyoatoma cf. euompbaloides Conrad Loxonema hamiltoniae Hall PTEROPODA Sfwlinlinfl fi^anrplla (Hall) .... ... Connlaria cf. undulata Conrad CEPHALOPODA Bactrites acicnlatus (Hall) Bactrites acicnlas Hall A^oniatites expansus (Vanuxem) Parodieeras discoidenm (Conrad) TUILOBITA Cyphaspis cf. stephanophora Hall Phacopa cristata Hall Phaeops cristata var. pipa Hall OSTBACODA Leperditia subrotanda ? Bollia ungula Jones Bollla obesa Ulrich 93 The Middle Devonian Deposits of Makyland stone occurs in the beds under consideration and contains both Agoniatites expansus and Bactrites acicidatus. The former species is practically restricted to the horizon of the Goniatite limestone in New York. A fourth element consists of 8 species that are confined to the Onon- daga in ISTew York, including Anoplotheca acutipUcata and several trilo- bites. The first-named species is so abundant indeed that this member may be called the zone of Anoplotheca acutiplicata. .Two species also are known in New York in formations older than, the Onondaga. The 10 Onondaga and pre-Onondaga species constitute 36 per cent of the species significant for correlation. The question may be raised whether some species have especial value for purposes ■ of correlation. The trilobites are highly plastic forms usually indicating geological horizons with considerable accuracy. The 3 species occurring in this fauna are restricted to the Onondaga in New York while a large number of trilobites found elsewhere in the fauna by Kindle suggest a close relationship of the beds to the Onondaga. The goniatites are also of high value for correlation because they are free swimming forms that underwent rapid changes. The two species that occur in this fauiia are found in the Marcellus in New York, one being diagnostic of the Goniatite limestone, while the other occurs also in the Hamilton. It is thus seen that there are two conspicuous elements in the fauna, one indicating a relationship to the Onondaga and the other to the Marcellus. Kindle, who has studied this fauna from New York to Tennessee, em- phasizes the importance of the trilobites and other Onondaga elements of the fauna. Other observers would perhaps give weight to the later elements of the fauna, holding that the most significant species are the later migrants into the region. The faunal relations may be summarized in the following table : Number Total number of species and varieties 45 Species not possessing significance for correlation 17 Occurring in this fauna only 7 Occurring in the Onondaga and Marcellus 8 Relations not assured 2 Per Cent 36 3. 5 3. 5 29 64 3. ,5 46 3, .5 Maryland Geological Survey 93 Number Species possessing significance for correlation 28 Occurring in New York only in the Onondaga or earlief formations 10 In Oriskany 1 In Schoharie 1 In Onondaga 18 Occurring in New York only in the Marcellus or later formations 17 In Marcellus 1 In Marcellus and Hamilton 12 In Genesee 1 This table shows the clearly preponderating relationship of the fauna as a whole to the Marcellus fauna of New York. The stratigraphic relations indicate no less clearly an age earlier than the upper part, at least, of the Marcellus of New York. The Marcellus is characterized by Liorhynclms limitare, which may be considered its guide fossil both in New York and Maryland. The beds containing this species overlie the fauna under consideration in Maryland and the adjoin- ing states, and also throughout the Appalachian region according to Kin- dle. The constancy of this position indicates that the Onondaga fauna of Maryland is older than the zone of Liorhynchus limitare.^ Litho- logically the fissile dark shales found in some of the lower beds of this member suggest the Marcelhis while the other beds resemble the shale of the Hamilton. The foregoing facts show that these deposits were laid down in a basin in which many Onondaga species were present, but after the advent of many other forms restricted in New York to the Marcellus and Hamilton, * Prosser reported L. limitare from the lower beds of the Romney in a number of sections in Maryland, particularly at 21st Bridge and on the Wil- liams Road 3i/^ miles southeast of Cumberland. Kindle who has since examined the same sections failed to And that species at the horizons indi- cated by Prosser. Anoplotfieca acutiplicata, which is thought by Kindle to be diagnostic of the Onondaga, is also reported by "Weller from the Newfoundland Grit and the Monroe shales of New Jersey, both of which oVerlie the Onondaga limestone (Pal. N. J., vol. iii, 1903, pp. 105, 106). It is associated in the Monroe shales with Tropidoleptus carinatus. It is also reported by Prosser as occurring rarely in the Hamilton of Maryland. 94 The Middle Devonian Deposits of Maryland and that they aie faunally most closely related to the Marcellus. It is further evident that they are older than the zone of Liorhynchus limitare in Maryland. The determination of the exact age of these beds is difficult since the principles of correlation of deposits of this type are not well established. It is evident that faunas that are successive in one area must frequently be contemporaneous elsewhere, since the advent of highly developed species immediately succeeding another fauna in one region indicates that both were in existence earlier in some other basin and hence were, for a time at least, coexistent. When therefore a mingling of the species of two such faunas is observed in a third area it is at times impossible to affirm their precise age with certainty. The following methods of solution appear possible under such circum- stances; the study of the direction of migration of the species and their relations to sediments and physical conditions, the emphasis of certain species rather than others in correlation, the determination of the rela- tions of the fauna as a whole and correlation by some recognizable horizon. The first of these methods appears the most decisive. Unfortunately knowledge of the necessary data is rarely obtainable in an early stage of the investigation so that while this method has been used with much success in the study of the Upper Devonian it does not appear to be con- clusive here. Mr. Kindle has contributed a valuable discussion of this aspect of the problem in another part of the present volume. The second method appears to lead to very different results accordingly as certain elements of the fauna are emphasized rather than others. If we assume that the Marcellus of Maryland may represent but a part of the Marcellus of New York, a possible assumption in view of the varying limits of that formation, then the beds under consideration may be of early Marcellus age. This view would accord not only with the fact, so often observed, that species of an earlier fauna may persist and become mingled with those of a later; but also with the presence, of so large a number of species restricted to the Marcellus and later beds in New York. Indeed many students would not hestitate to assume that species observed in later faunas elsewhere are, in general, the latest immigrants Maryland Geological Survey 95 into such an association, and hence are entitled to peculiar weight in correlation. Although this conclusion may be uncertain, especially when, as in the present case, the sediments of the beds to be correlated are like those of the later and unlike those of the earlier formation, nevertheless it is believed that particular weight should be given to the species found elsewhere in later formations, as has been done in the reference of the Helderberg to the Devonian and the Eichmond to the Silurian. If, on the contrary, it is assumed that the zone of Liorhynchus Umitare represents approximately the same interval in New York and Maryland, then these beds are older than much of the Marcellus of New York and are syn- chronous, at least in part, with the Onondaga. This view, which is that of Kindle, is favored not only by the position of the beds below the Mar- cellus of Maryland, btit also by the presence in them of so many species that are restricted to the Onondaga in New York, including such plastic forms as trilobites. When the emphasis of certain elements of the fauna leads to divergent results particular weight may be attached to the relations of the fauna as a whole. This criterion indicates again a close relationship of the beds to the Marcellus, since it has been shown that over 60 per cent of the significant species occurring in them are restricted to the Marcelllus and later formations of New York. The entire argument leads to the con- clusion that the beds are of early Marcellus age and also in part contem- poraneous with the Onondaga. The explanation of these facts may perhaps be found in the conditions shown to exist in New York, where the upper beds of the Onondaga are of the same age as the lower beds of the Marcellus, and hence their faunas are contemporaneous. In other words the beds under discussion may have been deposited when both the Onondaga and Marcellus faunas were co- existent in this area, a condition which would fully explain the mingling of the faunas in the same beds and especially the presence of such highly significant species as the Onondaga trilobites and the Marcellus goniatites. Thus while the limestones of the Onondaga were accumulating ofE-shore in New York dark shales were being deposited on shore in the Appa- 96 The Middle Devonian Deposits of Maryland lachian province, species of Onondaga type invading and mingling with those of Marcellus type in the latter sediments. Upon the termination of the Onondaga, Marcellus species persisted in the east and the later shale deposits of New York and Maryland were formed. The difference be- tween the faunas of the shales of New York and Maryland is to be ex- plained by the differences of habitat, black muds prevailing in New York while more arenaceous clays were deposited, in Maryland. The Maryland beds may also be older in part than the corresponding shale deposits of New York. This explanation would fully harmonize with the conditions shown by Clarke to exist in New York and would explain the undoubted fact that the sediments were laid down in Maryland in a basin occupied simultaneously by numerous species of both the Onondaga and Marcellus faunas. Agoniatites expansus appears in largest numbers in the upper 50 feet of this member where it is associated with Bactrites aciculatus precisely as it occurs in the Goniatite limestone of New York, to which horizon the former species is essentially restricted in that State. The limestone is impure and argillaceous and also increases in thickness in the western sections as in New York, being best seen in Maryland at 2 1st Bridge. Although it is not possible to afBrm with confidence that the Goniatite limestone is the same in Maryland and New York, nevertheless their resemblance is very suggestive and it is believed that they may represent the same horizon. If this is true then the upper beds represent the hori- zon of the top of the Onondaga of western New York and of the Goniatite limestone in the Marcellus of central New York, while the lower beds may be older than the base of the Marcellus of that State. It also seems pos- sible that a hiatus may exist in the Maryland section as is suggested by the apparent unconformity at the top of the Oriskany. The suggested relations of the New York and Maryland sections are shown in the diagram on the following page.^ It must he remembered, however, that the precise correlation is but tentative and is not regarded as proved. ^ The figure illustrating the conditions in New York is taken from Clarke's discussion in Bull. N. Y. State Mus., No. 49, 1901, p. 137. Maryland Geological Sukvey 27 This interpretation seems to accord fully with the results given by Kindle elsewhere in this volume ' and at the same time to explain the manifestly close faunal relationship of this member to the Marcellus of New York. The propriety of applying the name Onondaga may be questioned. The lithological and faunal differences that separate the beds from the over- lying Marcellus make it desirable to discriminate them by a distinctive term. In view of the marked contrast between them and the Onondaga limestone of Wew York, both in lithology and fauna, it is believed that it might have been fitting to give them a new name. They are, however. NEW YORK AfARYLAND Pig. 1. — Diagram showing suggested relations between the Upper Devonian of Maryland and New York. called the Onondaga member of the Eomney in deference to the usage of the U. S. Geological Survey. Marcellus Member.'' The Marcellus member of the Eomney formation has a very meager fauna, most of the strata being barren of organic remains. The species found, however, clearly show that it is to be correlated with part of the Marcellus of New York. The table on the following page gives a list of the species and indicates their range in the New York section. One of these species is new. All of the remaining occur in the Mar- cellus of New York. Four species are found also in the Hamilton of New York while three pass into the Upper Devonian. Two species, 1 See also Bull. U. S. Geol. Survey, No. 508, 1912. ' Contributed by Charles K. Swartz. 98. The Middle Devonian Deposits of Maeyland Liorhynchus limitare and L. mysia, are especially diagnostic of the Mar- cellus. LitHologically the sediments closely resemble the Marcellus shale of New York, consisting chiefly of dark or black, carbonaceous, fissile shale. Thin beds of limestone are also present as in the corresponding formation in New York, although this is a less conspicuous feature in the deposits of Maryland. These facts fully establish the Marcellus age of the beds. The age of the blue fissile shales that lie between the strata containing the Marcellus fauna and the beds carrying the Hamilton fauna is open to question, no fossils having been observed in them up to the present. Marcellus Species a 1 fa 2 a w 0} to a u o EKACHIOPODA Ambocoeli a virginiana Prosser + + + + + + Strophalosia truncata (Hall) + + + + + + + CamarotDCChia prolifiea Hall Liorhynchus limitare (Vanuxem) Liorhynchus cf. myaia Hall PELEOTPODA Buchiola restrostriata (Von Buch) + Nucula corbuliformis Hall + PTEROPODA Styliolina fissurella (Hall) + Prosser has included them' in the Hamilton member, while Kindle refers them to the Marcellus member. Lithologically they probably resemble the Marcellus beds more closely than they do the overlying Hamilton shale which, in general, is not fissile, but blocky, and breaks into irregu- lar, many-sided fragments. Hamilton Member ' The rocks overlying the Marcellus shale of the Eomney formation and extending northeasterly from northern West Virginia across Maryland and Pennsylvania to New York have been much more frequently corre- ' Contributed by Charles S. Prosser. Marylanb Geological Survey 99 lated with the Hamilton beds of New York. Plall and other paleon- tologists have identified collections of fossils from these rocks in northern West Virginia and from intermediate localities between that state and New York as composed of Hamilton species. If the various geological maps, reports, and papers describing the Devonian formations from West Virginia to New York are put together and considered it will be found that this correlation is strongly supported by visible continuity. Further- more the stratigraphic position of these beds strongly supports this correlation. The paleontological data is much more extensive regarding the Hamil- ton beds than it is as yet for the Marcellus shale. The table of distribution gives the list of species recorded by the writer from the Hamilton beds of Maryland and their range in the New York formations. The total number of species is 147 of which 21 are limited to Maryland leaving 126 identical or closely related species which also occur in New York. An enumeration of the totals for the New York Devonian formations shows that 3 identical species occur in the Helderbergian series ; 1 identical in the Oriskany ; 6 identical in the Schoharie ; 17 identical, doubtfully 4 more, and 2 affili- ated occur in the Onondaga; 47 identical, 1 more doubtfully, and 7 affiliated in the Marcellus; 92 identical and 32 affiliated in the Hamilton; 2 identical in the Tully-; 4 identical and 1 affiliated in the Genesee; 2 identical in the Portage; 4 identical and 2 affiliated in the Naples; 10 identical and 1 affiliated in the Sherburne; 55 identical, 2 more doubt- fully, and 9 affiliated in the Ithaca, and 18 identical, 4 more doubtfully, and 3 affiliated in the Chemung. Adding these numbers, the total number of entries for each New York formation is as follows: Helderbergian series 3, Oriskany sandstone 1, Schoharie grit 6, Onondaga limestone 23, Marcellus shale 55, Hamilton beds 124, Tully limestone 2; Genesee shale 5, Portage beds 2, Naples beds 6, Sherburne sandstone 11, Ithaca beds G6, and the Chemung beds 25. Judging from the number of entries it is then seen that the Maryland beds show the closest relationship with the Onondaga, Marcellus, Hamilton, Ithaca, and Chemung formations of New York; and especially with the Marcellus, Hamilton, and Ithaca. On examining the total number of entries for these three formations it is 100 The Middle Devonian Deposits of Maeyland found that the Marcellus has 44.3 per cent as many as the Hamilfon and the Ithaca 53.8 per cent. This is not remarkable, however, when it is recalled first, that a large percentage of the species in the Marcellus shale of ISTew York continue into the Hamilton beds of that state, as has been shown by Clarke; second, the Ithaca fauna is sequential to the Hamilton and in the Ithaca region contains a large percentage of Hamilton species. When followed to the eastward and after the disappearance of the Tully limestone and Genesee shale in the Ohenango Valley, the writer has shown that a still larger number of the Hamilton species lived into Ithaca time, although part of them were represented by simply a few individuals which were the last feeble representatives of their species. These rare indi- viduals have been recorded in the range of the species making the faunas of the Hamilton and Ithaca beds of New York seem more closely related than they actually are and the same is true regarding the faunas of the Maryland beds and the Ithaca beds of New York. This explanation is sufficient to show that the table gives full expression to the closeness of the relationship which exists between the fauna of the Maryland beds and the faunas of the Marcellus shale and Ithaca beds of New York as com- pared with that which exists between the fauna of the Maryland beds and the New York Hamilton fauna. Eestating the tabulation then, it is shown that there are more than twice as many entries common to the Maryland and New York Hamilton beds as to the Maryland and New York Marcellus ; and nearly twice as many for the Maryland and New York Hamilton beds as for the Maryland and New York Ithaca. There- fore the paleontological evidence strongly supports the correlation of the Maryland beds, which represent in general the middle and upper portions of the Eomney formation, with the Hamilton beds of New York. An examination of the tables shows that the following number of species of the Hamilton beds of Maryland occur also in the formations of New York. Number of species occurring in the Onondaga of N. Y. 17 Marcellus " 47 Hamilton " 92 " " Sherburne " 10 Ithaca " 55 Chemung " 18 Maryland Geological Survey 101 Eecently H. S. Williams has published an extended account of what he calls the Tropidoleptus cwrinatus fauna of the Hamilton formation/ Faunally he considers the Hamilton formation as including the deposits between the top of the Onondaga limestone and the base of the Tully limestone of central New York, which have generally been divided into the Marcellus shale and the Hamilton beds. He writes as follows: " Faunally, the series of sediments, as they are exhibited in central ISTew York (beginning at the top of the Onondaga (Comiferous) limestone and terminating at the base of the Tully limestone), presents a continuity which leaves no doubt as to the genetic succession of a common fauna from the base to the top. In dealing with this fauna, only the species between the limits of the top of the Onondaga limestone and the base of the Tully limestone, when these are present, will be considered as belonging typically to the Tropidoleptus fauna." ' It will be seen, there- fore, that these sediments represent what Dana called the Hamilton period, with the exception that they do not include the Tully limestone which, where it occurs, Dana apparently regarded as forming the top of this period;' that they correspond precisely with the Brian period or group of Clarke and Schuchert,* and also according to the writer's opinion, with the Marcellus and Hamilton members of the Eomney forma- tion of West Virginia and Maryland. Cleland in his " Study of the fauna of the Hamilton formation of the Cayuga Lake section in central New York " has also limited the Hamilton formation as indicated above, stating that "It is bounded above by the Tully and below by the Onondaga (Comiferous) limestone." ° Williams carefully tabulated the faunal lists of several students of the Hamilton formation, as defined above, and from those of the writer ' Amer. Jour. Sci., 4th Ser., Vol. XIII, 1902, pp. 421-432. U. S. Gaol. Surv., Bull. No. 210, 1903, pp. 42-68. 'IMd., p. 50. " Man. of Geol., 4tli Ed., 1895, pp. 576, 593. * Science, N. S., Vol. X, Dec. 15, 1899, pp. 876, 877. Univ. of the State of New York, Handbool!: 19, July, 1903, pp. 8, 22, 23. " U. S. Geol. Surv., Bull. No. 206, 1903, p. 20. 103 The Middle Devonian Deposits of Maryland prepared a table giving the 12 species occurring most frequently in it in eastern New York, another from the lists of Dr. Cleland giving the 14 most frequent species in the Cayuga Lake region, and a third from the lists of Grabau giving the 12 most frequent species from Eighteen Mile Creek in western New York. From these three tables another one was compiled by Williams which he called the " Tropidoleptits fauna : Standard list of dominant species for the New York-Ontario province." He furthermore stated that it was concluded on balancing up the various kinds of evidence that this list " contains the 12 most characteristic species of this fauna as it appears in the New York province, and shows the order of approximate rank they occupy in the fauna as a whole."' The 13 species composing this standard dominant list for New York is as follows : 1. Spirifer pennatus (^mucronatus). 2. Phacops rana. 3. Tropidoleptus carinatus. 4. Ambocoelia umbonata. 5. Athyris spiriferoides. 6. Palaeoneilo constricta. 7. Spirifer granulosus. 8. Chonetes coronatus. ', 9. Nuculites triqueter. 10. Nucula corbuliformis. 11. Nuculites oblongatus. 12. Nucula bellistriata.^ By reference to the Maryland lists it will be found that every one of the 13 species mentioned above as constituting the standard dominant list of the New York Hamilton is found in the Hamilton beds of Maryland. Furthermore, Williams prepared another table by adding to the stand- ard list the distributional value of all the species reported by Prosser in 37 faunules of the TJnadilla region, that were not considered in the standard list, which he called a "Eevised list of dominant species of the Hamilton formation of eastern New York and Pennsylvania, as '^Loc. cit.. p. 61. ' Ibid., p. 60. Maryland Geological Survey 103 expressed in 183 fauimles." This list contains the 13 species given in the standard one and the following four additional ones : 13. Liorhynchus laura. 14. Paracyclas lirata. 15. Chonetes scitulus. 16. Stropheodonta perplana. These four additional species likewise occur in the Hamilton beds of Maryland. The above review of the paleontological evidence shows conclusively the extension of the ISTew York Hamilton as far southwest in the Appalachian basin as Maryland and the northern part of West Virginia. Professor Williams after an examination of the preliminary lists from the Hamilton beds of Maryland arrived at essentially the same conclusion which he stated in the following paragraph : " In the list furnished me by Professor Prosser there appear 132 entries, 91 of which are positive identifications. Among the latter are found all of the dominant species of the Tropidoleptus carinatus fauna, as estimated from the New York statistics. This is sufficient to establish the extension of the Tropidoleptus fauna, in its integrity, as far south in the Appalachian trough as Maryland." ' Other facts brought out in this report by Clarke, Swartz, arid the writer, apparently show that the Hamilton beds of Maryland are suc- ceeded by deposits and faunas similar to those succeeding the Hamilton of New York and therefore it may be concluded that the deposits of the Hamilton beds from New York to West Virginia were brought to a close at about the same geological time. Geological Disteibution of Species. The geological range in New York and Maryland of the Middle De- vonian species listed in this volume is given in the tables of distribution. The following seven species, viz. : Orthonota undulaM Conrad, Pcdaeo- neilo clarJcei Prosser, Cydonema ( ?) marylandense Prosser, Orthoceras ^V. S. Geol. Surv., Bull. No. 210, 1903, p. 67. 104 Tpie Middle Devonian Deposits of Maryland suhulatum Hall (?), Orthoceras telamon Hall (?), Orthoceras emmeror turn Hall (?), and Spyroceras nuntium Hall were found only in West Virginia but on account of the nearness of their occurrence to the Mary- land areas they have been left in the Maryland fauna. A complete list of occurrences for each species will be found in the part devoted to the syste- matic paleontology. The geological range of the species in Maryland is compared with that of New York State, since the latter is the standard for the American Devonian and it is desired to learn with which New York formation the fauna of the Maryland Eomney is most closely related. Again, where the age of the beds in certain districts of New York is in question the reported occurrence of species in such localities has not been recorded. For example, the species are not listed in these tables which have been reported in the fossiliferous beds immediately succeeding the Oneonta sandstone in the Chenango Valley and to the eastward, because they have been referred to the Chemung by some geologists and to the Ithaca by others. In reference to the Ithaca fauna in eastern central New York it must be remembered that it is composed largely of Hamilton species; but it is to be noted in reference to many of the species that they occur infrequently and not in the abundance which characterizes their distri- bution in the Hamilton. Makyland Geological Sdevey 105 Geologicai, Range or Middle Devonian Species in Maryland and New York. Maryland New York .2 a o > c u s g o o a, 6-2 ■a S 1- u g 1 E 4) e 1 cd o O P ID d ,o 1 0) Portage a 1 SPECIES g 1 13 a a s 'a S 1 ocelenteeata. ■eolasma rectum (Hall) Amplexus hamiltoniss Hall iophyllum sp tiphyllum americanuin Milne-Edwards & Haime VERMES. * * * * » * * » # ■■'* .. ■ • .. '? ■+ ■• * * * # ■K i * * * * * * * * i » * » * * * * * * * * , * * « * ■■ •■ w * * * * * * * • • • • « • MOLLUSCOIDEA— BRYOZOA. ipalonaria tenuis DMcli & Bassler iticulipora (f) marylandensis Ulrieh & Bassler. MOLLUSOOIDEA— BRAOHIOPODA. rulella (?) paliformis Hall sula delia Hall (?) gula ligea Hall (?) ^la cf. nuda Hall '■'■ eula cf. oompta Hall & CSarke rula claxki Prosser iculoidea lodiensis var. media Hall niella hamiltonise Hall lidops bamiltoni^e Hall lidops cf , areolata Hall )pheodonta (Leptoatrophia) perplana (Oonrad). ipheodonta demissa (Oonrad) >pheodonta (Douvillina) inequistriata (CSonrad) Ipheodonta concava Hall lldostrophia pennsylvanica Kindle tasna rhomboidalis (Wilckens) uehelrtella rariabilis Prosser metes coronatus (Oonrad) oetea acitulus Hall netes setiger (Hall) netes lepidus Hall netes viclnus (Oastelnau) mcftea maiylandlcug Prosser iphaloma tnmcata (Hall) auctella of. spinulicosta Hall manella lentirailnris (Vajiuxera) lidoroella leuoosia Hall pidomella penelope Elall pldomella cvclas Hall (7") zophoria striatula (ScUotheim) (?) t = related form. lOG The Middlk Devonian Deposits oe Maryland Geological Range of Middle Devonian Species in Maryland and New York. — Continued. SPECIES Maryland New York c a "S o > ID a b a ? o Middle Devonian Romney Upper Devonian Jennings a o o u o Middle Devonian Upper Devonian E a 1 O 1 a S a s a c o S & Ch i 1" 1 =8 &4 -a a 0) a V s 1 o 3 1 a o 1 1 Portage 0) u 2 i MOLLUSCOIDEA—BEAOHIOPODA.— Continued. Camarotcechia congregata (Conrad) OamarotoBohia proliflca Hall Camarotcechia sappho Hall Camarotcechia sp Liorhynchus limitare (Vanuxem) Liorhynchns laura (Billings)? Liorhynchus cf. mysia Hall Centronella cf . ovata Hall « * * # *■ * * * * # * # * * + t ♦ * * * * » * * # * * * * * * * « + * * * « » Eunella lincklfeni Hall Tropidoleptus carinatus (Conrad) Atrypa reticularis (Linnfi) Cyrtina hamiltonensis Hall Spirifer mucronatus (Conrad) Spirifer granulosus (Conrad) Spirifer audaculus (C3onrad) Spirifer acuminatus (Conrad) Spirifer tuUius Hall Spirifer angustus Hall Spirifer (Reticularia) fimbriatus (Conrad) Spirifer cf. consobrinus (d'Orbigny) Spirifer sculptilis var. marylandensis Prosser Ambocoelia umbonata Conrad .' Ambocmlia virginiana Prosser ^ Amboccelia praeumbona Hall (?) ■ 'i Anoplotheca (Ccelospira) acutiplicata (Conrad) . . . Athvris spirifcroides (Eaton) Meristclla ? sp MOLLUSCA— PELECYPODA. Phthonia sectifrons (Conrad) Phothyris lanceolata Hall Orthonota undulata Conrad Orthonota (?) parvula Hall Gframmysia bisulcata COonrad) Grammysia arcuata (Conrad) Grammysia sp Grammysia circularis Hall (?) Euthydeama sp Tellinopsis subemarginata (Conrad) Panenka altemata Hall Panenka cf. dichotoma Hall Panenka obsolesoens Kindle Panenkk of. multiradiata Hall Buohiola retrostrlata von Buch ; . . . Buohiolja halli Clarke , Nucula oorbuliformis Hall , Nuoula'bellistrjata; (Conrad) Nucula i lirata (Conrad) . . . : :'.'.'.'.'.'." Nucula varicoea Hall.:...i :........ + = related form. Mar-sland Geological Survey 107 Geological Range of Middle Devonian Species in Maryland and New York.— Continued. Maryland New York a § Q 3 Middle Devonian Romney upper Devonian Jennings i £ a t- In this work the well known terms ventral valve and dorsal valve are used. Dr. J. M. Clarke and some other paleontologists in their later publications call the ventral the pedicle valve and the dorsal the brachial valve. Maryland Geological Suiipey 127 One specimen from the shales on the bank of Evitts Creek below Wolfe Mill agrees fairly -well with the figures and description of this species, except that the beak is not so pointed ; another one showing the interior of a valve from the B. & 0. E. R. cut at 21st Bridge agrees fairly well with this species. Length, 13 mm.; width, t mm. Occurrence. — Eomnkt Foemation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; B. & 0. E. E. cut at 21st Bridge. Collection. — Maryland Geological Survey. LiNGULA Cf. NUDA Hall Plate VIII, Eigs. 7, 8 Lingula nuda Hall, 1863, Sixteenth Rep. N. Y. State Cab. Nat. Hist., p. 22. Lingula nuda Hall, 1867, Pal. N. Y., vol. iv, p. 10, pi. ii, figs. 4-6. lAngula nuda Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 251. Lingula nuda Clarke, 1903, N. Y. State Mus. Bull. 65, p. 247. Description. — " Shell subelliptical ; length nearly twice as great as the width ; sides subparallel, very slightly curving, the greatest width near the center ; front truncated. Cardinal slopes rounded, the ventral valve a little more pointed and more convex than the dorsal valve. Dorsal valve nearly flat. Ventral valve, in exfoliated specimens, marked by a depressed line down the center. Surface marked by fine concentric striae, which, on the margins, are crowded and wrinlded." Hall, 1867. There is apparently a slightly raised median line, while the concentric striae are faintly shown near the margins of the shell. The specimen from Williams Eoad 3J miles southeast of Cumberland was sent to Dr. J. M. Clarke who wrote as follows regarding it: "The Lingula seems to me, notwithstanding its distortion by shearing, a specimen of L. nuda or L. densa. It agrees well with either in outline; better with the former in size." Prof. Schuchert made the following note regarding the same specimen : " It looks to me more like a young compressed L. punctata; but I would not be sure of this." In the writer's opinion the specimens approach L. nuda more nearly than any other species.' * The latter is shown on pi. viii, figs. 9, 10. 138 Systematic Paleontology — Middle Devonian Length, 7, 11 mm. ; width, 5-^, 7 mm. Occurrence. — Romney Formation, Onondaga Member. Williams Eoad 3i miles southeast of Cumberland. Hamilton Member. Oldtown Road near Cumberland; B. & 0. R. R. cut at 31st Bridge; Williams Eoad J mile east of Queen City Hotel, Cumberland; Williams Road, 3| miles southeast of Cumberland; on Oldtown Road east of Maryland Ave., Cumberland. Collection. — Maryland Geological Survey. Lingula cf. compta Hall and Clarke Plate VIII, Pig. 11 Lingula compta Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, p. 171, pi. 1, fig. 16. Lingula compta Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 246. Lingula compta Clarke, 1903, N. Y. State Mus., Bull. 65, p. 246. Description. — " Shell very narrow, with lateral margins nearly parallel for most of their length, the aaiterior margin transverse and the posterior less abruptly rounded. Shell-substance thin. Surface marked by fine concentric striae. A narrow median furrow extends from just behind the center of the brachial ( ?) valve nearly to the anterior margin. Length of this valve, 9 mm., greatest width, 4.5 mm." Hall and Clarke, 1892. This specimen is larger than the one figured by Hall and Clarke and its width in proportion to the length is somewhat greater. Length, 16 mm.; width, 9 mm. Occurrence. — Romney Formation, Hamilton Member. East bank of Evitts Creek below Wolfe Mill. Collection. — Maryland Geological Survey. Lingula clarki n. sp. Plate VIII, Pigs. 13, 13 Description.-~SheU. narrow, width about one-half the length, central portion of lateral margins parallel but tapering at each end toward the apex. Shell strongly convex along the median line from the beak well Maryland GeIological Survey 139 toward the front and sloping rather abruptly toward the lateral margins. Surface marked by fine concentric striae and some coarser lines of growth. This species somewhat resembles Lingula compta Hall and Clarke, but that species is laorger, neither so convex along the median line nor so pointed at the extremities; also L. ligea Hall, but that species is larger, wider in proportion to the length and not strongly convex along the median line. This species apparently is readily distinguished from others by its narrowness and strong median convexity. Length, 5^-8 mm. ; width, 24-1 mm. Named in honor of Dr. William B. Clark, State Geologist of Maryland. Occurrence. — Eomney Formation, Hamilton Member. B. & 0. E. R. cut at 21st Bridge. Collection. — ^Maryland Geological Survey. Superfamily DISCINACEA Family DISCINIDAE Genus ORBICULOIDEA d'Orbigny Oebiculoidea lodiensis var. media (Hall) Plate VIII, Figs. 14-17 Orbicula lodensis Vanuxem, 1842, Geol. N. Y., pt. ill, p. 168, fig. 1. OrWcula lodensis Hall, 1843, Geol. N. Y., pt. iv, p. 223, fig. 1. Discina media Hall, 1863, Sixteenth Rep. N. Y. State Cab. Nat. Hist., p. 27. Discina lodensis Hall, 1867, Pal. N. Y., vol. iv, p. 22, pi. i, fig. 14; pi. ii, fig. 35. Discina media Hall, 1867, Pal. N. Y., vol. iv, p. 20, pi. ii, figs. 25-29. Discina media Walcott, 1884, Mon. U. S. Geol. Surv., vol. vlii, p. 113. OrUculoidea lodensis Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. iv P, fig. 21. OrUculoidea media Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. iv B, figs. 15-17. OrUculoidea lodiensis media Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 279. OrUculoidea media Clarke, 1903, N. Y. State Mus., Bull. 65, p. 268. Description. — " Shell broadly elliptical or subcircular, variable in form. Dorsal valve very depressed-convex; apex excentric, pointed, and inclined towards the posterior border. Ventral valve flat, or a little convex just 9 130 Systematic Paleontology — Middle Devonian anterior to the foramen; foramen narrow, directly in the longitudinal axis of the shell, or often a little oblique. Surface finely and evenly striated by fine regular [concentric] elevated striae, distant from each other more than twice their width. The apex of the dorsal valve is about one-third, and sometimes less than one-third the length of the shell from the posterior margin. Perforation of the ventral valve narrowly oval or sublinear, about one-third the length of the shell from the posterior margin, and extending towards the edge of the shell." Hall, 1867. Hall noted the close relationship of Disdna media H. to D. lodiensis (Van.) suggesting that perhaps it was "only a well-marked variety of that species" (Pal. IST. Y., vol. iv, p. 31) in which Walcott concurred (Mon. TJ. S. Geol. Surv., vol. viii, p. 113) and it is now given by Schuehert as Orhiculoidea lodiensis media (Hall) (Bull. U. S. Geol. Surv., Ko. 87, p. 279). Dr. J. M. Clarke considers Orhiculoidea media and 0. lodiensis as probably the same species, the difference being due to different conditions of preservation. Some of the Marylaoid specimens were compared with the types in the N"ew York State Museum and it was found that the concentric striae were very similar to those on the specimen represented by fig. 25, pi. 2, vol. iv. Pal. N. Y. ; but the Maryland specimens are of considerably smaller size. They may also be compared with specimens of Orhiculoidea lodiensis (Van.) from the Genesee shale. The variety media is apparently distinguished from the species 0. lodiensis mainly by its generally larger size, coarser concentric striae which are also farther apart, and absence of the faint radiating folds. Kindle states that this is an abundant fossil of the Onondaga fauna at most localities from northeastern Pennsylvania to northern Virginia. Length, 6^-7 mm. ; width, 5^-6 mm. Occurrence. — Eomney Poemation, Onondaga Member. Twenty-first Bridge; Williams Eoad, three and one half miles east of Cumberland. Hamilton Member. East bank Evitts Creek below Wolfe Mill; Emst- ville. Collections. — Maryland Geological Survey; American Museum of Nat- ural History; Kew York State Museum. Maryland Geological Survey 131 SuperfamilyCRANIACEA Family CRANIIDAE Genus CRANIELLA Oehlert Craniella hamiltoniae Hall Plate IX, Pigs. 1-7 Crania hamiltoniae Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 77, figs. 4, 5 on p. 76. Crania hamiltoniae Hall, 1867, Pal. N. Y., vol. iv, p. 27, pi. iii, figs. 17-23. Craniella hamiltoniae Hall and Clarke, 1892, Pal. N. Y., vol. vili, pt. i, pp. 148, 153, pi. iv I, figs. 3-16. Craniella hamiltoniae Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 193. Craniella hamiltoniae Clarke, 1903, N. Y. State Mus., Bull. 65, p. 219. Craniella hamiltoniae Grabau and Shimer, 1907, N. Am. Index Fossils, vol. il, p. 208, fig. 244. Description. — Shell broadly oval or subcirculax. Dorsal valve sub- conical ; apex subcentral or eccentric, pointed in well preserved specimens, often worn or decorticated ; exterior surface marked by concentric lamel- lose striae. Ventral or lower valve marked by four strong impressions of the adductor muscles, which are variable in form ; vascular impressions strongly digitate. Three imperfectly preserved specimens of the dorsal or upper valve were found in the bluish shales on the bank of Bvitts Creek below Wolfe Mill ; which locality, of those yet studied in Maryland, has furnished the largest number of specimens of the Inarticulate Brachiopoda. The shell is partly preserved in these specimens and it is shown to be highly punc- tate. The other characters are imperfectly shown ; but the usual muscular scars and apparently the peculiar sigmoid vascular siuus of the upper of dorsal valve are present. It is to be remembered that Hall identified this species from "the Hamilton group in Maryland and Virginia" (Pal. K". Y., vol. iv, p. 28). The specimens were submitted to Prof. Charles Schuchert who agreed in this identification and called attention to the " sigmoid vascular sinus, the generic character of Craniella." Length, about 18 mm.; width, 19 mm. 133 Systematic Paleontology — Middle Devonian OccMJTprace.— EoMNEY Formation, Onondaga Membee. 1| miles south of Berkeley Springs, West Virginia. Hamilton Membek. East bank of Evitts Creek below Wolfe Mill. Collections.— lAarylajiA Geological Survey; Few York State Museum; American Museum of Natural History. Genus PHOLIDOPS Hall Pholtdops hamiltoniae Hall Plate IX, Fig. 8 Pholidops namiltoniae Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 92. Pholidops hamiltoniae Hall, 1867, Pal. N. Y., vol. iv, p. 32, pi. lii, figs. 6-9. Pholidops hamiltoniae Hall and Clarke, 1892, Pal. N. Y., vol. viil, pt: i, p. 157, pi. iv I, figs. 31-34. Pholidops hamiltoniae Schuchert, 1897, Bull. XJ. S. Geol. Surv., No. 87, p. 306. Pholidops hamiltoniae Clarke, 1903, N. Y. State Mus., Bull. 65, p. 283. Pholidops hamiltoniae Grabau and Shlmer, 1907, N. Am. Index Fossils, vol. ii, p. 209, fig. 245. Description. — Shell regularly and uniformly ovate, broader near the posterior end; apex eccentric, little elevated, and slightly inclining to the posterior side. Substance of the shell thin, and flattened toward the margins. Surface marked by line closely arranged lamellose striae and when magnified, shows indications of minute interrupted radiating striae. Interior smooth, except an ovate, somewhat auriculate, and sometimes slightly bilobed prominence beneath the apex, which marks the muscular impression. The casts of the interior show a comparatively large muscular impression, which is shield-shaped or subovate and somewhat auriculate, or with a deeper impression on each side above the middle. The Maryland specimens are imperfectly preserved, and but few char- acters are shown. They are minute, and one valve is somewhat convex with a rather deep muscular impression at the apex with the surface of the shell marked by lamellose concentric striae. One specimen apparently shows fine radiating striae; the outline of the shell, however, does not appear so ovate as that of P. hamiltoniae. The specimen with strong concentric lines is apparently nearly circular in outline and suggested a Maryland Geological Survey 133 comparison with Orbiculoidea minuta (HaJl) and this opinion was com- municated to Prof. Schnchert. He wrote, however, after examining the specimen that it is a PlwUdops and that the shell of " Orbiculoidea minuta is more phosphatic and does not show the strong concentric growth lines as in this specimen." The other specimens he said "are hardly good enough to make out and yet what one can see agrees with Pholidops hamiltoniae. The Pholidops have great distribution and it is safe to say that you have the P. hamiltoniae." Length, 1 mm. + ; width, about 1 mm. Occurrence. — Romney Forjiation, Onondaga Member. Williams Road 3J miles southeast of Cumberland and 25 yards west of Oriskany contact. Collection. — Maryland Geological Survey. Pholidops cf. areolata (Hall) Plate IX, Pigs. 9, 10 cf. Pholidops areolata Hall, 1863, 16th Kept. N. Y. State Cab. Nat. Hist., p. 31. cf. Pholidops areolata Hall, 1867, Nat. Hist. N. Y., Pal., vol. iv, p. 31, pi. ill, figs. 4, 5. Pholidops cf. areolata Kindle, 1912, Bull. U. S. Geol. Survey, No. 508, p. 70, pi. ii, figs. 7, 8. Description. — " Shell broadly subovate or scarcely circular, wider on the posterior third, broadly rounded behind and more narrowly rounded in front. The cast of one valve (the dorsal valve?) shows a deep ovate or subcordiform muscular scar, which is nearly surrounded by an elevated areola, and partially divided by a median ridge from above. The opposite (ventral ?) valve has a larger muscular scar, which is auriculated above, with the surrounding areola divided at the lower or anterior margin. Surface somewhat abruptly flattened on the posterior side, and more gently sloping on the front of the valve." Hall, 1867. " The shell is subovate, the width of the posterior portion being slightly greater than that of the anterior. Surface marked by strongly lamellose concentric striae. The mold of the interior of the ventral valve shows a 134 Systematic Paleontology — Middle Devonian strongly impressed muscular scar, deepest anteriorly, somewhat resemb- ling the impression of a bovine hoof." Kindle, 1912. Occurrence. — ^Romney Formation, Onondaga Member. Williams Road, 3^ miles east of Cumberland. Collection,. — U. S. National Museum. [E. M. Kindle.J Order PROTREMATA Superfamily STROPHOMENACEA Family STROPHOMENIDAE Genus STROPHEODONTA Hall Steopheodonta (Leptosteophia) peeplana (Conrad) Plate IX, Figs. 11-17 Strophomena perplana Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, p. 257, pi. xiv, fig. 11. Strophomena {Strophodonta) fragilis Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist.'p. 111. Strophomena perplana Rogers, 1858, Geol. Penna., vol. ii, pt. ii, p. 827, fig. 665. Strophodonta fragilis Hall, 1858, Geol. Iowa, vol. 1, pt. ii, p. 496, pi. iil, fig. 6. Strophodonta perplana Hall, 1867, Pal. N. Y., vol. iv, pp. 92, 98, pi. xi, fig. 22; pi. xil, figs. 13-15 ; pi. xvii, figs, la-lo. Strophodonta perplana Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Stropheodonta (Leptostrophia) perplana Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, p. 288, pi. xv, figs. 2-13. Stropheodonta perplana Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 425. Leptostrophia perplana Clarke, 1903, N. Y. State Mus., Bull. 65, p. 243. Stropheodonta (.Leptostrophia) perplana Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 217, fig. 264. Description. — Shell small to medium size, very thin, semielliptical ; slightly concavo-convex, and frequently nearly iiat; hinge-line equaling or often a little greater than the width of the shell below, cardinal extremi- ties usually somewhat salient; margins of the shell often a little contracted just below the cardinal extremities, making the width less than below; but the sides are frequently nearly straight for half their length, with the front broadly rounded. Ventral valve slightly convex, the greatest Maryland Geological Survey 135 convexity above the middle of its length; cardinal area narrow, vertically striated and crenukted on the inner margin; apex scarcely higher than the hinge-line. Dorsal valve slightly concave and frequently nearly flat. Surface marked by fine subeqiial striae, those of the ventral valve the finer, sharp and sometimes gently undulating, increasing both by bifur- cation and intercalation, and crossed by fine, close, even concentric striae; near the apex are frequently a few obscure concentric wrinkles which occur occasionally upon the body of the shell. The interior of the ventral valve marked by large flabelliform diductor muscular impressions, extend- ing more than half the length of the shell, with small adductors between and near the beak; the muscular impressions of the dorsal valve are not strongly marked and are separated above by a median ridge which divides in the bifurcating cardinal process and from each side a rounded ridge curves forward and outward ; the interior strongly pustulose. Some of the Maryland specimens are quite well preserved and clearly show the fine several times bifurcating striae, as well as the flat form of the shell, concentric wrinkles and slightly mucronate cardinal extremi- ties. Internal impressions of the ventral valve are not uncommon which show well the flabelliform diductor muscular impressions. A few speci- mens have a median ridge or cicatrix extending from the vicinity of the beak or central part of the valve to its front. On the median part of the shell the radiating striae converge toward this ridge and the concentric striae in crossing it curve toward the umbo. The ridge was probably pro- duced by an injury to the shell and the type specimen represented by fig. Ic on pi. 17, vol. iv, Eal. N". Y., has a similar ridge along the middle part of the opposite valve. The species is readily distinguished by its outline, nearly flat f oiin, fine, distinct, and nearly equal bifurcating' striae, while the muscular markings and pustulose surface of the interior are characteristic. Length, 25-33 mm.; with, 30-50 mm. Occurrence. — Romney Pokiiation, Hamilton Member. Williams Eoad, 3^ miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill ; Williams Eoad | mile east of Queen City Hotel, Cumberland ; 136 Systematic Paleoxtologt — Middle Devonian Williams Eoad, i mile east of Queen City Hotel, Cumberland; in Jen- nings Eun, i mile west of Corriganville ; Town Creek Road at George Diefenbaugh's; B. & 0. E. R. ciit at 21st Bridge; on Hancock- Harrisonville Eoad about 2 miles north of Hancock; McCoys Ferry; along Plintstone Creek in Gilpin; on National Eoad in Gilpin; west of iron bridge oyer Town Creek northeast of Oldtown; on road east of Pine Hill about 4 miles north of Oldtown; B. & 0. E. E. cut at Hancock Sta- tion, W. Va.; on road about half way between Eomney and Hanging Rock, W. Va. Collections.— MaxylanA Geological Survey; American Museum of Nat- ural History. Steopheodonta demissa (Conrad) Plate X, Fig. 1 Strophomena demissa Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viil, p. 258, pi. xiv, fig. 14. Strophomena (Strophodonta) demissa Hall, 1857, Tenth Rep. N. T. State Cab. Nat. Hist., p. 137, fig. 1. Strophomena demissa Rogers, 1858, Geol. Penna., vol. 11, p. 827, fig. 666. Strophodonta demissa Hall, 1858, Geol. Surv. Iowa, vol. i, pt. li, p. 495, pi. ill, fig. 5. StropUodonta demissa Hall, 1867, Pal. N. Y., vol. iv, p. 81, pi. xi, figs. 14-17; pi. xii, figs. 1-5; pi. xvii, figs. 2a-2s. Strophodonta demissa Keyes, ]891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Stropheodonta demissa Hall and Clarke, ] 892, Pal. N. Y., vol. viii, pt. i, pi. xiv, figs. 7-12. Stropheodonta demissa Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 421. Stropheodonta demissa Clarke, 1903, N. Y. State Mus., Bull. 65, p. 333. Stropheodonta demissa Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 217, fig. 263. ' Description. — Shell medium size ; semi-elliptical, generally wider than long although the proportions are often nearly equal; hinge-line variable in length in proportion to the width of the shell below; lateral margins abruptly contracted beneath the cardinal extremities, which are often auriculate. Ventral valve regularly convex, greatest elevation nearly central. Umbo small and prominent with the apex slightly incun'ed ; Maryland Geological Sdevei' 137 surface slightly concave toward the cardinal angles and sometimes a slightly raised median ridge crosses the valve. Dorsal valve moderately concave, rarely following the convexity of the opposite valve; sometimes an undefined median depression extends from beneath the beak to the front of the shell. Surface marked by numerous striae, about nine or ten of which are much stronger and more elevated on the umbo of the ventral valve, with finer striae appearing in the middle of the inter- vening space and on either side of the coarser ones; the striae frequently increasing by intercalation and bifurcation, until they become very num- erous and much finer at the margin; the striae of the dorsal valve similar to those of the ventral ; in well preserved specimens fine concentric striae cover the surface, and there are frequently heavy concentric lines of growth. The interior of the ventral valve, and impressions of the same, show a large flabelliform diductor muscular impression, separated towards the front and distinctly lobed, with small adductors between them, sepa- rated from each other by a depression; in thfe dorsal valve the adductor impressions are conspicuous, divided longitudinally by a narrow ridge, and often limited in front by elevated ridges; beyond the muscular im- pressions the interior surface of both valves is minutely pustulose. Specimens from Maryland are almost identical in form and markings with some of those figured by Hall from the Hamilton formation of New York, in particular see figs. 2d and 2g, pi. 17, vol. iv, Palaeontology New York, which are stated to be ventral and dorsal valves of the ordinary form. This species is readily distinguished from S. perplana (Con.') bv its thicker shells, greater convexity and much coarser striae which are slightly undulating and variable in strength so that the external appear- ance of the two species is quite different. Length, 23 mm.; width, 33 mm. Occurrence. — Eomney Formation-, Hamilton Member. East bank Evitts Creek below Wolfe Mill; in Jennings Eun, ^ mile west of Corrigan- ville; on Hancock-Harrisonville Eoad about 3 miles north of Hancock. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. 138 Systematic Paleontology — Middle Devonian Steopheodonta (Douvillina) inaequisteiata (Conrad) Plate X, Figs. 2-5 Strophomena inaeguistriata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vili, p. 254, pi. xiv, fig. 2. Strophomena inaequistriata Hall, 1843, Geol. N. Y., pt. Iv, p. 201, fig. 4 on p. 200. Strophomena {Strophodonta) inaequistriata Hall, 1857, Tentli Rep. N. Y. State Cab. Nat. Hist., p. 142. Strophodonta inaequistriata Hall, 1867, Pal. N. Y., vol. iv, p. 93, pi. xil, figs. 6-8; p. 106, pi. xviii, figs. 2a-2fc. Stropheodonta (Douvillina) inaeguistriata Hall and Clarke. 1892, Pal. N. Y., vol. viii, pt. i, p. 289, pi. xiv, figs. 1-6; pi. xv B, fig. 9. Stropheodonta inaequistriata Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 422. DouviMina inaequistriata Clarke, 1903, N. Y. State Mus., p. 231. Stropheodonta inaequistriata Grabau and Shlmer, 1907, N. Am. Index Fossils, vol. ii, p. 217, fig. 262. Description. — Shell generally less than medium size and somewhat semioval in outline; hinge-line longer than the width of the shell below; extremities acute, sometimes auriculate. Earely, the sides are nearly straight below the auriculate extremities, the basal curve rather straight- ened on each side and produced in a subnasute extension in the middle. Ventral valve usually regularly convex, often more gibbous in the middle and abruptly arched toward the hinge-line, depressed-convex on the disc, with the margin towards the front more abruptly curving; the beak is small, scarcely prominent on the hinge-line. Cardinal area is narrow- linear, extending to the extremities of the hinge-line, striated vertically, with the inner margins crenulate from one-half to two-thirds the length from the beak to the extremities ; no foramen. Dorsal valve moderately to deeply concave; cardinal area scarcely more than one-half as wide as on the ventral valve. Surface of the entire shell marked by slender dis- tant elevated striae, which are increased by interstitial additions, the interspaces occupied by much finer closely arranged striae, which are scarcely visible to the naked eye, and crossed by fine concentric striae. The muscular markings are well shown on both valves although subject to considerable variation; while just without the muscular areas the interior surface is rather strongly pustulose, and beyond this it is finely pustulose in lines corresponding to the external striae. Maeylajsid Geological Suevky 139 The angle specimen from Maryland shows mainly an internal impres- sion of the ventral valve; but on one side there is some of the shell clearly showing the stronger striae with three or four much finer ones occupying the interspaces. The specimen is considerably larger than the usual ones of this species; but it was shown to Dr. J. M. Clarke, who considered it a large specimen of the above species. The muscular area is high and sharply marked, a character which Dr. Clarke states is found in this species as well as a somewhat similar one in the Maryland specimens of Stropheodonta (Douvillina) cayuta Hall from the Jennings formation. This species is characterized by its small to medium size ; quite convex ventral valve; long hinge-line with acute to auriculate extremities and the surface marked by distinct distant striae between which are several much finer ones, scarcely visible to the naked eye. Length of Maryland specimen, 30 mm. ; width, 35 mm. Length of average N"ew York specimens, 15-31 mm. ; width, 35-38 mm. Occurrence. — Eomney Formation, Hamilton Member. East banlc Evitts Creek below Wolfe Mill; B. & 0. E. R. cut at 31st Bridge ( ?).' Collection. — Maryland Geological Survey. Stropheodonta concava Hall Plate X, Eigs. 6, 7 Btrophomena (Strophodonta) concava Hall, 1857, Tenth Rep. N. Y. State Cab. Na;t. Hist., pp. 115, 140, flg. 1. Strophodonta concava Hall, 1867, Pal. N. Y., vol. iv, p. 96, pi. xiv, figs. 2a-2d; pi. XV, figs. 1-5; pi. xvi, figs. lo-lTi. StropJieodonta concava Hall and Clarke, 1892, Pal. N. Y., vol. viil, pt. i, pi. xlv, figs. 16-23. Stropheodonta coticava Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 420. Stropheodonta concava Clarke, 1903, N. Y. State Mus., Bull. 65, p. 331. Stropheodonta concava Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 216, flg. 261. Description. — Shell large, concavo-convex or subhemispheric, broadly semielliptical or subcircular in outline; the hinge extremities are some- ' In general a ( ?) mark following a locality indicates that the specimen from that place is identified with a query. 140 Systematic Paleontology — Middle Devonian times salient but often rounded. Ventral valve varying from moderately to extremely convex, gibbons in the middle, rounded upon the umbo and little elevated above the hinge-line, with beak small and scarcely in- curved, while in some specimens a median ridge crosses the center of the valve; cardinal area about a line in width, gently narrowing towards the extremities, vertically striated, with the margin crenulated for more than half the distance from the center to the extremities. Dorsal valve usually almost flat or slightly concave in the upper and central portions, suddenly deflected towards the margin, in some specimens regularly concave; cardinal area very narrow and nearly linear throughout, striate and crenulate as in the ventral valve. Surface of the ventral valve is marked by sharply elevated, strongly crenulated striae, between which are sometimes one or two less elevated striae similarly crenulated, and still finer striae between the latter; in some specimens there are wider spaces of finer equal striae between the stronger ones; and in other specimens the striae are nearly all strong and sharply elevated, with few finer ones, which soon rise to the strength of the others ; close undulating concentric striae cover the whole surface; the dorsal valve is marked by distant sharp elevated striae, between which there are from three to six and rarely ten finer striae, which are very finely crenulated by concentric striae; the interior of the valves is finely pustulose. The Maryland collection contains a single imperfect specimen of the interior of a dorsal valve. A part of the strongly crenulated cardinal area is shown, a portion of the muscular impression outside of which it is strongly pustulose, and the pustules are larger in the central portion of the shell before reaching the deflected part toward the margin. The specimen appears somewhat like a large form of S. demissa (Conrad). Length, 37 mm.; width, 43 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill ( ?) ; on the Hancock-Harrison ville Eoad about 2 miles north of Hancock. Collections. — ^Maryland Gieological Survey; New York State Museum; American Museum of Natural History. Maryland Geological Survey 141 Genus PHOLIDOSTROPHIA Hall and Clarke Pholidostrophia pennsylvanica Kindle Plate X, Figs. 8, 9 Pholidostrophia pennsylvanicus Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 74, pi. V, figs. 1, 2. Description. — Shell small, concavo-coiivex or plano-convex. Ventral valve depressed convex, greatest viddth at hinge-line and salient cardinal angles. Surface without radiating striae but with some indications ol lamellose lines of growth. The impression of a single dorsal valve sup- posed to belong to this species is slightly concave and shows a very short slender septum extending 1 mm. from the hinge-line. The collection contains six or seven specimens. An average specimen has a width of 8 mm. at the hinge-line ajid a length of 6 mm. This shell resembles both P. iowensis (Hall) and Stropheodonta punti Claxke in its smooth exterior. It is smaller than either of tliese however, and does not possess the crescent-shaped ridges which characterize the dorsal valve of P. iowensis. The absence of these may leave some doubt as to the propriety of referring this shell to Pholidostrophia but the smooth surface and the general features of the shell strongly indicate its relationship to this group of the Strophcodontas. Occurrence. — Eomney Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cimiberland. Collection. — IT. S. National Museum. [E. M. Kindle.J Genus LEPTAENA Dalman Leptaena rhomboidalis (Wilckens) Plate X, Figs. 10, 11 Conchites rhomloidalis Wilckens, 1769, Nachricht von seltenen. Versteiner- ungen, p. 77, pi. vlii, figs. 43, 44. Strophomena undulosa Conrad, 1841, Fifth An. Rep. Geol. Surv. N. Y., p. 54. Strophomena depressa Vanuxem, 1842, Geol. N. Y., pt. iii, p. 79, flg. 5. Strophomena undulatus Vauuxem, 1842, Geol. N. Y., pt. iii, p. 139, fig. 3. Leptaena tenuistriata Hall, 1847, Pal. N. Y., vol. i, p. 108, pi. xxxi A, fig. 4. 143 Systematic Paleontology — Middle Devonian , Leptaena depressa Hall, 1852, Pal. N. Y., vol. 11, p. 62, pi. xxl, flg. 8; p. 257. pi. liii, fig. 6. Leptaena depressa Rogers, 1858, Geol. Penna., vol. 11, pt. 11, p. 823, fig. 630. Strophomena rugosa Hall, 1859, Pal. N. Y., p. 195, pi. xlx, fig. 1. Strophomena rhomboidalis Billings, 1861, Canadian Jour., vol. vi, p. 336, figs. Ill, 112. Strophomena rhomioidalis Hall, 1867, Pal. N. Y., vol. iv, p. 76, pi. xii, figs. 16-18; p. 414, pi. XV, figs. 15, 16. Leptaena rJiomlioidaUs Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, p. 279, pi. vlli, figs. 17-31; pi. xv A, figs. 40-42; pi. xx, figs. 21-24. Leptaena rhomhoidaUs Scliucliert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 240. Leptaena rtiomioidalis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 239. Leptaena rhomboidalis Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 226, figs. 273a, b. Description.- — Shell of more than medium size., semielliptical or sub- quadrate varying in its proportions of length and breadth; hinge-line straight and equal to greatest width of shell; cardinal extremities mostly rectangular, sometimes rounded and sometimes salient; the valves are geniculated and the proportions of the flattened part or disc and the recurved portion are very variable. The surface of the flattened part is marked by strong concentric, undulating elevations, which are parallel with the curve of geniculation and are bent outwards and often become obsolete on the cardinal angles; these elevations are most prominent on the part parallel to the front margin; they are very variable in number, ranging from six to sixteen. The entire surface is covered by radiating, fairly coarse, uniform striae. The ventral valve is slightly convex near the umbo, but flat or even somewhat depressed between the umbo and geniculation; dorsal valve generally corresponding in its concavity with the convexity of the ventral, but differing in its depth. The Maryland specimen consists of a single fragment of a ventral valve; but the strong concentric wrinkles and even striae leave no doubt as to the correctness of this identification. The species may be readily determined by its shape, the deep concentric wrinkling of the disc, the abrupt geniculation of both valves toward the dorsal side, and the uni- form, sharply marked striae. Length of average specimen from the Columbus limestone at Colum- bus, Ohio, 22 mm. ; width, 32 mm. Maeyland Geological Suevet 143 Occurrence. — Eomney Formation, Hamilton Member. Ernstville. Collections. — 'Maryland Geological Survey; American Museum of Nat- ural History. Genus LEPTAENISCA Beecher Leptaenisca austualis Kindle Plate XI, Figs. 1-5 Leptaenisca australis Kindle, 1912, Bull. U. S. Geol. Survey, No. 508, p. 78, pi. iv, figs. 8-12. Description. — Outline variable, as sliown in figure; length generally less than width; hinge line somewhat shorter than greatest width of shell. Shell concavo-convex. Ventral valve moderately convex. Surface marked by fine radiating striae, which are clearly defined only in the anterior part of the shell, and which are crossed by very fine concentric striae and stronger lines of growth. The muscular pit of the ventral valve is bord- ered laterally by the dental lamellae which curve toward each other slightly near the anterior margin of the pit. These lamellae, as they extend into the shell and away from the surface of the valve, are inclined laterally or away from each other. A short, low, median septum extends across the muscular pit from the posterior nearly or quite to the anterior margin of the pit. Molds of the interior of the ventral valve indicate a strongly postulose surface, increasing regularly in coarseness from the margin of the shell to the margin of the muscular impression. The collection con- tains a single, somewhat imperfect, mold of the interior of a dorsal valve believed to belong to this species. The distinctly bipartite character of the posterior portion of the eardinal''process is shown and, somewhat indistinctly, the quadripartite appearance of the anterior portion of the process is seen. A low thick median ridge is present in the anterior part of the mold. All of the species of this genus previously described from America are Helderberg shells. In surface characters they are quite unlike the present species. Two of them appear from the figures to be nonstriated species, but the third, L. concava, has radiating striae of unequal strength, each 144 Systematic Paleontology — Middle Devonian fifth or sixth being stronger than the intermediate ones. In this species the striae are all of about equal strength. Occurrence. — Eomney Formation, Onondaga Member. Tonoloway; 1% miles south of Berkeley Springs. Collection. — U. S. National Museum. [E. M. Kindle.J Genus SCHUCHERTELLA Girty^ SOHUCHERTELLA VARIABILIS B. sp. Plate XI, Pigs. 6-10 Schuchertella cf. perversa Kindle, 1912, Bull. U. S. Gaol. Surv., No. 508, p. 76. Description. — Shell semielliptical and symmetrical or with slight um- bonal distortion; hinge-line straight and somewhat less than the greatest width of the shell; lateral margins curving toward the hinge-line and the front of the shell. Ventral (?) valve slightly convex from the umbo toward the center and flattened towards the front and sides of the valve. Surface marked by 50 rather sharp and close radiating striae on the smaller specimens and in the middle of many of the interspaces is a short and much smaller intercalated one; while the larger specimen has about 60 of the strongest striae which extend quite or nearly to the umbo and most of the interspaces show an intercalcated one in the center, second in strength to the primary, with a still fainter one on each side, making three grades of striae; a few of the interspaces show only one. The surface also crossed by very fine, thread-like and closely arranged concentric striae which are the most conspicuous on the interspaces. " Dr. Girty, in 1904, proposed the generic name Schuchertella " for shells hav- ing the type of structure for which the name Orihothetes is at present in general use," for which he stated " there is no authority for spelling otherwise than Orthotetes." Dr. Girty shows that Fischer de "Waldheim applied the name Orthotetes to a different type of structure than that for which it has been used in recent years and therefore he has transferred it to the group of shells for which it was originally used, which later had been named Derbya by Waagen, and proposed the new name for the group left without a generic name (Proc. U. S. Nat. Mus., vol. xxvii, 1904, p. 734). Maryland Geological Survey 145 These specimens are mainly small and the best ones were obtained in the argillaceous shales on the Williams Road about one-fourth mile east of the Queen City Hotel, while others came from a calcareous stratum at the iron bridge over Town Creek about 31/^ miles northeast of Oldtown. Part of the specimens of this species considerably resemble Schucher- tella chemungensis (Conrad) var. perversa Hall, to which ihey were at first doubtfully referred. Further study led to greater uncertainty, and finally the specimens were sent to Dr. J. M. Clarke for his opinion re- garding their specific relationship. After an examination Dr. Clarke wrote as follows : " I have studied the specimens of Orthothetes you have sent and compared them with the types of 0. perversus. With re- gard to these fossils, so far as they occur in the Devonic, it is easy to see that they are in a certain sense ontogenetic expressions of a broad specific type, and it is often very difiicult to draw lines among the specimens as they have been drawn by their describers. These specimens show both an extremely simple form of plication and a more complicated expression, such as would naturally result from later growth. 0. perversus is such a species in external character as this larger specimen with intercalated plications, and yet the other specimens with simple plications seem only to express the more infantile condition longer continued. I hardly know what we shall do with facts of this kind. Doubtless the specimens axe all of the same species and I should be disposed, personally, to cut the Gordian knot by describing it as a distinct species, and if you call it 0. variabilis you would doubtless tell the truth in its name. My species 0. ielluliis from the Marcellus shales is very close to the larger of these forms and occasionally shows a simple equal plication of the smaller shells, i. e., the shells pass through the same variations as do the Mary- land, and yet I should hesitate to include them under that term, as the Marcellus species is much more sparsely plicate." Occurrence. — Eomnet Formation, Onondaga Member. W. Va. Central R. E. cut at 31st Bridge. Williams Road, 3% miles southeast of Cumberland. Hamilton Member. Williams Road, 14 ™ile east of Queen City Hotel, Cumberland; Town Creek, 3^^ miles northeast of 10 146 Systematic Paleontology — Middle Devonian Oldtown; Williams Eoad, 31,^ miles southeast of Cumberland; B. & 0. E. E. cut at 21st Bridge. Collection. — Maryland Geological Survey. Family PRODUCTIDAE Genus CHONETES Fischer de Waldheim Chonetes muoeonatus Hall Plate XI, Pigs. 11-17 Strophomena mucronata Hall, 1843, Geol. N. Y., pt. iv, p. 180, fig. 3. Chonetes laticosta Hall, 1857, Tenth Rep. N. Y. State Cat). Nat. Hist, p. 119. Chonetes mucronata Hall, 1867, Pal. N. Y., vol. iv, p. 124, pi. xx, figs, lo-ld; pi. 21, figs, la-lg. Chonetes mucronata Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. xvi, figs. 6, 7. Chonetes mucronatus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 176. Chonetes mucronatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 211. Chonetes mucronatus Grabau and Shlmer, 1907, N. Am. Index Fossils, vol. ii, p. 235, fig. 286. Descnption. — ^Shell small, semioval to semielliptical ; moderately con- vex (often flattened in shale and gibbous in limestone and arenaceous deposits) ; hinge-line equalling or a little greater than the width of the shell below, the extremities sometimes salient. The ventral valve is often quite gibbous, regularly rounded in the middle, suddenly depressed towards the cardinal angles which are flattened, and the area narrow and linear. The dorsal valve is moderately concave to nearly flat, and the area is scarcely more than the thickness of the shell. Surface marked by from twelve to twenty usually coarse, rather distant, simple rounded or subangular striae, a few of which on some specimens bifurcate to- wards the margin. The cardinal margin marked by two or three spines on each side of the apex, which are bent abruptly downwards and di- rected outwards almost parallel to the hinge-line, so that the outer one frequently appears to be a continuation of the cardinal extremity. In the interior of the ventral valve is a strong median septum reaching more than half the length of the valve, while the interiors of the valves are strongly pustulose. Maryland Geological Survey 147 The Maryland specimens agree closely with those from the Hamilton formation of New York which Professor Hall first described under the name of Chonetes laticosta and later referred to C. mucronatus, the origi- nal description of which referred to specimens from the Mareellus shale. It would be very difficult to find any difference between these specimens and many of those from similar deposits of the Hamilton formation in New York. On some of the specimens the comparatively long spines nearly parallel to the hinge-line are nicely shown, which give the cardinal angles a mucronate appearance. This species is readily distinguished by its size, outline, moderate convexity, strong rounded or subangular striae, and the two or three cardinal spines which curve abruptly outward par- allel to the hinge-line. Kindle states that this is one of the most abundant species of the Onondaga fauna being found nearly everywhere in it from New York to southwest Virginia. Length, 6 or 7 mm.; width, 8 to 10 mm. Occurrence. — ^Eomney Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Hamilton Member. Wil- liams Eoad, 33^ miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill ( ?) ; Williams Eoad 1/4 mile east of Queen City Hotel, Cumberland ; in Jennings Eun, % i^i^e "west of Corriganville ; Town Creek Eoad at George Dief enbaugh's ; B. & 0. E. E. cut at 31st Bridge ; on Old- town Eoad, east of Maryland Ave., Cumberland ; on the Hancock-Harrison- ville Eoad about 2 miles north of Hancock ; McCoys Ferry ; on National Eoad northeast of Cumberland ; along Flintstone Creek in Gilpin ; on National Eoad in Gilpin west of Lock No. 56 at Great Cacapon ; 14 mile north of Green Spring Furnace ; west of iron bridge over Town Creek northeast of Oldtown ; on National Eoad % mile west of Licking Creek ; on road east of Pine Hill about 4 miles north of Oldtown ; east side Warrior Mt. east of Eush ; B. & 0. E. E. cut at Hancock Station, W. Va. ; on road about half way between Eomney and Hanging Eoek, W. Va. ; on the Eomney-Hanging Eoek Eoad about i/^ mile north of Eomney, W. Va. ; 1 mile north of Eomney, W. Va. 148 Systematic Paleontology — Middle Devonian Collections. — Maryland Greological Survey; New York State Museum; American Museum of Natural History. Chonetes coeonatus (Conrad) Plate XI, Figs. 18-31 Strophomena carinata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 257, pi. xiv, fig. 13. ' Strophomena syrtalis Conrad, 1842, Jour. Acad. Nat. Sci., Phlla., vol. viii, p. 253, pi. xiv, fig. 1. Chonetes coronata Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 146, figs. 1, 2. Chonetes coronata Hall, 1867, Pal. N. Y., vol. iv, p. 133, pi. xxl, figs. 9-12. Chonetes coronata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi,.p. 29. Chonetes coronata Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. xvi, figs. 10, 11, 24, 26, 33, 39, 41, 43. Chonetes coronatus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 173. Chonetes carinatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 209. Chonetes coronatus Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 236, fig. 288. Description. — Shell large, broadly elliptical, some of the single valves approaching a rectangular form; the hinge-line is sometimes shorter than the width of the shell and the cardinal angles rounded, but gener- ally it is nearly or quite equal to the greatest width of the shell with the lateral margins nearly rectangular to the hinge-line; the cardinal angles are sometimes produced in short acute auriculate extensions. Ventral valve varying from moderately convex in the younger shells, to very gibbous in the older ones; sometimes a little flattened below the umbo and this space gradually widens toward the front, more frequently there is a shallow undefined sinus along the middle of the valve; the outline of the valve is regularly convex, but abruptly depressed towards the cardi- nal extremities, which are flattened and a little deflected toward the ven- tral side; the cardinal margin has from five to seven oblique spines on each side of the apex, although they are usually not preserved on the Maryland specimens, and the cardinal area is narrow. Dorsal valve is variably concave, sometimes following nearly the contour of the ventral valve, but often moderately concave or nearly flat in the middle and upper part, and more suddenly deflected towards the front and lateral Maryland Geological Survey 149 margins, while the cardinal extremities are flattened; the cardinal area is linear. Surface is marked by numerous closely arranged slender sub- equal striae, which are bifurcated or increased by intercalation, and are continued on the cardinal extremities to within a short distance of the hinge-line; on an average specimen there are 13 striae in the space of 5 mm. The interior of the ventral valve shows diverging dental lamellae and a narrow median ridge, while beyond the muscular and vascular areas the surface is strongly pustulose in both valves. In some of the Maryland specimens from the somewhat arenaceous shales, particularly from McCoys Ferry, the internal impressions show the reverse of the above characters in a median depression, diverging dental impressions, deeply pitted surface outside of the vascular markings, and strongly striate margin. This species occurs in abundance at McCoys Perry largely in the form of internal impressions which difEer in no respect from New York speci- mens found in similar deposits; the E. E. cut at 21st Bridge and Evitts Creek below Wolfe Mill furnished specimens in which the shell is pre- served ; while about 2 miles north of Hancock on the road from Hancock to Harrisonville, Pa., specimens are common some of which are smaller than the majority, show four or five cardinal spines and resemble figs. 10a and 106 on pi. xxi, vol. iv, Palaeontology of New York. There is apparently no difference in characters between the Maryland specimens and the several forms of the species found in New York. It is readily distinguished by its large size, convex ventral valve with the frequent shallow sinus, numerous closely arranged surface striae, while the pus- tules and striae are characteristic of the outer portion of the inside of the valves or internal impressions. Length, 10-20 mm. ; width, 13-38 mm. Occurrence. — Eomney Pormation, Hamilton Member. Williams Eoad, 3-J miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; Williams Eoad, J mile east of Queen City Hotel, Cumber- land; in Jennings Eun, J mile west of Corriganville ; B. & 0. E. E. cut at 21st Bridge; on National Eoad, ^ mile west of Tonoloway Eidge; on the Hancock-Harrisonville Eoad about 2 miles north of Hancock; 150 Systematic Paleontology— Middle Devonian McCoys Ferry; Ernstville; in mn at Hancock east of Catholic church; along Flintstone Creek in Gilpin; west of I^ock No. 56 at Great Caca- pon ; I mile north of Green Spring Furnace ; B. &. 0. E. K. cut at Han- cock Station, W. Va. Collections.— Karjla-ndi Geological Survey; New York State Museum; American Museum of Natural History. Chonetes scitulus Hall Plate XII, Pigs. 1-8 Chonetes sdtula Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 147. Chonetes scitula Hatl, 1867, Pal. N. Y., vol. iv, pp. 130, 141, pi. xxi, fig. 4; pi. xxli, figs. 6-11. Chonetes scitula Hall aud Clarke, 1892, Pal. N. Y., vol. vili, pt. 1, pi. xvl, figs. 3, 4, 27, 32, 40, 44. Chonetes scitulus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 178. Chonetes scitulus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 212. Chonetes scitulus Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 237, figs. 289a, b. Description. — Shell semioval; hinge-line often not quite equaling the greatest width of the shell. Ventral valve moderately gibbous in the middle and regularly curving to the front and lateral margins ; the gib- bous portions narrowing towards the hinge-line, and the umbo little elevated; abruptly depressed towards the cardinal angles, which are nearly fiat; cardinal area narrow and wider in the middle; delthyrium partially closed by a convex deltidium and the aperture filled by the cardinal process of the opposite valve; margin provided with from 12 to 14 spines; the interior shows a slender median ridge and two strong dental lamellae. Dorsal valve with a concavity less than the convexity of the opposite valve; cardinal angles flat; cardinal area linear, half as wide as that of the opposite valve ; the interior is strongly pustulose, with a somewhat broad depression along the center, in the middle of which there is a slender mesial ridge. Surface marked by fine subequal striae which are sometimes sharp and angular, sometimes rounded and often alternate in size toward the margin; of these 15 to 20 may be counted near the beak, while from bifurcation and intercalation there are from Maryland Geological Survey 151 50 to 60 on the margin; fine concentric striae are visible on well-pre- served specimens. There are specimens in Maryland which in size, outline and other characters agree closely with the specimens figured by Hall from the Few York Hamilton and stated to represent specimens of the ordinary proportions (see figs. 4a and ib, pi. xxi, vol. iv, Pal. IsT. Y.). Other specimens are perhaps twice the size of the former, but with the same general characters, which are also referred to this species. Numerous specimens of this size and general appearance have been collected by the writer in the Hamilton and Ithaca formations of New York which lie has considered as belonging to this species. In the office of the New York State Paleontologist are specimens from the Hamilton shales of that state labelled Chonetes scitulus which are fully as large as any of the Maryland specimens and marked by from 50 to 60 striae. The re- sult of this comparison apparently shows that the larger as well as the smaller Maryland specimens belong to this species. Some of the best specimens of this larger form were found in a bluish argillaceous shale on the West Virginia side of the Potomac between 3 and 4 miles south of Cumberland; other good specimens were found at Ernstville in Wash- ington County. This species is distinguished by its outline, consider- ably greater width than length, the large number of striae (from 50 to more than 60) at the margin and the obliquely directed cardinal spines. Length, 6-8 mm.; width, 9-11 mm. Length large specimen, 9-10 mm. ; width, 15-16 mm. Occurrence. — Eomney Formation, Hamilton Member. B. & 0. E. E. cut at 21st Bridge ( ?). Williams Eoad, 3I/2 miles southeast of Cumber- land ( ?) ; on National Eoad, 1^ mile west of Tonoloway Eidge; B. & 0. E. E. cut at 31st Bridge; on Oldtown Eoad, east of Maryland Ave., Cum- berland; McCoys Ferry; southwest of McCoys Perry; on the Hancock- Harrisonville Eoad about 2 miles north of Hancock; Ernstville; on National Eoad northeast of Cumberland; in run at Hancock, east of Catholic church; along Flintstone Creek in Gilpin; west of iron bridge over Town Creek northeast of Oldtown; B. & 0. E. E. cut opposite Han- cock, W. Va,; on road about half way between Eomney and Hanging 153 Systematic Paleontology — Middle Devonian Eock, W. Ya. ( ?) ; 1 mile north of Eomney, W. Va. ; on the Eomney- Hanging Eock Eoad about i mile north of Eomney, W. Va. ; W. Va. side Potomac Eiver 3 and 4 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Chonetes setigek (Hall) Plate XI, Pigs. 32-25 Strophomena setigera Hall, 1843, Geol. N. Y., pt. iv, p. 180, fig. 2, p. 222, fig. 3. Chonetes setigera de Koninck, 1847, Recher. Anlmaux Foss., vol. i, p. 215, pi. XX, fig. 7. Chonetes setigera Hall, 1867, Pal. N. Y., vol. Iv, p. 129, pi. xxi, fig. 2; p. 142, pi. xxil, figs. 1-5. Chonetes setigera Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. 1, pi. xvi, figs. 2, 5, 19. Chonetes setigerus Schuchert, 1897, Bull. U. S. Geol. Surv. No. 87, p. 178. Chonetes setiger Clarke, 1904, N. Y. State Mus., Mem. 6, p. 376. Chonetes setigerus Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 237, fig. 289a. Description. — Shell semielliptical ; the hinge-line equaling the greatest width of the shell, and rarely extending beyond. Ventral valve moder- ately convex, rarely a little gibbous in the middle; umbo scarcely rising above the hinge-line; the greatest elevation is above the middle of the shell and it gradually slopes toward the front and lateral margins be- coming flattened on the cardinal angles; the cardinal margin generally has three slender tubular spines on each side of the apex, which are bent a little outward as they leave the shell, and then rise almost vertically, or with a slight curve from the direction of the hinge-line. The striae are slender rounded or subangular, increasing by bifurcation and inter- calation so that there are from 36 to 50 on the margin. On well pre- served specimens the radial striae are crossed by fine concentric ones. Among the Maryland specimens there are forms similar to those figured by Hall on plates 21 and 33, vol. iv. Palaeontology of New York; and other specimens somewhat larger which agree with similar forms from the Hamilton and Ithaca formations of New York which have been referred by H. S. Williams and other paleontologists to this Maryland G-eological Survey 153 species. The species is characterized by its form, moderate convexity, nearly vertical cardinal spines and medium number of rounded or sub- angnlar striae. It is readily distinguished from C. mucronatus by the more numerous striae, which are also more angular and bifurcate more frequently, as well as the direction of the cardinal spines. It is more closely related to C. sdtulus, but it differs in its greater proportional length, by the smaller number of rounded, coarser striae, the usually greater convexity of the ventral valve towards the apex and the smaller number and vertical direction of the cardinal spines. Length, medium specimen, 7 mm. ; width, 8 mm. : Large specimen, length, 8-11 mm. ; width, 10-12 mm. Occurrence. — Romney Formation, Hamilton Member. B. & 0. E. E. cut at 31st Bridge. Williams Eoad, 3% miles southeast of Cumberland j east bank Evitts Creek below Wolfe Mill ( ?) ; in Jennings Eun, % mile west of Corriganville; on National Eoad, 3^ mile west of Tonoloway Eidge; B. & 0. E. E. cut at 21st Bridge; on Oldtown Eoad, east of Mary- land Ave., Cumberland ; McCoys Ferry ; southwest of McCoys Ferry ; on the Hancock-Harrisonville Eoad about 2 miles north of Hancock ; Emst- ville; on National Eoad northeast of Cumberland ; in run at Hancock east of Catholic church; along Plintstone Creek in Gilpin ; west of Lock No. 56 at Great Cacapon; west of iron bridge over Town Creek northeast of Oldtown; on National Eoad, -J mile west of Licking Creek; W. Va. side Potomac Eiver about 3 miles south of Cumberland ( ?) ; B. & 0. E. E. cut at Hancock Station, W. Va. ; on road about half way between Eom- ney and Hanging Eock, W. Va. Collections. — Maryland Geological Survey; American Museum of Natural History. Chonetes lepidus Hall Plate XII, Figs. 9-13 Chonetes lepida Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 148. Chonetes lepida Hall, 1867, Pal. N. Y., vol. iv, pp. 132, 142, pi. xxi, figs. 5a-5e; pi. xxii, flgs. 12, 13. Chonetes lepidus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 175. Chonetes lepidus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 211. Chonetes lepidus Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 237, flgs. 289d, e. 154 Systematic Paleontology — Middle Devonian Description. — Shell small; semielliptical to subhemispherical ; hinge- line about equaling the width of the shell below. Ventral valve more or less gibbous, with a longitudinal depression along the center in well marked specimens; curving abruptly to the front and sides, with car- dinal angles scarcely flattened; cardinal area narrow and distinctly wider in the middle; the delthyrium is small, partially closed by a pseudo-deltidium, and filled by the cardinal process of the opposite valve; there are generally two or three spines on each side of the center of the cardinal line and in some specimens five are shown. Dorsal valve follows the curvature of the ventral valve, with a lesser concavity; cardinal area scarcely equal to the thickuess of the shell; the interior shows a longitudinal depression, and the course of the striae is well de- fined and strongly papillose. Surface marked by rather strong angular bifurcating striae, of which there are ten or twelve near the umbo and twice as many or more on the margin; two of the striae, on each side of the center near the beak of the ventral valve, are generally larger and more prominent than the others, the space between them is depressed and occupied by two or three smaller striae, which are given off from the larger ones on each side. Among the numerous specimens of Chonetes from the Eomney rocks of Maryland are a considerable number of a small form which agree quite closely with the above description. The number of striae on the margin runs up to 34 but frequently bifurcation almost at the margin consid- erably increases the number. They are stronger than those of C. setiger or 0. scitulus, and the impressions of some of the ventral valves appar- ently show two stronger striae near the center with the depressed area between them occupied by smaller striae ; others, however, apparently do not show this depression. There are also specimens which are difficult to separate and it appears to the writer that Nicholson's opinion ' that this species is the young of 0. scitulus may be correct. An examination of the specimen from the Marcellus shale represented by figure 12 on pi. xxii, vol. iv, Palseontology of New York, shows that there are about 36 striae near the margin of the shell, while the central depfessed area is no more *Rept. PalEeontology Province Ontario, 1874, p. 74. Maryland Geological Sdevey 155 conspicuous than on part of the Maryland specimens. Internal impres- sions from the Hamilton shales of 'New York in the office of the State Paleontologist labeled Chonetes lepidiis are as large and identical in all particulars with similar specimens from Maryland. The characteristics of the species are its small size, the longitudinal mesial depression of the ventral valve, bounded on each side by larger and more prominent striae with smaller ones between, and the rather strong bifurcating striae, of which there are ten or twelve near the umbo and twice as many or more on the margin. Length, 3^-6 mm. ; width, 3-7 mm. Occurrence. — -Eomney Formation, Onondaga Member. Hanging Book, W. Va. ( ?) . Hamilton Member. B. & 0. R. E. cut at 31st Bridge. East bank Evitts Creek below Wolfe Mill; Town Creek Eoad at Geo. Diefenbaugh's ( ?) ; on National Eoad i/^ mile west of Tonoloway Eidge ; B. & 0. E. E. cut at 21st Bridge; Williams Eoad 31^ miles southeast of Cumberland; McCoys Perry; on National Road northeast of Cumberland; in run at Hancock east of Catholic church; along Mintstone Creek in Gil- pin: on National Eoad in Gilpin; i/4 mile north of Green Spring Furnace ; west of iron bridge over Town Creek northeast of Oldtown ; on the Eom- ney-Hanging Eock Eoad, about % mile north of Eonmey, W. Va. ; W. Va. side Potomac Eiver about 3 miles south of Cumberland; B. & 0. E. E. cut at Hancock Station, W. Va. ; on road about half way between Eomney and Hanging Eock, W. Va. Collections.— Maijlani Geological Survey; American Museum of Nat- ural History. Chonetes vicinus (Castelnau) Plate XII, Figs. 14-21 Leptaena vicina Castelnau, 1843, Systeme Sil. I'Amgrique Septentrionale, p. 39, pi. xlv, fig. 9. Chonetes vicina de Koninck, 1847, Recher. Anlmaux Foss., pt. 1, p. 203. Chonetes deflecta Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 149. Chonetes deflecta Hall, 1867, Pal. N. Y., vol. iv, p. 126, pi. xxi, figs. 7, 8. Chonetes deflecta Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. I, pi. xvi, fig. 28. Chonetes vicinus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 180. Chonetes vicinus Grabau and Shimfir, 1907, N. Am. Index Fossils, vol. li, p. 236, fig. 287. 156 Systematic Palkontology — Middle Devonian Description. — Shell semielliptical ; length and width as four to five or eight to nine^ but rarely proportionally wider. Ventral valve extremely gibbous, regularly arched, the greatest elevation being about the middle of the length; abruptly depressed towards the cardinal angles, which are flattened, with the extremities deflected to the ventral side ; the umbo is slightly elevated above the cardinal margin; cardinal area narrow; the interior shows strong dental lamellae, a somewhat angular median ridge terminates above the middle of the valve, and the surface is finely pustu- lose in the middle, a little more coarsely pustulose along the deflected line and nearly or quite smooth towards the margins. Dorsal valve deeply concave, but not equaling the convexity of the ventral valve; cardinal area more than half as wide as that of the ventral valve ; the interior sur- face beyond the vascular impressions is covered by elongate papillae, the marks of the striae being scarcely distinct. Surface marked by from twenty-six to thirty-four subangular or sometimes rounded striae which are often irregularly increased by bifurcation or intercalation towards the margin; in those with fewer striae, they are sharper and only half as wide as the interspaces, while in those with a larger number, the striae and interspaces are equal; there is a considerable space at the cardinal angles of each valve destitute of striae. Hall stated that the examination of large numbers of specimens showed so many extreme varieties that it appeared difficult to indicate reliable characters for separating this species from C. mucronatus. The principal difference appeared to be in the larger number of striae on the specimens referred to G. deflecta = C. vicinus. Among the Miaryland specimens of Chonetes are rather poorly preserved impressions which resemble this species more closely than any other. The ventral valves are gibbous, the cardinal angles flattened, the striae about thirty-four in number, and the interior of the valves pustulose. One rather large and gibbous ventral valve, which is partly exfoliated, shows about 36 striae across the central part of the shell which are considerably increased in number by bifurcation by the time the margin is reached. On the well preserved portion of the shell near the umbo the radiating striae are crossed by numerous, fine, thread-like concentric striae, which Maryland Geological Survey 157 are close together. On comparison it was found that the radiating striae on the Maryland specimens were finer than on specimens of this species from the Hamilton shales of Kew York. This species is distinguished by its strong convexitj', semielliptical outline, deflected cardinal angles, and finer, more numeroiis and more closely crowded striae than in C. mucro- natus. Length, 10 mm. ; width, 12' mm. Another specimen has the following proportions : Length, 10 mm. ; width, 11 mm. Occurrence. — Eomney Formation, Hamilton Member. Bast banlc Evitts Creek below Wolfe Mill; McCoys Ferry; southwest of McCoys Ferry ; along Flintstone Creek in Gilpin ; west of iron bridge over Town Creek northeast of Oldtown ; on road about half way between Eomney and Hanging Eock, W. Va. Collections. — Maryland Geological Survey; American Museum of Nat- ural History. Chonetes marylandicus n. sp. Plate XIII, Figs. 1-6 Description. — Shell medium size, semielliptical, hinge-line as long or slightly shorter than the greatest width of the shell. Ventral valve gibbous, the central part having the greatest convexity, from which it declines rapidly towards the front and is abruptly depressed towards the lateral margins and cardinal angles, the latter being flattened. The bases of at least three spines are shown on each side of the umbo, and the spines are either straight or inclined laterally; cardinal area rather nar- row, but wider than that of the opposite valve. Dorsal valve moderately concave, not equaling the convexity of the ventral valve. Surface of dorsal valve marked by from 34 to 60 rounded or sometimes subangular striae which increase by bifurcation and sometimes by intercalation, so that there may be even a larger number on the ventral margin, and the striae and interspaces are covered by very fine radiating, thread-like striae, while well preserved surfaces show similar, closely arranged, thread-like con- centric ones. Striae of ventral similar to those of dorsal valve. Interior of ventral valve has a median ridge which extends from the beak for 158 Systematic Paleontology — Middle Devonian about two-thirds its length and the interiors of both valves have numerous and closely arranged small pustules. The most distinctive specific character of this species is the large number of radiating, thread-like striae which cover both the coarser striae and the interspaces. It most closely resembles C. vicinus (Castelnau) but differs froni that species in the larger number of striae and especially in the fine radiating ones. Length, 6-9 mm. ; width, 10-13 mm. Ocewrrence. — Eomney Foemation, Hamilton Member. B. & 0. E. E. cut at 31st Bridge. Collection. — Maryland Geological Survey. Chonetes rugosus Kindle Plate XIII, Figs. 7-9 Chonetes rugosus Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 72, pi. iv, figs. 5-7. Description. — Shell medium size transverse in outline, slightly convex on the ventral side. Surface marked by fine closely placed striae number- ing about 100. All of the striae bifurcate before reaching the margin, some of them repeatedly. Six to ten concentric undulations or corruga- tions cross the striae. Those axe strongest in the median and anterior por- tions of the shell and die out toward the anterior margin. The hinge-line is mucronate, the extremities extending considerably beyond the sides of the shell. A strong rib-like process or pseudo hinge-line arises from the hinge-line about midway between the beak and the extremity of the mucronate extension of the hinge-line. This curves very gently upward from the hinge-line and extends to or beyond its extremities. ' A peculiar nonstriated, ear-like process is subtended between the hinge-line proper and the pseudo hinge-line. This, on the inner surface, is marked by a series of closely spaced diagonal denticulatioas. Dorsal valve and internal characters are unknown. The peculiar denticulated ear-like expansion posterior to the hinge- line distinguishes this from any other Chonetes. A single specimen doubtfully referred to this species shows two short outward directed spines Maryland Geological Suevet 159 on each side of the beak. Ordinary spines have not been observed on any other specimens referred to this species. Occurrence. — Eomnet Pormation, Onondaga Member. Williams Eoad 3% miles southeast of Cumberland. Collection. — U. S. National Museum. [B. M. Kindle.J Genus ANOPLIA Hall and Clarke Anoplia nucleata (Hall) Plate XIII, Pigs. 10-13 Leptaena nucleata Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 47. Leptaena f nucleata Hall, 1859, Pal. N. Y., vol. Hi, p. 419, pi. 94, fig. 1. Anoplia nucleata Kindle, 1912, Bull. U. S. Geol. Surv., No. 50S, p. 73, pi. v, figs. 8-11. Description. — Shell small, concavo-convex, and strongly arched. Sur- face without striae or plications. Interior of both valves strongly pustu- lose. Ventral valve very gibbous in the umbonal and median region, beak incurved. In the interior a strong septum extends from the beak about one-third the distance to the front of the shell. In nearly all specimens this septum terminates abruptly. In a few individuals, however, it is continued forward a short distance beyond its normal terminus as a pair of rather faintly developed, divergent, y-shaped arms. Most of the specimens from Mendota, Virginia, show moulds of the spine tube. This extremely slender tube originates on the inner surface of the shell, midway between the beak and the cardinal angle just inside the inner margin of the area, and crosses diagonally the marginal portion of the valve with a slight curve. It terminates at the side of the beak in a minute point apparently not reaching the outer surface of the shell. Dorsal valve moderately and regularly concave. Outer surface marked by a minute tripartite median process just inside the hinge-line. This comprises two short divergent lobes and a third median lobe stronger than the lateral one, having a length of about % of a mm. The interior of this valve is characterized by two slender sharp median ridges. These diverge slightly as they extend forward from the base of the cardinal process and terminate about % the distance from the hinge-line to the front. A 160 Systematic Paleontology — Middle Devonian narrow, elongate, muscular scar occupies, the posterior half of the space between these ridges. Outside this pair of median ridges is a second pair of poorly defined and very divergent ridges which appear to mark the outer limits of muscular areas. The peculiar, short, tripartite process on the exterior of the dorsal valve of this shell was correctly figured by Hall ahd Clarke ' in their work on the Brachiopoda, but in the latest figures of this shell which have appeared Dr. Clarke has figured as the interior of a dorsal valve' (PI. 41, Mg. 16) a specimen which evidently represents a mould of the exterior of the valve. This species occurs in the Onondaga fauna throughout the middle Allegheny region. Occurrence. — Eomney Foemation, Onondaga Member. Tonoloway, Maryland, 1% miles south of Berkeley Springs, West Virginia. Collection. — ^TJ. S. Kational Museum. [E. M. Kindle.] Genus STROPHALOSIA King Strophalosia truncata (Hall) Plate XIII, Pigs. 14-16 Strophomena pustulosa Hall, 1843, Geol. N. Y., pt. iv, p. 180, fig. 4. (Not Prodiictus pustulosus Phillips.) Productus truncatus Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 171. Productella truncata Hall, 1867, Pal. N. Y., vol. iv, p. 160, pi. xxiil, figs. 12-24. Produotella (Strophalosia (?)) truncata Whiteaves, 1889, Cont. Canadian Pal., vol. i, p. 112, pi. xvi, figs. 1, 2. Strophalosia truncata Beecher, 1890, Am. Jour. Sci., 3d ser., vol. xl, p. 241. Strophalosia truncata Hall and Clarke, 1892, Pal. N. Y., vol. vili, pt. i, p. 316, pi. XV B, figs. 24-26 ; pi. xvii, figs. 10-15. Strophalosia truncata Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 419. Strophalosia truncata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 330. Strophalosia truncata Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 240, fig. 292. Description. — ^Shell small, concavo-convex; hinge-line equaling or less than the greatest width of the shell. Ventral valve gibbous in the ' Pal. New York, vol. viii, pt. i, 1892, pi. xx, fig. 16. ^ Mem. New York State Mus. Nat. Hist., No. 9, 1908. Maryland Geological Survey 161 middle, broadly truncate on the -umbo, regularly curving to the front, abruptly depressed at the sides, and forming narrow flattened ears at the cardinal extremities. Dorsal valve moderately concave, minutely truncate, at the apex, the interior wrinkled and pustulose with a conspicuous de- pression at the umbo, and a short bifurcating cardinal process. Surface of the ventral valve wrinkled at the hinge-line, marked by a greater or less number of spiniferous ridges, supporting slender spines of moderate length; there is usually a row of two or three spines on the ears just below the hinge-margin, and they are often closely arranged about the limits of the truncation on the umbo, and more sparsely on the middle and front part of the valve ; the dorsal valve is wrinkled along the hinge- line, and the surface covered by numerous elongate spiniferous pustules, bearing, when perfect, long slender spines This species is not common in Maryland but the argillaceous shales of Evitts Creek below Wolfe MUl have furnished several specimens of dorsal valves as well as the dark gray impure limestone at the iron bridge, 4J miles northeast of Oldtown. Part of the specimens are internal im- pressions of the dorsal valve which show very well its wrinkled and pus- tulose character. The specimens agree quite closely with some of the type specimens from New York, especially with the one represented by fig. 23 on pi. xxiii, vol. iv, PalsBontology of New York. A gibbous ventral valve from the Williams Road about ^ mile east of the Queen City Hotel, Cumberland, is referred to this species although it is not conspicuously truncated and there are four spines in the row just below the hinge-line, but the surface shows a number of ridges upon which at some distance apart are bases of spines. This species is recognized by its small size, gibbous and truncate ventral valve, flattened cardinal extremities, slightly concave dorsal valve which is wrinkled and pustulose on the interior, and the scattered surface spines on both valves. Kindle states that this is a very common and widely distributed species of the Onondaga fauna, occurring both in the soft shales and the hard limestone beds. Length, 3-9 mm.; width, 3-12 mm. 11 163 Systematic Paleontology — Middle Devonian Occurrence. — Eomney Formation, Onondaga Member. W. Va. Cent. R. E. cut at 31st Bridge. Marcellus Member. Williams Road, 3% miles southeast of Cumberland. Hamilton Member. East bank Evitts Creek below Wolfe Mill ; Williams Road about 14 niil^ east of the Queen City Hotel. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History; U. S. National Museum. Genus PRODUCTELLA Hall Proddctella ef. spinulicosta Hall Plate XIII, Fig. 17 Productus spinulicostus Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 173. Productella spinuUcosta H.a.11, 1867, Pal. N. Y., vol. iv, p. 160, pi. xxill, figs. 6-8, 25-34. Productella spinulicosta Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. xvii, figs. 3-6. Productella spinuUcosta Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 318. Productella spinulicosta Clarke, 1903, N. Y. State Mus., Bull. 65, p. 292. Productella spinulicosta Grabau and Shlmer, 1907, N. Am. Index Fossils, vol. ii, p. 241, flgs. 293c, d. Description. — "Shell broad, semielliptical or somewhat orbicular; hinge-line generally a little less than the greatest width of the shell. Ventral valve varying in shells of different size, from moderately to extremely gibbous in the middle, with the beak strongly incurved. Dorsal valve moderately concave in its upper part, and becoming more concave or arcuate towards the front. Surface marked by fine strong concentric striae, which are sometimes crowded and wrinlded on the body of the shell. There are several rows of interrupted ridges or spine-bases, which in entire specimens support slender spines. The ears are strongly wrinkled, and support a row of four or five spines -just below the hinge- line." Hall, 18fi7. A small and somewhat imperfect ventral valve of Productella was found in the Mar}'] and collection which at least may be compared with this species and probably belongs to it. The valve is strongly gibbous in the central part. There is no tmncatioh of the umbo or evidence of its Maeyland Gkological Survey 163 having been attached by the surface, which is marked by concentric lines varying in strength from striae to wrinkles and interrupted radiating ridges which at intervals bear spine bases. The preserved ear is strongly wrinkled and shows a conspicuous row of four spines just below the hinge- line. It will be seen that the characters shown by this single valve agree very well with those enumerated by Hall in his description of the species. The specimen was submitted to Prof. Charles Sehuchert, who reported it to be " a Productella and very probably P. spinulicosta." Length, 9 mm. ; width, 8 mm. Occurrence. — Romney Poemation, Hamilton Member. Williams Road i mile east of Queen City Hotel, Cumberland. Collection. — ^Maryland Geological Survey. PeODCTOTELLA (?) SCHUOHEETI n. sp. Plate XIII, Fig. 21 Description. — Shell of moderate size; hinge-line equaling the greatest width of the shell. Ventral valve convex, the greatest convexity toward the umbonal region; gradually sloping toward the front and lower lateral margins, and abruptly depressed and flattened towards the cardino-lateral margins. Surface marked by about 100 fairly large striae extending almost to the cardinal extremities, which are slightly undulating and increase by bifurcation. There are faint concentric striae and an occa- sional wrinkle or line of growth. The specimens of this species consist of an imperfect ventral valve and a fragment of another valve ; but as it probably carries a form related to the group Lineati of the Carboniferous Productus, back into the Middle Devonian, it is thought worthy of description. The specimens were sub- mitted to Dr. J. M. Clarke and Prof. Sehuchert. Dr. Clarke said that they suggested Proditctella of the Carboniferous. Prof. Sehuchert wrote as follows : " These are not Ohonetes since there are no hinge spines nor indications of shell pimctures. The general form, striae and concentric markings indicate Productus of the type of P- cora. If this is so it is very interesting in extending the line of this prominent group of Pro- ductus. This type of Productus begins well developed in the Kinder- 164 Systematic Paleontology — Middle Devonian hook [Mississippian] so that one can look for the ancestors in the Devonian. It is probably the most interesting Brachiopod in the Mary- land collection. If you describe it as new, and it seems to be worthy, place it in Productella ( ?) ." Length, 19 mm. ; width, 20 mm. Named in honor of Prof. Charles Sehuchert, of Yale University. Occurrence. — Eomney Foemation, Hamilton Member. Brnstville. Collection. — ^Maryland Geological Survey. Family ORTHIDAE Genus DALMANELLA Hall and Clarke Dalmanella lenticulaeis (Vamixem) Plate XIII, Pigs. 23-35; Plate XIV, Figs. 11, 12 Orthis tenticularis "Vanuxem, 1842 (non Wahlenberg) , Geology New York Survey, Third GeoL Dist., p. 139, &g. 4. Dalmanella lenticularis Kindle, 1912, Bull. U. S. Gaol. Surv., No. 508, p. 79, pi. V, figs. 12-16. Description. — Shell suborbicular, subplano-convex. Cardinal angles obtuse or roxmded. Greatest width of shell about one-fourth greater than length of hinge-line. Ventral valve with a subcarinate, gently rounded, median elevation from which the shell slopes regularly to each side. A well developed muscular impression bordered laterally by strong hinge teeth characterizes the interior. The dorsal valve is depressed convex, with a shallow but distinct mesial depression extending the length of the shell. A strongly marked muscular scar extends to the middle of the valve. A broad, low, and sometimes indistinct median ridge divides it longitudinally. Posteriorly it terminates in a bifurcated cardinal process. The entire surface is covered by coarse bifurcating striae, somewhat ir- regular in size, which are grouped in fascicles of four or five. These are crossed by fine concentric striae. The specimens in this fauna are some- what smaller than those figured by Hall. Occurrence. — Eomney Formation, Onondaga Member. Williams Eoad 31/2 miles northeast of Cumberland. Collection. — ^TJ. S. National Museum. [E. M. Kindle.] Maryland Geological Survey 165 Genus RHIPIDOMELLA Oehlert EhIPIDOMELLA VANUXEMl Hall Plate XIII, Pigs. 26-29 Orthis vanuxemi Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 135, figs. 1-7. Orthis vanuxemi Hall, 1867, Pal. N. Y., vol. iv, pp. 40, 47, pi. v, fig. 6; pi. vi, figs. Za-Zr. Orthis vanuxemi Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Bhipidom^ella vanuxemi Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. 1, p. 225, pi. vi, figs. 14, 15; pi. vi A, figs. 7, 8. Rhipidomella vanuxemi Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, pp. 352, 353. Rhipidomella vanuxemi Clarke, 1903, N. Y. State Mus., Bull. 65, p. 299. Rhipidomella vanuxemi Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 265, figs. 320a-c. Description. — Shell subcircular or transversely suboval, compressed; hinge-line very short; margins of the valves crenulated within from the external striae; interior minutely punctate. Ventral valve nearly flat or a little concave towards the front, moderately convex in the nmbonal re- gion; beak small extending little beyond the opposite one; cardinal area very small, less than half the greatest width of the shell; delthyrium comparatively large, triangular and partly filled by cardinal process of opposite valve; the teeth are prominent and the interior of the valve is marked by a large flabelliform diductor impression, which reaches from one-half to two-thirds the length of the shell and in the median line is the adductor impression. Dorsal valve convex; beak scarcely distinct from the cardinal border; cardinal process prominent, which is continued in a rounded median ridge for half the length of the shell. Surface marked by fine, closely arranged, radiating tubular striae, which are perforate at intervals and increase both by implantation and bifurcation. These are crossed by fine concentric striae and at greater intervals by concentric, imbricating lines of growth; entire surface when magnified granulate or punctate. There are specimens of this shell as well as internal impressions which practically agree almost precisely with specimens from the Hamilton shales of JSTew York. It was also reported by Hall from Maryland and 166 Systematic Paleontology — Middle Devonian Virginia ^ and " a cast of a ventral valve supposed to be of this species, from Cumberland, Md.," was figured,'' which, was apparently repeated in volume 8 without question regarding its specific identity.' This species is distinguished by its subcircular or transversely suboval outline, ventral valve nearly flat or slightly concave becoming moderately convex near the beak, with large muscular area in its interior, dorsal valve convex. Length, 27 mm. ; width, 29 mm. Kindle states that the specimens of the Onondaga fauna which are referred to this species are somewhat smaller than the average size of the species as seen in the Hamilton, seldom exceeding a length of 14 and a width of 16 mm. In other features than size they correspond closely to the ordinary type of this shell. Occurrence. — Eomney Formation, Onondaga Member. Tonoloway. Hamilton Member. East bank Evitts Creek below Wolfe Mill; Williams Road, % mile east of Queen City Hotel, Cumberland ; Williams Eoad, % mile east of Queen City Hotel, Cumberland ; Ernstville. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Ehipidomella lbucosia Hall Plate XIV, Pigs. 1-5 Orthis leuoosia Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist, p. 80. Orfhis leuoosia Hall, 1867, Pal. N. Y., vol. iv, pp. 48, 63, pi. vii, flgs. ia-ii; pi. viii, flgs. 9, 10. Orthis leucosia Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Bhipidomella leucosia Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, p. 225, pi. vi, fig. 16; pi. vi A, flg. 9. Rhipidomella leucosia Schuchert, 1897, Bull. IT. S. Geol. Surv., No. 87, p. 349. Bhipiaomella leucosia Clarke, 1903, N. Y. State Mus., Bull. 65, p. 298. BMpidomella leucosia Grahau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 265, figs. 320 d, e. Description. — Shell broadly ovate, greatest width below the middle, somewhat obtusely pointed at the beak; cardinal area short and small, being less than half the width of the shell ; bealis approximate. Ventral ' Pal. N. Y., vol. iv, p. 48. "/Sid., pi. 6, fig. 3r. ' Loo. cit., pt. i, pi. vi, flg. 15. Maryland Geological Suevey 167 valve gibbous towards the umbo, depressed convex in the center and flattened towards the front; the front margin straight, or without sinus; delthyrium very broad, nearly twice as wide as high. Dorsal valve the more gibbous, the greatest convexity above the middle, longitudinally marked by a median depression which is sometimes obsolete ; the interior shows a prominent cardinal process, which is continued in a strong median ridge for about one-half the length of the valve. Surface marked by fine, radiating, bifurcating striae, which are crossed by finer concentric ones, and by more distant subimbricating lamellose lines of growth; minute tubular openings occur on the surface of the striae; the external striae usually mark the inner margins of the valves. Hall noted the close agreement of this species with R. vanuxemi, but stated that it differed in being more ovate in shape, the cardinal extrem- ities are less roimded, the sides slope almost directly nearly to the middle of the shell and the dorsal valve is more gibbous. He referred speci- mens from Cumberland, Md., to this species and figured an internal impression of a ventral valve which was stated to be "probably of this species."* Comparatively few specimens of this species were found in Maryland; but there are a few impressions which show at least a part of its distinctive characters and apparently ought to be referred to this species. As already stated the species closely resembles R. vanuxemi but these impressions differ from that species in their more ovate outline, greater convexity of valves, and more pointed posterior end. Length, 32 mm. ; greatest width, 32 mm. ; width on hinge-line, 9 mm. Occurrence. — ^Eomney Poemation, Hamilton Membee. Williams Road, f mile east of Queen City Hotel, Cumberland. Collections. — Maryland Geological Survey; !N"ew York State Museum; American Museum of Natural History. EHIPTDOMELLA PENELOPE Hall Plate XIV, Figs. 6-9 Orthis penelope Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 79, flgs. 1, 2. Orthis penelope Hall, 1867, Pal. N. Y., vol. iv, p. 50, pi. vi, flgs. 2a-2m. 'Pal. N. Y., vol. iv, pi. vii, fig. ii. 168 Systematio Paleontology — Middle Devonian Rhipidomella penelope Hall and Clarke, 1892, Pal. N. Y., vol. vUi, pt. 1, pp. 211, 225, pi. vi, figs. 6-13; pi. vi A, figs. 10, (? 11). RMpidomella penelope Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 351. Rhipidomella penelope Clarke, 1903, N. Y. State Mus., Bull. No. 65, p. 298. RMpidomella penelope Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 265, figs. 320f, g. Description. — Shell large, oblate, proportions of length and breadth about as four to five, plano-convex ; hinge-line about two-fifths the width of the shell. Ventral valve depressed-convex above, sometimes a little gibbous towards the umbo, flat or often concave in the middle and below, the front without sinuosity; the interior marked by a subcircular or broadly ovate flabellate muscular impression, which occupies more than half the length and breadth of the valve. Dorsal valve regularly convex, the greatest convexity about the center, with a very slight mesial depres- sion or flattening along the center ; the interior shows a prominent card- inal process, which is continued in a median ridge sometimes nearly to the front of the shell. Surface marked by- fine radiating bifurcating striae, which are arched upwards near the cardinal extremities, and crossed by fine concentric lines as well as lamellose lines of growth, the radiating striae frequently have the appearance of being broken or in- terrupted, from the peculiar manner in which the pores open upon the surface. This species is apparently rare in Maryland; but a large, although broken, specimen from. Evitts Creek below Wolfe Mill is referred to it. The species was identified by Hall from Cumberland, Md., and " a cast of the dorsal valve " from that locality figured.'' This species is quite similar to R. vanuxemi but is generally considered larger, the striae are stronger, the tubular openings of the striae are more elongate, and the muscular area smaller and more rounded. Length, 33 mm. ; width, 38 mm. Occurrence. — Eomnet Foemation, Hamilton Member. East bank Evitts Creek below Wolfe Mill ( ?) . Collections. —Maryland Geological Survey ; New York State Museum ; American Museum of Natural History. ' Pal. N. Y., vol. iv, pi. vi, fig. 2»i. Maryland Geological Survey 169 Ehipidomella oyclas Hall ( ?) Plate XIV, Fig. 10 Orthis cycles Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 78. Orthis cyclas Hall, 1867, Pal. N. Y., vol. Iv, p. 52, pi. vil, figs. 2, 3. Rhipidomella cyclas Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, p. 225. Rhipidomella cyclas Schuchert, 1897, Bull. U. S. Geol. Surv., Ko. 87, p. 348. Description. — Shell rather small, transversely subelliptical to sub- quadrate, the specimens from Ernstville, Md., are subelliptical while those from Hanging Eock, W. Va., are more quadrate in outline. Valves rather flat with greatest gibbosity near the umbo; cardinal line about one-half the greatest width of the shell. Surface marked by strong and prominent striae which increase both by bifurcation and implantation, and one speci- men shows fine thread-like concentric striae which are thickest toward the front of the shell. Shell structure strongly and finely punctate. But few specimens of this form were found in Maryland and West Virginia and they are doubtfully referred to this species. On account of the size, prominent striae and some other characters the specimens from Hanging Eock, West Virginia, were at first referred to this species with a query. The specimens from Ernstville, Md., are broader than Rhipir domella vanuxemi Hall, which they resemble somewhat, a character which appears to be constant and not produced by pressure. Dr. Clarke after examining the specimens said "they are perhaps R. vanuxemi distorted by pressure, still the breadth appears to be constant and perhaps they are entitled to be called a new species." The Ernstville specimens were sub- mitted to Prof. Schuchert, who wrote me " I think they are Rhipidomella cyclas Hall. If your other specimens have a long hinge-line, or at least longer than R. vanuxemi, they are R. cyclas." The specimen from Wil- liams Eoad which is figured was examined by Dr. J. M. Clarke, who said that "it is as good a RMpidomella cyclas as any of the New York Hamilton specimens. It is not known, however, what this species is and perhaps it is only the young form of R. vanuxemi." The figured speci- mens from Ernstville and Williams Eoad, Md., and from Hanging Eock, W. Va., were also examined by Dr. Grabau, who agreed in comparing them with R. cyclas. As already stated the author is not confident of the 170 Systematic Paleontology — Middle Devonian specific identification of these specimens; but on account of the cor- respondence of certain characters with those of E. cyclas they have been referred to that species with a query." Length of Ernstville specimens, 10-14 mm. ; width, 14-20 mm. Length of Hanging Rock specimens, 7-8 mm. ; width, 9-10 mm. Length of Williams Eoad specimen, about 9.3 mm. ; width about 9.8 mm. Occurrence. — Eomney Formation, Onondaga Member ( ?). Hanging Eock, W. Va. Hamilton Member. Williams Eoad 3J miles southeast of Cumberland; Ernstville; Licking Creek east of Warren Point. Collection. — Maryland Geological Survey. Genus SCHIZOPHORIA King ScHizopHORiA striatula (Schlotheim) (?) Plate XIV, Figs. 13, 14 Anomia terebratulites striatulus Schlotheim, 1813, Min. Taschenbuch, viii, pi. i, fig. 6. Orthis striatula Davidson, 1865, Brit. Devonian Brach., Pal. Soc, p. 87, pi. xvii, figs. 4-7. Orthis impressa Hall, 1843, Geol. N. Y., pt. iv, p. 267, fig. 2. OrtMs ioweiisis Hall, 1858, Geol. Surv. Iowa, vol. i, pt. ii, p. 488, pi. ii, fig. 4. Orthis impressa Hall, 1867, Pal. N. Y., vol. iv, p. 60, pi. viii, figs. 11-19. Orthis iowensis White, 1880, Second Ann. Rep. Indiana Bureau Statistics and Geol., p. 501, pi. V, figs. 10-12. Orthis iowensis White, 1881, Tenth Rep. State Geol. Indiana, p. 133, pi. v, figs. 10-12. OrtMs impressa Walcott, 1884, Mon. U. S. Geol. Surv., vol. viii, p. 115, pi. xiii, fig. 13. Orthis striatula Williams, 1889, Am. Geologist, vol. iii, p. 232. Schizophoria iowensis Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pp. 212, 226, pi. vi A, fig. 29. Schizophoria impressa Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pp. 212, 216, pi. vi, fig. 31; pi. vi A, figs. 26, 27. ' Dr. Kindle's Bulletin on the Onondaga Fauna of the Allegheny Region has appeared since the following description was in type. It then appeared to the writer that perhaps part of these specimens might be referred to Dalmanella lenticularis (Vanuxem) and the figured ones were sent to Dr. Kindle, who wrote December 17, 1912, that those from Ernstville and Hanging Rock, W. Va., " represent D. lenticUlaris in my judgment and doubtless came from the beds I have referred to the Onondaga." On the explanation of Plate XIV the names for the specimens from these two localities have been changed to Dalm,anella lenticularis (Vanuxem) . Dr. Kindle also wrote that " The specimen numbered 4940 [from Williams Road] I would identify as you have indicated as RMpi- domella cydlas ? Hall." Maryland Geological Survey 171 ScMzophoria striatula Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 375. Schizophoria striatula Grabau and Shlmer, 1909, N. Am. Index Fossils, vol. 1, p. 268, figs. 321d-f. Description. — A single specimen of a par% exfoliated ventral valve ( ?) was found, npon which the description is based. Shell considerably wider than long; greatest width near the middle; moderately convex at the sides and flattened toward the umbo ; a shallow sinus begins near the beak which broadens and deepens toward the front; surface apparently marked by fine, even striae and the texture is conspicuously punctate. This specimen was shown Dr. John M. Clarke, who stated that he would call it a Schizophoria sp., but would not identify it specifically; although on account of the deep sinus it is to be compared with 8. impressa Hall. Prof. Schuchert after examining it wrote " I would make it Schiz- ophoria striatula Schl. ( ?) ." On account of its similarity to this species, together with the fact that Dr. E. M. Kindle has recently identified it from the Falls of the Ohio and other localities in Indiana, from both the Sellersburg beds and Jeffersonville limestone, which are regarded as representing respectively the Hamilton formation and Onondaga lime- stone,' it is referred to this species with a question, although it was found in the lower part of the Romney formation in Maryland. Length, 12 mm. ; width, 16 mm. Occurrence. — Romney Formation, Hamilton Member. Ernstville. Collection. — Maryland Geological Survey. Order TELOTREMATA Superfamily RHYNCHOTMELLACEA Family RHYNCHONELLIDAE Genus CAMAROTOECHIA Hall and Clarke Camarotoeohia oongregata (Conrad) Plate XIV, Figs. 15-17 Atrypa congregata Conrad, 1841, Fifth An. Rep. N. Y. Geol. Surv., p. 55. RhyncTionella (Stenocisma) congregata Hall, 1867, Pal. N. Y., vol. iv, p. 341, pi. liv, figs. 44-59. Camarotoechia congregata Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 192, pi. Ivli, figs. 15-27. ^Ind. Dept. Geol. and Nat. Resources; 25th An. Rept., 1900 (1901), p. 626. 173 Systematic Paleontology — Middle Devonian- CamarotoecMa congregata Schuchert, 1897, Bull. IT. S. Geol. Surv., No. 87, p. 165. CamarotoecMa congregata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 203. Description.- — Shell robust, varying from short-ovate to subglobose; length and width nearly equal or a little wider than long ; front rounded or straight in the middle ; sides curved abruptly ; apex pointed. Ventral valve with a moderate sinus which often begins at about one-third the length from the apex and becomes conspicuous towards the front; beak, in old shells, closely arcuate over the apex of the opposite valve, in young shells, nearly straight or slightly incurved. Dorsal valve gibbous in old shells, regularly convex in young specimens; mesial fold scarcely con- spicuous on the upper half of the shell, sometimes prominent near the margin ; in the interior a distinct septum reaching half the length of the valve. Surface, in young shells, marked by nine or ten distinct sub- angular or rounded plications ; in older shells, by eighteen to twenty-two, of which three or four occupy the mesial sinus and four or five the mesial fold ; there are also slender concentric striae, which are sometimes a little imbricated near the front margin. This species occurs in some of the coarse arenaceous shales of Mary- land; but it is not common except in occasional thin zones, specimens from which agree fairly well with those of the New York Hamilton. The broader forms of the Maryland specimens agree in form, and in number and strength of plications, fairly well with the New York type specimens. There are others which are more pointed than most of the New York specimens, while the plications are more slender. The species is char- acterized by its robust form, abrupt curvature of sides, rather moderate fold and sinus with the exception that the latter is well marked toward the front of the shell, three or four plications in the sinus and four or five on the mesial fold. Length, 13-19 mm.; width, 13-19 mm. Occurrence. — Romnet Foemation, Hamilton Member. B. & 0. E. R. cut at 31st Bridge ( ?) . Western Md. ; Williams Road, 3% miles southeast of Cumberland; on the Hancock-Harrisonville Road about 3 miles north of Hancock; in run at Hancock, east of Catholic church; along Plintstone Creek in Gilpin ( ?) ; west of iron bridge over Town Creek northeast of Maryland Geological Suevby 173 Oldtown; on Eomney-Hanging Rock Road about I/2 i^ile north of Eom- ney, W. Va. ( ?) ; B. & 0. E. E. cut at Hancock Station, W. Va. ( ?) . Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Camaeotoectiia prolipica Hall Plate XV, Figs. 1-3 Rhynchonella (Stenocisma) proliflca Hall, 1867, Pal. N. Y., vol. iv, p. 343, pi. liv A, figs. 1-10. Stenoschisma proliflca Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. CamarotoecMa proliflca Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 192, pi. Ivii, figs. 42, 43. CamarotoecMa proliflca Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 168. Description. — Shell subtriangular-ovate ; length and width about equal; front rounded, with a shallow sinus and gentle elevation, depressed in young shells and becoming gibbous in older ones. Ventral valve depressed- convex in the middle, elevated or a little gibbotis on the umbo, curving to the sides and with a shallow sinus below the middle; apex slightly in- curved. Dorsal valve equally convex with the ventral, sometimes a little more convex ; below the middle of the valve the mesial fold becomes more or less elevated, but rarely rises conspicuously above the general outline; in the interior is a short septum. Surface marked by from about twenty to twenty-four angular plications, of which three occupy the mesial sinus and four the mesial fold. A partly covered and more or less exfoliated ventral valve from a cal- careous layer in West Virginia, opposite Madders Island, four miles south of Cumberland, is refeiTcd to this species as well as specimens from other localities. The plications are fully as small and angular as those repre- sented in the figures of New York specimens and rather more numerous than on some of them with which they have been compared; there are three plications in the sinus, and the valve is rather more convex in the middle than in specimens from arenaceous shales. This species is dis- tinguished by its shape, slender angular plications, and shallow sinus with three plications. Length, 9 mm.; width, 8 mm. of Potomac Eiver specimen. Occurrence. — ^Romn-et Formation, Onondaga Member. B. & 0. R. R. cut at 21st Bridge ( ?). Hamilton Member. B. &. 0. R. R. cut at 31st 174 Systematic Paleontology — Middle Devonian Bridge. "Williams Eoad, 3% miles southeast of Cumberland ; on National Road nori;heast of Cumberland ; on road east of Pine Hill about 4 miles north of Oldtown; W. Va. side Potomac River, 4 miles south of Cumber- land. Collections. — Maryland Geological Survey; American Museum of Nat- ural History. Camaeotoechia SAPPHO Hall Plate XV, Fig. 4 Bhynohonella sappho Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 87. RhyncUonella (Stenooisma) sappho Hall, 1867, Pal. N. Y., vol. iv, p. 340, pi. liv, figs. 33-43. Camarotoechia sappfio Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. il, p. 192, pi. Ml, figs. 10-14. Camarotoechia sappho Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 168. Camarotoechia sappho Grabau and Shinier, 1909, N. Am. Index Fossils, vol. i, p. 288, figs. 354c, d. Description. — Shell large ; gibbous, subelliptical ; nearly straight in the middle of the front, abruptly pointed at the beak; sides rounded to the mesial fold and sinus. Ventral valve depressed-convex, somewhat gibbous on the umbo ; flattened and somewhat depressed in the middle towards the front; sinus becomes well marked about one-third the distance from the apex towards the front; apex abruptly acute, and more or less incurved according to age. Dorsal valve gibbous, regularly arching transversely; the mesial fold becoming conspicuous only towards the front; in young shells only moderately convex. Surface marked by eighteen to twenty- four plications, a smaller number in young specimens, those toward the cardinal margin less elevated; about four to six mark the sinus and fold. In old shells the plications are grooved towards the front, and those of the sides of the dorsal valve are abruptly bent towards the ventral valve. The shell is concentrically marked by fine thread-like elevated striae, which are more conspicuous and strongly undulating towards the front. An exfoliated ventral valve of this species is among the Johns Hopkins collections from western Maryland, the exact locality of which is unknown. It is rather more triangular in shape than the normal adult forms of this species, and the sinus, which is rather deeper and more sharply defined, contains three conspicuous plications with a less strongly defined fourth Maryland Geological Survey 175 one at one side. This species is distinguished by its shape, size, strong plications, broad sinus and fold towards the front of the shell marked by from four to six plications. Length of Maryland specimen, 36 mm.; width, 31 mm. Occurrence. — Eomney Formation, Hamilton Member. Western Maryland; on the Eomney-Hanging Eock Road about ^ mile north of Eomney, W. Va. Collections. — ^Maryland Geological Survey ; American Museum of Nat- ural History. Gamarotoechia sp. Plate XV, Mg. 5 Description. — The figured oxfoliaited ventral valve does not agree closely with figured specimens ; but Prof. Sehuehert and Dr. J. M. Clarke, both of whom have seen the specimen, agree that it is better not to describe it as a new species. The shell is of medium size; sinus deep and well marked, containing three rather large and prominent plications; sides with three or four plications which are elevated and conspicuous near the margin. In some respects the specimen resembles GamarotoecMa congregata (Con.) ; but the lateral plications are stronger and more highly raised at the margin, in this respect something like Pugnax. Dr. Clarke also suggested that it be compared with G. sappho Hall. Length, 17 mm. ; width, 17 mm. Occurrence. — Eomney Formation, Hamilton Member. Flintstone Creek in Gilpin; Williams Eoad i mile east of Queen City Hotel, Cum- berland. Collection. — ^Maryland Geological Survey. Genus LIORHYNCHUS Hall LlORHYNOHDS LIMITARE (Vanuxcm) Plate XV, Pigs. 6-8 OrtMs Hmitaris Vanuxem, 1842, Geol. N. Y., pt. ill, p. 146, flg. 3. Atfypa Hmitaris Hall, 1843, Geol. N. Y., pt. iv, p. 182, flg. 11. Atrypa Hmitaris Rogers, 1858, Geol. Penna., vol. il, pt. il, p. 826, flg. 652. Leiorhynchus Hmitaris Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 85. 176 Systematic Paleontology — Middle Devonian Leiorhynchus Hmitaris Hall, 1867, Pal. N. Y., val. iv, p. 356, pi. Ivi, figs. 6-21. Liorhynchus Hmitaris Hall and Clarke, 1893, Pal. N. Y., vol. vili, pt. li, p. 194, pi. lix, figs. 1-5. LeiorhyncHus limitare Schucliert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 237. Liorhynchus limitare Clarke, 1903, N. Y. State Mus., Bull. 65, p. 253. Leiorhynchus limitare Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 289, figs. 357a, b. Description. — Shell ovate, suborbicular or transverse; moderately or extremely gibbous, except in thin shales, where it is almost fiat; sinus and mesial fold more or less developed. Ventral valve in young shells scarcely less convex than the opposite, becoming gradually more dis- similar with growth; in old shells it is rather gibbous near the beak, gradually depressed below, becoming deeply sinuate, produced in front and abruptly truncate. Dorsal valve more convex than ventral, gibbous in old shells, the mesial fold becoming developed below the middle of its length ; umbo gibbous and often rising nearly as high as the beak of the ventral valve. Surface marked by numerous angular or subangular pli- cations, those of the mesial fold and sinus distinctly bifurcating, while sometimes a few of those on the sides are divided ; concentrically marked by fine striae. In the fissile ■ black shales, forming the lower part of the Eomney formation in Maryland (the best locality noted is the southern end of the B. & 0. R. E. cut at 21st Bridge), specimens are common of a nearly flat Liorhynchus, the form of which is due to crushing, which are referred to this species. The outline is similar to that of the young specimen of L. muUicosta = laura represented by fig. 36 on pi. Ivi, vol. iv, Palaeontology of New York; but none of these specimens reach the size of the adult of that species, the plications are somewhat finer, and those of the mesial fold and sinus distinctly bifurcate. While the specimens do not agree in form with those from the calcareous layers of the Marcellus shales, they are similar to the flattened specimen from "thinly laminated shales" represented by fig. 31 of the above-mentioned plate, and also similar in general appearance to specimens of this species which the writer has col- lected in the thin black shales of the Few York Marcellus. The Mary- land specimens show no appreciable differences from flattened speei- Maryland Geological Survey 177 mens in the office of tlie New York State Paleontologist labeled Lio- rhynchus Umitare from the fissile Marcellus shales of Western New York. The size, form, strength of plications and concentric striae are about identical. Specimens were submitted to Prof. Charles Schnchert, who wrote as follows : " It is very difficult to be certain of these crushed specimens, but they are usually called L. Umitare when from the Marcellus, and these are." There is not a very marked difference between young specimens of L. laura and L. Umitare, but the smaller size and finer plica- tions of these specimens refer them to the latter species. It is also to be noted that these specimens in size, shape and strength of plications are similar to L. dubium Hall of the Marcellus shale. Length, 8-13 mm. ; width, 8-14 mm. Occurrence. — Eomney Formation, Marcellus Member. B. & 0. E. E. cut at 21st Bridge; W. Va. Cent. E. E. cut at 21st Bridge; Wil- liams Eoad, 3^ miles southeast of Cumberland. Collections. — Maryland Geological Survey; New York State Museum. LiORHYNCHUS LAURA (Billings) Plate XV, Pigs. 9-12 Bhynchonella (?) laura Billings, May, 1860, Canadian Jour., vol. v, p. 273, figs. 26-28. Leiorhynchus multicosta Hall, December, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 85, figs. 14, 15 on p. 94. Leiorhynchus multicosta Hall, 1867, Pal. N. Y., vol. iv, p. 358, pi. Ivi, figs. 26-40. Liorhynchus multicosta and laura Hall and Clarke, 1893, Pal. N. Y., vol. vili, pt. ii, p. 194, pi. lix, figs. 8-10, 13-17. Leiorhynchus laura Schuchert, 1897, Bull. TJ. S. Geol. Surv., No. 87, p. 237. Leiorhynchus laura Shimer and Grabau, 1902, Bull. Geol. Soc. Amer., vol. 13, pp. 168-170. Liorhynchus multicostum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 253. Leiorhynchus laura Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 289, fig. 357c. Description,. — Shell ovate, with the length and greatest width nearly equal, in compressed specimens the width is often greater than the length. Ventral valve gibbous on the umbo, curving to the sides, becoming grad- ually depressed in the center and forming a sinus which is broad and 12 178 Systematic Paleontology — Middle Devonian gently defined below the middle of the shell. Dorsal valve much more convex than the ventral, the greatest gibbosity a little above the middle, the center elevated in a broad mesial fold. Surface marked by numerous rounded or subangular plications, of which from three to seven are de- pressed in the sinus and a corresponding number elevated on the fold, the plications of the fold and sinus bifurcate, while those of the sides are simple or obscurely bifurcating, and all usually become obsolete at one- third to one-fourth the length of the shell from the apex ; concentrically marked by raised thread-like striae. In the arenaceous shales of the Eomney formation and above the fissile black shales, are specimens of Liorhynchus which are not much larger than those from the black shales, but are marked by somewhat coarser pli- cations. These specimens are never abundant and they have been referred to L. laura, although most of them are smaller than, the figured specimens of that species. Length, 8-13 mm.; width, 9-13 mm. Occurrence. — Eomney Formation, Hamilton Member. Williams Eoad, 3 J miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey; New York State Museum. Liorhynchus cf . mysia Plate XV, Figs. 13-17 Leiorhynchus mysia Hall, 1867, Pal. N. Y., vol. Iv, p. 357, pi. Ivi, flgs. 1-5. Description. — " Shell small, suboricular ; valves subequally convex, with a few strong plications reaching half way from the margin to the beak of the shell. This species is distinguished by its small size, circular form, and proportionally much stronger plications, of which there are at least three on each side of the fold and sinus, terminating near the middle of the shell. In a few larger individuals, the plications near the middle of the shell have a greater extent. A single plication marks the sinus. The length of the shell is usually less than three-eighths of an inch ; width a little greater. One individual measures nearly a quarter of an inch in Maryland Geological Survey 179 length. In a specimen of L. limitaris of the same size, the plications are scarcely perceptible." Hall, 1867. Occurrence. — Eomkey Formation, Marcellds Member. Williams Road, 314 miles southeast of Cumberland. Collection. — U. S. ISTational Museum. [E. M. Kindle.] Centronella ef . ovata Hall Plate XVI, Figs. 1-3 Centronella ovata Hall, 1867, Pal. N. Y., vol. Iv, p. 419, pi. Ixi A, figs. 47-49. Description. — Shell small, oval or slightly ovate ; width and height as four to five, greatest width near the middle of the length. Dorsal valve depressed convex, without perceptible sinus. Ventral valve much deeper than the dorsal, subcarinate along the center, most ventricose just below the beak, which is strongly incurved ; lateral margins of the bealc slightly carinate. Surface marked only by concentric lines of growth. This species resembles C juUa in form, but is a narrower shell, with a less convex dorsal valve ; the ventral valve is more ventricose and carinate along the middle, and the beak more strongly incurved. Hall, 1867. Occurrence. — Romney Formation, Onondaga Member. One mile east of Oldtown, in cut of Western Maryland Railroad. Collection. — U. S. National Museum. [E. M. Kindle.] Superfamily TEREBRATULACEA Family TEREBRATULIDAE Subfamily TEREBRATULINAE Genus EUNELLA Hall and Clarke Eunella lincklaeni Hall Plate XV, Figs. 18-23 Terebratula Uncklaetii Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 88, ' Cryptonella lincklaeni Hall, 1861, Fourteenth Rep. N. Y. State Cab. Nat. Hist., p. 101. 180 Systematic Paleontology — Middle Devonian Cryptonella ( ?) Uncklaeni Hall, 1867, Pal. N. Y., vol. Iv, p. 397, pi. Ix, figs. 49-65. Terebratula Uncklaeni Hall, 1867, Pal. N. Y., vol. Iv, Corrigenda. Eunella Uncklaeni Hall and Clarke, 1893, Pal. N. Y., vol. vili, pt. 11, p. 290, pi. Ixxx, figs. 28-32. Eunella Uncklaeni Scliucliert, 1897, Bull. V. S. Geol. Surv., No. 87, p. 223. Eunella Uncklaeni Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 303, fig. 378. Description. — Shell ovate or subelliptieal, usually broader below tbe middle, varying from moderately convex to gibbous and sometimes sub- cylindrical; front rounded, subtruncate, or a little depressed. Ventral valve sometimes a little flattened towards the front or marked by a narrov,- mesial depression; beak more or less abruptly incurved and truncate by a foramen of moderate size. Dorsal valve with the greatest convexity about the middle of the length, and thence curving regularly to the sides and base. Surface marked by fine concentric striae of growth, which are sometimes crowded together towards the front, causing a thickening of the shell ; shell-struciture distinctly punctate. The Maryland specimens are all in the condition of rather poorly pre- served internal or external impressions which were found in arenaceous shales. Although crushed and more or less imperfectly preserved the specimens agree fairly well with figures 64 and 65 of pi. Ix, vol. iv, Palaeontology of New York, wTiich represent dorsal and ventral internal impressions of this species, showing in a similar manner the cavities left by the dental and hinge plates and apparently the diverging muscular or vascular lines. One internal impression when magnified shows a rather regular pustulose surface as represented in fig. 23, pi. xv, the pustules being casts of the punctae of the shell structure. Dr. B. R. Cumings of Indiana University examined this specimen with great care under enlargements from 5 to 85 diameters and found this delineation to be correct; He also examined very perfectly preserved shells in the Yale University Museum and stated that he got " precisely similar appearance with similar preservation." He also reported that "the outer surface of the shell in Eunella appears minutely pustulose, owing to the elevation of the mouth of the punctae." Length, 19 mm.; width, 13 mm. Maryland Geological Subvey 181 Occurrence. — Eomnhy Formation, Hamilton Member. West of iron bridge over Town Creek northeast of Oldtown; on road east of Pine Hill about 4 miles north of Oldtown. Collections. — Maryland Geological Survey ; American Museum of Kat- ural History. Family TEREBRATELLIDAE Subfamily TROPIDOLEPTIINAE Genus TROPIDOLEPTUS Hall Tropidolkptus caeinatus (Conrad) Plate XVI, Figs. 7-14 Strophomena carinata Conrad, 1839, Third Ann. Rep. N. Y. Geol. Survey, p. 64. Tropidoleptus carinatus Hall, 1857, Tenth Rep., N. Y. State Cab. Nat. Hist., p. 151, figs. 1, 2. Tropidoleptus carinatus Rogers, 1858, Geol. Penna., vol. 11, pt. 11, p. 828, fig. 672. Tropidoleptus carinatus Hall, 1867, Pal. N. Y., p. 407, pi. Ixli, figs. 2a-2c, 3a-3p, 3r-3M, Sw, Zx. Tropidoleptus carinatus Keyes, 1891, Johns Hopkins Univ. Circ, vol. xl, p. 29. Tropidoleptus carinatus Hall and Clarke, 1893, Pal. N. Y., vol. vlU, pt. 11, p. 304, figs. 227, 228, pi. Ixxxii, figs. 26-36. Tropidoleptus carinatus Schuchert, 1897, Bull. XT. S. Geol. Survey, No. 87, p. 457. Tropidoleptus carinatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 344. Tropidoleptus carinatus Grabau and Shlmer, 1909, N. Am. Index Fossils, vol. i, p. 305, fig. 382. Description. — Shell concavo-convex; outline generally semielliptical, but the lateral margins are sometimes nearly straight and the front broadly rounded; hinge-line equaling, greater or less than the width of the shell, so that the cardinal extremities vary from rounded to mucro- nate. Ventral valve convex; broadly subearinate along the middle, due to the greater width and prominence of the central plication, and sloping to the lateral margins and front. Cardinal extremities deflected ; average width of cardinal area about 1 mm., the outer margin sloping toward the extremities, the area striated longitudinally and divided by a broad, open delthyrium. Dorsal valve varying from strongly concave to nearly flat. 183 Systematic Paleontology — Middle Devonian in part of the specimens with a median depression below the middle of the valve. There is a narrow cardinal area interrupted in the middle by a wide, convex ehilidium. In the interior of this valve a median septum extends from the anterior part of the cardinal process to the anterior third of the shell. Surface marked by about eighteen to twenty broad, simple, rounded plications which are generally wider than the interspaces. There are iine, undulating, concentric striae, and a few stronger imbri- cating lamellae mark the stages of growth of the shell. The specimens from Maryland show about all the forms of this species which are represented in the Palaeontology of !N'ew York (see vol. iv, pi. Ixii), as from the arenaceous,ferruginous shales east of Hancock are speci- mens similar to figures 3c and 3e, while the bluish, slightly calcareous shales at 21st Bridge contain very large forms, even larger than figure 31 of the N". Y. Palasontology, which are likewise characterized by coarse plications that become inconspicuous on the thickened margin of the shell. The figures of the Maryland specimens show one of normal size and another of the large form. ISfot infrequently the shell substance is well preserved and the punctate structure beautifully shown. Length of average adult, 20 mm. ; width, 25 mm. ; length of large speci- men, 28 mm. ; width, 38 mm. Occurrence. — Eomney Formation, Hamilton Member. B. & 0. E. E. cut at 21st Bridge. Williams Eoad, 3i/^ miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; Williams Eoad, % mile east of Queen City Hotel, Cumberland; Williams Eoad, i^ mile east of Queen City Hotel, Cumberland; Town Creek Eoad at George Diefen- baugh's; B. & 0. E. E. cut at 21st Bridge; on National Eoad, % mile west of Tonoloway Eidge; on Oldtown Eoad east of Maryland Ave., Cumberland; McCoys Ferry; southwest of McCoys Ferry; on the Han- cock-Harrisonville Eoad about 2 miles north of Hancock; in run at HaJicock east. of Catholic church; along Flintstone Creek in Gilpin; on National Eoad in Gilpin ; west of iron bridge over Town Creek north- east of Oldtown; on National Eoad % mile west of licking Creek; on road east of Pine Hil! about 4 miles north of Oldtown; B. & 0. E. E. cut at Hancock Station, W. Va, ; on road about half way between Eomney and Maryland Geological Survey 183 Hanging Eock, W. Va. ; on the Eomney-Hanging Rock Eoad about % mile north of Eomney, W. Va. Collections. — Maryland Geological Survey; New York State Museum. Superfamily SPIRIFERACEA Family ATRYPIDAE Genus ATRYPA Dalman Ateypa KETicnLARis (Linne) Plate XVI, Figs. 4-6 Anomia reticularis Linng, 1767, Systema Naturae, ed. xii, vol. 1, p. 1132. Atrypa Chemung ensis Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, p. 265. Atrypa chemungensis Vanuxem, 1842, Geol. N. Y., pt. Ill, p. 182, fig. 4. Terehratula reticularis Hall, 1849, Am. Jour. Scl., 2d ser., vol. xx, p. 227. Atrypa reticularis Hall, 1852, Pal. N. Y., vol. ii, p. 72, pi. xxlli, fig. 8; p. 270, pi. IV. fig. 5. Atrypa reticularis Hall, 1859, Pal. N. Y., vol. ill, p. 253, pl. xlll, fig. 1. Atrypa reticularis Hall, 1867, Pal. N. Y., vol. iv, p. 316, pl. lii, figs. 1-3, 7-12; pl. llil, figs. 3-19 ; pl. liii A, figs. 22, 23. Atrypa reticularis Nicholson, 1874, Rep. Pal. Ontario, p. 79. Atrypa reticularis Nettelrotti, 1889, Kentucky Fossil Shells, p. 91, pl. xiv, flgs. 12-23; pl. XV, fig. 1. Atrypa reticularis Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 165, fig. 153; pl. Iv, figs. 1-17. Atrypa reticularis Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 154. Atrypa reticularis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 195. Atrypa reticularis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 310, figs. 389a, 389b, 392a-c. Descripiion. — Shell large but variable in form and dimensions; usu- ally oblong-ovate, with the greatest width a little below the hinge-line. Ventral valve usually moderately convex near the umbo, flattened toward the sides, and markedly depressed in front, with occasionally a broad but shallow sinus towards the front margin; beak small, incurved, and per- forated by a small foramen. Dorsal valve convex, always more so than the ventral, and frequently very gibbous; greatest convexity near the middle, from which it slopes abruptly to the lateral margins; generally without a mesial fold corresponding to the sinus of the ventral valve. Surface marked by clear rounded or sub-angular plications, which in- 184 Systematic Paleontology — Middle Devonian crease toward the margins by bifurcation and intercalation, and are crossed by concentric lines of growth giving a reticulated appearance to the shell. The muscular areas are conspicuous, outside of which the surface is papillose, vascular markings are sometimes visible near the margin and in the dorsal valve there is a septum in the upper part of the muscular area. (For description see Nicholson 1874, and Nettelroth 1889.) As is generally the case with the Maryland material most of the speci- mens are impressions, but a few preserve the shell. The latter have been compared with typical specimens of this species and A. spinosa Hall from the Hamilton shales of New York and they clearly belong to A. reticularis rather than to A. spinosa. The plications on a part of the Maryland specimens are somewhat coarser than on those from New York, but are not as coarse as the costae of A. spinosa and do not show at all the nodose or strongly reticulated surface of that species. Specimens were shown Dr. J. M. Clarke, who regards them as Hamilton representatives of A. reticularis, clearly distinct from A. spinosa. There is a marked and constant difference in large numbers of specimens representing these two species from Eighteen Mile Creek in western New York and apparently only A. reticidaris is represented in the Maryland Collection. This seems odd because Atrypa spinosa is the species which has been reported from Maryland and Virginia. A figure of this species is given by Eogers from the Hamilton of Pennsylvania;^ while Hall stated that "In collections from the Hamilton group near Cumberland (Md.) and the adjacent parts of Virginia, there are many casts and exfoliated shells of A. spinosa, but none of them with the finer costae, or that can be referred to A. reticularis." ' And in another place it is stated that " In casts of this species [A. spinosal from the Hamilton group of Maryland and Virginia, we find the same characteristic features preserved as above described [under the specific description of this species] ." ' This identi- fication of Hall apparently has been followed by later observers, for ' Geol. Penna., 1858, vol. ii, pt. ii, p. 828, fig. 671. ' Pal. N. Y., vol. iv, 1867, p. 324. ' Hid., p. 323. Maryland Geological Survey 185 Keyes reported Atrypa spinosa from the Hamilton of western Mar\'land ' and Prof. Schuehert listed it as from Maryland and Virginia." It is not intended to state that A. spinosa does not occur in this region; but according to the writer's observations and the collections of the State Survey the common species is A. reticularis. This species is distinguished by its large size, shape, great convexity of dorsal and slight convexity of ventral valve, closely incurved ventral beak, rounded bifurcating plications crossed by concentric striae and lines of growth. In A. spinosa the valves are more nearly equally convex, the radiating plications are much coarser, and fewer, and are crossed by very conspicuous concentric lamellae which give a highly reticulated and nodose appearance to the surface of the shell. Length, 18-42 mm. ; width, 20-35 mm. Occurrence. — Romney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill ; on National Eoad northeast of Cumber- land ; along Plintstone Creek in Gilpin. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Family SPIRIFERIDAE Genus CYRTINA Davidson Cyetina hamiltonensis Hall Plate XVII, Figs. 1-9 Gyrtia namiltonensis Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 166. Cyrtina namiltonensis Hall, 1867, Pal. N. Y., vol. iv, p. 268, pi. xxvli, figs. 1-4; pi. xliv, figs. 26-33, 38-52. Cyrtina hamiltonensis Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Cyrtina hamiltonensis Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 46, pi. xxviii, figs. 23-33, 43, 45, 46, 53. Cyrtina hamiltonensis Schuehert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 198. Cyrtina hamiltonensis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 224. Cyrtina hamiltonensis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 313, figs. 393a-c. Description. — Shell small and spirifer-like ; hinge-line equal to the greatest width of the shell; proportions of length, breadth and height ' Johns Hopkins Univ. Circ, vol. xi, 1891, p. 29. = Bull. U. S. Geol. Surv., No. 87, p. 156. 186 Systematic Paleontology — Middle Devonian variable. Ventral valve obliquely subpyramidal ; beak very prominent, straight or incurved, frequently distorted or turned to one side; mesial sinus wide and sharply defined with rounded or subangular bottom; cardinal area high, triangular, generally arcuate with angular margins; delthyrium narrow, covered by an elongate, convex pseudo-deltidium which is perforated below the apex by an elongate foramen; the internal impressions show a slit in the bottom of the sinus extending from the beak toward the front of the valve for one-half or more of its length which represents a longitudinal median septum. Dorsal valve slightly convex; broad, prominent mesial fold with sometimes a slight groove along its center which is bounded by broader furrows than those between the plica- tions ; beak scarcely rising above the hinge-line ; cardinal area narrow and linear. Surface marked by six to eight simple, rounded plications on each side of the fold and sinus, crossed by fine concentric lines of growth which are infrequently shown on the impressions of the Maryland speci- mens; surface minutely granulose or papillose; shell structure distinctly punctate. This species is not abundant in Maryland and not as common in occur- rence as in the Hamilton formation of New York. The Maryland speci- mens are mainly impressions found in the rather arenaceous shales or thin bedded sandstones of the Eomney formation; but in this condition they agree very closely with specimens from similar lithologic deposits of the Kew York Hamilton. T'his species is readily distinguished by the very convex ventral valve with high generally arcuate cardinal area; slightly convex dorsal valve; small number of plications; granulose surface mark- ing and punctate shell structure. Length, 7-10 ram. ; width, 10-15 mm. Occurrence. — Romney Formation, Onondaga Member ( ?) . Hanging Eock, W. Va. Hamilton Member. East bank Evitts Creek below Wolfe Mill ; on Oldtown Eoad east of Maryland Ave., Cumberland ; on the Hancock-Harrisonville Eoad about 3 miles north of Hancock; McCoys Eerry; on Ifational Eoad northeast of Cumberland; in run at Hancock east of Catholic church ; I mile north of Green Spring Furnace ; west of iron bridge over Town Creek northeast of Oldtown; on road, east of Pine Maryland Geological Survey 187 Hill about 4 miles north of Oldtown; B. & 0. E. E. cut at Hancock Sta- tioHj W. Va. ; on road about half way between Eomney and Hanging Eoek, W. Va.; on the Eomney-Hanging Eock Eoad about -J mile north of Eomney, W. Va. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Genus SPIRIFER Sowerby Spirifer muceonatds (Conrad) Plate XVII, Figs. 10-18 Probably Terehratula pennata Atwater, 1820, Amer. Jour. Sci. Arts, vol. li, p. 244, pi. i, flgs. 2, 3. Helthyris mucronata Conrad, 1841, Fiftb Ann. Rep. Geol. Surv. N. Y., p. 54. Spirifer wMcronata Billings, 1856, Canadian Nat. Geol., vol. i, p. 474, pi. vii, flgs. 9, 10. Spirifer mucronata Rogers, 1858, Geol. Penna., vol. li, pt. ii, p. 828, fig. 668. Spirifera mucronata Billings, 1861, Canadian Jour., n. ser., vol. vi, p. 254, figs. 59-62. Spirifera m,ucronata Hall, 1867, Pal. N. Y., vol. iv, p. 216, pi. xxxlv, figs. 1-32. Spirifera pennata Keyes, 1891, Johns Hopkins Univ. Circ., vol. xi, p. 29. Spirifer mucronatus Hall and Clarke, 1893, Pal. N. Y., vol. viil, pt. ii, pp. 14, 17, 36, pi. xxix, fig. 8, pi. xxxiv, flgs. 13-22. Spirifer pennatus Schuchert, Bull. U. S. Geol. Surv., No. 87, p. 401. Svirifer mucronatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 321. Spirifer mucronatus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 330, fig. 421. Spirifer mucronatus Cleland, 1911, Fossils and Stratigraphy M§d. Devonio Wisconsin, p. 80. Description. — Shell medium size; more or less gibbous; cardinal areas low, and cardinal angles sometimes truncate but usually extended and often prolonged into mucronate points which give the hinge-line a length of two to five times that of the shell. Ventral valve often scarcely more convex than the dorsal ; beak small and incurved over the narrow cardinal area which is longitudinally striated ; mesial sinus is sharply defined quite to the apex and limited by angular plications which are stronger than the adjacent ones. The sinus is generally shallow and rounded in the bottom, but sometimes flat or with a small fold in the center. In the interior is a small striated muscular area. Dorsal valve moderately con- 188 Systematic Paleontology — Middle Devonian- vex ; mesial fold prominent, flat or rounded above and frequently marked by a median groove. Beak incurved; cardinal area extremely narrow, about one-third as high as that of the ventral valve. Surface marked by from eight to fifteen or more suhangular plications on either side of the mesial sinus or fold, the outer ones of which do not reach the beak. On well preserved specimens the plications are crossed by numerous iine lamellose striae which become crowded and closely imbricating towards the front of the shell, sometimes marking several lines of interrupted growth. At some localities in Maryland this species is very abundant forming a considerable part of the rock. As illustrations may be cited the locality about two miles north of Hancock on the road from that tovm to Har- risonville, Pa. ; one near the bridge over Town Creek three miles northeast of Oldtown; while on Evitts Creek below Wolfe Mill are specimens with the shell beautifully preserved. Among the Maryland specimens may be found examples of most of the forms figured in Palaeontology of N. Y. (see vol. iv, pi. xxxiv). Figures 10 and 11 of this report repre;-ent a specimen from Evitts Creek with truncate cardinal angles similar to the narrow form shown by figure 8 in the Palaeontology of N'ew York ; while at McCoys Perry an extremely mucronate specimen was obtained with a length of 15 mm., and a width of 35 mm. for one-half of the shell along the hinge-line, of which the mucronate point was fully 30 mm: in length. The great majority of the specimens are exfoliated and furnish only internal impressions. Length of nonmucronate specimen, 15 mm. ; width, 36 mm. ; length of nonmucronate triangular shaped specimen, 33 mm.; width, 45 mm.; length of average specimen, 16 mm. ; width, 39 mm. ; length of mucronate specimen but not extreme, 15 mm. ; width, 60 mm. ; length of another specimen, 18 mm.; width, 50 mm. In reference to the synonymy of this species Miller and Schuchert con- sider DeUhyris mucronata Con. as a synonym of Terebratida pennata Atwater; while Dr. J. M. Clarke states that "I see no good reason for calling Spirifer mucronatus Conrad S. pennatus Atwater. It may be true that the latter is what we mean bv 8. mucronatus but it would be difiBcult Maryland Geological Survey 189 to demonstrate it as no one knows where or what the original specimen is. It seems to me wiser and safer to retain Conrad's name as we know definitely what Conrad was talking about." ^ Atwater's figures are crude and from them the writer would hardly feel warranted in accepting the .identity of the two forms. Prof. Schuchert's observation, however, is that " Atwater's specimen was found in the drift of Ohio. Mr. Miller is correct in regarding it the same as the well-known S. mucronatus." ^ Atwater's home was in Circleville, Pickaway County, in southern central Ohio, and it is apparently generally considered that the specimen was found in that vicinity. Much of Pickaway County is deeply covered by drift and known as the Pickaway plains, the greater part of which is underlain by the Ohio shale, which is the case geologically at Circleville. Atwater states that the specimen " is a light drab-colored limestone," ' but did not state whether it was loose or obtained from solid rock. Miller in calling atten tion to the synonymy of the species stated that " Circleville is not fai- distant from exposures of the Hamilton group " ; * still the distance to rocks containing typical specimens of Spirifer mucronatus is probably considerably greater than he supposed. 'In Deep Cut north of Front's Station, about six miles south of Sanduskj^, at the locality given by Newberry.' The writer collected typical specimens of this species from the light gray calcareous shale of Hamilton age which occurs in the ditch below the base of the black Huron shale. Again, in the drift overlying the Eichmond formation on the bank of Morris Hill Eun about four miles south of Waynesville, in southwestern Ohio, a very characteristic specimen of this species was obtained. This locality is south of west of Circleville and, therefore, it is shown that specimens of this species have been carried in the drift farther to the south than Circleville. Occurrence. — Eomney Formatiox, Hamilton Member. B. & 0. E. E. cut at 31st Bridge (?). Williams Eoad, 3% miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; Williams ' Letter from Dr. J. M. Clarke, April 20, 1901. ' Bull. U. S. Geol. Surv., No. 87, p. 401. ' Loc. cit., p. 245. ■* Proc. Davenport Acad. Nat. Science, vol. ii, p. 220. " Rept. Geol. Surv. Ohio, vol. ii, pt. 1, 1874, p. 190. 190 Systematic Paleontology — Middle Devonian Eoad % mile east of Queen City Hotel, Cumberland; Williams Eoad, 14 mile east of Queen City Hotel, Cumberland; in Jennings Run, % mile west of Corriganville; Town Creek Road at Geo. Diefenbaugh's; east side Warrior Mt. east of Rush; on N"ational Road % mile west of Tonoloway Ridge; B. & 0. R. R. cut at 21st Bridge; on Oldtown Road, east of Maryland Ave., Ctimberland; McCoys Perry; south- west of McCoys Perry; on the Hancock-Harrisonville Road about 2 miles north of Hancock; on National Road northeast of Cumberland; in run at Hancock east of Catholic church; along Plintstone Creek in Gilpin; on National Road in Gilpin; on road east of Pine Hill about 4 miles north of Oldtown; west of Lock No. 56 at Great Cacapon; west of iron bridge over Town Creek northeast of Oldtown; on National Eoad, ■J mile west of Licking Creek ; on the Romney-Hanging Rock Road about ■J mile north of Romney, W. Va. ; on road about half way between Romney and Hanging Rock, W. Va. ; W. Va. side Potomac River, about 3 and again about 4 miles south of Cumberland; B. & 0. R. R. cut at Hancock Station, W. Va. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Spikifee granulosus (Conrad) Plate XVIII, Pigs. 1-6 Delthyris granulosa Conrad, 1839, Third Ann. Rep. Geol. Surv. N. Y., p. 65. Delthyris granuUfera Hall, 1843, Geol. N. Y., pt. iv, p. 206, fig. 1. Spirifer granuUfera Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 163. Delthyris congesta Rogers, 1858, Geol. Penna., vol. li, pt. ii, p. 828, figs. 670, 673. Spirifera granuUfera Hall, 1867, Pal. N. Y., vol. iv, p. 223, pi. xxxvi, figs. 1-13. Spirifera granuUfera Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Spirifer granulosus Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 29, 30, 31, 39; pi. xxiii, figs. 1-15; pi. xxix, figs. 9-12. Spirifer granulosus Sohuchert, 189,7, Bull. U. S. Geol. Surv., No. 87, p. 391. Spirifer granulosus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 317. Spirifer granulosus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 328, fig. 417. Description. — Shell large, ventricose to gibbous; hinge-line generally equal to the greatest width of the shell; cardinal extremities obtuse. Maryland Geological Survey 191 sometimes rounded. Ventral valve most prominent near the umbo, gradually sloping to the cardinal angles; beak incurved; cardinal area moderately high, vertically striated, and divided by a rather large, triangular delthyrium; mesial sinus distinct, subangular in upper part and broad deeply rounded depression in front, often -with a slight groove along the center and sometimes with a faintly marked plication on each side. Interior of valve shows broad striated muscular impres- sion, the upper part bounded by strong dental plates. Dorsal valve generally the most ventricose with the greatest convexity at about the middle; mesial fold prominent and rounded with medial rounded de- pression. Surface marked by from eighteen to twenty-two simple, low, rounded plications on each side of fold and sinus; entire surface of shell in excellently preserved specimens covered by very fine interrupted longi- tudinal striae which form numerous small pustules or granules, the latter are usually shown on fairly well preserved surfaces; concentric lines of growth and striae are often conspicuous toward the front of the shell. The Maryland specimens show the variations of this species as found in New York specimens. It is never as abundant in Maryland as Spirifer mucronatus (Conrad), although a common species at certain localities, as on Evitts Creek below Wolfe Mill. The species is readily distinguished on account of its large size, form, broad plications, and strongly granulose surface. Length of average specimen, 48 mm., width, 57 mm.; internal cast length, 38 mm., width, 57 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; in Jennings Eun ^ mile west of Cor- riganville; Town Creek Eoad at George Diefenbaugh's ; B. & 0. E. E. cut at 21st Bridge; on Oldtown Eoad east of Maryland Ave., Cumber- land; on the Hancock-Harrisonville Eoad about 3 miles north of Han- cock ; McCoys Perry ; on National Eoad northeast of Cumberland ; along Flintstone Creek in Gilpin; west of iron bridge over Town Creek north- east of Oldtown; on National Eoad -J mile west of Licking Creek; on road east of Pine Hill about 4 miles north of Oldtown; B. & 0. E. E. 193 Systematic Paleontology — Middle Devonian cut at Hancock Station, W. Va.; on the Romney-Hanging Eock Road about I mile north of Romney, W. Va. Collections.— M-BLTyland Geological Survey; New York State Museum; American Museum of Natural History. Spirifee audaculus (Conrad) Plate XVIII, Figs. 7-9 Delthyris audacula Conrad, 1842, Jour. Acad. Nat. Sci. Phlla., vol. viil, p. 262. Delthyris medialis Hall, 1843, Geol. N. Y., pt. iv, p. 208, fig. 8. Spirifer medialis Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 157. Delthyris medialis Rogers, 1858, Geol. Penna., vol. 11, pt. ii, p. 828, fig. 669. Spirifera medialis Hall, 1867, Pal. N. Y., vol. Iv, p. 227, pi. xxxviii, figs. 1-25. Bpirifera audacula Whitfield, 1882, Geol. Wisconsin, vol. iv, p. 329, pi. xxv, figs. 25, 26. Spirifera medialis Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Spirifer. audaculus Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 29-31, 39, pi. xxiv, figs. 1-13; pi. xxix, fig. 5. Spirifer audaculus Schuchert, 1897, Bull. IT. S. Geol. Surv., No. 87, p. 382. Spirifer audaculus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 309. Spirifer audaculus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 329, fig. 420a. Description. — Shell medium size; valves moderately convex in young specimens, becoming ventricose in old shells; hinge-line generally ex- tended beyond the width of the shell below. Ventral valve usually more convex than the dorsal; incurved beak; cardinal area commonly of more than medium height; longitudinally striated and divided in the middle by . the delthyrium which is about twice as high as wide ; mesial sinus well defined, extending to the apex, of moderate width, rather deep and generally rounded at the bottom. Dorsal valve moderately convex; beak small and slightly incurved ; cardinal area linear ; mesial fold prominent, rising abruptly at the sides and rounded or slightly flattened on top; cardinal angles slightly reflected. Surface marked by twenty or more simple plications on each side of the fold and sinus and the principal ones, especially of the ventral valve, are often marked along the center by a threadlike groove; toward the front are numerous, often imbricat- ing, concentric lines. Maryland Geological Survey 193 In Maryland- this species occurs less frequently than either Spirifer mucronatus or S. gra/rmlosus and most of the specimens are internal impressions. For this reason it is not always easy to separate S. audch cuius from S. granulosus; however, the size, shape and narrower plications of the former generally distinguish the species. Hall's description of the species states that the surface is " marked by from twenty to thirty simple plications on each side of the mesial fold and sinus " while the Maryland specimens rarely show twenty clearly marked plications. An examination, however, of the New York type specimens indicates that part of them scarcely show more than eighteen sharply defined plications. In general 8. audaculus is readily distinguished from S. mucronatus by its larger size, much greater convexity, high ventral cardinal area, and absence of extended hinge-line; from S. granulosus by its smaller size, narrower plications, and absence of granulose surface. Length, 25-35 mm.; width, 35-45 mm. Occurrence. — Eomney Formation, Hamilton Member. Williams Eoad, 31/^ miles southeast of Cumberland ( ?) ; Williams Road,!^: mile east of Queen City Hotel, Cumberland; east bank Evitts Creek below Wolfe Mill; on Hancock-Harrisonville Road about 3 miles north of Hancock; McCoys Ferry; on National Road, % mile west of Licking Creek; east side Warrior Mt. east of Rush; B. & 0. R. R. cut at Hancock Station, W. Va. (?). Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Spirieer acuminatds (Conrad) Plate XVIII, Fig. 10 Delthyris acuminata Conrad, 1839, Third Ann. Rep. N. Y. Geol. Surv., p. 65. Spirifer acuminata Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 135. Spirifera acuminata Hall, 1867, Pal. N. Y., vol. iv, pp. 198, 234, pi. xxix, flgs. 9-18; pi. XXXV, fig. 24. Spirifera acuminata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Spirifer acuminatus Hall and Clarke, 1893, vol. vii, pt. ii, pp. 31, 39, pi. xxxix, flgs. 39-42. Spirifer acuminatus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 380. 13 194 Systematic Paleontology — Middle Devonian Spirifer acuminatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 308. Spirifer acuminatus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 326, fig. 414. Description. — Shell large, ventricose; hinge-line usually less than the width of the shell; cardinal extremities rounded or truncate. Ventral not so convex as dorsal valve; wide mesial sinus which is well defined in. the upper part, becomes wider, deeper and less distinctly defined in the middle of the shell and is greatly produced in front. Dorsal valve gib- bous, highly elevated in the middle into a sharply angular mesial fold and curving from the sides of the fold to the margins of the shell, except at the cardinal angles, where it is a little flattened. Surface marked by from sixteen to twenty plications on each side of the fold and sinus, three or four of which nearest the center are deeply grooved to dichoto- mous from below the middle of their length; the first ten or twelve plications on each side of the center cover the greater part of the valve. This species is rare in Maryland and in the Johns Hopkins Collection is represented by a single broken internal impression of the dorsal valve. There is, however, apparently no doubt regarding its identity for the sharp angular fold and central dichotomoiis plications are well shown. Hall mentioned an impression of this species in the Museum of Marietta College, Ohio, which he stated " from its character, has been derived from the southwestern extension of the Hamilton group, perhaps in Vir- ginia " ;' and Keyes listed it in his paper on the " Paleozoic fossils of Maryland.'"' This species is easily distinguished from the other Spir- ifers by the high, sharply angular mesial fold and deep sinus, with the few dichotomous plications on each side. Length, 30 mm. ; width, 36 mm., and a comparison of figures indi- cates that the proportions are about as five to six. Occurrence. — Eomney Formation, Hamilton Member. McCoys Perry. Collections. — Maryland Geological Survey; 'New York State Museum; American Museum of Natural History. > Pal. N. Y., vol. Iv, p. 202. ' Johns Hopkins Univ. Circ, vol. xi, p. 29. Maryland Geological Survey 195 Spirifer tullius Hall Plate XIX, Figs. 1-7 Spirifera tullia Hall, 1S67, Pal. N. Y., vol. iv, p. 218, pi. 35, figs. 1-9. Spirifer tuUius Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 14, 35, pi. xxil, fig. 18; pi. xxxvii, figs. 6, 7. Spirifer tullius Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 408. Spirifer tullius Clarke, 1903, N. Y. State Mus., Bull. 65, p. 326. Spirifer tullius Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1, p. 332, fig. 422e. Description. — Shell small, subelliptical, gibbous; hinge-line equal or greater than the width of the shell. Ventral valve gibbous, greatest con- vexity above the middle of the shell, curving abruptly to the sides and a little flattened at the cardinal angles, mesial sinus sharply defined quite to the beak, not deep, rounded in the bottom; high cardinal area. Dor- sal valve moderately convex; mesial fold well defined, wide below and narrow above, flattened and sometimes depressed on the summit; shell curving gently to the lateral margins with slightly flattened cardinal angles. Surface marked by fourteen or more simple, low, flattened or rounded plications on each side of the fold and sinus, which in exfoliated specimens are frequently subangular; the entire surface marked by fine continuous radiating striae, which are most clearly shown on the inter- vals between the plications and on the fold and sinus. This species resembles somewhat young specimens of Spirifer audacu- liis; but is distinguished by its more gibbous form, more nearly parallel lateral margins, broader plications and especially by its conspicuous ra- diating striae. Hall reported this species only from central IvTew York ; but since then its occurrence has been noted in Erie County, Kew York, by Professor Grabau," in eastern central and eastern New York by the writer,' while Professor Whiteaves has reported a variety of the species from the Athabasca Eiver in British America." ' Bull. Buffalo Soc. Nat. Hist., 1899, vol. vi, p. 208. '15th An. Rep. State Geol. N. Y., 1895, p. 129; 17th iUci., 1899, p. 202; Bull. U. S. Geol. Surv., No. 120, 1894, p. 41. ' Cont. Canadian Pal., vol. i, pt. iii, 1891, p. 224. 196 Systematic Paleontology — Middle Devonian The Maryland specimens have about twelve clearly defined plications which is found on comparison to be the number on some of the type specimens from New York. Dr. John M. Clarke examined specimens from the Maryland Eomney and stated that they were probably Spirifer tullius. Length, 14 mm. ; width, 20 mm. Occurrence. — Eomney Foemation, Hamilton Member. Eun at Hancock east of Catholic church; on Hancock-Harrisonville Eoad about 2 miles north of Hancock; along Flintstone Creek in Gilpin; B. & 0. E. E. cut at Hancock Station, W. Va. Collections.— KaTylandi Geological Survey; New York State Museum. Spirifee angustus Hall Plate XIX, Figs. 8, 9 Spirifer angusta Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist, p. 164, fig. in text. Spirifera angusta Hall, 1867, Pal. N. Y., vol. iv, p. 230, pi. xxxviii A, figs. 23-32. Spirifera angusta Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Spirifer angustus Hall and Clarke, 1893, Pal. N. Y., vol. vlii, pt. ii, pp. 31, 39, pi. xxiv, figs. 14-17. Spirifer angustus Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 381. Spirifer angustus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 308. Spirifer angustus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 330, fig. 420b. Description. — Shell with depressed pyramidal outline; great lateral extension with attenuate and acuminate cardinal angles ; valves very un- equally convex with finely plicate surface. Ventral valve proportionally very deep, forming nearly the entire thickness of the shell; cardinal area extremely elevated and inclined forward, the height nearly equal to the length of the valve; delthyrium about twice as high as wide and grooved on the sides. Dorsal valve slightly convex; mesial fold low and narrow; cardinal area very narrow. Surface marked by about forty-four or more fine, simple and rounded plications on each valve, few of which reach to the beak. The Maryland specimens are mostly external impressions found in- frequently in arenaceous shales and consequently quite imperfectly pre- served. They clearly show, however, the high cardinal area and long Maryland Geological Survey 197 mucronate hinge-line. This species is generally readily distinguished by the high, inclined cardinal area and extended hinge-line. The dorsal valve resembles quite closely some forms of S. mucronatus, but the high cardinal area of the ventral valve readily separates them. Young speci- mens resemble S. OMdaculus, while the mucronate extensions of the hinge- line are rarely preserved in internal impressions so that it is apparently shorter than in other specimens. Length, 12-15 mm. ; width, 50-56 mm. Occurrence. — Eomney Formation', Hamilton Member. McCoys Ferry (?) ; east side Warrior Mt. east of Eush; east bank Evitts Creek below Wolfe Mill ( ?) ; B. & 0. E. E. cut at 31st Bridge. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Spirifer (Eeticularia) fimbeiatus (Conrad) Plate XIX, Figs. 10-13 Delthyris fimbriatus Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. vlii, p. 263. Bpirifer fimhriatus Hall, 1858, Geol. Surv. Iowa, vol. 1, pt. ii, p. 505, pi. iv, fig. 5. 8pirifera fim'briata Hall, 1867, Pal. N. Y., vol. Iv, p. 214, pi. xxxlii, figs. 1-21. Spirifera conradana Miller, 1883, Amer. Pal. Foss., 2d ed., p. 372. Spirifera conradana Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Bpirifer fimiriatus Hall and Clarke, 1893, Pal. N. Y., vol. viil, pt. ii, pp. 17, 20, 21, 33, 37, pi. xxxvi, figs. 17-22; pi. xxxviii, figs. 9, 10. Reticularia fimiriata Schuchert, 1897, Bull. V. S. Geol. Surv., No. 87, p. 342. Bpirifer fimhriatus Clarke, N. Y. State Mus., Bull. 65, p. 316. Reticularia fimbriata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 338, figs. 431a, \>. Description. — Outline transversely subelliptical ; hinge-line less than the width of the shell; cardinal angles rounded; valves gibbous and regularly convex. Ventral valve has well defined sinus, usually shallow and roimded, sometimes deep and angular; beak small and incurved over the cardinal area which is high and concave, extending about one-half the width of the shell. Dorsal valve slighly flattened at the cardinal angles ; mesial fold abruptly elevated in the lower part, low and frequently but imperfectly defined toward the beak. Surface of each valve marked by 198 Systematic Paleontology — Middle Devonian from six to eighteen low, rounded, often obscure plications; concentric imbricating and lamellose striae, which are sometimes distant and fre- quently crowded; the concentric striae studded with elongated spines or tubercles, which are arranged in parallel bands and may be regarded as interrupted radiating striae. But few specimens of this species have been found in Maryland and only a single imperfectly preserved ventral valve was available for com- parison in compiling the above description. The small number of low, rounded plications, conspicuous concentric striae and concentric rows of tubercles, however, readily distinguish the species from any other found in the Middle Devonian of Maryland. Concerning the specimens occurring in the Onondaga member, Kindle says : " The collection contains three small specmiens of a Reticularia having a breadth along the hinge-line of about 5 mm. and with 3 to 4 plications on each side of the fold and sinus. These probably represent either immature individuals or a dwarfed form of B. fimbriata." Length, 15-25 mm.; width, 20-35 mm. Occurrence. — Ro:mxey Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Hamilton Member. East bank Bvitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Xatural History. Spieifee cf. coNSOBEiNus (d'Orbigny) Plate XIX, Pig. 13 Delthyris ziczac Hall (non Roemer), 1843, Geol. N. Y., pt. Iv, pp. 200, 201, fig. 5. Spirifera consoirina d'Orbigny, 1850, Prodrome Pal., i, p. 98. Spirifera ziczac Hall, 1867, Pal. N. Y., vol. iv, p. 222, pi. xxxv, figs. 15-23. Spirifer consohrinus Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 16, 36, pi. xxxlv, flgs. 9, 18; pi. xxxvii, figs. 9, 10. Delthyris consobrina Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 206. Spirifer {Delthyris) consoirimis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 331, figs. 422a, b. Description. — Shell medium size, gibbous, semielliptical in outline, with the hinge-line equaling or greater than the width of the shell below; Maryland Geological Survey 199 the cardinal extremities truncate or aurieulate. Ventral valve the more convex, the greatest convexity being somewhat above the middle; sides regularly curving to the lateral margins, sinus deep and wide towards the front, rounded or flat in the bottom, produced in front, and sharply defined by the adjacent angular plications, which are stronger than the others; beak incurved. Cardinal area elevated and concave. Dorsal valve moderately convex at the sides; the mesial fold abruptly elevated, rapidly expanding below, flattened upon the summit, and usually marked by a mesial depression. Surface marked by from eight to ten or even twelve strong angular plications on each side of the shell, those towards the cardinal extremities being less elevated and often obscure, crossed by concentric zigzag lamellose lines of growth between which are finer lines. A few specimens have been found in Maryland which are referred pro- visionally to this species, the best one of which is an internal impression found on Town Creek, about six miles north of Oldtown. The sinus is deep, about as broad as in specimens of this species, and is sharply de- fined by a plication on each side which is stronger than the others. There are seven prominent plications and two or three inconspicuous ones near tlie cardinal angle on each side of the shell and the con- spicuous plications near the anterior margin of the shell are crossed by prominent concentric zigzag lines. The posterior portion of the impres- sion is pustulose, and the hinge-line is rather longer than the greatest width of the shell. The proportions of this specimen are nearer those of Spirifer scidptilis Hall than of this species and the concentric striae are similar to those on the type specimen of 8. sculptilis in the office of the State Paleontologist of New York; but there are only three plications on that specimen while the number of plications for the species does not exceed five on a side according to the description. The Maryland speci- men has nine or ten plications, a character which agrees with S. con- sohrinus and furthermore the sinus is deep and broad as in that species. Length, 19 -f- mm.; width, 36 mm. Occurrence. — Eomney Foemation, Hamilton Member. Town Greek 6 miles north of Oldtown. Collection. — Maryland Geological Survey. 200 Systematic Paleontology — Middle Devonian- Spieifee sculptilis vae. maeylandensis n. var. Plate XIX, Figs. 14-16 Description. — Bather more than one-half of the dorsal valve and its ex- ternal impression were found in the Maryland Collection. These speci- mens show eight angular plications on one side of the mesial fold which is bifurcated by a furrow, the surface is strongly marked by conspicuous imbricating, concentric striae, while the cardinal angle is mucronate with somewhat corrugated surface. These specimens differ from the figures and description of S. scidptilis in having a more mucronate cardinal angle and a larger number of plications, eight on a side instead of from three to five. The specimens were sent to Prof. Schuchert who returned them labeled Spirifer sculptilis. They were also examined by Dr. Grabau who sent me the following notes : " They come nearest to S. sculptilis. Too many plications. It is more mucronate which is a primitive eharactei with this group of Spirifers, since they are mucronate when young. It has more plications than normal which is an advanced character. Either new species or variety of S. sculptilis." It does not appear to the writer advisable to base a new species upon this imperfect material; but on account of the divergence from the normal forms of the species it is re- garded and described as a variety. Length, 15 mm. ± ; width, 44 mm. rt. Occurrence. — Eomney Poemation, Hamilton Membee. East side Warrior Mt. east of Push. Collections. — Maryland Geological Survey. Genus AMBOCOELIA Hall Amboooelia dmbonata Conrad Plate XX, Figs. 1, 2 Orthis umbonata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vili, p. 264, pi. xiv, fig. 4. Aml)ocoelia umtonata Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist, p. 71. Ambocoelia umtonata Hall, 1867, Pal. N. Y., vol. Iv, p. 259, pi. xliv, flgs. 7-18. Maryland Geological Survey 301 Amhocoelia umbonata Keyes, ,1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Ambocoelia umbonata Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pi. xxix, flg. 17; pi. xxxix, figs. 4-9. Ambocoelia umbonata Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 141. Ambocoelia umbonata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 343, figs. 4380, d. Description. — Shell plano-convex, almost hemispherical contour, rather wider than long; hinge-line generally equal to the width of the shell; cardinal angles rounded. Ventral valve very gibbous; umbo high and incurved; mesial sinus strong, distinct and continuous from the beak to the front; cardinal area comparatively large., arched and of considerable height. Dorsal valve semielliptical ; faintly convex in the upper central part, concave below the middle and at the sides; beak scarcely elevated above the hinge-line; without mesial fold, furrow or impressed line Surface marked by line concentric striae which ate sometimes crowded and imbricating towards the front of the valves, and by very fine radiat- ing striae which are only shown on excellently preserved specimens and hence are rarely seen. The Maryland specimens are generally in the condition of impressions although occasionally more or less of the shell is preserved. The im- pressions of some of the ventral valves show a striated muscular area toward the beak and pustulose markings over the central part of the valve. Some of the specimens are fully as large as any from New York and in fact broader, a condition apparently due to crushing, while others are smaller than the normal ones. The species is readily identified by its smooth surface, with the exception of the concentric and radiating striae the latter of which are shown only on exceptionally well preserved speci- mens; the very convex ventral valve with its strongly marked median sinus and the nearly flat dorsal valve without ridge or furrow. Concerning the species found in the Onondaga fauna, Kindle says : The specimens which are here referred to this species seem to show a considerable range of variation which may possibly include an undescrlbed species. Although one of the most abundant and widely distributed species In the fauna it usually occurs in soft shales which furnish rather poorly preserved and often flattened material. The character of this material scarcely justifies detailed consideration of the types of variation observed. Hall' states that "■ Pal. New York, vol. 4, 1867, p. 259. 202 Systematic Paleontology — JIiddlb Devonian the surface of this species is marked by " very fine radiating and concentric striae." In most of the specimens, both in my collection and in other collec- tions bearing the name A. umbonata, the surface is smooth. In some specimens, however, concentric striae are well developed but none have been observed showing radiating striae. Shells with a strongly lamellose dorsal valve are not uncommon. These as well as smooth shells frequently show a distinct fold near the front of the dorsal valve. Length, 6-10 mm.; width, 8-12 mm. There are some specimens smaller than the normal ones, but apparently belonging to this species, which have a length and width of about 4 mm. Occurrence. — Romney Formation, Oxoxdaga Member. Williams Road, 3% miles southeast of Cumberland; Hancock; Hanging Eock, W. Va. Hamilton Member. Williams Road, 3^/^ miles southeast of Cumberland; east bank Evitts Creek below AYolfe Mill; Williams Road, % mile east of Queen City Hotel, Cumberland ; in Jennings Run, % mile west of Corriganville ; Town Creek Road at George Dief enbaugh's ; Licking Creek east of Warren Point; on Oldtown Road east of Mary- land Ave., Cumberland; Ernatville; in run at Hancock east of Catholic church; along Flintstone Creek in Gilpin; on National Road in Gilpin; west of iron bridge over Town Creek northeast of Oldtown ; on Eomney- Hanging Rock Road, about -J- mile north of Romney, W. Va. ; 1 mile north of Romney, W. Ya. ; B. & 0. R. R. cut at Hancock Station, W. Va.; W. Va. side Potomac River, 4 miles south of Cumberland. Collections. — Maryland Gieological Survey; American Museum of Natural History. Ambocoelia virginiana n. sp. Plate XX, Figs. 3-6 cf. Ambocoelia umbonata var. cf. nana Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 83, pi. v, figs. 20-23. Description. — Shell very small; plano-convex; hinge-line straight, less than the greatest width of the shell, cardinal angles rounded. Ventral valve gibbous, umbo elevated with incurved beak; a narrow deep mesial sinus which is sharply defined extending from the beak to the front of the shell; part of the specimens show a single plication beginning near the center of the valve, extending to its front and bordering the sinus. Dor- Maryland Geological Survey 203 sal valve slightly convex near the umbo and flattened toward the front; a small fold begins about one third of the length from the umbo, extends to the front of the valve, and near the front is limited on each side by a shallow furrow. Surface marked by concentric and very fine radiating striae. This shell is similar to a minute form of Ambocoelia umhonata (Con.) ; but it differs from that species in its constant small size and the sharper sides of the sinus. The specimens occur in large numbers form- ing a large proportion of a thin calcareous stratum and they are uniformly small and similar to the specimen described. The material was shown Dr. J. M. Clarke and it is his opinion that the constant small size and angular sinus entitles this form to rank as a species. Hall described a form from the I\Iarcellus shale as Orthis nucleus (Geol. ISr. Y., pt. iv, p. 181 and fig. 8 on p. 180), which later was termed Ambocoelia nucleus (Thirteenth Eeport on the State Cabinet p. 71), and finally made a synonym of Ambocoelia umhonata (Pal. N. Y., vol. iv, pp. 259, 260), that apparently approaches this species in many respects. Specimens of this form have not been seen by the writer, but it is be- lieved that the species here described is uniformly much smaller. It is to be noted, however, that the description of Ambocoelia micleus states that the sinus " is often very conspicuous, being narrow and sharply de- pressed " (Pal. IST. Y., vol. iv, p. 260) ; but in the original description is the statement that the upper [dorsal] valve is flat (Geol. K. Y., pt. iv, p. 181) although later it is stated that a diminutive form similar to the A. nucleus of the Marcellus shale " sometimes occurs in the compact cal- careous beds of the Hamilton group in great numbers .... and in these the dorsal valve is more convex than usual" (Pal. X. Y., vol. iv, p. 360). A virginiana is also somewhat similar to the form which Dr. Grabau first described as variety nana of A. umbonata (Sixteenth An. Eep. State Geologist [N. Y.], 1899, p. 276, figs. 3-7 on p. 277) from near the base of the Hamilton shales on the shore of Lake Erie in western iSTew York and which he later raised to the rank of a species (Bull., Buffalo Soc. Nat. Sciences, vol. vi, 1899, p. 217, fig. 126 on p. 218). Finally, Miss 304 Systematic Paleontology — Middle Devonian Wood has reported the same species from the Stafford limestone in the Marcellus shale of Erie County, N. Y., stating that a thin bed of lime- stone is largely composed of shells of this species and Strophalosia truncata (N. Y. State Museum, Bull. 49, 1901, p. 145, and see p. 165 for description together with figures 31-23 of pi. 9). The surface of this species, however, differs strikingly from that of A. virginiana in being spinous as indicated by the numerous elongated pits, the shell is also con- siderably larger, the average dimensions being given as length 5.3-6 mm. and width 7.2-7.9 mm.; while the dorsal valve is marked by a shallow sinus instead of a low fold with a sinus on each side toward the front as in the latter species. Occasionally in some of the iron stained shales are small flattened •specimens of Ambocoelia, which apparently belong to this species. The most numerous specimens of this species seen by the writer occur in a cut on the Eomney branch of the B. & 0. E. E. between Green Spring and Springiield, about three miles south of Green Spring, W. Va. At this locality is a thin, very dark gray limestone containing large numbers of this species, and they are also abundant in some of the associated brown- ish shales. This outcrop is in the Marcellus shales of the Eomney for- mation.' Length, 1^ mm. ; width 2 mm. Occurrence. — Eomney Fokmation, Marcellus Membek. One mile east of Oldtown ; three miles south of Green Spring, W. Va. Hamilton Membee. East bank Evitts Creek below Wolfe Mill ; W. Va. side Potomac Eiver, 1% miles below Cumberland. Collection. — Maryland Geological Survey. Ambocoelia peaeumbona Hall ( ?) Plate XX, Pigs. 7, 8 Orthis praeumlona Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 167. Ambocoelia praeumbona Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 71. Ambocoelia praeumbona Hall, 1867, Pal. N. Y., vol. iv, p. 2C2, pi. xliv, figs. 1-6. Ambocoelia praeumbona Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 141. ' The specimen figured from south of Green Spring was sent to Kindle who wrote that it was probably a new species. Maryland Geological Survey 305 A.mbocoelia praeumbona Clarke, 1903, N. Y. State Mus., Bull. 65, p. 188. Aml)ocoeUa praeum.'bona Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 342, figs. 438a, b. Description. — Shell obliquely semiglobose or ovoid, the hinge-line less than the width of the shell ; cardinal extremities rounded ; surface with- out plications. Ventral valve extremely convex or ventricose, with a shallow impressed line which has nearly the character of a narrow shallow sinus; beak large and incurved; cardinal area of moderate dimensions, proportionally high, with the lateral margins not defined; fissure par- tially covered by an arching pseudo-deltidium. Dorsal valve moderately and evenly convex, usually without mesial fold or sinus, the cardinal ex- tremities rounded; sometimes there is a narrow impressed line down the center of the valve. Surface essentially smooth, or marked only by con- centric striae, which are sometimes crowded into imbricating folds; the impression of the ventral valve has a large often pustulose muscular area, margined by a thickening of the shell. In many specimens the length and width are nearly equal, the dimensions being about three- fourths of an inch. A large internal impression of a ventral valve together with a few other imperfect specimens in the Maryland Collection are provisionally re- ferred to this species. In the umbonal region is a well marked sinus which becomes broader and shallower toward the front of the shell; there is also a shallow indistinct furrow between the ridges limiting the sinus and the lateral margin of the shell. Strong concentric wrinkles of growth occur toward the margin and the rather large pustulose mus- cular area is fairly well shown in the umbonal region. In some respects the specimen suggests an unusually large form of Ambocoelia umbonaia (Con.), but it was sent to Prof. Schuchert and he wrote me as follows: "This looks more like A. praeumiona [than A. umbonata] only the sinus is very much marked. However, this character is somewhat due to its being an internal cast of the shell and may not have been so strong on the outside." On re-examination Prof. Schuchert wrote as follows: "At first I was going to label this specimen A. praeumbom but the ven- tral sinus is against this identification. However, the specimens are so 206 Systematic Paleontology — Middle Devonian much extended on the hinge and so much larger that I do not think they can he referred to A. unibonata. Think about making it a variety if after a study of the material you can find characters sufficiently constant." The specimen was later submitted to Dr. J. M. Clarke who apparently referred it to this species since he wrote " Why not Amhocoelia praeum- hona Hall ? " After this study it appears better to the writer, at present, to refer these specimens with a question to A. praeumbona. Length, 14 mm. ; width, 18 mm. Occurrence. — Eomnet Formation, Hamilton Member. Ernstville. Collection. — Maryland Geological Survey. Family ATHYRIDAE Genus NUCLEOSPIRA Hall XUCLEOSPIHA CONCINNA Hall Plate XX, Figs. 12-15 Atrypa concinna Hall, 1843, Geol. N. Y., pt. iv, p. 200, fig. 3. Nucleospira concinna Hall, 1859, Twelfth Rep. N. Y. State Cab. Nat. Hist, pp. 25, 26. Nucleospira concinna Hall, 1867, Pal. N. Y., vol. iv, p. 379, pi. xlv, figs, 33-57. Nucleospira concinna Keyes, 1891, .Johns Hopkins Univ. Circ, vol. xi, p. 29. Nucleospira concinna Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 145, fig. 131; pi. xlviii, figs. 12-17, 19-34; pi. Ixxxiv, fig. 38. Nucleospira concinna Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 273. Nucleospira concinna Clarke, 1903, N. Y. State Mus., Bull. 65, p. 263. Nucleospira concinna Gratau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 349, fig. 454. Description. — Shells fairly small; bi-convex; nearly circular in out- line, the width being usually a little greater than the length ; valves sub- equal; hinge-line about one-third, and sometimes half as long as the width of the shell. Ventral valve regularly convex, the greatest con- vexity a little above the middle curving regularly to the sides and front; umbo prominent, the beak pointed and incurved over the apex of the dorsal valve ; there is generally a narrow depressed line from the beak to the front of the valve. Dorsal valve regularly convex, becoming a little depressed toward the front, the greatest convexity a little above the cen- ter; there is usually a depressed line along the middle of the valve. Maryland Geological Survey 207 Surface usually smooth or very finely papillose, but in its perfect condi- tion covered by numerous fine seta. The Maryland specimens are rather poorly preserved internal impres- sions which occur infrequently. They show distinctly a shallow furrow which extends from the vicinity of the beak to the front of the ventral valve, produced by the internal medium septum. This species is dis- tinguished by its small size, nearly circular outline, subequally convex valves, generally smooth surface, and median furrow of internal impres- sions, especially of ventral valve. Concerning the specimens found in the Onondaga, Kindle states: This species is represented by numerous ventral valves but the dorsal valve has not been observed. Nearly all of the specimens represent casts of the interior but one silicified specimen shows the base of the fine setae over the anterior third of the shell and a highly papillose surface over the remainder of the shell. The outline of the muscular scars is not very clearly shown in the specimens. Two narrow ridges on either side of the septum appear to represent them in the casts. Length, 10 mm.; width, 11 mm. OccuiTence. — ^Romnet Formation, Onondaga Member. Williams Road, 31/2 miles southeast of Cumberland ; Tonoloway. Hamilton Mem- ber. Ernstville. Colledions.-^'Kaxjla.ndL Geological Survey; New York State Museum; American Museum of Natural History. Genus ANOPLOTHECA Sandberger Subgenus COELOSPIRA Hall Anoplotheca (Coelospiea) acutiplicata (Conrad) Plate XX, Figs. 16-23 Atrypa acutiplicata Conrad, 1841, Fifth Ann. Rep. N. Y. Geol. Survey, p. 54. Atrypa acutiplicata Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., 1862, pi. xi, fig. 17. Leptocoelia acutiplicata Hall, 1867, Pal. N. Y., vol. iv, p. 365, pi. Ivii, flgs. 30-39. Anoplotheca (Coelospira) acutiplicata Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 136, pi. liii, figs. 32-39. Anoplotheca acutipUcata Schuchert, 1897, Bull. IT. S. Geol. Surv., No. 87, p. 144. 308 Systematic Paleontology — Middle Devoniaii Coelospira acutipHcata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 214. Anoplotheca acutipHcata Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 84, pi. vi, figs. 1-15. Description. — The shell is plano-convex, compressed and of moderate size. The ventral valve is moderately convex, with the beak slightly incurved.' The dorsal valve is depressed-convex, sometimes flat or con- cave from compression. Surface marked by from six to eight strongly angular plications; on the ventral valve two plications are slightly ele- vated, giving an abrupt sinuosity in front, while the central one on the dorsal valve is depressed and margined on each side by a larger one. The shell is concentrically marked by strong imbricating lines of growth. This species has previously been considered as confined to the Onondaga (Corniferous) limestone; with the exception that it is doubtfully identi- fied by Dr. Weller from the Monroe shales at Greenwood Lake, Few Jersey, which he apparently considered as of Hamilton age.' There is apparently no doubt regarding the correctness of the identification of the Maryland specimens for they were submitted to Dr. J. M. Clarke who identified them as belonging to this species, a conclusion fully corrobo- rated by subsequent study. The Maryland specimens a,re principally impressions preserved in bituminous shales which are considerably more flattened than the specimens from the Onondaga limestone. Gutta- percha impressions of some of these specimens, however, reproduce very nearly the form and markings of the dorsal and ventral valves of this species as shown by figures 34 and 35 of plate Ivii, vol. iv. Palaeontology of New York. The plications have almost identically the same form and strength as those of the figures just mentioned, are nine or ten in number and rather broad and sharply marked by the imbricating concentric lines. ' In Professor Hall's description the terms dorsal and ventral are applied to the opposite valves as compared with this description as may readily be seen by referring to the description on p. 365, vol. iv. Palaeontology, N. Y., and especially by consulting figures 34 and 35 of plate 57 which are called respec- tively dorsal and ventral valves. Hall and Clarke, however, reversed the nam- ing of these valves in pt. ii, vol. viii, Palaeontology, N. Y., where on plate 53, fig. 35 ventral valve of vol. iv reappears as fig. 32 which is called dorsal and fig. 34 dorsal of vol. iv as ventral valve of fig. 34 of vol. viii. ^ Geol. Surv. N. J., Rep. on Paleontology, vol. iii, 1903, pp. 106, 107, 383. Maryland Geological Survey 309 This species is characterized by its plano-convex to nearly flat shape, ovate to orbicular form, eight to ten rather broad and rounded plications crossed by sharp imbricating lines, the central plication on the dorsal valve considerably depressed and bordered on each side by the strongest one of the valve, while on the ventral valve two plications are somewhat depressed in a broader and more shallow sinus the boundaries of which are not indicated by two as prominent plications as on the dorsal valve. Kindle repeats that this is probably the most abundant and widely distributed species in the Onondaga fauna, occurring in most of the collections from New York to southwestern Virginia. Length, 10-14 mm.; width, 14-17 mm. Occurrence. — Romney Formation, Onondaga Member. B. & 0. E. E. cut at 31st Bridge; Williams Eoad, 3^ miles southeast of Cumber- land. Hamilton Member. Bast bank Evitts Greek below Wolfe Mill. Collections. — Maryland Geological Survey; American Museum of Nat- ural History; U. S. National Museum. AnOPLOTHECA CAMILLA (Hall) Plate XX, Fig. 34 Goelospira concava Hall, 1867 (non Hall 1863), Pal. New York, vol. 4, 1867, p. 329. Goelospira Camilla Hall, 1867, ibidem, pi. 52, figs. 13-19. Anoplotheca Camilla Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 85. This rather diminutive brachiopod is represented by only a few posi- tively determined specimens in the collection. Although comparatively rare it has been found both in the non-calcareous shale and the lime- stone in three states and is probably coextensive with the Onondaga fauna in its distribution. Occurrence.— 'RoM.NBY Formation, Onondaga Member. Williams Eoad 3% miles southeast of Cumberland. Collection. — U. S. National Museum. [B. M. Kindle.] 14 210 Systematic Paleontology — IIiddlb Devonian Genus VITULINA Hall VlTULINA PUSTDLOSA Hall Plate XX, Figs. 25, 26 VituUna pustulosa Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 82. TituUna pustulosa Hall, 1867, Pal. N. Y., vol. iv, p. 410, pi. Ixii, figs, la-li. Titulina pustulosa Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 139, 317, pi. Ixxxii, figs. 18-25. VituUna pustulosa Prosser, 1894, Bull. U. S. Geol. Surv., No. 120, p. 21. Titulina pustulosa Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 459. YituUna pustulosa Clarke, 1903, N. Y. State Mus., Bull. 65, p. 345. Vitulina pustulosa Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 351, fig. 458. Description. — Shell subplano-convex, semielliptieal ; hinge-line equal- ing or a little less than the width of the shell. Ventral valve convex; median part raised in a broad fold which is subangnlar to flat near the beak and grooved along the center to the front of the valve, with four or five rounded or subangnlar plications on each side; delthyrium large and wide, reaching to the apex. Dorsal valve flat or slightly convex, with a wide mesial depression which is nearly flat in the bottom, and in large specimens contains a simple or double low plication toward the front; plications on the side similar to those of the ventral valve; very narrow cardinal area. Surface marked by interrupted radiating lines which form rows of elongated pustules; substance flnely punctate. This is a rare species in Maryland but a few impressions have been found on the National Eoad to the northeast of Cumberland. They are mainly specimens of the ventral valve and one agrees quite closely with the " ventral valve of a large individual " flgured by Hall.' The propor- tion of the width to the length of another specimen is somewhat greater than in the Kew York specimens, while a fragment of an external im- pression shows beautifully the impressions of the elongated pustules. The author found abundant specimens of this species at Marshalls Palls, Monroe Co. in northeastern Penna. ; while there is a specimen of an internal impression of a small ventral valve from Perry Co., Penna., in ' Pal. N. Y., vol. iv, pi. Ixil, fig. la. Maryland Geological Survey 311 the Geological Museum of the Ohio State University. This species is distinguished by its shape, size, small number of rounded plications, fold on ventral with sinus on dorsal valve, and pustulose surface. Length, 9 nun. ; width, 12 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Greek below Wolfe Mill; Williams Eoad, 3^ miles southeast of Cumberland ( ?) ; on Oldtown Eoad east of Maryland Ave., Cumberland; on National Eoad northeast of Cumberland; on road about half way be- tween Eomney and Hanging Eock, W. Va. ; on Eomney-Hanging Eock Eoad about ^ mile north of Eomney, W. Va. Collections. — ^Maryland Geological Survey; New York State Museum; American Museum of Natural History. Genus ATHYRIS McCoy Ati-iyris spiriferoides (Eaton) Plate XXI, Eigs. 1, 2 Terel)ratula spiriferoides Eaton, 1831, Am. Jour. Sci., vol. xxi, p. 137. Atrypa concentrica Conrad, 1838, An. Rep. Geol. Surv. N. Y., p. 111. Atrypa concentrica Hall, 1843, Geol. N. Y., pt. iv, p. 198, figs. 5, 5a. Spirifera spiriferoides Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 153, figs. 1, 2. Spirifera spiriferoides Rogers, 1858, Geol. Penna., vol. 11, pt. 11, p. 828, fig. 667. Athyris spiriferoides Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 93, figs. 1-4. Athyris spiriferoides Hall, 1867, Pal. N. Y., vol. Iv, p. 285, pi. xlvi, figs. 5-31. Athyris spiriferoides Keyes, 1891, Johns Hopkins Univ. Circ, vol. xl, p. 29. Athyris spiriferoides Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 89, figs. 60, 61; pi. xlv, figs. 11-27. Athyris spiriferoides Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 149. Athyris spiriferoides Clarke, 1903, N. Y. State Mus., Bull. 65, p. 192. Athyris spiriferoides Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 353, fig. 461. Not Terebratula concentrica von Buch. Description. — Shell varying from transversely oval to suborbicular and sometimes subquadrate; hinge-line short; the cardinal extremities rounded. Ventral valve moderately gibbous, often regularly convex above the middle, and deeply sinuate toward the front; umbo gibbous, beak 213 Systematic Paleontology — Middle Devonian incurved and covering that of the opposite valve; apex perforate; the interior shows two strong teeth; the muscular impressions begin at the base of the rostral cavity, and continue to a little below the middle of the length of the valve; outside the muscular impression the surface is often variously marked by vascular impressions. Dorsal valve gibbous, much more convex than the opposite valve; umbo prominent; outline regularly convex above the middle and curving abruptly to the sides; the usually undefined mesial fold becomes visible below the middle of the valve, and usually very conspicuous toward the front, which is abruptly elevated. Surface marked by concentric lines of growth, the lamellae often closely imbricated and sometimes nearly wanting near the umbo but crowded toward the front of the shell ; well preserved specimens occa- sionally marked by fine interrupted and soaxcely distinct radiating striae. The majority of the Maryland specimens are internal impressions ; but there are a few in which the shell is more or less perfectly preserved. A ventral valve of the latter closely agrees with the more oval form of this species from the Hamilton formation of New York and there are internal impressions very similar to the ventral one figured by Hall from Hardy County, Va.^ The specimens are not so gibbous as those from the cal- careous shales of western Kew York, and perhaps this difference is partly due to crushing in connection with the folding of the Maryland rocks. The species is distinguished by the size, shape, greater convexity of dorsal valve, broad and shallow sinus on anterior part of ventral valve which is often deep near the margin forming a nasute front; conspicuous surface lamellae; and the outline of the muscular impressions on the interior of the valves or internal impressions. Length, 33 mm. ; width, 33 imn. Occurrence. — Eomney Formation, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill; B. & 0. E. E. cut at 31st Bridge; west of iron bridge over Town Creek northeast of Oldtown. Collections.— Karyl3.ni Geological Survey; New York State Museum; American Museum of Natural History. > Pal. N. Y., vol. iv, pi. xlvl, fig. 29. Maryland Geological Suevey 213 Genus MERISTELLA Hall Meristella (?) sp. Plate XXI, Pigs. 3, 4 Description. — Shell ovoid, minute. Ventral valve very gibbons in the umbonal region and along the median line to its front but sloping steeply from this line toward the lateral margins. No evidence of punctate struc- ture and surface smooth with the exception of fine concentric lines and perhaps very fine radiating striae. Dorsal valve ( ?) (associated with the gibbous valve are a number of smaller ones, differently marled which perhaps are dorsal valves of this species), with clearly marked concentric lines of growth, four or five rather indistinct folds and very fine radiating striae. This minute shell was doubtfully referred to the genus Meristella by the writer in the preliminaiy identification and further study has failed in locating it more accurately. He has also availed himself of the kind- ness of Prof. Schuchert and Doctors J. M. Clarke and Grabau — to secure their opinions, given below, regarding tlie systematic position, of these specimens. " I should say that these specimens are of the genus Meristella. There is no punctate shell and therefore not a Centronella. I don't know this shell." Schuchert. "Valve looks like Centronella. Shell texture does not agree therewith. T am not familiar with this shell. Might be called Meristella provisionally." Clarke. " T have been trying to satisfy myself that the small Brachiopod is a Meristella. I don't know what else it can be unless it is a Centronella. It does not compare well with any form I know — may it not be a young Centronella? " Grabau. Length, 3 mm. ; width, about 2 mm. Occurrence. — ^Eomney Foemation-, Maecellus Member. W. Va. Cent. E. E. cut at 31st Bridge. Hamilton Membee. West of iron bridge over Town Creek northeast of Oldtovm ( ?). Collection. — Maryland Geological Survey. 214 Systematic Paleontology — Middle Devonian MOLLUSCA^ Class PELECYPODA Order PRIONODESMACEA Family SOLEMYACIDAE Genus PHTHONIA Hall PlITHONIA BECTIFKONS (Coiirad) Plate XXI, Figs. 5-7 Cypricardites seotifrons Conrad, 1842, Jour. Acad. Nat. Scl., Phila, vol. viii, p. 245, pi. xiil, fig. 8. Phthonia sectifrons Hall, 1870, Prelim. Notice Damelllbranchiata, 2, p. 70. Phthonia sectifrons Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 475, pi. Ixxviii, figs. 10-13. Phthonia sectifrons Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Phthonia sectifrons Clarke, 1903, N. Y. State Mus., Bull. 65, p. 489. Description. — " Shell above the medium size, elongate, subelliptical, somewhat obovate; length more than twice the height measured at the posterior end; basal margin nearly straight in the middle, curving grad- ually at the anterior and more abiTiptly at the posterior end; anterior end short, narrowly rounded ; posterior extremity rounded below, oblique and subtruncate above. Valves depressed, convex along the basal and posterior portions, becoming somewhat gibbous in the middle and above; beaks subanterior, small, low and appressed; umbonal slope obtusely subangular in the upper part; above this, and slightly diverging, is another low ridge extending to the middle of the posterior end. Surface marked by iine concentric striae, and by numerous fine radii extending from the beak to all parts of the shell, which are stronger on the umbonal ridge and anterior end than those on the middle of the shell; at the crossing of the radii and concentric striae, the test is raised into minute elongate nodes." Hall, 1885. A broken external impression of a left valve of this species was found on the Williams Eoad near the Church 3^ miles southeast of Cumberland. It was compared with the type specimens in the office of the N". Y. * Contributed by Charles S. Prosser with the addition of Onondaga species by E. M. Kindle as indicated. Maryland Geological Survey 215 State Paleontologist and is apparently correctly identified. This species is readily distinguished by its elongate form, fine concentric striae and radii with stronger radii on the umbonal ridge and anterior end. Occurrence. — Romnry Formation, Hamilton Member. Williams Road 3| miles southeast of Cumberland. Collections. — ^Maryland Geological Survey; 'New York State Museum; American Museum of Natural History. Family SOLENOPSIDAE Genus PROTHYRIS Meek Pkothykis lanceolata Hall Plate XXI, Figs. 8-10 Prothyris lanceolata Hall, 1883, Pal. N. Y., vol. v, pt. i, plates and expla., pi. Ixxvi, figs. 2-8. Prothyris lanceolata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 460, pi. Ixxvi, flgs. 2-8. Prothyris lanceolata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 492. Prothyris lanceolata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 377, fig. 477e. Description. — Shell of medium size, elongate-lanceolate; length three times the height ; basal margin very gently curving, often nearly straight on the anterior half; posterior extremity pointed, very obliquely truncate above; anterior end truncate, margin reflexed, with a slight constriction behind it and without any conspicuous limiting notch; cardinal line about two-thirds the length of the shell. Valves moderately convex in the posterior part, gibbous in the middle and umbonal portions; beaks subanterior, not prominent, slightly incurved; umbonal slope angular above, extending to the posterior extremity, often merging into the general convexity of the shell bplow the middle; post-cardinal slope narrow, slightly concave. Surface marked by fine concentric striae, which are sometimes somewhat fasciculate, producing gentle undulations. A single good specimen of the right valve of this species was found in the blue shales on the West Virginia bank of the Potomac about three miles south of Cumberland. The species is readily recognized by its elongate lanceolate form, truncate and reflexed anterior margin with a 216 Systematic Paleontology — Middle Devonian slight constriction behind it, angular umbonal ridge and pointed posterior end. Length, 23 mm. ; height, 6 mm. Occurrence. — Eomnby Formation, Hamilton Membee. McCoys Ferry; southwest of McCoys Ferry; west of Lock No. 56 at Great Cacapon ; "W. Va. side Potomac Eiver about 3 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Genus ORTHONOTA Conrad Okthonota undulata Conrad Plate XXI, Figs. 11-13 OrtJionota undutata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 51, fig. 6. Orthonota undulata Vanuxem, 1842, Geol. N. Y., pt. ili, p. 150, flg. 2. OrtJionota undulata Rogers, 1858, Geol. Penna., vol. ii, pt. ii, p. 827, fig. 661. Orthonota undulata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 87. Orthonota undulata Hall, 1885, Pal. N. Y., vol. v, pt. 1, Lamellibranchiata ii, p. 478, pi. Ixxviii, figs. 37-42. Orthonota undulata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 469. Orthonota undulata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 378, fig. 480. Description. — " Shell large, extremely elongate, with parallel dorsal and ventral margins; length three times the greatest height; basal margin nearly straight; slightly constricted anterior to the middle; posterior end somewhat vertically truncated ; anterior end short, extending for a little distance along the hinge-line and abruptly rounded; cardinal line straight, extending for about three-fourths the length of the shell. Valves of moderate convexity ; beaks subanterior small, low, scarcely elevated above the hinge-line ; cincture narrow, distinct, extending from the beak to the basal margin, which is sometimes gently constricted; umbonal ridge prominent, rounded, limited below by a narrow furrow, and extending to the post-inferior extremity ; cardinal slope wide, marked by a distinct fold along the middle of its length. Surface marked by fine concentric striae, which are in some parts crowded and fasciculate on the body of the shell ; marked by distinct undulations upon the anterior end and post-cardinal slope." Hall, 1885. Maryland Geological Survey 217 Several well defined specimens of this species were found in the Hamil- ton shales of Washington County. It is an easily recognized species from its elongate form, parallel dorsal and ventral margins, umhonal ridge and furrow, ridge and furrows on cardinal slope and the conspicuous undula- tions of the anterior end and cardinal slope. Length, 33-45 + mm. ; height, about 12 mm. at posterior extremity. Occurrence. — ^Eomney Formation, Hamilton Member. B. & 0. R. E. cut at Hancock Station, W. Va. Collections. — ^Majyland Geological Survey; ISTew York State Museum; American Museum of I^atural History. OrTHONOTA (?) PARVDLA Hall Plate XXII, Figs. 1, 2 Orthonota parvula Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 88. Orthonota (?) parvula Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 482, pi. Ixv, figs. 2, 3; pi. Ixxviii, figs. 29-32. Orthonota (?) parvula Clarke, 1903, N. Y. State Mus., Bull. 65, p. 468. Description. — "Shell small, elongate subtrapezoidal ; length three times the height; ventral and dorsal margins straight and subparallel; posterior extremity vertically or obliquely truncate below and curving forward above; anterior end narrowly and regularly rounded from the cardinal margin. Valves moderately convex below and posteriorly, becom- ing gibbous in the middle and umbonal regions; beaks at about the anterior fourth, flattened and incurved, rising very little above the hinge- line; umbonal slope angular, extending to the post-inferior extremity; post-cardinal slope flat or slightly concave; sometimes obscurely marked by a depression or fold below the middle. Surface marked by extremely fine, thread-like concentric striae, which are often lamellose on the post- cardinal slope." Hall, 1885. The blue shales of Evitts Creek below Wolfe Mill have furnished a few clearly marked specimens of this easily recognized species, although smaller than the average of those found in Few York. Its most marked characters are the elongate, subtrapezoidal form; straight ventral and dorsal margins; angular umbonal ridge; flat to slightly concave post- 218 Systematic Paleontology — Middle Devonian cardinal slope; and fine surface striae without the undulations of 0. undulata. Length, 10 mm. ; height, 3 mm. Occurrence. — Eomney Formation, Hamilton Membek. East bank Evitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Family GRAMMYSIIDAE Genus GRAMMYSIA de Verneuil Grammysia bisulcata (Conrad) Plate XXII, Pig. 3 Pterinea Msulcata Conrad, 1838, Geol. Surv. N. Y., An. Rep., p. 116. Cypricardites tisulcata Conrad, 1841, Geol. Surv. N. Y., An. Rep. p. 52. Grammysia hamiltonensis de Verneuil, 1847, Bull. Soc. G^ol., France, 2d sgr., tome iv, p. 696. Grammysia iisulcata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 49. Grammysia Msulcata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata 11, p. 359, pi. liv, figs. 1-16; pi. Ivi, fig. 1; pi. xciii, fig. 25. Grammysia Msulcata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Grammysia Msulcata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 397. Grammysia Msulcata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 381, fig. 485b. Description. — " Shell large, ovoid ; length once and a half the height ; basal margin broadly curved; with a constriction near the middle of its length; posterior margin abruptly rounded below and broadly curving or subtruncate above; anterior end abruptly rounded below the deep lunule; cardinal line nearly straight, more than half as long as the shell. Valves regularly convex below and gibbous or ventricose in the middle and above; beaks subanterior, strong, incurved over the cardinal line; umbo prominent, gibbous, with a cincture consisting of a strong fold with a furrow on each side, extending from the beak to the basal margin at about the middle of its length. Surface marked by fine concentric striae, which, on some portions of the shell, are aggregated into fascicles; and by strong persistent concentric ridges or folds, which are stronger upon the anterior part of the shell and distinctly undulated in crossing the cincture." Hall, 1885. Maryland Geological Survey 219 A very m^ich distorted specimen was found at McCoys Ferry in Wash- ington County, which is referred to the above species. The specimens are so badly crushed and poorly preserved that it is not advisable to at- tempt any description. Occurrence. — Romnet Formation, Hamilton Member. McCoys Ferry ; southwest of McCoys Ferry ; on National Road northeast of Cum- berland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Grammysia arcuata (Conrad) Plate XXII, Figs. 4-10 Posidonia ( ?) arcuata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 53. Grammysia arcuata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 56. Grammysia arcuata Hall, 1885, Pal. N. Y., vol. v, pt. 1, Lamellibranchiata ii, p. 373, pi. 1x1, figs. 1-9; pi. Ixiii, fig. 6 ( ?), pi. xciii, fig. 27. Grammysia arcuata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Grammysia arcuata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 396. Grammysia arcuata Clark and Mathews, 1906, Md. Geol. Surv., vol. vi, pi. xvii, fig. 10. Grammysia arcuata Grahau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 383, figs. 486e, f. Description. — "Shell of medium size, ovate; length about one-third greater than the height; basal margin moderately curved, straight or slightly concave along the middle ; posterior extremity regularly rounded ; anterior end varies from regularly and narrowly rounded to obliquely trun- cate below and abruptly rounded above; cardinal line nearly straight, slightly declining posteriorly. Valves regularly convex below and pos- teriorly, becoming gibbous above and in the umbonal region ; beaks suban- terior, large and prominent, inclined forward ; umbonal ridge not defined. Surface marked by fine, close concentric striae and by strong rounded or subangular concentric undulations which are usually continuous from the lunule to the margin of the escutcheon ; these undulations are sometimes duplicated, or others intercalated on the anterior half of the shell, which are thence continuous to the posterior termination." Hall, 1885. 230 Systematic Paleontology — Middle Devonian The Maryland specimens are fragmentary or badly distorted by pres- sure ; but they have the strong undulations with intercalated ones, promi- nent beaks and some of the other characters which characterize this species. Furthermore, the species was identified by Hall from the soft shales of the Hamilton group at Pattersons Creek, [West] Virginia (Pal. N". Y., vol. V, pt. i, Lamellibranchiata II, p. 374). Length, 40 mm. ; height, 20 mm. or more, specimen badly crushed. Occurrence. — Eomney Foiijmation, Hamilton Membek. Town Creek about 6 miles north of Oldtown; Pine Hill 5 miles north of Oldtown; McCoys Perry; southwest of McCoys Perry; Williams .Eoad, 3^ miles southeast of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Geammysia sp. Description. — This genus is represented in the Onondaga of Maryland by a single specimen showing only the anterior portion of a right valve. It represents a species of the same general type as G. subwrcuaia. Occurrence. — Eomney Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Collection. — ^U. S. National Museum. [E. M. Kindle.] Geammysia circdlakis Hall ( ?) Plate XXIII, Pigs. 1-3 Orammysia circularis Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 51. Grammysia circularis Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 364, pi. Ivii, figs. 3-6; pi. Iviii, fig. 13. Orammysia circularis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 398. Grammysia circularis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 383, fig. 486g. Description. — Shell varv'ing from medium to large size, subcircular in outline, ventricose; length about one-fifth greater than the height; basal margin regularly rounded, except a slight sinuosity posterior to the Maryland Geological Survey 221 middle; posterior margin regularly rounded from the post-inferior ex- tremity to the cardinal line which is short and rounded ; anterior end short and narrow, regularly curving from the lunule into the basal inargin. Valves regularly convex along the lower portion, becoming gibbous and ventricose above and in the umbonal region; beaks subanterior, prominent and strongly incurved; the beak and umbo marked by a cincture, consist- ing of a ridge and shallow furrows, which becomes somewhat obsolete on the middle of the valve, but is continued to the basal margin, marking the shell in its passage by an undulation in the striae which produces a slight projection in the center, with a shallow constriction posterior to it and these features alternate in the two valves. Surface marked by fine con- centric striae, which become fasciculate toward the base and on the anterior end, forming distinct ridges or undulations of the surface; no radiating striae have been observed; the hinge has a strongly marked Ugamental area extending half the length of the shell, and a well defined lunule. The species is readily distinguished by its subcircular outline, and absence of a distinct cincture below the middle of the valve. A single, exfoliated, imperfect left valve from the B. & 0. E. E. cut at 21st Bridge is doubtfully referred to this species on account of its general resemblance and marked subcircular outline. It shows fine concentric striae and also distinct undulations which are much more conspicuous on the anterior than the posterior part of the specimen. The outline is too imperfect to give correct proportions; but the speci- men as preserved has a length of about 68 mm. and height of 65 mm. Occurrence. — Eomnby Formation, Hamilton Member. B. & 0. E. E. cut at 21st Bridge; on Hancock-Harrisonville Eoad about 3 miles north of Hancock. Collection. — Maryland Geological Survey. Genus EUTHYDESMA Euthydesma sp. Description. — An indeterminate species of the genus Euthydesma occurs in the Onondaga fauna at Cumberland. 333 Systematic Paleontology — Middle Devonian Occurrence. — Eomney Foemation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Collection. — IT. S. National Museum. [E. M. Kindle.] Genus TELLINOPSIS Hall Tellinopsis subemaeginata (Conrad) Plate XXII, Figs. 11, 13 Nuculites subemarginata Conrad, 1842, Jour. Acad. Nat. Scl., Phila., vol. vlii, p. 249, pi. XV, fig. 5. Tellinopsis subemarginata Hall, 1870, Prelim. Notice Lamellibrancliiata 2, p. 80. Tellinopsis subemarginata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamelli- brancliiata ii, p. 464, pi. Ixxvi, figs. 21-31. Tellinopsis subemarginata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 521. Tellinopsis subemarginata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 386, fig. 488d. Description. — " Shell large, elliptical, subquadrate ; length more than once and a half the height; basal margin straight or gently curving; pos- terior extremity subemarginate in the middle and rounded above and belov, sometimes truncate or rounded with no emargination ; anterior end regularly rounded, large, usually equaling or greater than the posterior half of the shell ; cardinal line gently arcuate. Valves moderately convex below and toward the extremities, becoming gibbous in the middle and umbonal region; beaks subeentral, rather prominent, elevated above the hinge-line and incurved; umbonal slope rounded, distinct, defined above by a depression which is sometimes a furrow extending from the beak to the middle of the posterior margin or below, producing a slight emargi- nation. Surface marked by fine concentric striae, which are sometimes fascicled, producing undulations of the surface, and also by radiating striae which are more or less distinct." Hall, 1885. A few well preserved specimens of this species have been found in the bluish somewhat arenaceous shales of Evitts Creek below Wolfe Mill and on the southern bank of the Potomac Eiver three miles below Cumberland. The flattened space, limited on each side 'by a low ridge, which extends from the anterior side of the umbo to the antero-basal margin of some of Maryland Geological Survey 22Z the New York specimens is but imperfectly shown^ if at all, on these specimens. But the following distinctive characters are present: sub- central beaks ; subemarginate posterior end ; oblique depression extending from the beak to the posterior margin; large rounded anterior end; fine concentric and, on part of the specimens, fine distant radiating striae. Length of three specimens, 22, 30 and 33 mm. ; height, 12, 17, and 20 mm. Occurrence. — ^Romney Formation, Hamilton Member. Williams Eoad, 3 J miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; on Oldtown Eoad, east of Maryland Ave., Cnmberland; W. Va. side Potomac River about 3 miles south of Cumberland. Collections. — Maryland Geological Survey ; New York State Museum ; American Museum of Natural History. Family CARDIOLIDAE Genus PANENKA Banande Panenka alternata Hall Plate XXIV, Fig. 1 Panenka alternata Hall, 1885, New York State Geol. Surv., Paleontology, vol. V, pt. i, Lamelllbr., pp. 416, 417, text fig. 462. Description. — Shell very large, with broadly ovate outline and mod- erately convex. Surface marked by about 40 strong radii which are suba,ngular in the umbonal region but which become broadly rounded or flattened in the posterior and marginal portions of the shell. In the extreme posterior marginal region they are obsolescent. The radii are separated by broad flat interspaces and crossed by very fine concentric striae. The collection contains a single right valve which appears to be identical with the shell figured and described by Hall. Occurrence. — Romnby Formation, Onondaga Member. One mile east of Oldtown. Collection. — U. S. National Museum. [E. M. Kindle.J 324 Ststematic Paleontology — Middle Devonian PANENKA Cf . DICHOTOMA Hall Plate XXIII, Fig. 5 Cardiola ? dichotoma Hall, 1883, Pal. N. Y., vol. v, pt. 1, plates and explana- tions, pi. 70, fig. 21. Fanenka dichotoma Hall, 1885, New York State Geol. Surv., Paleontology, vol. V, pt. i, Lamellibr., p. 416, pi. Ixx, fig. 21; pi. xciv, fig. 13. Description. — A fragmentary right valve -which is shown in the figure is believed to represent this species. The imperfection of the specimen, however, scarcely permits of definite specific determination. Beak prominent, incurved and distinctly directed forward. Surface marked by prominent, rather slender, closely placed plications which occasionally bifurcate. Pine concentric striae cross the plications. Occurrence. — Romnet Formation, Onondaga Member. One mile east of Oldtown. Collection. — U. S. National Museum. [E. M. Kindle.J Panenea obsolescens n. sp. Plate XXIV, Figs. 3, 3 Description.— ^hsW. large, broadly ovate, depressed convex, length ex- ceeding the height. Pallia! margin regularly rounded from the anterior to the middle of the posterior end whence it extends in a nearly straight line to the hinge-line, curving slightly fo^rward before reaching it. Hinge- line long and straight. Surface marked by fine concentric striae and numerous radii which become obsolescent in the posterior third of the shell. The resulting smooth, nearly flat posterior third of the shell, together with the nearly straight upper half of the posterior margin nearly vertical to the hinge-line, are the distinctive features of the species which sharply distinguish it from any other shell known to the author. The species is represented by a single right valve; this has the beak broken away so that its shape and extension as suggested by the line in the figure can only be inferred. Occurrence. — Eomnet Formation, Onondaga Member. One mile east of Oldtown in cut of Western Maryland Eailroad. Collection. — U. S. National Museum. [E. M. Kindle.] Maryland Geological Suevey 225 PaNENKA ef. MULTIRADIATA Hall Plate XXIII, Pig. 11 Panenka multiradiata Hall, 1885, Pal. N. Y., vol. v, pt. i, p. 417, pi. Ixix, fig. 5; pi. xciv, fig. 18. Description. — Shell large, subcircular or broadly ovate; length greater than the height. Pallial margin regularly rounded from the anterior to the middle of the posterior end, whence it is a little more abruptly curving to the post-cardinal extremity. Anterior end short and regularly rounded. Posterior end expanded. Valves regularly convex below, becoming gib- bous or ventricose in the middle and above. Hinge-line short, straight, ligamental area short and high. Test thin. Surface marked by nimier- ous, closely arranged, flattened or convex radii. Hall, 1885. Occurrence. — ^Eomney Poemation, Onondaga Member. One mile east of Oldtown in cut of Western Maryland Eailroad. Collection. — U. S. National Museum. [E. M. Kindle.] Family PRAECARDIIDAE Genus BUCHIOLA Barrande BuoHiOLA HALLi Clarke Plate XXIII, Pig. 4 Glyptocardia speciosa Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, pi. Ixx, fig. 9; pi. Ixxx, fig. 10. ' BucMola halli Clarke, 1904, N. Y. State Mus., Mem. vi, pt. 2, p. 301, pi. x, figs. 15, 16. Description. — Shell rather small, length greater than the height so that the valve is somewhat elliptical in outliae, basal margin regularly curving, convexity regular and greater toward the beak. Surface marked by 11 or 12 broad plications, i mm. in width on the median portion of the shell, which are limited laterally by an angular slightly raised ridge; the plications are crossed by conspicuous striated raised ridges which are not so strong on the lateral margins and fail toward the basal one, while the ridges are separated by depressions; between the plications are slightly narrower, smooth evenly rounded furrows which show no indication of the 15 336 Systematic Paleontology — Middle Devonian conspicuous concentric ridges of the plications, the character which dis- tinguishes this species from the other Buchiolas. Length, 7 mm. ; height, 6 mm. Occurrence. — Eomney Formation, Hamilton Mbmbee. East bank Evitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey ; American Museum of Nat- ural History. BUCHIOLA RETEOSTEIATA (vOn Buch)' Occurrence. — Eomney Formation, Marcellus Member. 31st Bridge. Collection. — U. S. National Museum. [E. M. Kindle.] Superfamily NUCULACEA Family NUCULIDAE Genus NUCULA Lamarck NUCULA COEBULIFORMIS Hall Plate XXIII, Figs. 6-10 Nucula coriuliformis Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 2. Nucula corbuUformis Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata il, p. 319, pi. xlvi, flgs. (10, 11 ?), 24-34 (35-37 ?). Nucula corluliformis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 460. Nucula corhuliformis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 396, fig. 503f. Description. — " Shell of medium size, or smaller, broadly triangular, subovate; length about one-fourth greater than the height; basal margin broadly curving, more abruptly rounded at the posterior extremity; an- terior end sloping rapidly from the beaks and rounded below; posterior end longer and more pointed; cardinal line declining from the beaks in both directions. Valves convex, gibbous in the umbonal region; beaks usually at about the anterior third, sometimes subcentral, short, moder- ately elevated, broad and slightly incurved; umbonal slope not distinctly ' For description and synonymy of this species see page 613. Maryland Geological Survey 221! defined, rounded, direct, extending to the post basal extremity. Surface marked by very fine concentric striae, and by irregular varices of growth, which sometimes produce strong undulations in the surface of the shell." Hall, 1885. This is one of the most abundant species of Nucula found in Mary- land and most of the variations represented by the figures of the JSTew York specimens occur. The larger specimens from the arenaceous shales of Evitts Creek below Wolfe Mill are somewhat flattened and show promi- nent varices of growth between which are the fine concentric striae; while specimens from the West Virginia side of the Potomac Eiver three miles below Cumberland are rather smaller, not compressed and quite gibbous in the umbonal region. This species is readily identified from the posi- tion of the beaks, its subequilateral triangular form, fine concentric striae and irregular varices. Length, 10-19 mm. ; height, 8^-15 mm. Occurrence. — Eomney FoiiMATiON^ Hamilton Member. B. & 0. E. E. cut at aist Bridge; W. Va. Cent. E. E. cut at 21st Bridge. Williams Eoad, 3% miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; in Jennings Eun % mile west of Corriganville ; on east side Wamor Mt. east of Eush ; on Oldtown Eoad east of Maryland Ave., Cum- berland; McCoys Perry; southwest of McCoys Ferry; on Hancock-Har- risonville Eoad about 2 miles north of Hancock; Ernstville; W. Va. side Potomac Eiver 3 and 4 miles south of Cumberland ; on Eomney-Hanging Eock Eoad about i/^ mile north of Eomney, W. Va. ( ?) ; hill 3 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. NucfJLA bellistriata (Conrad) Plate XXV, Eigs. 1-5 Nuculites bellastriata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 40. Nucula bellastriata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 2. Nucula bellistriata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibrancliiata ii, p. 318, pi. xlvi, figs. 1-9. 228 Systematic Paleontology — Middle Devonian Nucula lenistriatiis Clarke, 1903, N. Y. State Mus., Bull. 6B, p. 459. Nucula belUstriata Grabau and Shlmer, 1909, N. Am. Index Fossils, vol. 1, p. 395. fig. 503e. Description. — " Shell of medium size, broadly ovate, usually somewliat wider behiad; length about one-fourth greater than the height; basal margin regularly curving; posterior end broad and rounded; anterior end short, declining rapidly from the beaks, and abruptly rounded below ; cardinal line oblique and arcuate. Valves convex, gibbous on the umbo; beaks at about the anterior fourth, appressed, rising above the hinge-liae, directed forward ; umbonal slope rounded, extending from the beaks in an arching direction, to above the post-basal extremity. Surface marked by fine, regular, sharp, concentric striae, which do not appear to be aggre- gated into fascicles, but are sometimes interrupted, and the surface undulated by strong varices of growth." Hall, 1885. The Maryland specimens are mostly somewhat smaller than the figured specimens from New York and again their proportionate length is hardly so great. Still it is thought that they belong to this species which is distinguished by its outline, position of the beak and regular concentric striae, while some of the specimens show varices of growth as represented on figs. 2, 6 and 7 of pi. xlvi of the Palaeontology of New York. The internal impression represented by figures 4 and 5 was identified as this species by Dr. Grabau, and it is essentially smooth with the exception of the conspicuous anterior and posterior muscular impressions which are somewhat wrinkled, the beaks are distant and a thin sharp ridge marks the hinge-line from the anterior to the posterior muscular impression. Length, 7-15 mm. ; height, 6-12 mm. Occurrence. — Eomney Formation.. PIamilton Member. B. & 0. R. E. cut at 21st Bridge ( ?) . Williams Eoad, i^ mile east of Queen City Hotel, Cumberland; on National Eoad, 14 mile west of Tonoloway Eidge; on Oldtown Eoad, east of Maryland Ave., Cumberland; east bank of Evitts Creek below Wolfe Mill; along Plintstone Creek in Gilpin; 1 mile north of Eomney, W. Va. . Collections. — Maryland Geological Survey ; New York State Museum ; American Museum of Natural History. Maryland Geological Survey 239 NoouLA LiRATA (Coiirad) Plate XXV, Pigs. 6-8 and 9, 10 ( ?) NucuUtes lirata Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, p. 250, pi. XV, fig. 7. Nucula lirata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 3. Nucula lirata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 316, pi. xlv, figs. 5, 11, 15, 17-22, 24, 25; pi. xciii, flg. 5. Nucula lirata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 462. Nucula lirata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 395, flg. 503d. Description. — "Shell of medium size, ovate-triangular; length from one-third to one-fourth greater than the height; basal margin regularly curving, more abruptly rounded at the posterior extremity; cardinal margin slightly arcuate, gradually sloping toward the posterior; anterior end short, subtruncate, usually abruptly rounded. Valves very gibbous, ventricose in the umbonal region; bealcs, at the anterior third or fourth of the length of the shell, distant, elevated, rising considerably above the hinge-line; umbo very prominent. Test thick, marked by regular, strong, subangular concentric undulations, which are crossed by extremely fine radiating striae." Hall, 1885. This species is represented by but few specimens in Maryland ; but one from the bank of Evitts Creek below Wolfe Mill, has the shape of this species; its heavy concentric undulations, part of which show fine con- centric striae on their surface; while the best preserved portions of the shell show the veij fine radiating striae. There are internal impressions from western Marjdand and, Pattersons Creek, West Virginia, which apparently belong to this species. The complete impression is much thicker than that of N. iellistriata, and the muscular impressions al- though larger are smooth and scarcely so prominent. It is difficult to determine whether these iatemal impressions belong to N. lirata or N. randalli and one was sent to Dr. Grabau who wrote " I should prefer N. lirata but it is very difficult to decide. The form agrees better with that species." It is to be remembered, however, that Hall figured a much larger and more gibbous specimen than any of these, which is given as N. 330 Systematic Paleontology — Middle Devonian randaUi from Cumberland/ and this specimen is represented as having smooth muscular impressions while fig. 35 of the same plate represents an internal impression of N. Urata with striated posterior muscular im- pressions. This species is readily distinguished from the associated ones by the strong concentric undulations and fine radiating striae. Length, 15 mm. ; height, 11 mm. Ocawrrence. — Eomney Formation, Hamilton Membee. East bank Evitts Creek below Wolfe Mill. Collections.— KsxjVdJiA. Geological Survey; New York State Museum; American Museum of jSTatural History. Nuoula vaeicosa Hall Plate XXV, Eigs. 11-16 Nucula varicosa Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 2. Nucula varicosa Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 319, pi. xlvi, figs. 12-23; pi. xciii, fig. 4. Nucula varicosa Clarke, 1903, N. Y. State Mus., Bull. 65, p. 463. Description. — Shell of medium size, ovate- triangular ; length somewhat greater than the height; basal margin curving, more abruptly rounded posteriorly; post-cardinal margin arcuate or subtruncate; anterior end very short and abruptly rounded below. Valves gibbous, ventricose in the umbonal region. Beaks subanterior, prominent, incurved, arching over the hinge-line. Umbonal slope narrowly rounded, axehing upward and extending from the beaks to the post-basal extremity; post-cardinal slope narrow. Test strong, marked by fine, irregular, concentric striae, and by numerous varices of growth, which are closely arranged on the marginal portions of the shell. Hinge strong, and posterior to the beaks it is marked by a narrow row of very fine transverse teeth. Specimens vary in length from 15-18 mm.; and in height from 13-16 mm. Hall, 1885, condensed. The varices of these specimens are not quite so strong as on the type specimens of this species nor the beaks as high, yet they are higher than ^Pal. N. Y., vol. V, pt. i, Lamellibranchiata il, explanation figures 26 and 27 of plate 45. Maryland Geological Survey 831 in N. iellistriata. On comparison with specimens of N. varicosa in the office of the "New York State Paleontologist they were found to be very- similar and therefore are referred to this species. This species is closely related to N. iellistriata (Con.) ; but is distinguished by its more erect and triangular form, higher beaks, finer concentric striae and numerous strong varices of growth. Length, 14-18 mm. ; height, 11-13 mm. Occurrence. — Eomney PoRirATiO]sr, Hamilton Member. East bank Bvitts Creek below Wolfe Mill; and from another place in western Mary- land the exact locality of which is not stated; on the Eomney-Hanging Eock Eoad about ^ mile north of Eomney, W. Va. ( ?) . Collections. — Maryland Geological Survey; New York State Museum. Genus NUCULITES Conrad NuouLiTES OBLONGATUS Conrad Plate XXV, Pigs. 17-20 Nuculites oblongatus Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 50, plate, fig. 8. Nuculites oilongatus Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 4. Nuculites oblongatus Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 324, pi. xlvii, flgs. 1-12. Nuculites oblongatus Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Nuculites oblongatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 465. Nuculites oblongatus Grahau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 398, figs. 509a-c. Description. — Shell large, elongate ovate, widest at the anterior end; length usually more than twice the height; basal margin nearly straight, sometimes gently arcuate; posterior extremity abruptly rounded; cardinal line slightly oblique, gently arcuate; anterior end short and rounded and in the inside is a strong vertical clavicular ridge just anterior to the beaks which extends for more than half the height of the shell and in the internal impressions is represented by a strong furrow. Valves depressed- convex in the lower and posterior portions, more convex on the anterior end and in the umbonal region ; beaks at about the anterior fourth, ap- pressed, not rising above the hinge-line ; umbonal slope broadly rounded and undefined. Test thick in the upper part of the shell ; surface marked 333 Systematic Paleontology — Middle Devonian by very fine concentric striae, which axe sometimes slightly fasciculate on the lower portion of the shell ; hinge furnished with numerous transverse teeth. This species is common in the Hamilton shales of Maryland and is represented by various forms from the short young specimens up to the adult ones of normal size and shape as well as by some very elongated specimens due to crushing. Hall reported this species from the Hamilton formation at Pattersons Creek, [W.] Va. (Pal. N. Y., vol v, pt. i, Lamel- libranchiata, ii, p. 325) and on pi. xlvii, figs. 7, 11 and 13 are stated to be from the Hamilton group, near Cumberland, Md. This species is readily recognized from its elongate ovate outline, widest at the anterior end, and by the strong vertical clavicle in the interior of the shell or its impression in the internal mould. Length, 10-33 mm.; height, 5-11 mm. One elongated specimen is 33 mm. in length. Occurrence. — Eomney' Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill ; Williams Eoad I mile east of Queen City Hotel, Cumberland; on National Eoad ^ mile west of Tonoloway Eidge; on Oldtown Eoad east of Maryland Ave., Cumberland; McCoys Ferry; southwest of McCoys Ferry ; Ernstville ; on ISTational Eoad northeast of Cumberland ; along Flintstone Creek in Gilpin ; west of iron bridge over Town Creek northeast of Oldtown; W. Va. side Potomac Eiver 4 miles south of Cumberland ; hill 3 miles south of Cumberland. Co ZZecfiow^.— Maryland Geological Survey; New York State Museum; American Museum of Natural History. NucuLiTES TRiQUETEE Conrad Plate XXVI, Figs. 1-5 Nuculites triqueter Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 50. Nuculites triqueter Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 4. Nuculites triqueter Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata, ii, p. 326, pi. xlvii, figs. 17-28; pi. xciii, figs. 8-10. Nuculites triqueter Clarke, 1903, N. Y. State Mus., Bull. 65, p. 466. Nuculites triqueter Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1, p. 398, figs. 509d-f. Maryland Geological Survey 233 Description. — Shell of mediTim size, or larger, trigonal, short; length greater than the height; basal margin regularly curving, sometimes straight on the posterior portion, abruptly rounded at both extremities; posterior margin obliquely truncate; anterior end short, rounded; cardinal margin arcuate. Valves convex, gibbous in the middle and above; beaks at the anterior third or fourth, very prominent, incurved, arching over the hinge ; umbo prominent and gibbous ; umbonal ridge distinct, subangular, extending from the beak to the post-inferior extremity; post-cardinal slope short, descending abruptly from the angular umbonal ridge to the obliquely truncate posterior margin. Test thin, marked by very fine concentric striae; hinge comparatively short, furnished with more than twenty small teeth, which are continued in a row under the beaks without interruption; muscular scars faintly marked; clavicular ridge very strong, sharply defined and curved. This species is common in the bluish somewhat arenaceous Hamilton shales of Maryland and West Virginia in which the various forms have been obtained. It was reported by Hall from the Hamilton group " at Pattersons Creek, [W.] Virginia " (Pal. N". Y., vol. v, pt. i, Lamellibran- chiata ii, p. 337) and on pi. xlvii a cast of the left valve is figured from the Hamilton group at Cumberland, Md. This is a very clearly defined species and is readily recognized from its short trigonal outline; obliquely truncate posterior margin and short abrupt post-cardinal slope; sub- angular, distinct umbonal ridge; and by the strong, sharply-defined and curved clavicular ridge which in the internal impressions is represented by the conspicuous, deep and curved furrow. Length, 9J-16 mm. ; height, 8-14 mm. ; depth, 4-11 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; W. Va. Cent. E. E. cut at 21st Bridge; B. & 0. E. E. cut at 21st Bridge; Williams Eoad 3l^ miles southeast of Cumberland; McCoys Perry; southwest of McCoys Perry; along Flint- stone Creek in Gilpin ; W. Va. side Potomac Eiver 3 and 4 miles south of Cumberland ; hill about 3 miles south of Cumberland. Collections.— MaxyUni Geological Siirvey; New York State Museum; American Museum of Natural History. 334 Systematic Paleontology — Middle Devonian NUOULITES GKABAUI n. sp. Plate XXVI, Pig. 6 Description. — Shell rather less than medium size, cimeiform, widest along line extending from beak to basal margin, pointed posteriorly; length considerably less than twice the height; anterior end of shell rounded, basal margin and cardinal line of posterior part of shell strongly inclined toward each other so that the posterior half of the shell is de- cidedly pointed. Valve depressed-convex in the lower and posterior por- tions and only moderately convex in the umbonal region ; beak subcentral, six mm. from the anterior and nine mm. from the posterior extremity; just anterior to the beak is a broad and prominent clavicular ridge which extends two-thirds of the distance across the shell, curving slightly toward the anterior end. The above description was based upon a single internal impression of a right valve from McCoys Perry and consequently nothing is known regard- ing the surface markings of the species. Its more nearly central beak and pointed posterior end separate it from N. ollongatus; while its flatness, lack of angular umbonal ridge and more central beak distinguish it from N. cuneiformis. The writer hesitated to describe this specimen as a new species therefore consulted Dr. Grabau who wrote as follows : " Why not a new species? Its beak is too central to agree with N. ollongatus and of course you have not much more to go on. Still I think you are safe in giving it a new specific name." In view of the above statement it is described as a new species and named in honor of Dr. Grabau. Later, additional specimens were found southwest of McCoys Ferry. Length, 16 mm.; height, 9^ mm. Occurrence. — Eomney Pormation, Hamilton Member. McCoys Perry ; southwest of McCoys Perry. Collection. — Maryland Geological Survey. ISTucuLiTES modulatus Kindle Plate XXVI, Pigs. 7, 8 Nuculites modulatus Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 89, pi. vil, figs. 13, 14. Maryland Geological Suevbt 335 Description. — Shell elongate, oval, length usually about two-thirds the width. Cardinal lines nearly straight or slightly arcuate. Basal margin regularly arcuate, anterior and posterior naargins broadly rounded. A nearly vertical clavicle extends from the hinge-line just anterior to the beaks two-thirds the distance to the basal margin. Valves moderately convex in the umbonal region, less convex in the lower and posterior portions. Beaks anteriorly placed, appressed and not rising above the hinge-line. Umbonal slope undefined and broadly rounded blending with the depressed posterior border. Transverse teeth slightly arched, with the crest toward the beak. Surface marked by fine con- centric striae. Three specimens measure respectively 7, 8, and 8 mm. in length, and 11, 14 and 13 mm. in height. This species is rather closely allied to Nuculites ohlongus from the Hamilton. It is distinguished from this shell, however, by the greater proportional width, the broader, more regularly rounded, posterior margin, and the less pronounced umbonal slope. Occurrence. — Eomnet Poemation, Ononoaga Member. Williams Eoad, 3% miles southeast of Cumberland. Collection. — U. S. National Museum. [E. M. Kindle.] Family LEDIDAE Genus PALAEONEILO Hall Palaeoneilo con-stricta (Conrad) Plate XXVI, Figs. 9-13 Nuculites constricta Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, p. 249, pi. XV, flg. 8. Nucula lellatula Hall, 1843, Geol. N. Y., pt. iv, p. 197, flg. 7 on p. 196. Palaeoneilo constricta Hall, 1870, Prelim. Notice Lamellibranchlata 2, p.- 7. Palaeoneilo constricta Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibrancliiata ii, p. 333, pi. xlviii, figs. 1-16; pi. 11, flg. 17. Palaeoneilo constricta Clarke, 1903, N. Y. State Mus., Bull. 65, p. 474. Palaeoneilo constricta Clarke, 1904, N. Y. State Mua., Mem. 6, pt. 2, p. 311, pi. XV, figs. 9-13. Palaenoeilo constricta Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 400, figs. 510a, b. 236 Systematic Paleontology — ^Middle Deivonlai?^ Description. — Shell of medium size or smaller; ovate-cuneate, sub- nasute behind; proportions of length and height variable but the length usually about one-third greater; basal margin rounded in the middle and at anterior end, straight or slightly constricted toward the posterior end; anterior end abruptly rounded; posterior extremity contracted, cuneate or subnasute, constricted below ; cardinal line abruptly declining anterior to the beak, and more gently declining to the posterior. Valves convex below and posteriorly, becoming gibbous above the middle and in the umbonal region ; beaks at about the anterior third, prominent, rising above the hinge-line; umbonal ridge rounded, not strongly defined, with a de- pression or undefined furrow below it, which extends from immediately posterior to the beak to the post-inferior margin. Surface, in well pre- served specimens, marked by fine, regular and even, thread-like striae, which frequently become obsolescent in the furrow and on the post- cardinal slope; hinge marked by numerous crenulations, which are coarser toward the anterior and posterior extremities. A considerable number of well preserved, typical specimens of this' species were obtained in the bluish finely arenaceous shales of the Hamil- ton beds in Maryland. This species was also identified by Hall from the Hamilton group of " Pattersons Creek, [W.] Va." (Pal. N". Y., vol. v, pt. i, Lamellibranchiata ii, p. 334) while figures 9 and 14 of plate xlviii are stated to be from the Hamilton group, near Cumberland, Md. This species is readily identified by its constricted and projecting posterior end, its form, and fine, regular, even, thread-like striae which axe much fainter or obsolete on the posterior part of the shell. E. M. Elindle makes the following statement concerning specimens found in the Onondaga member : A PalaeoneUo having apparently most of the essential characters of P. constricta occurs in the same bed with numerous specimens of Chonetes mucronatus. It has the constricted postero-basal margin of that species and fine concentric striae but is rather more gibbous in the umbonal region than ordinary examples of P. constricta. Length, 13-17 mm. ; height, 9-11 mm. Occurrence. — Romney Fo'rmation, Onondaga Member. Williams Eoad, 3y2 miles southeast of Cumberland. Hamilton Member. East Maryland. Geological Survey 237 bank Evitts Creek below Wolfe Mill ; Williams Road 14 mile east of Queen City Hotel, Cumberland; B. & 0. R. E. cut at 31st Bridge ; Williams Road 3^ miles southeast of Cumberland; McCoys Perry; southwest of McCoys Perry; on National Road northeast of Cumberland; on the Romney- Hanging Rock Road about i mile north of Romney, W. Va. ; 1 mile north of Romney, W. Va. Collections. — ^Maryland Geological Survey; New York State Museum; American Museum of Natural History. Palaeoneilo plana Hall Plate XXVI, Pigs. 13-15 Palaeoneilo plana Hall, 1870, Prelim. Notice Lamellibranohiata 2, p. 7. Palaeoneilo plana Hall, 1885, Pal. N. Y., vol. v, pt. 1, Lamellibranchiata ii, p. 334, pi. xlviii, figs. 21-28. Palaeoneilo plana Clarke, 1903, N. Y. State Mus., Bull. 65, p. 478. Palaeoneilo plana Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 399, fig. 510f. Description. — " Shell below the medium size, transversely elliptical, compressed, elongate and somewhat pointed behind ; length almost twice the height; basal margin regularly and gently rounded, with a slight and undefined constriction near the posterior end which is acutely rounded ; anterior end regularly rounded ; cardinal line declining on each side of the beak. Valves depressed-convex; beaks anterior to the center, small, rising but little above the hinge-line; umbonal slope not defined, obscurely indicated by an undefined depression, which scarcely constricts the margin. Surface marked by very fine concentric striae, which are often obscure or obsolete." Hall, 1885. Several specimens of a small Palaeoneilo were found in rather thin blue shales which agree fairly well with the above description and are referred to this species. Part of the specimens are smaller than the type ones of P. plama but agree closely with the outlines and proportions of that species. One specimen resembles very closely fig. 21, pi. xlviii, Lamelli- branchiata ii, pt. i, vol. v. Pal. N. Y., with the exception of the posterior constriction which is slightly stronger than in this species and in this character something like P. constricta. The species is closely related to 238 Systematic Paleontology— tMiddlb Devonian P. consiricta Hall but as stated by Hall it is distinguished by its delicate texture, smaller size, more elongate form, and more central beaks. Length, of the smaller specimens, 11 mm. ; height, 6 mm. A larger specimen which is referred to this species is 22 mm. in length and 12 mm. in height. Occurrence. — Eomney Pokmation, Hamilton Membek. East bank Evitts Creek below Wolfe Mill; W. Va. side Potomac Eiver about 3 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Palaeoneilo maxima (Conrad) (?) Plate XXVI, Fig. 16 Nuculites maxima Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 50. Tellina (?) ovata Hall, 1843, Geol. N. Y., pt. iv, p. 196, fig. 6. Palaeoneila maxima Hall, 1870, Prelim. Notice Lamellibrancliiata 2, p. 9. Palaeoneilo maxima Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibrancliiata ii, p. 335, pi. xlviii, figs. 29-38. Description. — "Shell large, ovate-acute; length one-half greater than the height; basal margin very convex in the middle, curving regularly to the anterior end ; posterior extremity narrow and abruptly rounded, or subtruncate at the termination; anterior end somewhat narrowly rounded; cardinal line declining rapidly on either side of the beak. Valves regu- larly convex below, becoming gibbous in the middle and above; beaks anterior to the center, prominent, small, with the apices very slightly incurved ; umbonal ridge distinct, subangular, extending to the upper side of the posterior extremity; the furrow below is broad, obscure and unde- fined. Surface marked by fine concentric striae, which are often very obscure or obsolescent." Hall, 1885. A left valve of this species was obtained from the blue shales of Evitts Creek below Wolfe Mill, which agrees closely with the above description; but the posterior constriction is rather sharper than on specimens of this species in the ofiBce of the N. Y. State Paleontologist. The specimen was shown Dr. J. M. Clarke who suggests that it be compared with both P. Mahtland Geological Survey 339 maxima and P. constricta. Dr. Grabau refers it to P. maxima (?). Observing that " the sulcus is a trifle stronger than usual in this species and more like that of P. constricta." The species is characterized by its size, very gibbous form, abruptly contracted posterior end and rather obscure concentric striae. Length, 24 mm. ; height, 15 mm. Occurrence. — Eomney Formation-, Hamilton Member. Evitts Creek below Wolfe Mill. Collection. — Maryland Geological Survey. Palaeoneilo eeounda Hall Plate XXVI, Figs. 18-21 Palaeoneilo fecutida Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 8. Palaeoneilo fecunda Hall, 1885, Pal. N. Y., vol. v, pt. J, Lamellibranchiata ii, p. 336, pi. xlix, figs. 13, 15-24. Palaeoneilo fecunda Keyes, 1891, Johns Hopkins TJniv. Giro., vol. xi, p. 29. Palaeoneilo fecunda Clarke, 1903, N. Y. State Mus., Bull. 65, p. 476. Palaeoneilo fecunda Grabau and Shlmer, 1909, N. Am. Index Fossils, vol. 1, p. 399, figs. 510k, 1. Description. — "Shell large, elongate-ovate; length nearly twice the height; basal margin broadly curving; posterior end obtusely rounded or doubly truncate; anterior end regularly rounded; cardinal line arcuate. Valves regularly convex below, gibbous above and in the umbonal region ; beaks at less than the anterior third from the end, moderately elevated above the hinge-line; umbonal slope flattened, giving a slight angularity to the shell above and below it, and an oblique truncation to the posterior extremity. Test thick, marked in the anterior portion by fine, regular concentric striae, some of which become elevated into sharp, lamelliform striae, with finer intermediate ones on the posterior half of the shell." Hall, 1885. A left valve of this species was found on the Williams Koad one-fourth mile east of the Queen City Hotel and Hall figured several specimens from the Hamilton group, near Cumberland, Md. (Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, pi. xlix, figs. 18-24) and also reported it from Hardy County [W.] Virginia (iUd., p. 337). The specimen repre- 340 Systematic Paleontology — Middle Devonian sented by fig. 18 on pi. xlix from the vicinity of Cumberland is rather shorter than the majority of specimens of this species and it is almost of the same size and proportions as the Williams Eoad specimen. This species is closely related to P. tenidstriata Hall and P. muta Hall but is separated by its fine concentric striae, some of which become elevated into sharp lamellae, with finer intermediate ones on the posterior part of the shell. The striae of P. tenidstriata as compared with P. fecunda are finer and more irregular becoming crowded together on the posterior part of the shell, while in P. muta the strong, lamellose striae extend from the posterior to the anterior margin of the shell. Length, 25 mm. ; height, 16 mm. Occurrence. — ^Eomnby Formation, Hamilton Member. Williams Eoad i mile east of Queen City Hotel, Cumberland. Collections. — Maryland Geological Survey; Kew York State Museum. Palaeonmlo peeplana vae. grabadi n. var. Plate XXVI, Figs. 32, 33 Description. — Shell rather large, length less than twice the height; basal margin curving; umbonal slope marked by two ridges separated by a conspicuous sulcus. Entire surface marked with regular, strong, ele- vated lamellae extending from the anterior to the posterior extremities, between which are fine striae. The specimen upon which the above description is based is an external impression of a right valve which is broken and somewhat imperfectly preserved. It differs clearly from P- perplana in the conspicuous lamellae extending entirely across the shell from its anterior to the posterior end while in that species they " are usually obsolete, except on the posterior portion of the shell." ' N'either does it agree an.y more closely with any other species. Professor Grabau who examined the specimen wrote me as follows : " It comes nearest to P. perplana of the New York beds, but is more rugose and has a somewhat deeper umbonal channel, though I think much of the apparent depth of this is due to crushing. It would • Hall, Lamellibranehiata ii, p. 339. Maryland Geological Survey 241 seem to me like an accelerated derivative from perplana in which the adult coarse concentric lamellae of P. perplana appear early and become accentuated by the time adult conditions are reached in this specimen. I think you are safe in giving it a varietal name. It corresponds closely with no species I know." Length, 33^ mm. ; height, 15J mm. Occurrence. — Eomney Formation, Hamilton Member. Bvitts Creek below Wolfe Mill. Collection. — Maryland Geological Survey. Palaeoneilo emarginata (Conrad) Plate XXVII, Figs. 1-6 NucuHtes emarginata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 50. Palaeoneilo emarginata Hall, 1870, Prelim. Notice Lamelllbranchiata 2, p. 7. Palaeoneilo emarginata Hall, 1885, Pal. N. Y., vol. v, pt. 1, Lamelllbranchiata 11, p. 338, pi. 1, figs. 1-11. Palaeoneilo emarginata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 475. Palaeoneilo emarginata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 400, figs. 510m-p. Description. — "Shell of medium size or larger, subelliptical ; length usually more than twice the height; basal margin gently curving or nearly straight from the post-inferior angle to the anterior end, where it is more abruptly rounded; posterior margin deeply sinuate; anterior end regularly and somewhat abruptly rounded; cardinal line gently arcuate. Valves regularly convex in the lower anterior half, becoming gibbous above; beaks at a little less than the anterior third from the end; umbonal slope marked by a strong elevation or ridge, with a: depression above it, which produces a marked emargination ; the post-cardinal extremity, above this, is produced into a linguiform extension, which is sometimes angular, but usually abruptly rounded at the termination. Surface marked by strong, elevated, distant, lamellose, concentric ridges, extending the entire length of the shelly between which are very fine concentric striae; the intermediate striae become obscure or obsolete, according to the degree of weathering and nature of the matrix." Hall, 1885. 16 243 Systematic Paleontology — ^Middle Devonian A considerable number of specimens of this species were obtained from the Hamilton shales of Maryland. Hall identified the species from the Hamilton group, near Cumberland, Md. (Pal. F. Y., vol. v, pt. i, Lamel- libranchiata ii, p. 339) and the Maryland specimens agree fully with the figures of the New York specimens. This is a sharply differentiated species and is distinguished by its deeply emarginate posterior margin; strong, elevated, distant, lamelliform concentric striae, with finer striae between; strong umbonal ridge, with depression above it and broad con- spicuously marked sinus below. Length, 16-30 mm.; height, 7-11 mm. Occurrence. — -Eomney Formation, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill ; Williams Eoad | mile east of Queen City Hotel, Cumberland; Williams Eoad J mile east of Queen City Hotel, Cumberland; B. & 0. E. E. cut at 31st Bridge; McCoys Perry; south- west of McCoys Perry. Collections. — Maryland Geological Survey; Kew York State Museum; American Museum of Natural History. Palaeoneilo tenuistriata Hall (?) Plate XXVII, Fig. 7 Palaeoneilo tenuistriata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 9. Palaeoneilo tenuistriata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranclilata ii, p. 336, pi. xlix, figs. 1-12, 14, pi. xciii, fig. 13. Palaeoneilo tenuistriata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Palaeoneilo tenuistriata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 479. Palaeoneilo tenuistriata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 399, fig. 510c. Description. — Shell large, ovate-elliptical; length more than one-third greater than the height; basal margin regularly curving; posterior end doubly truncate; cardinal line gently arcuate; anterior end short, rounded. Valves convex, gibbous above the middle and in the umbonal region; beaks at about the anterior third, moderately prominent, nearly straight, little elevated above the hinge-line; the posterior end of the shell is de- pressed-convex, with a more or less distinct depression extending to the post-inferior extremity from just posterior to the beaks, giving a trunca- Maeyland Geological Survey g4a tion and slight constriction of the margin. Test thick, especially in the dorsal region; surface marked by very fine concentric striae, which are often crowded together on the basal and posterior portions of the shell, forming irregular undulations of growth; in some well-preserved speci- mens the concentric striae are elevated into sharp lamellae. A specimen of average size has apparently about the following dimensions: length, 33 mm. and height, 19 mm. The Maryland Collection contains a rather imperfect and worn speci- men which is referred with some hesitation to this species. The length in comparison with the height is less than that in normal specimens of P tenuistriata; but it shows similar fine concentric striae with heavier lines of growth toward the margin and the general appearance is quite near that of the larger forms of this species. The specimen was examined by Dr. Grabau who wrote as follows: "Agrees well with P. constricta in anterior position of beak but does not agree absolutely with any of the New York types. Except for the less proportional length it would agree fairly well with P. temiistriata. Should be tempted to call it a short variety of that species." Another specimen of what appears to be a large Palaeoneilo from Evitts Creek is referred with doubt to this species. Dr. Grabau examined the specimen and wrote "P. tenuistriata perhaps. It has outline more of Elymella cf. nuculoides Hall and sulcus is weak, this may be due to pres- sure however." It is to be remembered that Hall figured a specimen of this species from "near Cumberland, Md.," and also reported it from " Pattersons Creek, [W.] Va." ' Length of specimen from McCoys Ferry, 33 -f mm. ; height, 23 mm. Length of specimen from Evitts Creek, 40 mm. ; height, 27 mm. Occurence. — Komnet Poemation, Hamiltoit Member. McCoys Ferry ; southwest of McCoys Ferry ; east bank Evitts Creek below "Wolfe Mill; B. & 0. K. E. cut at 21st Bridge; "W. Va. side Potomac Eiver about 3 miles south of Cumberland. Collection. — Maryland Geological Survey. ' Pal. N. Y., vol. V, pt. i, Lamellibranchiata ii, p. 336, and pi. xlix, explanation figs. 12, 14. 244 Systematic Paleontology — Middle Devonian Palaeoneilo claekei n. sp. Plate XXVII, Pigs. 10-13 Description. — Shell large, elongate-ovate; length somewhat less than twice the height; basal margin nearly straight or slightly concave near the middle. Anterior end rounded; posterior end truncate to slightly rounded. Valves convex, the greatest convexity along the middle line and near the umbo; the left valve crossed by a shallow sinus which ex- tends obliquely from the umbo about to the middle of the basal margin, apparently not so conspicuous on the right valve; beaks at about the an- terior third. Test thin, and apparently marked with medium sized con- centric striae which extend from the anterior to the posterior end. Hinge marked by numerous crenulations or taxodont teeth, which are coarser toward the posterior extiemity. The specimens are more or less completely exfoliated so that it is difficult to describe their surface characters. The species is distinguished by its elongate form, striae and shallow sinus. Length, 30-34 mm. ; height, 16-19 mm. Named in honor of Dr. John M. Clarke. Occurrence. — ^Eomney Poemation, Hamilton Member. W. Va. side Potomac River about 3 miles south of Cumberland. Collection. — Maryland Geological Survey. Palaeoneilo eowei n. sp. Plate XXVII, Pigs. 14, 15 Description. — Shell large, elongate-ovate and very gibbous in the umbonal region; length considerably less than twice the height; basal margin curving and anterior end rounded. Valve strongly convex espe- cially toward the umbo ; beak prominent and near the anterior end. Sur- face markings unknown. Anterior and posterior muscular impressions strongly marked, hinge marked by numerous crenulations apparently of about equal strength. The above description is based upon an internal impression of a left valve from the National Eoad % mile west of Tonoloway Ridge ; but the Maryland Geological Survey 245 shape, position of beak and great convexity in the umbonal region ap- parently separate it from other species. Later, additional specimens were found at other localities. Length, 24 mm.; height, 16 mm. Named in honor of the late Dr. E. B. Eowe whose field work con- tributed greatly to the exact knowledge of the Maryland Paleozoic. Occurrence. — ^Romney Fokmatiok, Hamilton Member. McCoys Ferry; on National Eoad J mile west of Tonoloway Ridge; on Hancock- Harrisonville Eoad about 2 miles north of Hancock. Collection. — Maryland Geological Survey. Palaeonbilo makylandica n. sp. Plate XXVII, Fig. 16 Description. — Shell medium size and extremely elongated ; length more than twice the height; basal margin convex below the umbonal slope, rounded toward the anterior end and gradually tapering toward the pos- terior extremity. Eight valve convex especially along the umbonal slope, anterior end rounded, posterior part tapering to almost a point and crossed by a very slight depression; beaks well anterior; left valve of specimen distorted and broken. Surface apparently marked by fine, con- centric striae and occasional stronger ones, especially toward the margin. This specimen is much more elongate than any species of Palaeoneilo with which the writer is acquainted, a form that is not considered due to distortion by pressure. Length, 35 mm.; height, about 15 mm. Occurrence. — -Eomney Formation, Hamilton Member. On Han- eock-Harrisonville Eoad about 2 miles north of Hancock. Collection. — Maryland Geological Survey. Genus TANCREDIOPSIS Beushausen Tancrediopsis clarkei n. sp. Plate XXVIII, Figs. 1, 2 Description. — Shell above medium size; length more than twice the height, beak posterior to the middle and conspicuous; portion of shell 246 Systematic Paleontology — Middle Deyonian anterior to the beak longer, larger and higher than the posterior part; hinge and ventral margins of anterior part snbparallel and anterior end conspicuously rounded ; posterior part of shell contracts rapidly from the bealc toward that extremity which is obliquely truncate; well defined, angular ridge extends from the bealc to the post-basal extremity and the shell slopes rather rapidly from it to the hinge-line; valve moderately convex which is most marked in middle part. Surface marked by rather coarse, clearly defined concentric striae which after crossing the umbonal ridge continue to the hinge-line parallel to the posterior margin. Only a single external impression of a right valve is contained in the Maryland Collection, but this is quite well preserved. It is somewhat similar to Gtenodonta (Tancrediopsis) suhcontracta Beushausen,' from the Lower and Middle Devonian of the Ehine. The similarity at least is so marked that is very evident it may be referred to this subgenus of Beushausen. In Beushausen's work Gtenodonta is a genus compris- ing a large number of species under which Palaeondh Hall emend., Tan- crediopsis and others appear as subgenera. In the writer's opinion Pdlaeoneilo is clearly entitled to generic rank and he would raise Tan- crediopsis to the same position. In regard to the orienting of the shell, as to which end shall be called anterior and which posterior, Beushausen's description of C. suhcontracta and Hall's of a similar shell Tellinomya = Gtenodonta nasuta" supplemented by Salter's later account ° have been followed. The specific name is given in honor of Dr. J. M. Clarke. Length, 38 mm. ; height, llj mm. Occurrence.- — Eomney Formation, Hamilton Member. Western Maryland. Gollection. — Maryland Geological Survey. 'Abhand. d. Kon. Preuss. geol. Landesanstalt, N. F., Heft 17, 1895, p. 94; Atlas pi. vlii, figs. 14-16. " Pal. N. Y., vol. i, 1847, p. 152. 'Geol. Surv. Canada, Figs, and desc. Canadian Org. remains, Dec. 1. 1859, p. 36, pi. 8, figs. 1, 2. Maryland Geological Survey 247 Genus LEDA Schumacher Leda diversa Hall Plate XXVIII, Figs. 3, 4 Leda (Nuculana) diversa Hall, 1883, Pal. N. Y., vol. v, pt. i, plates and explanations, pi. xlvii, figs. 31-37. Leda diversa Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 329, pi. xlvii, figs. 31-37. Leda diversa Clarke, 1903, N. Y. State Mus., Bull. 65, p. 406. Leda diversa Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 401, fig. 511c. Description. — " Shell smaal, ovate-cuneate ; length about twice the height; basal margin curving in the anterior portion, becoming straight or nearly so, behind; posterior extremity acuminate; anterior end pro- portionately large, declining rapidly from the beak and regularly rounded below. Valves gibbous in the anterior and umbonal regions, attenuated behind; beaks at about the anterior third, prominent, in- curved, rising above the hinge-line; umbo prominent; umbonal ridge subangular, extending from the beaks to the posterior extremity, the sur- face sloping abruptly from this ridge to the hinge-line. Surface marked by fine, regular, concentric striae which are merged into the umbonal ridge and are obsolete on the cardinal slope." Hall, 1885. An exfoliated left valve, apparently of this species, was found at McCoys Ferry ; no evidence of the striae remains, but the form and pro- portions are those of this species. Length, 13 nun. ; height, 5J mm. Occurrence. — Eomney Formation, Hamilton Member. McCoys Perry; southwest of McCoys Ferry. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Leda rostellata (Conrad) Plate XXVIII, Figs. 5-7 2iucuUtes rostellata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 50. Leda (?) rostellata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 5. Leda rostellata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 330, pi. xlvii, figs. 42-47. 248 Systematic Paleontology — Middle Devonian Leda rostellata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 407. Leda rostellata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 401, fig. Slid. Description. — " Shell small, falciform ; length more than twice the height; basal margin gently curving from the posterior extremity, more rapidly curving anteriorly ; posterior end attenuate, arching upward, with the extremity narrowly rounded or subtnmcate; anterior end compara- tively short, abruptly rounded; cardinal line oblique, declining pos- teriorly, and regularly curved. Valves convex, somewhd.t gibbous in the umbonal region, depressed-convex posteriorly ; beaks between the an- terior third and fourth of the length of the shell; umbonal ridge dis- tinctly defined, sharply angular above. Surface marked by fine, regular, equal, sharp concentric striae, which converge upon the posterior end of the shell, cross the umbonal angle, and are obsolescent on the post-car- dinal slope; hinge crenulated with minute teeth which extend half the distance from the beak to the posterior end." Hall, 1885. On the National Eoad west of Tonoloway Eidge a broken right valve of what is considered a young specimen of this species was found. Although the posterior end is wanting, still it apparently is of falciform shape and the surface is marked by very fine, sharp concentric striae, which are finer and more regular than those of L. diversa. Later, addi- tional specimens were found at other localities. Occurrence. — Romney Formation, Hamilton Member. B. & 0. K. R. cut at 31st Bridge ; in Jennings Run ^2, ^^^ ''^^est of Corriganville ( ?) ; on National Road i/^ mile west of Tonoloway Ridge. Collections. — Maryland Geological Survey; New York State Museum. Superfamily ARCACEA Family PARALLELODONTIDAE Genus PARALLELODON Meek Pakallelodon hamiltoniab (Hall) Plate XXVIII, Figs. 8-13 Macrodon hamiltoniae Hall, 1870, Prelim. Notice Lamellibrancliiata 2, p. 13. Mac7-odon hamiltoniae Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchlata ii, p. 349, pi. li, figs. 1-7, 9, 10. Maryland Geological Survey 349 Parallelodon hamiltoniae Cleland, 1903, Bull. U. S. Geol. Surv., No. 206, p. 65. Macrodon Tiamiltoniae Clarke, 1903, N. Y. State Mus., Bull. 65, p. 437. Parallelodon hamiltoniae Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 403, flgs. 517b, c. Description. — " Shell of medium size or larger, subelliptical or sub- ovate, wider behind; length about twice the height; basal margin broadly curving, sometimes nearly straight in the anterior portion; posterior ex- tremity broadly rounded; sometimes subtruncate in the upper half; anterior end abruptly rounded or subtruncate; cardinal line essentially straight, obtusely subangular at both extremities. Valves convex in the posterior portion and gibbous in the anterior and umbonal portions; beaks subanterior, prominent, rising above the hinge-line. Surface marked by regular, subequidistant, lamellose, concentric lines and by fine radiating striae, which are usually interrupted at the edges of the lamellae and become thickened at their lower extension; the radii are stronger on the posterior part of the shell." Hall, 1885. This species is represented by a considerable number of specimens in the rather coarse Hamilton shales of Maryland and shows all the char- acteristic features. It was also reported by Hall "from the Hamilton group, near Cumberland, Md." (Pal. N. Y., vol. v, pt. i, Lamelli- branchiata ii, p. 350) and a left valve of a large individual from near Cumberland represented by figure 10 on plate li. The most marked characters of the species are the nearly straight hinge-line with the sub- angular ends; rounded posterior end; strong, distant lamellose concentric lines ; and fine interrupted radii, which are strongest on the posterior part of the shell. Length, 17-34 mm. ; height, 9-13 mm. Occurrence. — Eomney Formation, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill; on Hancock-Harrisonville Eoad about 3 miles north of Hancock; Emstville; along FHntstone Creek in Gilpin. Collections. — Maryland Geological Survey; American Museum of Natural History. 250 Systematic Paleoktologt — Middle Devonian- Superfamily PTERIACEA Family PTERINEIDAE Genus PTERINEA Goldfuss Pteeinea flabellum (Conrad) Plate XXIX, Figs. 1-4 Avimila flahella Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vill, p. 238, pi. xii, fig. 8. Avicula flatiella Vanuxem, 1843, Geol. N. Y., pt. lii, p. 152, fig. 3. Avioula flabella Rogers, 1858, Geol. Penna., vol. ii, p. 826, fig. 659. Pterinea flatella Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibrancliiata i, p. 93, pi. xiv, figs. 1-21; pi. xv, figs. 1, 4-6, 8-10; pi. Ixxxill, figs. 11, 12. Pterinea flabella Keyes, 1891, Johns Hopkins Univ. Clrc, vol. xi, p. 29. Pterinea flalellum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 494. Cornellites flaiella H. S. Williams, 1908, Proc. U. S. Nat. Mus., vol. xxxiv, p. 90. Pterinea (Cornellites) flabellum Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 421, fig. 551. Description. — Shell large; broad or narro-w ovate, oblique, rarely erect; length from t-wo-thirds to nearly equal the height. Left valve more or less convex, often gibbous and arcuate; right valve ilat or concave, -with a little convexity on the umbo ; hinge-line straight, extended an the pos- terior side, and length greater than that of the valve; beak of left valve near the anterior extremity of the hinge-line and curving forward over it; umbonal region gibbous; beak of right valve depressed and not rising above the hinge; wing large, triangular, nearly flat, margin concave and extremity acute; ear of left valve a simple rounded convex lobe. Test thick; left valve marked with from six to twelve strong rounded rays, which start near the beak and continue simple to the margin; the inter- spaces are marked by smaller, alternating costae; there are also strong, concentric, lamellose striae of growth; in the partially exfoliated condi- tion, and in the easts, the ears show the concentric striae and the wings evidences of the rays. This species is common in the rather coarse arenaceous Hamilton de- posits of Maryland. The specimens are nearly all exfoliated or impres- sions; but they show very well the most striking characters of the species; Maryland Geological Survey 351 its large size; convex left valve and flat or concave right one; large, triangular wing; small well defined ear; and strong, rounded rays on the left valve, with smaller intermediate ones. Length parallel to hinge-line, of about an average specimen, 37 mm. ; length of hinge-line, about 40 mm.; height, about 45 mm. and extreme distance from beak to base, 54 mm. Occurrence. — Eomney Formation, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill; Town Creek Eoad at George Diefen- baugh's; on National Eoad J mile west of Tonoloway Eidge; on Oldtown Eoad, east of Marj'land Ave., Cumberland; on Hancock-Harrisonville Eoad about 2 miles north of Hancock; on ISTational Eoad northeast of Cumberland; along Plintstone Creek in Gdlpin; west of iron bridge over Town Creek, northeast of Oldtown; east side Warrior Mt. east of Eush; on road about half way between Eomney and Hanging Eock, W. Va. ( ?) . Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Pterinea sp. Plate XXIX, Fig. 5 Pterinea sp. undet. Kindle, 1912, Bull. U. S. Geol. Survey, No. 508, p. 91, pi. viii, flg. 4. Description. — " The collection from southwestern Virginia includes two left valves of an undetermined Peterinea. The best-preserved specimen, which is figured, though nearly flat, shows evidence of having been mod- erately convex in the crumpled fracture line resulting from pressure. The shell is large and erect; height and length nearly equal; margin regularly curved. Hinge-line straight, equal to or greater than the greatest length of the shell. Beak anterior; ear small, limited by a dis- tinct sulcus ; wing broad and rather sharply delimited from the rest of the shell. Surface of the valve marked by strong elevated radii which are separated by wide flat interspaces. These show a slight posterior curva- ture in the upper portion of their course. The ear and wing are marked by radii of much less strength than the body of the valve, but the entire 353 Systematic Paleontology — Middle Devonian surface is cancellated by concentric strife of equal strength, which are rather widely spaced. In outline and general appearance this shell is comparable with P. consimilis of the Chemung. The radii of P. con- dmilis, however, are flattened and those of this species are rounded." Kindle, 1913. Occurrence. — Eomnet Foemation, Onondaga Member. Near Cum- berland. Collection. — U. S. National Museum. [E. M. Kindle.] Genus LIOPTERIA Hall LiOPTEEIA Cf. CONEADI Hall Plate XXVIII, Pig. 13 Leiopteria conradi Hall, 1883, Pal. N. Y., vol. v, pt. i, plates and explanations, pi. XX, figs. 1, 2, 4. Leiopteria conradi Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibranclilata i, p. 159, pi. XX, figs. 1, 2, 4; pi. Ixxxviii, figs. 1-4. Liopteria conradi Clarke, 1903, N. Y. State Mus., Bull. 65, p. 426. Description. — Shell above the medium size, subrhomboidal ; length a little greater than the height; anterior margin straight, nearly vertical; basal and posterior margins regularly rounded. Valves subequally con- vex; the left valve somewhat more convex than the right. Hinge-line straight, longer than the length of the valve, greatly extended posteriorly. Beaks acute, directed forward, prominent, situated near the anterior end of the shell; umbonal region gibbous. Ear short, separated from the valve by a rounded depression or sulcus, extremity rounded; wing tri- angular, much extended, margin concave, extremity acuminate. Test, as indicated by casts or partially exfoliated specimens, marked by fine, closely arranged, concentric lines of growth, which at irregular intervals are crowded and raised into rounded or subangular fascicles, giving the surface a decidedly undulated aspect; the striae become more crowded upon the cardinal expansions, especially upon the ear. A partially exfoliated left valve in the Maryland Collection in outline and markings resembles the above species to a considerable extent. The Maryland Geological Suevby 253 concentric lines of growth are conspicuous and have a somewhat im- bricating appearance in addition to which are fine concentric striae ; the lines of growth and striae are very much crowded on the ear, which is perhaps a little larger than on the figiired specimens of this species. The proportion of length and height of this specimen is apparently more equal than for the normal forms of the species, although perhaps the greater height is partly due to crushing. Length and height, about 37 mm. Occwrrence. — ^Eomnet Fokmation, Hamilton Member. West of iron bridge over Town Creek northeast of Oldtown. Collection. — Maryland Geological Survey. LlOPTEEIA LAEVIS Hall Plate XXIX, Fig. 6 Leiopteria laevis Hall, 1883, Nat. Hist. New York, Paleontology, vol. v, pt. i, Lamelllbr. (adv. copy), pi. xvll, figs. 5-11. Leiopteria laevis Hall, 1884, Nat. Hist. New York, Paleontology, vol. v, pt. i, Lamellibr. 1, p. 158, pi. xvii, flgs. 5-11; pi. xx, flg. 5. Leiopteria laevis Hall, 1884, Thirty-fifth Hep. New York State Mus. Nat. Hist., p. 334. Leiopteria laevis Cleland, 1903, Bull. U. S. Geol. Surv., No. 206, p. 67. Leiopteria laevis Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 95, pi. viii, flg. 5. Description. — This species is represented in the collection by a single left valve. Hall * described the species as follows : " Shell small, sub- rhomboidal; body obliquely ovate; length and height nearly equal; greatest length below the middle ; margins regularly rounded, somewhat extended on the post-basal side. Left valve more convex than the right; the greatest convexity in both valves is above the middle. Hinge-line straight on the posterior side of the bealc, turning abruptly down in front; entire length greater than the length of the shell. Beaks obtuse, rounded, inclined forward, situated at the anterior third of the shell, that of the left valve quite prominent. Umbonal region of left valve prominent, subtending an acute angle. Ear triangular, nearly equi- 'Pal. New York, vol. v, pt. i: i, 1884, pp. 158-159, pi. 17, figs. 5-11; pi. 20, fig. 5. 254 Systematic Paleontology — Middle Devonian' lateral, with a strong angular fold along the middle, separated from the body of the valve by a distinct rounded sulcus and broad byssal sinus; margin rounded; extremity obtuse. Wing triangular, flat, limited by the post-umbonal slope; margin concave; extremity acute. Test thin, marked with distinct concentric striae of growth, which are crowded and conspicuous on the wings. There are often obscure traces of radii, which are more distinct on the wing in casts or exfoliated specimens. Liga- mental area narrow, with a single distinct groove. Some specimens apparently indicate the existence of an oblique lateral tooth on the posterior side of the umbo." The writer's specimen is smaller than those described by Hall, the height of the shell being only 5 mm. and the length of the hinge-line 6 mm. Occurrence. — Romney Formation, Onondaga Mbmbee. Williams Eoad, 3% miles southeast of Crmiberland. Collection. — TJ. S. National Museum. [E. M. Kindle.J Genus LEPTODESMA Hall Leptodesma eogeesi Hall Plate XXIX, Pigs., 7-10 Leptodesma rogersi Hall, 1883, Pal. N. Y., vol. v, pt. i, plates and explanations, pi. xxl, figs. 1-9. Leptodesma rogersi Hall, 1884, Pal. N. Y., vol. v, pt. 1, Lamelllbranchiata i, p. 176, pi. xxi, figs. 1-9. Leptodesma rogersi Clarke, 1903, N. Y. State Mus., Bull. 65, p. 419. Leptodesma rogersi Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 426, fig. 5561). Description.— Shell of small or medium size, subrhomboidal ; body ovate, very oblique; length greater than the height; anterior and basal margins broadly rounded; posterior margin extended and abruptly re- curved. Valves eqiially convex above; right one somewhat depressed be- low, comparatively higher than the left. Hinge-line straight, longer than the length of the shell. Beaks subanterior, obtuse, nearly erect, prominent, umbonal region gibbous, oblique. The anterior extremity is scarcely alate or auriculate, consisting of a rounded extension, straight Maryland Gkological Survey 355 above and slightly sinuate at the base, wing comparatively large, tri- angular, joining the body of the valve near the posterior extremity, de- fined by the crowding and curving of the concentric striae; extremity prolonged into a mucronate spine which extends beyond the posterior limit of the valve. Test thin, marked by closely arranged concentric striae, which at irregular intervals are crowded into fascicles, producing a gently undulating surface ; on the wing the striae are closely arranged, and just below the hinge-line are turned backward along the spiniform extension of the wing. One specimen has a length from beak to base of 24 mm., height 15 mm., hinge-line about 30 mm.; small specimens are often less than 10 mm. in length and height. (Hall, 1884, condensed.) The external impression of a left valve occurs in the Maryland Collec- tion which is apparently a small specimen of this species. The end of the spine is gone or else it is not as long as usual while the concentric striae are rather sharper and quite similar to those on some specimens of L. sociale Hall in the New York State Museum. Another specimen not so well preserved was found at the same locality which Dr. Grabau compared with Leptodesma rogersi calling attention, however, to the fact that the shell is less oblique than in most specimens of this species. Length, 9 mm.; height, 6 mm. Occurrence. — ^Romkey Formation-, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill. Collection. — Maryland Geological Survey. Family AMBONYCHIIDAE Genus MYTILARCA Hall Mytilarca (Plethomytilus) oviformis (Conrad) Plate XXIX, Pigs. 11-13 Inoceramus oviformis Conrad, 1842, Jour. Acad. Nat. Sci., Phlla., vol. viii, p. 246, pi. 13, flg. 7. Mytilarca oviformis Hall, 1870, Prelim. Notice Lamellibranchlata 2, p. 21. Mytilarca (Plethomytilus) oviformis Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibranchiata i, p. 255, pi. xxxl, flgs. 1-8; pi. Ixxxvii, fig. 8. 256 Systematic Paleontology — Middle Devonian MytUarca oviformis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 457. Plethomytilus oviformis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1, p. 434, figs. 567d, e. Description. — " Shell large ; body ovate, erect, wide posteriorly and acute above; length about one-fifth greater than the height; ventral mar- gin for nearly half the length of the shell nearly direct, thence gently curving into the posterior extremity which is broadly rounded; dorsal margin very gently curved. Valves equal, regularly convex in the pos- terior part, becoming gibbous in the umbonal region ; hinge-line straight, less than the height of the shell; beaks prominent, anterior acute, and incurved, rising .above the cardinal line. Test thick, marked by fine, close striae of growth which at intervals are fasciculate and raised into lamellose ridges and very much crowded and elevated on the ventral side of the shell; ligamental area wide, finely striated longitudinally." Hall, 1884. Several broken specimens were found the form of which and other char- acters apparently leave no doubt regarding their identity with the above species. A large specimen from western Maryland, the exact locality unknown, was sent to Dr. Grabau who wrote as follows : " I have a specimen (internal mold) of Plethomytilus oviformis from the Encrinal limestone of Eighteen Mile Creek [N. Y.] which is of the same size as this specimen. Placed side by side they appear to be perfectly identical, the differences being such as can easily be accounted for by the fragments broken away on your specimen." The species is well defined by its large size, ovate outline; truncate front; wide ligamental area; and beaks pro- jecting above the cardinal line. Length, 58 + mm. ; too badly broken to determinate the height. Length, of a smaller specimen, 45 mm. ; height, 32 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below "Wolfe Mill; cut on B. & 0. E. E. cut at 21st Bridge; along Flintstone Creek in iGrilpin; western Maryland, but exact locality unlmown. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Maryland Geological Sukvey 257 Family CONOCARDIIDAE Genus CONOCARDIUM Bronn CONOCARDIDM NOEMALE Hall Plate XXX, Figs. 1-2 Oonocardium normale Hall, 1883, Pal. N. Y., vol. v, pt. 1, pi. 68, figs. 17-19. Conocardiwm normale Hall, 1885, Pal. N. Y., vol. v, pt. i, 2, p. 411, pi. Ixviii, figs. 17-19. Description.- — Shell large, subovate, trigonal; length about twice the height; basal margin regularly curving. Posterior extremity obliquely truncate. Cardinal line straight. Anterior end narrow, nasute. Valves ventricose, abruptly contracted anteriorly and truncate behind. Beaks posterior to the center, prominent, strongly incurred. Umbonal slope angular, continuing to the post-inferior margin. Post-cardinal slope concave. Test thick, body of the shell marked by numerous radii, between which are undulating lamellose concentric striae. When the shell is exfoliated the radii become stronger and the intermediate surface is marked by fine radiating striae. With the growth of the shell the anterior rays become greatly strengthened and semi-tubular. The cast of the foot- sheath is bilobed, and doubly pointed behind. Two specimens measure respectively 50 and 60 mm. in length, 35 and 33 mm. in height, and 26 and 30 mm. in the depth of both valves. This species bears a close re- semblance to the elongate forms of C ouneus. There is, however, no tendency to a duplication of the ribs, which is a common feature in the specimens from tlie Schoharie grit. Hall, 1885. Occurrence. — Eomney Poemation, HAMiLax)N Membee. ISTear Cum- berland. Collection. — Ifew York State Museum. CONOCAEDIUM CDMBEELANDI^ Swartz n. Sp. Plate XXX, Figs. 3, 4 Description.— Shell small, ovate cuneate; length and height subequal. Valves gibbous in center, very abruptly contracted anteriorly; anterior extremity extended, nasute; truncate posteriorly. Beaks a little behind 17 358 Systematic Paleontology — Middle Devonian center of cardinal margin; nmbonal slope angular, continuing to post- inferior margin; postcardinal slope concave. Anterior and posterior extremities gaping. Surface ornamented by radial plications, whicli are about 1 mm. apart upon middle and anterior parts of shell 25 mm. long. Plications become obsolete near anterior extremity. They are duplicated and much closer upon postcardinal surface, where they are crossed by conspicuous fine concentric striae. The middle and anterior part of shell is also crossed by lamellose lines of growth. Length 20 mm.; height 20 mm. This species closely resembles C. cuneus var. nasidum but differs ia the much more abrupt constriction of its anterior end. The specimens ob- served are internal casts. Occurrence. — Eomney Poemation, Hamilton Member. Little Eun, east of Hancock; Williams Eoad, 3V^ miles southeast of Cumberland. Collection. — Maryland Geological Survey. [C. K. Swartz.] Family PTERIIDAE Genus ACTINOPTERIA Hall Actinopteria decussata Hall Plate XXX, Pigs. 5-8 Avicula decussata Hall, 1843, Geol. N. T., pt. Iv, p. 203, figs. 1, 2. Actinopteria decussata Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibranchiata i, p. Ill, pi. xvii, figs. 24, 28; pi. xvlll, figs. 1-15; pi. xx, fig. 19; pi. Ixxxiv, fig. 4. Actinopteria decussata Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Actinopteria decussata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 351. Actinopteria decussata Gratiau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 449. fig. 591c. Description. — Shell large, subrhomboidal ; body subovate, very oblique; length about one-fourth greater than the height ; margins regularly curv- ing, the anterior sometimes nearly vertical, the posterior more abruptly rounded. Valves convex, the right valve less convex and smaller than the left one; hinge-line straight, less than the length of the valve; beak acute, prominent, inclined forward, close to the anterior end of the shell; Maryland Geological Sukvet 259 umbonal region prominent, and in the left valve gibbous; ear small, separated from the valve by a broad snlcus, beyond which it is a mere fold in the shell ; wing large, triangular, flat, extending nearly to the margin of the valve, limited by a somewhat distinct sulcus and the abrupt bend- ing of the concentric striae; margin concave. Test thick; left valve marked with strong, prominent, rounded radii, regularly alternating with finer ones on the posterior half of the valve; crossed at regular intervals by strong concentric lamellae which generally interrupt the radii; on the right valve the markings are much subdued, the rays often obsolete, espe- cially on its lower part, and the concentric lamellae are simple undulations of the surface; from maceration or exfoliation these surface characters are usually only partially preserved. A number of rather imperfectly preserved impressions of this species were found in the rather coarse arenaceous shales and sandstones of the Maryland Hamilton. They possess the distinctive specific characters in the extreme obliquity of the body; large, triangular wing; small ear, separated from valve by broad sulcus; rounded radii, with smaller ones between, interrupted by prominent concentric lamellae. The specimens are too imperfect for satisfactory measurements. Occurrence. — Eomney Formation, Hamilton Member. B. & 0. E. E. cut at 31st Bridge ( ?) ; east bank Evitts Creek below Wolfe Mill; on road east of Pine Hill about 4 miles north of Oldtown. Collections. — ^Maryland Geological Survey; New York State Museum; American Museum of Natural History. AOTINOPTERIA BOTDI VAR. GIBBOSA n. Var. Plate XXX, Figs. 9, 10 Description. — Shell of medium size, with straight hinge-line and some- what rounded anterior and front margins. Eight valve moderately convex and left valve strongly convex and gibbous along the umbonal ridge ; ear short and limited by a sulcus which is more sharply defined on the left valve; wing not distinctly separated from the body of the shell. Left valve marked by numerous, strong, simple rays which extend from the 360 Systematic Paleontology — Middle Devonian umbo to the margin and are crossed by concentric somewhat elevated lamellae which are most conspicnous on the wing ; on the right valve the rays occur on the wing and the posterior half of the body of the shell while the concentric lamellae are similar to those of the opposite valve. This specimen, in general, is quite similar to certain forms of A. loydi except that the body of the left valve is strongly gibbous so that there is a much greater difference in the convexity of the two valves, while on the right valve the rays extend over about one-half of its body instead of being obsolete. It is thought that the marked difference in these two characters is of sufficient importance to warrant the separation of this specimen as a variety from the normal form of A. boydi. This opinion in the main is supported by that of Dr. Grabau who examined the speci- men and stated that he would make it a new variety at least, emphasizing the difference in convexity of valves and the extension of rays on body of right valve. Length, about 38 mm. ; height, about 34 mm. Occurrence. — Eomney Formation, Hamilton Member. On Town Creek 4 miles northeast of Oldtown; Town Creek Eoad at Geo. Diefen- baugh's. Collection. — Mandand Geological Survey. Actinopteeia sp. Plate XXX, Fig. 11 Description. — Shell small and convex, the convexity of the left valve being the greater which is quite marked on its body; ear small and sep- arated by a shallow sulcus from the body, wing not sharply separated from the body and outline unknown. The surface of the left valve shows numerous simple, fairly strong rays, with generally a finer one between two that are heavy ; crossed by regular, sharp concentric lines which give a somewhat reticulated appearance to the surface. Eight valve exfoliated, not showing the surface markings. This specimen is related to A. boydi and is probably a new species but on account of its broken and imperfect condition it is thought better not Maryland Geological Suevey 361 to name it at present. The specimen, however, has been seen by Dr. Grabau who regards it as a new species. Length, about 28 mm. ; height, about 25 mm. Occurrence. — ^Eomney Formatiost, Hamilton Member. "West of iron bridge over Town Creek northeast of Oldtown. Collection. — Maryland Geological Survey. Family MYALINIDAE Genus MODIELLA Hall MoDiELLA PYGMAEA (Conrad) Plate XXXI, Figs. 1-5 Pterinea pygmaea Conrad, 1842, Jour. Acad. Nat. Sci., Phlla., vol. vili, p. 251, pi. xiii, fig. 15. Modiella pygmaea Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 514, pi Ixxvi, figs. 9-20. Modiella pygmaea Clarke, 1903, N. Y. State Mus., Bull. 65, p. 443. Modiella pygmaea Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 456, fig. 606d. Description. — " Shell small, obliquely obovate ; length one-third greater than the height; basal margin arcuate anterior to the middle, broadly and distinctly curving to the post-inferior extremity; posterior extremity obliquely and broadly curved ; anterior end short, auriculate, limited by a depression extending from just anterior to the beak to the basal margin and producing a more or less distinct sinus. Valves very convex in the middle and upper portions of the shell; beaks subanterior, small, closely appressed and incurved; umbonal slope not distinctly limited, rather prominent, arcuate, extending to the post-inferior extremity. Surface marked by fine concentric striae, crossed by curving, radiating striae which are more distinct on the body of the shell just posterior to the sinus." Hall, 1885. Several specimens of this species were obtained from the thinner and more argillaceous Hamilton shales of Maryland and West Virginia. There is apparently no marked difference between these southern specimens and those from the typical localities for this species in central New York. It is readily identified by its shape and size, short anterior and broader 363 Systematic Paleoni'OLOGT — Middle Devonian posterior end, with a curved to obliquely truncate posterior margin; auri- eulate anterior margin, the ear defined by a distinct sulcus; and curved radiating striae. Length, 10-15 mm. ; height, 7-10 mm. Occurrence. — Komney Formation, Hamilton Membek. Williams Eoad 3| miles southeast of Cumberland; east bank Evitts Creek below Wolfe Mill; Williams Eoad J mile east of Queen City Hotel, Cumber- land; W. Va. side Potomac Eiver about 3 miles south of Cumberland; W. Va. side Potomac Eiver 4 miles south of Cumberland; hill 3 miles south of Cumberland. Collections. — Maryland Geological Survey; N"ew York State Museum; American Museum of Katural History. Superfamily NAIADACEA Family CARDINIIDAE Genus NYASSA Hall JSTyassa aeguta Hall (?) Plate XXXI, Fig. 6 Nyassa arguta Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 28. Nyassa arguta Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibrancliiata ii, p. 354, pi. liii, figs. 7-20. Nyassa arguta Clarke, 1903, N. Y. State Mus., Bull. 65, p. 467. Nj/assw arguta Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 478, fig. 639. Description. — Shell of medium to large size, elongate subelliptical or ovate-arcuate; length about twice the height; basal margin nearly straight, often slightly arcuate or contracted posterior to tlie middle, abruptly recurved at the post-inferior extremity; posterior margin curved or ob- liquely subtruncate; cardinal line gently arcuate; anterior end narrowed and abruptly rounded. Valves depressed below, gibbous above and in the umbonal region; beaks subanterior, small, closely appressed, rising but little above the hinge-line; umbonal ridge prominent, rounded or sub- angular, arcuate, extending to the post-inferior extremity; below and parallel with the ridge there is a flattening or depression of the shell ex- Maryland Geological Survey 263 tending from the beaks and producing a constriction or sinuosity in the basal margin. Test thick, marked by lamellose concentric lines of growth, without other ornamentation. The hinge is characterized by numerous small teeth or callosities beneath the beak, which appear to be without special arrangement, the posterior ones being directed backward and some- times more elongated; lateral teeth two or three in number, parallel and extending nearly to the post-cardinal extremitjf; anterior muscular im- pression deep and strong; specimens vary in length from 31 to 53 mm. and in height from 11 to 24J mm. An imperfect internal impression of a left valve was obtained at McCoys Ferry which is with some hesitation referred to this species. It has a similar outline and proportions with prominent arcuate, um- bonal ridge and conspicuous parallel lateral teeth; but there is a con- spicuous and fairly deep furrow extending from slightly in front of the beak obliquely across the anterior part of the shell which is farther forward and more prominent than the oblique constriction crossing N. arguta. The furrow of this specimen is perhaps partly due to crushing. Later, additional specimens were obtained at other localities. Length, 39 mm. ; height, 19 -j- mm. Occurrence. — ^Komney Formation, Hamilton Member. McCoys Ferry; southwest of McCoys Ferry; on east side Warrior Mt. east of Rush. Collection. — ^Maryland Geological Survey. Superfamily PECTINACEA Family PECTINIDAE Genus AVICULOPECTEN McCoy» AvicDLOPECTEN PRiNCEPs (Conrad) Plate XXXI, Figs. 10, 11; Plate XXXII, Figs. 1, 2 Monotis princeps Conrad, 1838, An. Rep. N. Y. Geol. Surv., p. 117. Avicula parilis Conrad, 1842, Proc. Acad. Nat. Sci. Phlla., vol. viii, p. 239, pi. cxli, fig. 9. " Dr. G. H. Girty has recently stated that the spelling AvicuUpecten is the etymologically correct one (Amer. Geol., vol. xxxiii, 1894, p. 295). 364 Systematic Paleontology — Middib Devonian Aviculopecten princeps Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibranchiata i, p. 1, pi. i, figs. 10, 11; pi. V, figs. 18, 19, 23, 24; pi. vi, figs. 1-9; pi. xxiv, fig. 7; pi. ixxxi, figs. 13-17. Aviculopecten princeps Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Aviculopecten princeps Clarke, 1903, N. Y. State Mus., Bull. 65, p. 365. Aviculopecten princeps Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 487, fig. 650b. Description. — Shell large, obliquely broad-ovate; axis inclined more than 60° to the hinge-line; length and height nearly equal; anterior margin convex. Valves depressed; left valve regularly convex; right valve nearly flat, or very moderately convex. Hinge-line straight with a length of from two-thirds to more than three-fourths the length of the shell. Beaks obtuse, rounded, anterior to the middle of the hinge. Ears large; triangular; posterior one the larger; and defined by the abrupt slope of the side of the umbo, while the anterior one is separated by a distinct sulcus; lateral margins concave, becoming convex at the hinge- line. Byssal-sinus broad, rounded, well-defined and indicated on the ear by a sulcus extending to the extremity of the beak. The right valve is flatter and proportionally broader than the left. Test thin, marked by numerous regular alternating rays, which increase in number by inter- stitial additions, and become broader and stronger towards the margins. These radiating ribs are crossed by very fine, sharp striae of growth. On the ears the rays are nearly obsolete, and the lines of growth are sharper and stronger than on the body of the shell. The dimensions of the shells of this species are very variable. Large individuals have a height of 80 mm. with nearly equal length, and a hinge-line of 50 mm. The grad- ation from this form is very gradual to those in which the height is equal to, or greater than, the length, and where the length of the hinge- line is nearly equal that of the shell. Hall, 1884, condensed. The Maryland specimens available for study are broken and quite im- perfectly preserved ; but after comparison with authentic specimens of this species in the New York State Museum it is thought that they are correctly identified. A fragment of a large valve shows nicely the strong radiating rays toward the margin of the shell with smaller intercalated ones. The figured left valve from the Williams Eoad near Cumberland Maryland Geological Survey 365 shows well the alternation and intercalation of the rays together with their faint appearance on the eai's. Length, of medium specimen, about 30 mm. ; height, about 45 mm. Occurrence. — ^Eomney Pormation, Hamilton Member. B. & 0. E. E. cut at 21st Bridge ( ?) ; Williams Eoad J mile northeast of Queen City Hotel, Cumberland ; McCoys Ferry ; southwest of McCoys Ferry ; on Hancoek-Harrisonville Eoad about 3 miles north of Hancock; west of iron bridge over Town Creek northeast of Oldtown ( ?). Collections. — Maryland Geological Survey ; ISTew York State Museum ; American Museum of Natural History. AviCULOPECTja^^ EQUILATEEA (Hall) Plate XXXII, Figs. 3, 4 Avicula equilatera Hall, 1843, Nat. Hist. N. Y. Geology, vol. iv, p. 180, text fig. 7; p. 181, table illus. 39, fig. 7. Avicula equilatera Owen and Hall, 1847, Amer. Jour. Sci., 2d ser., vol. Hi, p. 59, fig. 7 in text. Aviculopecten equilatera Hall, 1859, 12tli Kept. N. Y. State Cab. Nat. Hist., p. 89. Avicula equilatera Lincklaen, 1861, 14th Rept. N. Y. State Cab. Nat. Hist., pi. xii, fig. 7. Aviculopecten equilaterus Lesley, 1889, Geol. Survey Penn., Rept. P4, p. 74, 1 text fig. Aviculopecten ? equilatera "Whitfield, 1891, Annals N. Y. Acad. Sci., vol. v, p. 551, pi. xi, fig. 16. Aviculopecten ? equilatera Whitfield, 1893, Geol. Survey Ohio, Paleontology, vol. vii, p. 445, fig. 16. Aviculopecten equilatera Kindle, Bull. U. S. Geol. Surv., No. 508, p. 93, pi. viii, figs. 2, 3, 1912. Description. — Shell small and slightly oblique, depressed convex. Hinge-line straight, equal to greatest length of shell. Beak nearly central on hinge-line. Anterior cardinal angle apparently mucronate ; margin of shell below the cardinal line slightly sinuate and gently rounded to the posterior margin, which is nearly straight but is directed slightly back- ward in descending from the hinge-line to the rounded posterior margin. Surface covered with 15 to 20 strong rounded plications, which are crossed by finer concentric undulations. 266 Systematic Paleontology — ^Middle Devonian The species is represented by two left valves which appear to be identical with the Marcellus species described by Hall. Occurrence. — Romney Formation, Onondaga Member. Eidgeville, W. Va., and Blair County, Pa. Collection. — U. S. National Museum. [E. M. Kindle.] AVICULOPECTBN Sp. Plate XXXI, Fig. 13 Description. — A species of Aviculopecten not sufficiently well preserved to permit confident identification is found in the fauna. Its finely can- cellated surface suggests A. canceUatus of the Chemung of New York. Occurrence. — ^Eomney Formation, Hamilton Member. Hancock. Collection. — Maryland Geological Survey. Superfamily MYTILACEA Family MODIOLOPSIDAE Genus MODIOMORPHA Hall Modiomorpha concentrica (Conrad) Plate XXXII, Figs. 5-9 Pterinea concentrica Conrad, 1838, Geol. Surv., N. Y., An. Rep., p. 116. Cypricardites concentrica Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 52. Modiola concentrica Hall, 1843, Geol. Surv. N. Y., pt. iv, p. 196, fig. 9. Modiomorpha concentrica Hall, 1870, Prelim. Notice Lamellibranchlata 2, p. 73. Modiomorpha concentrica Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamelli- branchiata ii, p. 275, pi. xxxiv, flgs. 9, 10; pi. xxxv, figs. 1-5; pi. xxxvi, figs. 1-16 (17, 18?). Modiomorpha concentrica Keyes, 1891, Johns Hopkins Univ. Clrc, vol. xi, p. 29. Modiomorpha concentrica Clarke, 1903, N. Y. State Mus., Bull. 65, p. 448. Modiomorpha concentrica Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 515, figs. 692d, 694d. Description. — " Shell of medium size, ovate, extremely variable in its proportions ; length less than twice the height ; basal margin often nearly Maryland Geological Survey 267 straight, usually a little concave on the anterior third; posterior margin abruptly rounded below and more gently curving above; anterior end produced beyond the beaks, abruptly rounded, limited by a broad de- pression extending from the beak to about the anterior third of the basal margin; cardinal margin oblique in the prevailing forms, moderately arcuate. Valves moderately convex, gibbous along the umbonal slope; the point of greatest convexity is about the anterior third of the length of the shell ; hinge-line extending half or more than half the length of the shell; beaks subanterior, small, appressed and directed forward; a sub- angular elevation of the umbonal region, usually dying out about the middle of the length of the shell. Test comparatively thick, strongly ornamented by regular concentric, rounded or subangular striae, which become lamellose and coalescing on the anterior end of the valves, where they are less prominent; anterior muscular impression strong, striated, situated just within the anterior margin ; posterior impression large and shallow." Hall, 1885. Several specimens which are referred to this species were found in the coarser arenaceous shales of the Hamilton in Maryland. Part of the specimens are internal impressions; but others are more or less exfoliated ones of the shell. On part of them the concentric striae are somewhat coarser than on most of the figured New York specimens ; but others appear to agree with those from that state. This species is closely related to M. mytiloides (Con.) ; but these specimens are apparently differentiated from it by their smaller size, more arcuate form, more gibbous umbonal region and the strong, regular, concentric striae. Hall identified this species from the Hamilton shales, near Cumberland (Pal. IST. Y., vol. v, pt. i, Lamellibranchiata ii, p. 376) and figured the interior of two specimens from Cumberland (ibid., pi. xxxvi, figs. 14, 16). One of the more doubt- ful specimens was submitted to Dr. Grabau who agreed in referring it to M. concentrica; as well as another specimen from western Maryland the exact locality of which is unknown. Length, 40-60 nun.; height, 35-37 mm. Occurrence. — Eomnet Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; Williams Eoad 3 J miles southeast of 268 Ststematic Paleontology — Middle Devoniai^^ Ciimberland ( ?) ; on Hancock-Harrisonville Eoad about 2 miles north of Hancock; on N'ational Eoad northeast of Cumberland; along Mintstone Creek in Gilpin ; on the Eomney-Hanging Eock Eoad about ^ mile north of Eomney, W. Va. Collections. — Maryland Geological Survey; N'ew York State Museum; American Museum of Natural History. MODiOMOEPHA SUBALATA (Conrad) Plate XXXIII, Pigs. 1-6 Cypricardites suialata Conrad, 1841, Geol. Surv. N. Y., An. Rep., p. 83. Modiomorpha subalata Hall, 1870, Prelim. Notice Lamellibrancliiata 2, p. 77. ModiomorpTia subalata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 283, pi. XXXV, figs. 6, 7; pi. xxxix, flgs. 1-14, 16. Modiomorpna subalata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 453. Modiomorpha suhalata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 515, fig. 692b. Description. — " Shell of medium size or smaller, subquadrangular, or subovate; subalate posteriorly, with the extremity obliquely truncate; length more than one-third greater than the height; basal margin straight or slightly concave on the anterior half, and thence regularly curving to the post-basal extremity; posterior margin abruptly recurved below, and continuing with a gentle curvature, or in a nearly straight line, to the cardinal margin; cardinal margin oblique, nearly straight; anterior end short, abruptly rounded, often a little concave below the beaks, and limited by a more or less defined sinus, which extends from the beak to the basal margin, usually at a point less than one-third the length of the shell from the anterior end. Valves moderately convex below and in the posterior portion, more convex in the middle; hinge-line oblique, about half the length of the shell ; bealss subanterior, incurved and directed for- ward, somewhat compressed; umbo prominent, flattened anteriorly; the post-umbonal slope angular, gibbous above and gradually declining to the post-basal extremity. Test thin, marked by fine concentric striae, which are sometimes fasciculate, forming distinct elevations upon the posterior slope, and often distinct angular striae upon the antero-basal portion of Maryland Geological Survey 269 the shell, frequently becoming nearly obsolete on the umbonal region." Hall, 1885. This species as compared with M. concentrica occurs in the bluer and more argillaceous Hamilton shales of Maryland. It is a well marked species and differs from the other Modiomorphas found in Marylaiad in the more nearly parallel cardinal and basal margins; well marked, angular umbonal ridge; subtruncate posterior end; and the obsolescence of the striae on the umbonal region. The small specimen represented by figure 5 was thought at first to show very imperfectly preserved fine striae on the posterior portion of the shell and for this reason it was referred to Modiella pygmaea (Conrad). Further study, however, taking more account of its form leads me to conclude that it is a young specimen of Modiomorpha subalata (Conrad), still younger than the one represented by fig. 1, pi. xxxix, Lamellihranchiata ii, vol. v, pt. i, Paleontology of Few York. The specimen was submitted to Dr. Grabau with the above opinion who wrote me as follows : " You are right I think. I should call it young M. snhalata. The form hardly warrants reference to Modiella." Length, 35-35 mm.; height, 15-30 mm. Occurrence. — Romney Formation, Onondaga Member. Williams Eoad 3^ miles southeast of Cumberland ( ?) . Hamilton Member. East bank Evitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Modiomorpha MYTiLOiDES (Conrad) (?) Plate XXXIII, Pig. 7 Cypricardites mytiloides Conrad, 1841, Geol. Surv. N. Y., 5th An. Rep., p. 52. Modiomorpha planulata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 74. Modiomorpha mytiloides Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 277, pi. xxxvii, fig. 3; pi. xxxviii, flgs. 1-16. Modiomorpha mytiloides Clarke, 1903, N. Y. State Mus., Bull. 65, p. 450. Modiomorpha mytiloides Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 514, flg. 691b. 270 Systematic Paleontology — ^Middle Devonian Description. — Shell larger than the medium size, rhomboid-ovate, oblique ; length less than twice the height ; basal margin nearly straight, or very slightly concave anterior to the middle, curving to the anterior and posterior extremities; posterior margin abruptly curving below and more gently recurving toward the cardinal line; cardinal margin arcuate; anterior end narrow, extended, abruptly curved on the margin, somewhat defined by the sinus which extends from anterior to the beak to the middle of the shell. Valves moderately convex; in old shells gibbous in the umbonal region. Hinge-line oblique, extending to about the middle of the shell. Beaks appressed, situated a little more than one-fourth the length of the shell from the anterior end ; umbonal region not defined ; convex in young shells, becoming more gibbous in older individuals. Test of moderate thickness, concentrically striated with irregular lines of growth which are sometimes elevated into concentric ridges. The anterior muscular impression is well marked and situated just within the anterior margin below the beak. Length, from 50 to 91 mm. ; height, from S9 to 50 mm. The Maryland Collection contains a left valve, from the east bank of Evitts Creek below Wolfe Mill, from which the umbonal region is missing, that has been referred to this species. It is smaller than the normal speci- mens of this species and probably the shell had not reached maturity but the proportions of length and height agree with those of this species. The slope from the umbonal ridge to the cardinal line is more marked than in M. mytiloides and resembles more nearly that of M. suhalata but the con- centric striae and the marked contraction of the anterior end are distinc- tive characters of the former species. Another specimen of apparently an immature right valve of this species was found in western Maryland, the exact locality of which is unknown. Length, 36 mm. ; height, 31 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; on Hancock-Harrisonville Eoad about 3 miles north of Hancock. Collection. — Maryland Geological Survey. Maryland Geological Survey 371 Genus GONIOPHORA Phillips GONIOPHOEA hamiltonensis Hall Plate XXXIII, Figs. 11-13 Sanguinolites hamUtonensis Hall, 1870, Prelim. Notice Lamellibranchiata, il, p. 36. GoniopJiora hamiltonensis S. A. Miller, 1877, Cat. Amer. Pal. Foss., p. 192. Goniophora hamiltonensis Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibran- chiata ii, p. 296, pi. xliil, figs. 8-15, 17-21. Goniophora hamiltonensis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 390. Goniophora hamiltonensis Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 519, fig. 699c. Description. — " Shell large, trapezoidal ; length more than twice the height; basal margin gently cvrving, sometimes nearly straight and slightly affected by the sinus; posterior margin obliquely truncate; an- terior margin concave below the beak and abruptly rounded below; car- dinal line very slightly arcuate, extending for two-thirds the length of the shell. Valves moderately convex below the umbonal ridge, and con- cave above it to the cardinal line; bealcs subanterior, small, closely incurved, situated from one-fourth to one-sixth the length of the shell from the anterior margin; umbonal ridge angular, strongly, defined, arching over the beaks and extending in nearly a direct line to the post- basal extremity; umbonal region scarcely gibbous, separated from the anterior end by a broad undefined sinus, which becomes obsolete in some specimens. Test of moderate thickness, marked by regular, prominent, lamellose striae." Hall, 1885. A small, exfoliated and somewhat imperfect right valve was found on the road from Hancock to Harrisonville, Penna., which is referred to this species. It has a sharp and prominent umbonal ridge, extending in a direct line from the beak to the post-basal extremity, while the posterior margin is apparently quite truncate, characters which are diagnostic of this species. It resembles quite closely fig. 12, pi. xliii, ii Lamellibran- chiata, pt. i, vol. V, Pal. N". Y., and similar exfoliated specimens of this species in the New York State Museum. Length, 20 mm. ; height, 11 mm. 373 Systematic Paleontology — Middle Devonian Occurrence. — Eomney Formation, Hamilton Member. On Han- coek-Harrisonville Eoad about 3 miles north of Hancock. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Order ANOMALODESMACEA Superfamily ANATINACEA Family PHOLADELLIDAE Genus PHOLADELLA Hall Pholadella eadiata (Conrad) Plate XXXIII, Pigs. 14-16 NuoiiUtes radiata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vlii, p. 248, pi. xli, fig. 16. Pholadella radiata Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 63. Pholadella radiata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 469, pi. Ixxviii, figs. 15-21; pi. xcvi, fig. 1. Pholadella radiata Clarke, 1903, N. Y. State Mus., Bull. 65, p. 488. Pholadella radiata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 528, fig. 716. Description. — " Shell from small to medium size, elongate-ovate, cun- eate ; length about twice the height ; basal margin regularly rounded, curv- ing in a greater or less degree according to the age of the individual ; pos- terior extremity more or less obliquely, or sometimes vertically, truncate; anterior end short, obliquely truncated by the lunule and narrowly rounded below, lunule deep, marked by an abrupt incurving of the margin; escutcheon large and well defined; cardinal line straight; some- times a little concave. Valves, in their usual condition of preservation, moderately convex below and gibbous in the middle; beaks subanterior, prominent, strongly incurved; cincture extending from the beaks to the base of the shell as a marked depression and producing a slight sinuosity in the margin; umbonal slope prominent, often distinctly angular, extend- ing to the post-inferior extremity; post-cardinal slope gently concave, often marked by a slight fold along the middle or by two or more radii. Surface marked by fine concentric striae and anterior to the cincture Maryland Geological Sukvey 273 concentric ribs; also by strong radii diverging from the beak, usually marking that portion of the shell between the cincture and the umbonal ridge, sometimes covering the entire surface." Hall, 1885. A perfectly marked specimen of this species was found on the road from Hancock to Harrisonville, Pa., two miles north of Hancock, Washington County, on which the surface markings, so characteristic of this species, are well preserved. It was also reported by Hall from the HamiU ton group near Cumberland, Md. (Pal. N. Y., vol. v, pt. i, Lamel- libranehiata ii, p. 470) one specimen of which was figured (pi. xcvi, fig. 1). This species is readily identified by its small size; cuneate outline; prominent cincture extending from the beak to the base; concentric striae and ribs anterior to the cincture; prominent radii generally from the cincture to the umbonal ridge; and obliquely to vertically truncate pos- terior end. Length, about 20 mm., posterior end broken; height, 12 mm. Occurrence. — Komney Formation, Hamilton Member. On Han- cock-Harrisonville Eoad about 2 miles north of Hancock. Collections. — ^Maryland Geological Survey; New York State Museum; American Museum of Natural History. Order TELEODESMACEA Superfamily CYPRICARDIACEA Family PLEUROPHORIDAE Genus CYPRICARDELLA Hall Cypricardella bellistriata (Conrad) Plate XXXIY, Pigs. 1-4 Microdon lellastriata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 247, pi. xiii, flg. 12. Microdon lellastriata Hall, 1843, Geol. N. Y., pt. Iv, p. 196, fig. 2. Microdon lellastriata Rogers, 1858, Geol. Penna., vol. ii, p. 827, fig. 660. Microdon (Cypricardella) bellUtriatus Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchlata ii, p. 308, p). xlii, figs. 17-20; pi. Ixxlii, figs. 7-22; pi. Ixxiv, figs. 5-10. 18 274 Systematic Paleoxtologt — Middle Devonian Cypricardella helUstriatus Grabau, 1899, Bull. Buffalo Soc. Nat. Scl., vol, vi, p. 252, fig. 169. Miorodon {Gypricardella) helUstriatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 439. Gypricardella bellistriata Cockerell, 1905, Am. Geol., vol. xxxvl, p. 330. Gypricardella hellistriata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1, p. 535, figs. 727c, d. Description. — " Shell of medinm size or larger ; form subrhomboidal to STibelliptical ; extremely variable proportions of length and height vary- ing from a length of twice' the height, to a length of less than one-third greater than the height ; basal margin regularly curving anteriorly, often nearly straight in the posterior half; posterior margin almost vertically subtmncate, sometimes gently curving; anterior end narrowed, prolonged below and abruptly rounded at the extremity, constricted above by a dis- tinct limule; cardinal line nearly straight. Valves depressed-convex, becoming moderately convex in the umbonal region; beaks usually at about the anterior third, but often nearer the anterior extremity, small, closely appressed, scarcely rising above the hinge-line; umbonal slope continued as a low undefined ridge to the post-basal angle. Test of moderate thiclmess, marked by strong, even, angular striae, which continue nearly uniform in character over the entire shell." Hall, 1885. This species is common in the thinner, somewhat arenaceous Hamilton shales of Evitts Creek below Wolfe Mill. The specimens agree closely in form and markings with those figured from New York and they present similar variations in reference to the proportions of length and height. It was identified by Hall from the Hamilton shales near Cumberland, Md. (Pal. IST. Y., vol. v, pt. 1, Lamellibranchiata ii, p. 309) and the cardinal view of a specimen from this locality is figured (pi. xlii, fig. 17). The species is readily recognized by its form; nearly vertically truncate posterior end; projecting lower part of anterior end; and strong, even, angular concentric striae. Length, 26, 30, 34 mm. ; height, 31, 20, 36 mm. Occurrence. — Eomney Foematton, Hamilton Member. East bank Evitts Creek below Wolfe Mill ; Williams Road, I mile east of Queen City Hotel, Cumberland; B. & 0. B. E. cut at 21st Bridge; along Plintstone Creek in Gilpin. Maryland Geological Survey 375 Collections. — Maryland Geological Survey; American Museum of Nat- ural History. Cypricardella tenuistriata (Hall) Plate XXXIV, Fig. 3 Microdon tenuistriata Hall, 1870, Prelim. Notice Lamellibranchlata 2, p. 32. MicroCion (Cypricardella) termistriatus Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamelllbranchiata ii, p. 310, pi. xlil, Hg. 16; pi. Ixxiii, figs. 23-30; pi. Ixxiv, figs. 20, 21. Microdon tenuistriatus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 443. Cypricardella tenuistriata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1. p. 534, figs. 727a, b. Description. — " Shell large, quadrangularly subovate ; length one-fourth greater than the height ; basal mai'gin regularly curving ; posterior margin subtruncate, from oblique to nearly vertical and gently curving; anterior end rapidly declining from the beak and abruptly rounded below; car- dinal line gently arcuate. Valves depressed-convex below, rising into moderate convexity in the umbonal region; beaks at about the anterior third, small and appressed, rising a little above the hinge-line; umbonal slope scarcely defined, extending in a slightly arching direction to the post-basal extremity. Test thin, marked by fine, unequal, concentric striae, which are at intervals raised into lamelliform undulations." Hall, 188-5. A much smaller number of specimens belonging to this species was found than of C. hellistnata. Several characteristic specimens, however, were obtained and a figure of a cardinal view of a specimen of this species from the Hamilton group, at Cumberland, Md., was given by Hall (Pal. N. Y., vol. v, pt. 1, Lamellibranchlata ii, pi. xlii, fig. 16). This species is readily distinguished from C. bellistriata by its larger size; more strongly curving basal line; less prominent umbonal slope; and finer and less clearly defined striae. Length, 42 mm.; height, 39 + mm. Occurrence. — Eomney Formation, Hamilton Member. Williams Eoad I mile east of Queen City Hotel, Cumberland; on Hancock-Har- risonville Eoad about 2 miles north of Hancock. Collections. — Maryland Geological Survey ; American Museum of Nat- ural History. 276 Systematic Paleontology — Middle Devonian Genus CYPRICARDINIA Hall Cypeicaedinia indenta (Conrad) Plate XXXiy, Figs. 6-10 Cypricardites indenta Conrad, 1S42, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 244, pi. xii, fig. 12. Cypricardinia indenta Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 83. (In part.) Cypricardinia indenta Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 485, pi. Ixxix, figs. 6-16, 23; pi. xcvi, fig. 2. Cypricardinia indenta Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Cypricardinia indenta Clarke, 1903, N. Y. State Mus., Bull. 65, p. 378. Cypricardinia indenta Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 536, fig. 729c. Description. — " Shell of medium size^ subrhomboid-ovate shape ; length more than one-third greater than the height; basal margin nearly straight, slightly sinuate anterior to the middle; posterior extremity abruptly rounded below and obliquely truncate above; anterior end very short, rounded below ; cardinal line straight, oblique. Eight valve very convex, often extremely gibbous; left valve usually depressed convex below and posteriorly, becoming moderately gibbous in the umbonal region; beaks nearly anterior, small and appressed, rising but little above the hinge- line ; cincture distinct on the right valve, less marked upon the left one ; umbonal slope rounded and prominent on the right valve, subangular on the left one. Surface marked by extremely fine concentric striae and by unequally distant but somewhat regular lamellose, imbricating, concentric undulations; and in well preserved specimens the entire surface is marked by fine striae, which radiate from the apex of the shell." Hall, 1885. Several specimens of this species were collected; most of which were obtained from the shales on Evitts Creek below Wolfe Mill. They are tjfpical and do not differ in any noticeable respect from those figured from the Hamilton of N'ew York. Hall reported the species from Hardy County, [W.] Virginia (Pal. N". Y., vol. v, pt. 1, Lamellibranchiata ii, p. 486). Like a number of the other Pelecypoda found in the Maryland Hamilton it is a sharply defined species so that there is no uncertainty regarding its identification. Its most striking characters are the shape; the strong, unequally distant, lamellose concentric undulations: fine Maryland Geological Sdkvey 277 radiating striae; convex valves; slightly sinuate basal margin; and distinct cincture on right, which is not marked on the left valve. Length, 11 mm.; height, 6 mm. Occurrence. — Eomney Formation, HAMtLTON Member. East bank Evitts Creek below Wolfe Mill; B. & 0. E. E. cut at 21st Bridge. Collections. — ^Maryland Geological Survey; NeAv York State Museum; American Musemn of Natural History. ■ Superfamily LUCINACEA Family LUCINIDAE Genus PARACYCLAS Hall Paracyclas lirata Conrad Plate XXXIV, Figs. 11-14 Posidonia lirata Conrad, 1838, Geol. Surv. N. Y., An. Rep., p. 16, pi. [un- numbered], fig. 12. Lucina {Paracyclas) lirata Hall and Whitfield, 1872, Twenty-fourth An. Rep. N. Y. State Mus. Nat. Hist., p. 200. Paracyclas lirata Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, p. 441, pi. Ixxii, figs. 2-19 ; pi. xcv, fig. 19. Paracyclas lirata Clarke, 1903. N. Y. State Mus., Bull. 65, p. 483. Paracyclas lirata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 555, fig. 760b. Description. — " Shell of medium size, subcircular or broadly elliptical ; length a little greater than the height; margins regularly rounded; car- dinal line short, less than half the length of the shell. Valves moderately convex below, becoming gibbous on the middle and above; beaks anterior to the center, small, appressed, rising but little above the hinge-line; post-cardinal slope not defined. Surface marked by fine concentric striae, and by strong subangular concentric ridges, which are more or less sharply defined, depending upon the condition of the specimen and the nature of the matrix in which the fossil is imbedded." Hall, 1885. Several specimens of medium size of this species were collected and one of the large forms. These do not show any particular variation from the forms figured from New York and are clearly that ppecies. Their most 278 Systematic Paleontology — Middle Devonian prominent characters are their medium size; nearly circular outline; and strong, irregular concentric ridges. Length, medium size, 13, 13 mm. ; height, 12 mm. There is a large specimen from McCoys Ferry which is somewhat elon- gated by pressure and measures 39 mm. in length by 37 in height (plate xxxiv, fig. 15). This has very strong concentric ridges which usuall^y divide at a distance from the margins. It has not been separated from P. lirata., because but a single specimen is known although it may prove to be distinct enough to form a new variety. The specimen was submitted to Dr. Grabau who wrote " I think perhaps the stronger compound wrinkles would make this a distinct variety of P. lirata." Occurrence. — Eomney Formation, Hatmilton Member. East bank Evitts Creek below Wolfe Mill ( ?) ; McCoys Perry; southwest of McCoys Ferry; on Oldtown Eoad east of Maryland Ave., Cumberland; on Han- cock-Harrisonville Eoad about 3 miles north of Hancock; on ISTational Eoad in Gilpin; west of Lock No. 56 at Great Cacapon; W. Va. side Potomac Eiver about 3 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Paeacyclas tenuis Hall Plate XXXIV, Pigs. 16, 17 Paraoyclas tenuis Hall, 1883, Pal. N. Y., vol. v, pt. 1, plates and explanations, pi. Ixxii, figs. 20-22. Paraoyclas tenuis Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamelllbranehiata ii, p. 443, pi. Ixxii, figs. 20-22; pi. xcv, ng. 25. Paracyolas tenuis Clarke, 1903, N. Y. State Mus., Bull. 65, p. 485. Description. — "Shell small, subcircular; length and height about equal; margins regularly curving; cardinal line short. Valves moderately convex; beaks a little anterior to the middle, small, closely appressed, scarcely rising above the hinge-line; post-cardinal slope curved and rap- idly declining backward, limited by the ligamental groove, which is very distincth' marked. Test extremely thin; surface marked by very fine concentric striae, which are sometimes aggregated into fascicles toward tlie pallial margin." Hall, 1883. Maryland Geological Survey 279 The external impressions of two left valves apparently of this species were found in the thin shales of Evitts Creek. The shells are small, apparently thin, with length and height about equal, surface marked by very fine concentric striae and one specimen in addition shows rather indistinct concentric ridges. The valve with simply the fine striae is quite near specimens of this species which the writer has collected in the Hamilton beds of New York. Length, 8^ mm.; height, 9 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill. Collections. — ]\faryland Geological Survey; New York State Museum. Superfamily SOLENACEA Family SOLENIDAE Genus PALAEOSOLEN Hall Palaeosolen minutus n. sp. Plate XXXIV, Pig. 18 Description. — Shell solenoid and rather small; length three times the height; basal and cardinal margins nearly parallel, the cardinal straight and the basal slightly rounded toward the extremities; anterior end ap- parently rounded; posterior extremity truncate and probably gaping. Valves somewhat convex their entire length; beaks subanterior and not clearly defined; umbonal slope marked by a very indistinct diagonal groove. Surface anterior to the umbonal groove marked by fine concentric striae while posterior to it the impression apparently shows indistinct undulations. This species is apparently closely related to P. siliquoideus Hall but differs from it in its much smaller size and greater proportionate height. This specimen has only one-fifth the length and nearly one-half the height of P. siliquoideus. Length, 13 mm.; height, 4^ mm. Occurrence. — Eomney' Formation, Hamilton Member. Williams Eoad |- mile east of Queen City Hotel, Cumberland. CoZZeciiOM.— Maryland Geological Survey. 380 Systematic Paleontology — Middle Devoxian Class GASTROPODA Subclass STREPTONEURA Order ASPIDOBRANCHIA Suborder RHIPIDOGLOSSA Family PLEUROTOMARIIDAE Genus PLEUROTOMARIA Defrance Subgenus BEMBEXIA Oehlert Pleukotomaria (Bembesia) sulcomakginata Conrad Plate XXXV, Pigs. 1-5 Pleurotomaria sulcomarginata Conrad, 1842, Jour. Acad. Nat. Scl., Phila., vol. viii, p. 272, pi. xvi, fig. 13. Pleurotomaria sulcomarginata Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 46, pi. v, figs. 9, 10. Pleurotomaria sulcomarginata Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 69, pi. xix, figs. 8-17. Bembexia sulcomarginata lllricli and Scofield, 1897, Geol. Minn., vol. iii, pt. ii, p. 955. Bem'bexia sulcomarginata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 647, fig. 883. Description. — " Shell depressed troehiform; spine moderately elevated; apex minute; volutions four or five, very depressed convex on the upper side, gradually enlarging to the last one which becomes somewhat ventri- cose; aperture subquadrate, somewhat wider than high, the columella much extended below. Surface marked by two distinct, narrow, revolving carinae on each volution, one just below the suture, and the other near the periphery, with finer intermediate striae which are rarely visible; the entire surface marked by strong, regular and even concentric striae which crenulate the revolving carinae, and, passing over the lower one, bend backward to the concave peripheral band ; suture sometimes sharply canal- iculate." Hall, 1879. A considerable number of fairly large and smooth, with the exception of a convex band about the periphery of the last whorl, internal impres- sions occur in the Hamilton beds of Maryland and the adjacent part of Maryland Geological Survey 281 West Virginia. In addition, however, there are in some of the finer and more argillaceous shales rather badly crushed specimens of the shell which show distinctly the characteristic surface markings. Furthermore, Hall stated that "this species extends in a southwesterly direction to Maryland and Virginia " and that casts of the species from Maryland rounded or subangular on the periphery " measure one inch and a half in diameter, and one inch and three-eighths in height, and consist of about five distinct volutions " (Pal. N. Y., vol. v, pt. ii, p. 70) ; while a large internal cast from the Hamilton group at Cumberland is figured (see pi. xix, fig. 15). Large internal impressions agreeing in size, number of whorls and apparently all characters, except that perhaps the revolving band on the body- whorl is not so strong, with the figure Just mentioned were collected on the West Virginia bank of the Potomac Eiver, opposite bladder's Island, four miles south of Cumberland ; while specimens from the same side of the river about three miles south of Cumberland agree closely in form, strength of striae and other characters with figure 9 of the same plate which represents a specimen from the Hamilton of New York. Internal impressions and the outside of specimens from West Virginia and Maryland were compared with corresponding ones, labeled as belonging to this species, in the office of the New York State Paleon- tologist and found to agree satisfactorily. The most distinctive char- acters of the species are the shape, size, carinae and strong concentric striae. Length, 35, 32, 18 mm.; width, 40, 37, 22 mm. Occurrence. — ^Romney Pormation, Hamilton Member. East side Warrior Mt. east of Eush ; Town Creek Eoad at Geo. Diefenbaugh's ; on National Eoad ^ mile west of Tonoloway Eidge ( ?) ; west of iron bridge over Town Creek northeast of Oldtown ; on Oldtown Eoad east of Mary- land Ave., Cumberland; on Hancock-Harrisonville Eoad about 2 miles north of Hancock; Emstville; along Flintstone Creek in Gilpin; W. Va, side Potomac River 3 and 4 miles south of Cumberland; on road about half way between Romney and Hanging Eock, W. Va. ; on Romnfiy-Hang- ing Eock Eoad about i mile north of Eomney, W. Va. Collections.— MavylajiA Geological Survey; American Museum of Nat- ural History. 283 Systematic Paleontology — Middle Devonian Subgenus GYROMA Oehlert Pleueotomaria (Gyroma) capillaria Conrad Plate XXXV, Figs. 6-8 Pleurotomaria capillaria Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 271, pi. xvi, fig. 11. Pleurotomaria capillaria Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist, p. 45, pi. V, fig. 2. Pleurotomaria capillaria Hall, 1879, Pal. N. Y., vol. v, pt. il, p. 77, pi. xx, figs. 18-21. Pleurotomaria capillaria Clarke, 1903, N. Y. State Mus., Bull. 65, p. 555. Gyroma capillaria Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 647, fig. 882. Description. — " Shell turreted, one-fourth to one-third higher than wide; volutions four or more, somewhat rapidly increasing in size, the last one ventricose, subangulated above by two or three prominent re- volving earinae, and rounded on the lower side; aperture subrhomboidal. Surface on the upper side of the volutions marked by two or three re- volving earinae, with finer intermediate ones or strong striae, and all are crenulated by finer distant transverse striae; lower side of volutions marked by regular, strong, revolving cariniform striae, which are more approximate as they approach the umbilical depression, and all crenulated by concentric striae; peripheral band narrow and prominent, margins carinate, and the intermediate space marked only by curving striae; above and below the band, there is usually a broader smooth space than between the cariniform striae." Hall, 1879. A few specimens were obtained, mostly from Evitts Creek below Wolfe Mill, which possess the typical surface markings of this species. The proportions of height and width are nearly equal on one specimen and therefore do not agree with the above description, but the specimen is somewhat shortened by ■ pressure ; while in a smaller one that is not crushed the proportions are about normal. This species is xecognized most readily from its size, shape, and revolving striae which are never equal, and are crenulated by the finer transverse striae. Length, shortened by crushing, 17, 14 mm.; width, 17, 10| mm. Maryland Geological Sukvey 283 Occurrence. — Eomney Foemation, Hajiilton Member. East bank Evitts Creek below Wolfe Mill; on Hancock-Harrison villa Eoad about 2 miles north of Hancock; B. & 0. E. E. cut at Hancock Station, W. Va. (?). Collections. — Maryland Geological Survey; Xe\\- York State Museum; American Museum of Natural History. Subgenus TREPOSPIRA Ulrich and Scofield Plecrotomaria (Trepospira) rotalia Hall ( ?) Plate XXXV, Figs, 9, 10 Pleurotomaria rotalia Hall, 1861, Descriptions of New Species of Fossils, p. 18. Pleurotomaria rotalia Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 46, pi. V, fig. 11. Pleurotomaria rotalia Hall, 1879, Pal. N. Y., vol. v, pt. il, p. 71, pi. xix, figs. 20-25. Trepospira rotalia Ulrich and Scofield, 1897, Geol. Minn., vol. iii, pt. ii, p. 957. Trepospira rotalia Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 648. Description. — " Shell small, depressed-trochif orm ; apex minute ; spire consisting of about four volutions, which gradually expand to the aper- ture; slope of the spire from the apex to the periphery nearly in the same plane, being very slightly convex ; aperture subquadrate ; lower side concave, with a comparatively large umbilical depression, which is sur- rounded by a distinct areola. Surface very finely and closely striate parallel to lines of growth; striae not prominent, sometimes obscurely fasciculate, and always bending abruptly backward as they approach the narrow peripheral band ; suture line depressed and narrowly canaliculate, with sometimes a subdued or obsolescent revolving carina just below, near the upper margin of the volution." Hall 1879. The specimens are mainly broken, smooth, internal impressions not showing much more than the body-whorl and a part of the first volution of the spire, however, so far as preserved they apparently agree with figure 35 of the Palffiontology of New York which represents an enlarged 384 Systematic Paleontology — Middle Devonian smooth internal impression " of this species and further agree in having a less elevated spire than P. svlcomarginaia. On a portion of the body- whorl one specimen has preserved the surface markings; fine and close striae parallel to lines of growth like those of P. rotaliaj while there are no indications of revolving striae. It is thought that the low spire and fine concentric striae, which are the two, most distinguishing characters of P. rotalia, are sufficient evidence for referring these specimens with a question to this species. Length, not shown ; width, 13-19 mm. Occurrence. — Eomney Formation, Hamilton Member. McCoys Ferry; southwest of McCoys Ferry; National Eoad ^ mile west of Tonolo- way Eidge ; in Jennings Eun J mile west of Corriganville ; Ernstville. Collection. — Maryland Geological Survey. Subgenus EURYZONE Koken Pleurotomaria (Euryzone)itys Hall (?) Plate XXXV, Figs. 11-13 Turto Uneatus Hall, 1843, Geol. N. Y., pt. iv, p. 198, fig. 1. Pleurotomaria lineata Hall, 1861, Descriptions of New Species of Fossils, p. 16. Pleurotomaria lineata Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 44, pi. v, fig. 3. Pleurotomaria itys Hall, 1876, Illustrations of Devonian fossils: Gasteropoda, pi. 20. Pleurotomaria itys Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 76, pi. xx, figs. 8-17. Pleurotomaria itys Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Pleurotomaria itys Clarke, 1903, N. Y". State Mus., Bull. 65, p. 556. Euryzone itys Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 645, fig. 879e. Description. — "Shell turbinate; spire ascending, higher than wide; volutions four or five, regularly and evenly convex, gradually expanding to the body-whorl, which is ventricose, rounded below and concave in the middle ; umbilicus small or none ; aperture broadly oval, somewhat higher than wide. Surface marked by strong, regular, revolving striae on the upper and lower sides of the volutions, crossed and cancellated by fine, ^ Loo. cit., vol. v, pt. ii, pi. xix. Maryland Geological Survey 385 concentric striae, which are directed gently backward from the suture, and scarcely showing any greater curve as they approach the peripheral band; the band is of moderate width, simple, and limited on the two sides by a linear carina, within which the simple concentric striae make an abrupt retral curve; the concentric striae above and below the band are of similar character, while the revolving striae are finer on the lower side." Hall, 1879. The Maryland specimens are in the form of smooth internal impres- sions which show scarcely any structural markings. In size they agree very well with the specimen represented by figs. 11 and 13, pi. XX, pt. ii, vol. V, Pal. N. Y., but there is no indication of the sutural band, and apparently the body-whorl is not so closely attached to the base of the spire. Hall reported casts of this species in Maryland and [W.] Vir- ginia (loc. cit. p. 77) and gave two views of an internal cast (pi. xx, figs. 9 and 10) from Cumberland which show, however, somewhat faintly a spiral band on the last volution. Some of the specimens were submitted to Dr. Grabau who wrote as follows : " I should incline to 'P. itys, but these casts are so unreliable that I would not do more than refer it with a question mark." Length, about 20, 38 mm. ; width, about 18, 23 mm. Occurrence. — Eomnet Formation, Hamilton Member. Western Maryland; Williams Eoad, i mile east of Queen City Hotel, Cumber- land ; on National Eoad northeast of Cumberland ; Eobinson farm 2 miles south of Patterson Depot, W. Va. Collection. — Maryland Geological Survey. Genus BELLEROPHON Montf Subgenus BUCANOPSIS Ulrich Bellerophon (Bucanopsis) leda Hall Plate XXXVI, Figs. 1-3 Belleropnon leda Hall, 1861, Descriptions of New Species of Fossils, p. 30. Bellerophon leda Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 58. Bellerophon leda Hall, 1875, Twenty-seventh Rep. N. Y. State Mus. Nat. Hist., pi. Xiii, fig. 1. 286 Systematic Paleontology — Middle Devonian BelleropJion leda Hall, 1879, Pal. N. Y., vol. v, pt. il, p. 110, pi. xxiii, flgs. 2-16. Bucanopsis leda Ulrich and Scofleld, 1897, Geol. Minn., vol. lil, pt. li, p. 854. Bellerophon leda Clarke, 1903, N. Y. State Mus., Bull. 65, p. 524. Bellerophon (Bucanopsis) leda Clark and Mathews, 1906, Md. Geol. Surv., vol. vl, pi. xvii, flg. 12. Bucanopsis leda Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 623, ng. 837. Description. — " Shell subglobose, often a little flattened upon the dor- sum; body-whorl ventricose, very rapidly expanding; aperture very -wide; peristome abruptly spreading, broadly sinuate in front and sometimes with a deeper notch in the middle, the margin joining the volution a little on the ventral side, where it is thickened, somewhat abruptly curv- ing over and partially enclosing the small umbilicus. Surface marked by strong longitudinal or revolving striae, which alternate in size, are sometimes fasciculate, and often finer and more numerous on each side of the dorsal band than on the lateral portions of the shell; the ' revolving striae are cancellated by finer, subequal, thread-like transverse striae; the dorsal band is narrow, rarely elevated or sometimes scarcely raised above the surface, and usually flat or slightly concave, the concentric striae making an abrupt retral curve upon it in crossing." Hall, 1879. A broken specimen of this species was found in the thin argillaceous shales of Evitts Creek below Wolfe Mill. Although it is a very imper- fect specimen, still on account of the well preserved highly characteristic surface markings it is thought that there is no doubt regarding its identi- fication. The ventricose and expanded body-whorl; alternating revolv- ing striae, cancellated by transverse ones ; and ' flat dorsal band upon which the transverse striae make an abrupt retral curve are clearly shown and very distinctive characters. Length of imperfect specimen, 20 mm.; width, near front margin, 26 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Maryland Geological Survey 287 Subgenus PATELLOSTIUM Waagen Bellerophon- (Patellostidm) patulds Hall ( ?) Plate XXXV, Mg. 14 Bellerophon patulus Hall, 1843, Geol. N. Y., pt. iv, p. 196, fig. 1. Bellerophon patulus Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 57. Bellerophon patulus, 1879, Pal. N. Y., vol. v, pt. 11, p. 100, pi. xxii, figs. 17-30; pi. xxiv, figs. 3-10; pi. xxvi, figs. 10-12. Bellerophon patulus Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Patellostium patulus Ulrich and Scofleld, 1897, Geol. Minn., vol. lii, pt. ii, p. 854. Bellerophon patulus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 526. Ptomatis patulus Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 624, fig. 841. Description. — " Shell subglobose, ventrieose ; umbilicus small, closed before reaching the center; volutions rounded, the last one abruptly and widely dilated, giving a broad subcircular aperture, the width greater than the dorso-ventral diameter; the lip somewhat flattened and repand towards the exterior margin and broadly sinuate in front, contracted and more or less thickened at the postero-lateral margins, nearly inclosing and partially overlapping the volution on the posterior side, and extend- ing more or less entirely over the columellar lip in a thickened callus, the exterior portion of which is pustulose. Surface, on the expanded part of the outer volution, marked by fine, close, concentric striae, which are sometimes crowded in fascicles, giving an undulating surface; the posterior prominent part of the volution is marked on the back, and par- tially on the sides, by strong, even, arching costae, which are more abruptly and sometimes subangularly curved on the dorsal line. These costae sometimes continue for half the length of the volution anteriorly, gradually becoming obsolete on the middle and sides, and are never seen upon the broad expansion of the shell; the spaces between the costae marked by fine, close, concentric striae, and in well-preserved specimens, extremely fine revolving striae are sometimes visible. The interior cast is smooth. This shell can usually be readily distinguished by its widely expanded outer volution, the broad, shallow, sinuosity in the anterior 288 Systematic Palkontology — Middle Devonian- margin of the lip, and the absence of a]l markings on this part of the shell except striae of growth." Hall, 1879. In the Maryland Collection is a single smooth, broken and poorly pre- served internal impression which is doubtfully referred to this species. Hall states that " It is not rare in the form of casta near Cumberland, Md." (Pal. ]Sr. Y., vol. v, pt. ii, p. 103) and on comparison the specimen was found to agree as nearly with the interior views of some of the type specimens of this species in the office of the New York State Paleonto- logist as with those of any other species. Length, about 33 mm.; width of expanded part of lip more than 35 mm. Occurrence. — Eomney Fokmation, Hamilton Membee. Western Md. ; on road 1 mile north of Eomney, W. Va. ( ?) . Collection. — Maryland Geological Survey. Genus CYRTOLITES Conrad Subgenus CYRTONELLA Hall Cyktolites (Cyetonella) mitella Hall Plate XXXVT, Pigs. 4-7 Cyrtolites (?) mitella Hall, 1861, Descriptions of New Species of Fossils, p. 33. Cyrtolites mitella Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 61. Cyrtolites mitella Hall, 1876, Illustrations of Devonian Fossils: Gasteropoda, pi. XXV, figs. 16-18. Cyrtolites mitella Hall, 1879, Pal. N. Y., vol. v, pt. li, p. 123, pi. xxv, figs. 23-28. Description. — " Shell arcuate, subovoid, making altogether less than two volutions in the same plane ; the first volution very minute ; the body- whorl rapidly expanding to the aperture, which is nearly circular; the peristome scarcely spreading; the shell carinate, and the casts obtusely but distinctly angular on the dorsum; apparently not sinuate or but slightly undulated on the anterior margin. Surface marked by regular, sharply elevated, subparallel, transverse striae, which are comparatively distant (at least twice or thrice their width) near the apex and on the upper part of the outer volution, but become more crowded towards the front of the shell; on the upper part and sides of the shell the inter- Maryland Geological Survey 289 mediate spaces are regularly cancellated by short revolving striae which hardly rise so high as the transverse ones, giving the entire surface a pitted or finely reticulate character; approaching the margin, the spaces between these striae diminish, as the result of the rate of growth in the shell, and they often become so crowded as to present the character of simple undulating granulose lines of growth; the striae are not curved in passing over the rounded carina ; when the shell is partially exfoliated they give a lamellose-striate character to the surface. The fossil is usually found in the condition of casts of the interior, which preserve some marks of the transverse striae, but the exterior shell is rarely seen." Hall, 1879. There are internal impressions in the Maryland Collection which are referred to this species. The dorsum is conspicuously subcarinate, the transverse striae are clearly shown and are crowded toward the front of the shell, while the revolving striae are rather faintly shown on the upper part of one specimen. Length of largest specimen, about 23 mm. ; width, about the same. Occurrence. — Eomney Formation, Hamilton Member. About 4 miles north of Oldtown on road east of Pine Hill; B. & 0. E. E. cut at 21st Bridge; on National Eoad in Gilpin. Collections. — Maryland Geological Survey; American Museum of Katural History. Family TURBINIDAE Genus CYCLONEMA Hall Ctclonema hamiltoniae Hall (?) Cyclonema hamiltoniae Hall, 186.1., Descriptions of New Species of Fossils, etc., p. 19. Cyclonema TiamiUoniae Hall, 18G2, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 47, pi. V, fig. 16 (not 15). Cyclonema hamiltoniae Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 37, pi. xii, figs. 34-36. Bphaerodoma hamiltoniae Grabau and Shimer, 1909, N. Am. Index ;Fossils, vol. i, p. 701. Description. — "Shell subglobose-eonical ; height a little more than the width across the last volution ; volutions four or five ; apex minute and 19 390 Systematic Paleontology — Middle Devonian- gradually expanding to the body-whorl which is somewhat abruptly ventricose, flattened or a little concave for a short distance below the suture, and the space limited on the exterior side by a carina, which is the first of a series, marking the periphery of the volution. Surface marked by extremely fine lamellose lines of growth, which are directed backwards from the suture without bending or curvature in passing the carinations; the volutions, except the narrow concave space above, are marked by strong revolving elevated carinate lines, of which there are from fourteen to eighteen on the body- whorl; these carinae are usually simple and subequal, more or less distinctly defined, and sometimes alter- nately stronger and more subdued, or with two finer ones between the stronger; on each of the upper volutions there are three, four or five of these carinae preserved, and they are distinctly crenulated by the passage of the concentric striae, which are som.etimes also bent forward on ap- proaching the first carination." Hall, 1879. One specimen from the West Virginia side of the Potomac Eiver four miles below Cumberland shows very distinctly four whorls which are sim- ilar in form to those of this species. The surface markings, however, are imperfectly preserved; but on the upper half of the body-whorl are more or less clearly shown portions of seven revolving carinate lines. Similar carinate lines are very poorly shown on the lower half of this whorl, while the fine lines of growtli are scarcely shown at all. Length, 36 mm. ; width, 32 mm. Occurrence. — Eomnet Poemation, Hamilton Member. East side Warrior Mt. east of Eush; on Hancock-Harrisonville Eoad about 3 miles north of Hancock; W. Va. side Potomac Eiver 4 miles south of Cumber- land. Collection. — Maryland Geological Survey. Cyclonema libatdm var. geabaui n. var. Plate XXXVI, Pigs. 8, 9 Description. — Volutions four, subangular, sloping gradually from the suture to the first carinate ridge, of which two are visible on the upper Maryland Geological Survey 291 volutions and four on the upper half of the external impression of the body volution. The internal impression or mold of the body-whorl of this same specimen shows at least six carinate ridges or spirals. Surface marked by rather fine, closely arranged striae of growth. This description is based on the external and internal impressions of a specimen which is intermediate between C. liratum Hall and C. muUi- liratum Hall. It is probably nearer the former species and its most marked difference is in the greater number of carinate ridges on the body- whorl, since it probably has about eight while C. liratum is given as having about five, C. mtdtiliratum from ten to twelve, and C. hamiltoniae from fourteen to eighteen. There are some other rather slight differences in these species; but the variation in the number of carinate lines is the most conspicuous one. Dr. Grabau has clearly shown how these elevated lines or " spirals " increase in miraber in the development of this general type of Gastropoda. He says : " The primary ones are the first to appear, and they increase in number by the exogenous appearance of new ones on the upper and lower portions of the whorl, outside of those which appeared first. Secondary spirals appear ieiivemi the primary ones as these diverge, owing to the uniform increase in size of the whorls This teaches ua that in the primitive type of a series we may expect to find primary spirals only, even in the adult, and experience shows that these are char- acteristic of the earlier members of any series." ' These specimens were examined by Dr. Grabau who wrote as follows concerning the external impression : " This is most interesting. It is a form between G. liratum and C. hamiltoniae. It is nearer to C. liratum; but has a secondary spiral between the primary ones on the last volution. This indicates clearly a more accelerated condition than liratum; but these have not yet become so numerous as in hamiltoniae." Later he examined the internal mold and stated that it "gives evidence of additional spirals. While this is probably a descendant of the Ordovicic Cyclonemas it might be questioned whether it had not better be placed in a distinct genus." The name of this variety is given in honor of Dr. Grabau who first called my attention to " Araer. Nat, vol. xxxvi, Dec. 1902, p. 927. 293 Systematic Paleontology — Middle Devonian the importance of these carinate ridges in tracing the development of these species. Length, greater than 15 mm. ; width, probably more than 16 mm. Occwrrence. — Eomney Formation, Hamilton Member. Williams Eoad about S^ miles southeast of Cumberland and near the top of the Hamilton. Collection. — Maryland Geological Survey. Cyclonema ( ?) maeylandense n. sp. Plate XXXVI, Pig. 10 Description. — Shell subcorneal; width across the last volution a little less than the height (in tliis specimen about fths) ; volutions four. Body- whorl rather ventricose, upper portion sloping gradually from the suture to its conspicuous ventricose part ; the entire surface marked by revolving elevated lines of similar and medium strength of which there are about eighteen on the body-whorl, and eight or nine on the second whorl. In the number of revolving lines this specimen agrees quite closely with Cyclonema hamiltoniae Hall; but differs markedly from it in the grad- ually sloping upper part of the body-whorl marked by revolving lines while in the species Just cited tliat part of the body-whorl is more or less flattened and smooth. The collection contains but a single specimen of this species from west- em Maryland, the exact locality of which is unknown, which was sub- mitted to Dr. Grabau who wrote as follows : " I suppose the best thing to do would be to refer this to Cyclonema. I am, however, inclined with Ulrich to hold that there are no true Cyclonemas in the Devonic. The present specimen appears to be a more primitive type than the Ordovicic Cyclonemas, since the spiral lines are simple, i. e., only primary ones — as near as can be determined from this specimen — while typical Cyclonema eg. mix Conrad has intercalated spirals. Hall's C. doris from the Scho- harie is not unlike this, though I suspect his specimen was broken at the base. I should advise describing this specimen as Cyclonema ( ?) n. sp." Ulrich has expressed the following opinion regarding the Devonian Cy- Maryland Geological Survey 293 clonemas: "We have not had an opporttinity to examine any of the Devonian species that are referred to Gyclonema by various authors, but judging from the literature alone we feel satisfied that not one has a sufficient right to maintain its position in the genus." ^ Length, 26 mm. ; width, 22 mm. Occurrence. — Eomnet Formation, Hamiltost Member. W. Va. bank of Potomac Eiver 4 miles below Cumberland. Collection. — ^Marj'land Geological Survey. i^ATICOPSIS sp. Plate XXXVI, Fig. 11 Naticopsis sp. undet. Kindle, 1912, Bull. XJ. S. Geol. Survey, No. 508, p. 98, pi. viii, fig. 11. Description. — " Casts of a small species of Xaticopsis of undetermined identity occur in the dark shale at some localities." Kindle, 1912. Occurrence. — Eomney Formation, Onojjdaga Member. Williams Eoad 3y2 miles east of Cumberland. Collection. — U. S. National Museum. Order CTENOBRANCHIATA Suborder PLATYOPODA Superfamily GYMNOGLOSSA Family PYRAMIDELLIDAE Genus MACROCHILUS Phillips Macrochilcs hamiltoniae Hall Plate XXXVI, Figs. 12-15 MacrocMlus hamiltoniae Hall, 1861, Descriptions of New Species of Fossils, etc., p. 21. MacrocMlus hamiltoniae Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 49, pi. Iv, fig. 2. Macrochilus hamiltoniae Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 33, pi. xii, figs. 8-14. ' Geol. of Minn., vol. ili, pt. ii, 1897, p. 1058. 294 Systematic Paleontology — Middle Devonian Description. — " Shell very ventrieose; spire short, consisting of four or five volutions, the last one extremely ventrieose, making nearly two- thirds the entire height of the shell; aperture longitudinally oval, obtuse below. Surface distinctly striated by line lines of growth; suture-line deeply impressed/' Hall, 1879. The Maryland specimens arc all internal impressions which are almost if not quite smooth. The size and form of the shell, number of volutions, the ventrieose body-whorl which is about two-thirds the entire length of the shell (in one specimen the shell is 21 mm. in length and the body- whorl 14 mm.), and the deep suture-lines noted on the Maryland speci- mens are, however, quite distinctive characters of this species. Toward the aperture of several specimens are indications of somewhat strong folds, probably of growth and perhaps striae are faintly shown crossing the body-whorl in the same direction as the folds. Hall figured the opposite sides of an internal impression from the Hamilton at Cumberland, Md., which he called this species (Pal. N. Y., vol. V, pt. ii, pi. xii, iigs. 10, 11) and many of these specimens agree almost exactly with these two figures. The internal impressions are somewhat similar to those of Pleurotomaria itys Hall but do not show any indication of the spiral band which characterizes the internal impres- sions of that species. Length, 21-23 mm.; width, 18-19 mm. Occurrence. — Eomney Formation, Hamilton Member. Western Maryland. Collections. — ^Maryland Geological Survey ; American Museum of Nat- ural History. Genus LOXONEMA Phillips Loxonkma hamiltoniae Hall Plate XXXVI, Figs. 16-19 Loxonema nexilis Hall, 1843, Geol. N. Y., pt. Iv, p. 201 (not Phillips). Loxonema hamiltoniae Hall, 1861, Descriptions of New Species of Fossils, etc., p. 25. Maryland Geological Survey ^95 Loxonema hamiltoniae Hall, 1862, Fifteenth Rep. N. Y. State Gab. Nat. Hist, p. 53, pi. iv, fig. 8. Loxonema hamiltoniae Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 45, pi. xiii, figs. 15. 17. Loxonema hamiltoniae Clarke, 1903, N. Y. State Mus., Bull. 65, p. 539. Loxonema hamiltoniae Grabau and Shimer, 1909, N. Am. Index Fossils, vol. 1, p. 693, fig. 989. Description. — " Shell elongate; volutions moderately convex, about thir- teen in the largest specimens, verj' gradually increasing in size from the minute apex, the last one ventricose; aperture ovate, narrowing below; columella extended. Surface marked by longitudinal sharp, curving striae, which bend gently backward from the suture, and forward towards the base of the volution, having the greatest curve near the middle, those of the last volution curving abruptly backward to the columellar lip; striae separated by distinctly defined grooves which are a little wider than the ridges; the striae increasing in distance as the shell .grows older." Hall, 1879. A specimen in the Maryland Collection shows clearly five whorls and the impression of two additional ones. The volutions are fairly convex, crossed by rather coarse, sharp curving longitudinal striae, which are separated by grooves somewhat wider than the ridges. At the sutures there is no banding of the upper edge of the volution as in the closely related species of L. delphicola Hall, the absence of which together with the agreement of the other characters with those of L. hamiUoniae is regarded as proving the correctness of the identification of this specimen as L. hamiltoniae. All the type specimens of L. delphicola Hall in the ofiBce of the New York State Paleontologist show a prominent sutural band. Length of the last five volutions, 17 mm. ; width of last volution, about 8 mm. Occurrence. — Romney Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Hamilton Member. 41/^ miles northeast of Oldtown ; east bank Evitts Creek below Wolfe Mill ; on road about half way between Eomney and Hanging Rock, W. Va. ; on road 1 mile north of Romney, W. Va. ( ?) . 296 Systematic Paleontology — Middle Devonian Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Superfamily TAENIOGLOSSA Family CAPULIDAE Genus PLATYCERAS Conrad Platyoekas ekectum Hall ( ?) Plate XXXVII, Pigs. 1-3 AcrocuUa erecta Hall, 1843, Geol. N. Y., pt. iv, p. 174, fig. 6 on p. 172. Platyceras erectum Hall, 1861, Descriptions of New Species of Fossils, p. 4. Platyceras erectum Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 32. Platyceras erectum Hall, 1876, Illustrations of Devonian Fossils: Gastero- poda, pi. ii. Platyceras erectum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 5, pi. ii, figs. 4-11. Platyceras erectum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 549. Platyceras erectum, Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 683, fig. 963a. Description. — Shell regularly arcuate to the inrolled spire; nearly two volutions; the spire at the apex closely inrolled for about one and one-half volutions beyond which the body volution expands somewhat rapidly ; the aperture often spreading, not infrequently oblique with a sinuate perir stome. Surface marked by closely arranged, revolving, lamellose striae, which, upon the lower half of the body volution, are abruptly arched along narrow bands, corresponding with former sinuosities of the aperture. The collection contains several exfoliated and essentially smooth speci- mens which agree more nearly with this species than any other. The margins are very imperfectly shown but there are radiating bands or ridges shown on the lower part of the body volution of two specimens. The specimens were sent to Dr. Grabau with the question whether he would agree in referring them to P. erectum and he answered as follows : " That is as close as you can get I think. Each individual of Platyceras represents a distinct mutation, no two being exactly alike." Dr. Grabau has called attention to the difficulties attending the systematic study of Maryland Geological Suevey 297 the Devonian Platycera in the following language : " In the Devonian the phylogerontic [old aged] noncoiling Platycera abound. We find all degrees of coiling, from the close-coiled nonumbilicate Diaphorostoma, which appears with slight modifications throughout most of the series, to the straight ' Orthonychia,' which appears as a terminal member in most groups. Very often a number of species of ' Platyceras ' can be traced to a species of Diaphorostoma or Strophostylus occurring with them, the gradations being perfect. Prom such evidence it appears that the numer- ous species classed together as Platyceras must be split up into groups, each of which has been derived from a close-coiled ancestral species, prob- ably within the same geological horizon. If so, the name Platyceras becomes meaningless for generic purposes. The great difficulty which besets the proper breaking up of what appears most certainly to be a group of polj'phyletic origin lies in the small number of ornamental characters which can be made use of in tracing out relationships." ' Length of largest specimen, more than 23 mm. ; diameter from post- erior to anterior side of aperture, 11 mm. or more. Occurrence. — Eomney Foemation, Hamilton Member. On Han- cock-Harrisonville Road about 2 miles north of Hancock. Collection. — Maryland Geological Survey. PlATYCEEAS Cf. SYMMETEICUM Hall Plate XXXVII, Fig. 6 Description. — A single poorly preserved, exfoliated specimen which is incurved nearly in the same plane, the body-whorl expanded rapidly toward the front and about equally on each side of the dorsum while the surface shows obscure longitudinal ridges. The specimen was sent to Dr. Grabau who reported as follows : " I think no two Platycera ever agree. This. comes nearest to P. symmetricum it seems to me." Length, about 37 mm. ; transverse diameter of aperture, about 25 mm. ^ Am. Nat, vol. xxxvi, Dec. 1902, p. 939. 298 Systematic Paleontology — Middle Devonian Occurrence. — Eomney Foemation, Hamilton Member. East bank Evitts Ci-eek below Wolfe Mill. Collection. — Maryland Geological Survey. Genus DIAPHOROSTOMA Fischer DiAPHOROSTOMA LiNEATUM (Conrad) Plate XXXVII, Pigs. 7-12 Platyostoma Uneata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 276, pi. xvii, fig. 7. Platyostoma Uneata Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 21, pi. x, figs. 1-21. Diaphorostoma lineaium Clarke, 1901, N. Y. State Mus., Bull. 49, p. 131. DiapUorostoma Uneatum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 533. Diaphorostoma Uneatum Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, p. 680, fig. 953. Description. — ^" Sliell snbovate, approaching to subglobose; spire ele- vated above the body- whorl, though varying in degree; when entire, four or five volutions, but seldom preserving more than three, the apex being usually imperfect; the body-whorl usually very ventricose, regularly con- vex and a little depressed below the suture line ; aperture suborbicular in perfect specimens, sometimes siibrhomboidal ; outer lip thin, with a sharp entire margin, columellar lip thickened. Surface marked by fine, nearly equidistant, thread-like revolving striae, which are cancellated by fine concentric striae of about the same strength, but unequally distant. In well-preserved specimens, the surface is beautifully cancellated and in worn and partially exfoliated specimens, some remains of these surface markings are usually visible." Hall, 1879. This species is not common in Maryland but one specimen was obtained which apparently clearly belongs to this species. It shows three volution* of similar size, shape and appearance to the figures of this species from the Hamilton of New York, with the exception that the median part of the body-whorl is somewhat broadly ridged and not so regularly convex from the upper to the lower edge as represented in the figures. The surface markings are well preserved on portions of the last two volutions and show that it is beautifully cancellated, the revolving striae a little Maryland Geological Suevey 299 wavy and crossed bj' slightly finer concentric striae. The number of volutions, large ventricose body-whorl and cancellated surface are dis- tinctive characters of this species. Small, compressed specimens from Evitts Creek below Wolfe Mill and road east of Pine Hill about four miles north of Oldtown are identified by Dr. J. M. Clarke as " not very far from Platyostoma lineatum." Length, 33 mm. ; width, 27 mm. Occurrence. — Eomney FoRMiTioisr, Hamilton Member. Ernstville; Evitts Creek below Wolfe Mill ( ?) ; east of Pine Hill 4 miles north of Oldtown ( ?) ; lifational Eoad \ mile west of Tonoloway Eidge; southwest of McCoys Perry; west of Lock ifo. 56 at Great Cacapon. Collections. — Maryland Geological Survey; American Museum of Nat- ural History. Genus PLATYOSTOMA Conrad Platyostoma cf. BUOMrnALOiDES Conrad Plate XXXVII, Figs. 13-15 Platyostoma euomphaloides Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 25, pi. x, figs. 27-29. Platyostoma cf. euomphaloides Kindle, 1912, BulL U. S. Geol. Surv., No. 50S, p. 97. Description. — " Shell depressed subhemi spheric ; spire moderately ele- vated; volutions three or four, gradually enlarging from the apex — the last one expanded, not ventricose, with its exterior or periphery flat or slightly convex, and flattened or gently concave in the middle abo've; suture-line close. Aperture expanded, broadly subovoid ; the inner lip has thickened callous, which projects in a prominent rim along the posterior border of the aperture. Surface marked by fine concentric striae, which are crowded in fascicles." Hall, 1879. A crushed specimen bearing considerable resemblance to this species occurs in the collection. Occurrence. — Eomney Formation, Onondaga Member. Williams Eoad, 3% miles southeast of Cumberland. Collection. — IT. S. National Museum. [E. M. Kindle.] 300 Systejiatic Paleontology — Middle DEVoxLi^r Subclass EUTHYNEURA Order OPISTHOBRANCHIA Suborder PTEROPODA Family CAVOLINIIDAE Genus STYLIOLINA Karpinsky Styliolina fissueella (Hall) Plate XXXVII, Figs. 17-20 TentacuUtes fissurella Hall, 1843, Geol. N. Y., pt. iv, p. 180, figs. 9, 10 and p. 222, fig. 4. Styliola flssureUa Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 178, pi. xxxi A, figs. 1-28. Styliola (Styliolina) fissurella Clarke, 1885, Bull. U. S. Geol. Surv., No. 16, p. 57. Styliolina fissurella Clarke, 1891, Am. Geol., vol. vili, p. 88. Styliolina fissurella Clarke, 1892, Am. Jour. Sci., 3d ser., vol. xliii, p. 58. Styliolina fissurella Clarke, 1898, Fifteenth An. Rep. State Geologist [N. Y.], p. 54. Styliolina fissurella Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 282, fig. 214. Styliolina fissurella Clarke, 1903, N. Y. State Mus., Bull. 65, p. 570. Styliolina fissurella Clarke, 1904, N. Y. State Mus., Mem. 6, pt. 2, p. 342. Styliolina fissurella Grabau and Shlmer, 1910, N. Am. Index Fossils, vol. ii, p. 16, fig. 1229. Description.- — ■" Form an extremely slender, elongate cone, like the point of a small needle; apical portion of the tube solid; apex extremely minute, often bulbiform, and very gradually enlarging to the mouth. Surface often smooth and without any visible ornamentation, so far as can be determined ; or with fine striae of growth, which are unequally de- veloped on different parts of the shell ; also with fine longitudinal striae, which may be present with or without transverse striae ; usual length from one to two, sometimes two and a half, and rarely five millimeters." Hall, 1879. The Maryland specimens are smooth impressions except that the larger ones show very faint remains of transverse striae and a longitudinal depressed line along the central part of the shell which is probably due to pressure. This species is noted only infrequently in the Maryland Hamil- Maryland Geological Survey 301 ton beds, although in the succeeding Portage beds it is of common occur- rence. The distinguishing characters have been clearly stated by Pro- fessor Grabau as the "small size; needle-like form; minute, often bulbi- ferous apex; transverse and sometimes longitudinal striae; sharply de- pressed central fracture line in all the compressed specimens" (Bull. Buffalo Soc. Nat. Sciences, vol. vi, 1899, p. 283). Length 1-3 mm. ; width i/^ mm. at mouth of specimen 3 mm. in length. Occurrence. — Romnby Formation, Onondaga Member. Tonoloway, Md.; Williams Road, 3% miles east of Cumberland; B. & 0. R. R. cut at 21st Bridge; Hanging Rock, W. Va.; W. Va. Cent. R. R. cut at 21st Bridge. Marcellus Member. East of Oldtown. Hamilton Member. East bank Evitts Creek below Wolfe Mill ; west of iron bridge over Town Creek northeast of Oldtown ; Licking Creek east of Warren Point ; Emstville. Collections. — Maryland Geological Survey ; New York State Museum ; American Museum of Natural History. Suborder CONULARIDA Family TENTACULITIDAE Genus TENTACULITES Schlotheim Tentaculites attenuatus Hall Plate XXXVII, Fig. 21 ' Tentaculites attenuatus Hall, 1876, Illustrations Dev. Fossils: Pteropoda, pi. xxvi, figs. 19, 20. Tentaculites attenuatus Hall, 1879, Pal. N. Y., vol. v, pt. 11, p. 170, pi. xxxl, figs. 19, 20. Tentaculites attenuatus Gratau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 11. Description. — " Form elongate-conical, regularly expanding from the apex, and with no evidence of becoming cylindrical towards the aperture. The apical portion of the shell is very finely marked by acute annulations for a distance of about two and a half millimeters, without visible inter- mediate striae ; beyond this, toward the aperture, the annulations increase in distance, and the intermediate furrows are marked with one, two. 302 Systematic Palkoxtology^Middle Devonian three or more fine, regular, transverse striae — the usual number on the larger part of the tube being four or five, but sometimes increased, in exceptionally wide spaces, on some individuals, to eight."' Hall, 1879. Hall gave the entire length of the fossil as ten to twelve mm., rarely a little more and stated that it occurred as casts and impressions of the exterior shell in argillaceous sandstone. He also said that in general character and details of surface-marking it was very similar to T. Idlulus Hall, but differed in smaller size and in the irregularity in distance of the annulations. Among other localities it was reported from Saddleback Ridge, Huntingdon County, in southern central Pennsylvania. A number of specimens which are identified as this species have been noted in arenaceous shales or thiii-bedded sandstones in Maryland. They are mainly external impressions of the shell although occasionally a por- tion of the internal impression is preserved. The annulations occur at unequal distances between ivhich, near the aperture, are from three to five clearly marked striae, but the number of striae decrease toward the apical end until near that extremity there are none. Near the aperture of the shell there are eight annulations in a distance of 5 mm. It is thought that the size, irregularity in distance of the annulations, number and occurrence of the transverse striae satisfactorily refer these speci- mens to Tentaculites oMenuaius. Length, of most complete specimen, about 10 mm., but the extremity is wanting; width, at aperture, 1^ mm. Occurrence. — Eomney Pormation, Hamilton Member. On National Road \ mile west of Tonoloway Ridge; McCoys Perry; southwest of Mc- Coys Perry ; \ mile north of Green Spring Purnace. Collection. — Maryland Geological Survey. Tentaculites bellulus Hall Plate XXXVII, Pigs. 32-25 Tentaculites tellulus Hall, 1876, Illustrations Dev. Fossils: Pteropoda, pi. xxvl, figs. 15-18. Tentaculites heUulus Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 169, pi. xxxi, figs. 15-18, pi. xxxi A, figs. 48-51. Tentaculites hellulus Grabau and Shimer, 1910, N. Am. index Fossils, vol. ii, p. 11, fig. 1222. Makyland Geological Survey 303 Description. — Form extremely eloiigate-eonieal, slender, becoming more nearly cylindrical on approaching the mouth. The apical portion is extremely attenuate with regular and closely ai'ranged acute annulations, which near the apex are visible only under a strong lens, and the extreme portion is apparently smooth, the distance between the annulations in- creases toward the mouth and fine transverse, lamellose striae develop in the interspaces. The usual length is from 15 to 22 mm., and the largest individuals have a diameter at the mouth of nearly 3 mm. This species is distinguished from T. attenuatus by its larger size and regularity in distance of the annulations. Specimens longer than the preceding species with annulations at about a uniform distance apart, decreasing from the mouth toward the apex, the broader interspaces marked by fine transverse striae, are referred to this species. Length, about 14 mm. ; width, toward mouth, li/^ mm. Occurrence. — Eomney Poematiok, Hamilton Member. McCoys Ferry; vrest of iron bridge over Town Creek northeast of Oldtown; on road about half way between Eomney and Hanging Eock, W. Va. Collections.— MaxylKadi Geological Survey; American Museum of Nat- ural History. Textaculites bellulus var. potomacensis n. var. Plate XXXVIII, Figs. 1-3 Description. — External impressions which are more robust and longer than the normal forms of T. hellulus. The annulations are not so acute and have a steep posterior slope with a more gradual anterior one, while there is a larger number of transverse striae on the interspaces and slopes of the annulations. The size and number of striae apparently distinguish it from the normal specimens of tbis species. The specimen from McCoys Ferry was submitted to Dr. Grabau who wrote as follows : " I should be inclined to call it a variety of T. iellulus with some characters of T. scalariforrnis. Note the steeper posterior slopes of the anunlations:" 304 Systematic Paleontology — Middle Devonian Length of preserved portion, 25 mm. ; width, toward mouth, 3 mm. Occurrence. — Eomney Formation, Hamilton Member. McCoys Ferry; southwest of McCoys Perry. Collection. — Maryland Geological Survey. Family CONULARIIDAE Genus CONULARIA Miller Conularia ef . dndulata Conrad Plate XXXVIII, Pig. 4 Conularia undulata Conrad, 1841, 5th An. Rep. Pal. of N. Y., p. 57. Conularia undulata Conrad, 1861, Hall: Descriptions of New Species of Fossils, etc., p. 34. Conularia undulata Conrad, 1862, Hall: 15th An. Rep. N. Y. State Cab. Nat. Hist., p. 62. Conularia undulata Conrad, 1876, Hall: Illustrations of Devonian Fossils; Pteropoda, pi. 5. Description. — Form elongate-pyramidal, with a quadrangular base. Transverse section quadrangular, rhomboidal, with the faces subequal (equal ?) ; angles indented by the longitudinal grooves. Faces of the pyramid slightly convex in well preserved specimens, often entirely flat, or sometimes concave, the proportions modified from pressure; center of each face marked by a distinct shallow groove, along which there is a slight deflection of the transverse striae. Angles of the pyramid furrowed by a strongly marked groove, which is conspicuous in all conditions of the shell, and traversed by the surface-markings. Aperture of the fossil ■unknown. Summit truncated by a convex septum in the best preserved specimens. Shell extremely thin; in most of the specimens entirely dissolved. Surface, as determined from the best preserved specimens, and from external moulds, marked by fine transverse striae, which, upon the sides, are gentle curving towards the aperture, and slightly recurved in crossing the median groove, the striae are interrupted by minute pustulose eleva- tions, which give the surface, as seen under a strong lens, in its usual condition of preservation, a minutely crenulate or pustulose aspect. These elevations do not extend to the narrow interstriate spaces, which Maryland Geological Survey 305 are apparently quite smooth, and about twice as wide as the elevated striae, but vary with the growth and age of the shell. Hall, 1879. The collection includes six fragmentary specimens of Conularia. These are all more or less completely flattened, making specific determination uncertain. One of the specimens at least is comparable with and probably identical with C. undulata. Occurrence. — Romney Formation, Onondaga Member. Williams Road, 3y2 miles southeast of Cumberland. Collection. — U. S. National Museum. [E. M. Kindle.] Genus ENCHOSTOMA Miller and Gurley Enchostoma ? sp. Description. — The collection contains specimens of a cylindrical rod- like fossil about 1 mm. in diameter occurring in an earthy limestone. The specimens represent only fragments rather less than 1 inch in length composed of hard chitinous material. That these have had a con- siderable length is indicated by the barely perceptible amount of tapering seen in the individual specimens. Provisionally these may be referred to Enchostoma. Occurrence. — ^Romney Formation, Onondaga Member. Williams Road, 3% miles southeast of Cumberland. Collection. — ^U. S. National Museum. [E. M. Kindle.] Family TORELLELLIDAE Genus COLEOLUS Hall COLEOLUS tenuicinctus Hall Plate XXXVIII, Figs. 5-8 Coleoprion tenuicinctum Hall, 1876, Illustrations Dev. Fossils: Pteropoda, pi. xxvii, flgs. 1-4. Coleolus tenuicinctum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 185, pi. xxxii, flgs. 5-9, pi. xxxii A, flgs. 6-10. 20 306 Systematic Paleontology — Middle Devonian Coleoliis tenuicinotum Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 284, fig. 217. Coleolus tenuicinctum Kindle, 1901, Twenty-flfth An. Rep. Dept. Geol. & Nat. Res. Indiana, p. 735, pi. xxiii, flgs. 6, 7. Coleolus tenuioinctus Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 9, flg. 1219b. Description. — " Shell an extremely elongate, gradually and regularly tapering cone ; having in the largest individuals, a diameter of six milli- meters at the larger extremity, with a length of seventy-five millimeters. Surface marked by fine closely arranged striae, or frequently with more distant oblique annulations, receding from the aperature, or sinuate on the ventral side; interrupted longitudinal striae are visible in well pre- served specimens." Hall, 1879. Hall also stated that the specimens were generally in a crushed condi- tion and showed a line of fracture which may be mistaken for a longitudi- nal groove while the diameter and length vary to a considerable degree and no individual in the Hamilton shales has yet been found entire. Dr. J. M. Clarke has shown the presence of septa in another species described by Hall as Coleolus acicuJum and hence referred it to the genus Bactrites (Am. Geol., vol. xiv, 1894, p. 37, pi. ii, fig. 9) ; but so far as we are aware this character has not yet been observed in C. tenuicinctum and therefore the species is left in the genus Coleolus. The Maryland specimens are contained in an arenaceous shale and are long tapering cones which are flattened with a conspicuous longitudinal groove due to fracture. The more or less oblique annulations are well shown, but the concentric and longitudinal striae, very imperfectly. The specimens, however, are practically identical with many of this species which the writer has collected and examined from the Hamilton shales and there can be no question regarding their specific identity. Length of two longest specimens, which are broken and do not show complete length, 55 and 60 mm. ; width of both at larger extremity, 6 mm. Occurrence. — ^Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill; west of Lock No. 56 at Great Oaeapon. Collection. — Maryland Geological Survey. Maryland Geological Survey 307 Class CEPHALOPODA Subclass TETRABRANCHIATA Order NAUTILOIDEA Suborder ORTHOCHOANITES Family ORTHOCERATIDAE Genus ORTHOCERAS Breynius Oethoceras bebryx Hall ( ?) Plate XXXVIII, Mgs. 10, 11 Ortnoceras hebryx Hall 1876, 111. Dev. Fossils: Cephalopoda. Explanation pi. xxxix, figs. 1, 2. Orthoceras belryx Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 275, pi. xxxviii, fig. 10; pi. xxxix, fig. 2; pi. Ixxxiil, fig. 14; pi. Ixxxiv, figs. 11, 12. Orthoceras ielryx Clarke, 1903, N. Y. State Mus., Bull. 65, p. 618. Description. — Shell robust, straight, regularly enlarging from the apex ; transverse section, allowing for the degree of compression, subeircular. Living chamber not fully observed; air-chambers regular, increasing in depth from the apex, and varying in different individuals from six to ten mm. Septa smooth and thin, so far as observed; sutures, in specimens not distorted by compression, straight and horizontal; siphuncle monili- f orm, expanding between the septa, and having a diameter equal to, or two- thirds of, the depth of the air-chambers, the position is probably slightly eccentric. The test has not been preserved but the easts of the interior indicate a transversely lamellose-striate surface. A fragment, embracing a portion of the chamber of habitation and seventeen of the adjacent air- chambers, has a length of 330 mm. Several fragments of a large Orthoceras occur in the Maryland Col- lection, which probably belong to this species. They are mostly internal impressions, and the one figured shows apparently part of the living chamber and six air-chambers which vary in depth from 6^ to 9 mm. Another specimen shows a large chamber of habitation, which is flattened by crushing; while an external impression of a large specimen which 308 Systematic Paleontology — Middle Devonian- appears to be closely related to 0. hebryx, if not identical, shows trans- verse striae crossed by longitudinal ones giving the surface a reticulated appearance somewhat similar to that of 0. linteum Hall. Length of living chamber, 59 mm.; width near larger end, 48 mm.; length of six air-chambers following chamber of habitation of another specimen, 50 mm. Occurrence. — Romney Formation, Hamilton Membee. Oldtown Eoad near Cumberland; west of Lock No. 56 at Great Cacapon; on Old- town Eoad east of Maryland Ave., Cumberland ; on road east of Pine Hill about 4 miles north of Oldtown. Collection. — Maryland Geological Survey. Oethoceras subulatum Hall ( ?) Plate XXXIX, Mgs. 1, 2 Orthoceras suhulatv.m Hall, 1843, Geol. N. Y., pt. iv, p. 180, flg. 1. Orthoceras suiulatum Rogers, 1858, Geol. Penna., vol. ii, p. 826, fig. 654. Orthoceras subulatum. Hall, 1862, Fifteentli Rep. N. Y. State Cab. Nat. Hist., p. 77. Orthoceras suiulatum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 283, pi. xxxviii, fig. 3; pi. Ixxxlv, figs. 1, 2, 4, 6-10; pi. Ixxxvi, figs. 1, 2. Orthoceras suhulatum Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 288, fig. 221 on p. 287. Orthoceras subulatum Clarke, 1903, N. Y. State Mus., Bui. 65, p. 641. Orthoceras (Geisonoceras) subulatum Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 52, fig. 1252b. Description. — Shell straight, regularly enlarging from the apex nearly to the aperture; transverse section circular. Living chamber well devel- oped, having a length equal to about three times its diameter at the last septum, regularly expanding to a point near the aperture where it is slightly contracted ; air-chambers numerous, increasing in depth from the apex to the outer chamber, where the depth is about 3 mm. Septa smooth and thin ; siphuncle small and subcentral. Test thin, surface marked by very fine, irregular, lamellose striae of growth; some of the specimens show longitudinal striae, and more rarely very fine, filiform, longitudinal markings. The internal mould is essentially smooth, specimens from the softer shales often presenting a black and polished appearance ; the indi- Maeylakd Geological Survey 309 viduals never reaching a large size, nearly entire examples have a length of from 85 to 130 mm. The Maryland specimens are fragmentary and very imperfectly pre- served ; but smooth internal molds and fragments of external impressions with the outline and markings of this species have been referred to it. On comparison they were found to agree fairly well with specimens labeled as this species which are in the office of the State Paleontologist of New York; while the smooth, internal impression of a living chamber which is figured was submitted to Dr. J. M. Clarke, who reports that it is probably safe to refer it to 0. suiidatum Hall rather than 0. constric- ium Van., since the constriction is wanting which is the most important difference between the two species. The longest fragment in the collection has a length of 60 mm. Occurrence. — Eomnet Formation, Onondaga Membek. Williams Eoad, 3% miles southeast of Cumberland. Hamilton Membee. On W. Va. side Potomac River 3 miles south of Cumberland ; on road about half way between Eomney and Hanging Eock, W. Va. ( ?) . Collection. — Maryland Geological Survey. 0RTH0CEE.A.S CONSTRICTUM Vanuxcm Plate XXXIX, Figs. 5-8 Orthoceras constriotum Vaniixem, 1842, Geol. N. Y., pt. iil, p. 152, fig. 1. Orthooeras constrictum Hall, 1862, Fifteenth Rep. State Cab. Nat. Hist., p. 77. Orthoceras constrictum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 288, pi. Ixxxiv, figs. 13, 14, 16; pi. ixxxv, figs. 5, 10, 11, 13. Orthoceras constrictum Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Orthoceras constrictum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 621. Orthoceras constrictum Clark and Mathews, 1906, Md. Geol. Surv., vol. vi, pi. xvii, fig. 14. Orthoceras constrictum Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 51, fig. 1251. Description. — Shell straight, regularly enlarging from the apex to the chamber of habitation ; transverse section circular. Living chamber cylin- drical, well developed, having a length equal to four times the diameter at the last septum; anterior to the middle there is a very broad, gentle con- striction, which, in its position and strength, varies considerably, some- 310 Systematic Paleontology — Middle Devonian times becoming a very conspicuous feature; air-chambers numerous, regular, with a depth of from two to three mm. Septa smooth and thia; sutures straight and horizontal; siphuncle central. Test not preserved but some of the impressions show traces of lamellose striae of growth; the internal impression of the chambers is smooth, with the sutures but little impressed. This species is distinguished from 0. subulatum by its con- stricted and much more developed chamber of habitation; in the depth of the air-chambers and the position of the siphuncle the two species are very similar; it is further removed from 0. exile by the depth of the air-cham- bers and its central siphuncle. This species is represented in the Maryland Collection by a single fragment of a living chamber from the Oldtown Eoad near Cumberland; but the chajacteristie constriction is well shown and there is apparently no question but that it belongs to this species. Hall also reported the species at Cumberland, Md.^ Later, additional specimens were obtained from other localities. Length of the preserved part of the chamber of habitation, 38 mm.; width, about 19 mm. Occurrence. — Eomnby roEAiATiON, Hamilton Member. Oldtown Eoad near Cumberland; east bank Evitts Creek below Wolfe MiU (?); on Oldtown Eoad east of Maryland Ave., Cumberland; on road 1 mile north of Eomney, W. Va. ( ?) ; Wl Va. side Potomac Eiver about 3 miles south of Cumberland. Collections. — -Maryland Geological Survey; New York State Museum; American Museum of Natural History. Oethoceras ef. exile Hall Plate XXXIX, Fig. 9 Orthoceras exile Hall, 1861, Desc. New Species of Fossils, etc., p. 50. Orthoceras exile Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 78. pi. viii, fig. 5. Orthoceras exile Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 290, pi. xxxix, fig. 3; pi. Ixxxiv, fig. 3; pi. Ixxxv, figs. 1, 2, 14, 15. Orthoceras exile Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. ' Pal. N. Y., vol. V, pt. ii, p. 289. Maryland Geological Survey ail Orthoceras exile Grabau, 1899, Bull. Buffalo Soc. Nat. Scl., vol. vi, p. 288, fig. 222 on p. 287. Orthoceras exile Clarke, 1903, N. Y. State Mua, Bull. 65, p. 625. Orthoceras exile Grabau and Shimer, 1910, N. Am. Index Fossils, vol. 11, p. 52, fig. 1252a. Description. — Shell straight, slender, regularly and gradually enlarging from the apex; transverse section circular. Living chamber cylindrical, large, length equal to more than three times the diameter at the last septum; air-chambers numerous, increasing in depth toward the outer chamber, varying from two or three mm. to five mm. in the length of 100 mm., or about thirty chambers. Septa smooth and thin; sutures straight and horizontal ; siphuncle eccentric, distant from the nearest point on the walls of the air-chambers about one-third the diameter of the tube. Test and surface markings not observed; internal mold smooth, showing no traces of the surface markings. This species differs from 0. constridum and 0. subulatum m its eccentric siphuncle and more distant septa; while the septa are comparatively more frequent than in 0. telamon and 0. emaceratum, and the siphuncle is smaller and less eccentric than in the former. The Maryland specimens which are compared with this species are all fragmentary and part of them greatly flattened by crushing, so that the material scarcely admits of accurate specific identification. The depth of the air-chambers, however, varies from 3| to 4 mm. and the siphuncle is eccentric, characters which agree with those of 0. exile. Prof. Hall reported this species from Hamilton rocks at Cumberland, Maryland.* Occurrence. — ^Eomhtey FoRMATiour, Hamilton Member. Bast bank Bvitts Creek below Wolfe Mill. Collection. — ^Maryland Geological Survey. Orthoceras telamon Hall (?) Plate XL, Figs. 1-4 Orthoceras telamon Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 291, pi. Ixxxv, figs. 3, 4, 12. Orthoceras telamon Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 289, fig. 223 on p. 288. Orthoceras telamon Clarke, 1903, N. Y. State Mus., Bull. 65, p. 642. =■ Pal. N. Y., vol. V, pt. 11, p. 291. 313 Systematic Paleontology — Middle Devonian Description. — Shell straight, regularly and gradually enlarging from the apex; transverse section circular. Living-chamber cylindrical, well developed, having a length about three times the diameter of the tube at the last septum, and without any marked constriction or expansion toward the aperture; air-chambers regular, having a depth of iive mm. where the diameter of the tube is nine mm., and of eight mm. where the diameter is twenty mm. Septa apparently smooth and thin, the margins sometimes slightly thickened, and with a concavity equal to an arc of about 110° ; sutures straight, and somewhat oblique in a dorso-ventral direction; siphuncle large, eccentric, less than one- third the diameter of the tube from the ventral walls, with a diameter of two mm. where the tube measures twenty mm. in diameter, and diminishing but slightly toward the apex. Test and surface markings not preserved; internal mold smooth with the exception of a low, longitudinal ventral carina. This species is distinguished from 0. exile by the carina on the internal mold, the comparatively deeper air-chambers, and the more eccentric position of the siphuncle; it also closely approaches 0. emaceratum in several features, but the septa are a little more frequent, The specimens in the Maryland Collection referred to this species are broken and not very satisfactory for identification; but one shows five air-chambers or camerae each of which has a depth of five mm. and another large internal impression of a living chamber shows in the sep- tum at its base the siphuncle which is very eccentric, considerably more so than it is represented in the figure of 0. exile and agreeing with that of 0. telamon^ These specimens were submitted to Dr. J. M. Clarke who wrote as follows concerning them : " These specimens have rather deeper camerae and a more cylindrical body chamber than 0. exile, in these respects approaching more nearly 0. telamon H." Occurrence. — Eomney Poemation, Hamilton Membee. Eobinsons Farm 2 miles south of Patterson Depot, "W. Va. Collection. — Maryland Geological Survey. ' Pal. N. Y., vol. V, pt. li, pi. 85, flgs. 2 and 4. Maeyland Geological Suevey 313 Oethoceeas emaceeatum Hall ( ?) Plate XL, Fig. 7 Orthoceras emaceratum Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 170, pi. viii, fig. 7. Orthoceras emaceratum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 292, pi. xxxix, -fig. 4; pi. ixxxv, fig. 16. Orthoceras emaceratum Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 290, fig. 225 A on p. 289. Orthoceras emaceratum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 624. Description. — Sliell straight, slender, gradually enlarging from the apex; transverse section subeircular. Living-chamber not seen; air- chambers regular, gradually increasing in depth toward the living- chamber, varying from six to nine mm. in the length of eighty mm. Septa and siphuncle unknown; sutures straight and horizontal. Test not preserved, but some specimens show traces of transverse striae; in- ternal mold smooth, with the sutures but little impressed. One frag- ment, with twenty air-chambers, has a length of 125 mm., with a diameter at the smaller end of ten mm. The distinguishing characters are the depth of the chambers, compared with the diameter of the tube, and the small apical angle. In its general aspect and association it is similar to 0. aulax; but the marked surface ornaments on the latter species, which are also shown on the internal mold, are characteristic. In the Maryland Collection is a single flattened internal impression which probably belongs to this species. Five air-chambers and a portion of the sixth are shown which vary in depth from 6 to 6J mm. This specimen was examined by Dr. Eudolph Euedemann, who wrote as fol- lows concemiag it : " This is 0. emaceratum Hall, distinguished by its small apical angle and great depth of the air-chambers." Occurrence. — Komney Poemation, Hamilton Membee. W. Va. side Potomac Eiver 3 miles south of Cumberland. Collection. — Maryland Geological Survey. Oethoceeas cf. aulax Hall Plate XL, Fig. 8 Orthoceras anilax Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 293, pi. Ixxxiv, fig. 18. Orthoceras aulax Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, p. 289, fig. 224 on p. 288. Orthoceras aulax Clarke, 1903, N. Y. State Mus., Bull. 65, p. 618. 314 Systematic Paleontology — Middle Devonian Description. — " The tube is slender and the enlargement very gradual. Air-chambers, septa and siphuncle unknown. Surface marked by reg- ular, numerous, low, rounded transverse ridges, about twelve in the space of ten mm. ; the interspaces, or furrows, are regularly concave, and have a width equal to the ridges; portions of the surface also show that it was traversed by fine, sharp, longitudinal striae, crossing the ridges." Hall, 1879. The Maryland specimen is apparently a fragment of the living cham- ber 80 mm. in length which is marked by transverse ridges and furrows with 10 to 13 ridges in the space of 10 mm., and in appearance very similar to those represented on the figure of this species in the Palaeon- tology of New York.' Occurrence. — Eomney Foemation, Hamilton Member. Eoad east of Pine HUl about 4 miles north of Oldtown. CoZZecfMK.— Maryland Geological Survey. Family KIONOCERATIDAE Genus SPYROCERAS Hyatt Spyrocekas ceotalum (Hall) Plate XLI, Pigs. 1-5 Orthoceras crotalum HaU, 1861, Descriptions of New Species of Fossils, etc., p. 50. Orthoceras crotalum Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist, p. 78. Orthoceras crotalum Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 296, pi. xlii, figs. 1-9, 11, 12; pi. Ixxxii, figs. 1-6; pi. cxiii, fig. 13. Spyroceras crotalum Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Orthoceras (.Spyroceras) crotalum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 622. Spyroceras crotalum Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 64. Description. — Shell straight, regularly and rapidly enlarging from the apex, and becoming cylindrical toward the aperture; transverse section subcircular. Living-chamber small, cylindrical; length about two and a ^ Vol. V, pt. Ii, pi. 84, fig. 18. Maryland Geological Survey 315 half times the dieuneter at the last septum; aperture entire, without special contraction or expansion; air-chambers regular, numerous, more frequent than the annul ations; with a depth of about three mm. Septa smooth and thin ; sutures straight and horizontal, and bearing no uniform relation to the frequency or curyature of the annulations ; siphuncle sub- central. Test very thin, rarely preserved; tube ornamented with promi- nent annulations, which become more frequent and less marked toward the apex; on the chamber of habitation the annulations are very sharp and elevated, often curved and oblique ; the tube, for a distance of twenty mm. or more back of the aperture, is cylindrical and without annula- tions, but is marked by lamellose lines of growth. Surface marked by fine, regular, sharp, continuous longitudinal striae, crossed by finer, crowded, irregular striae, about fifteen to twenty longitudinal striae in the space of two mm. ; the internal mold is essentially smooth, with the exception of the prominent annulations. This species is distinguished from S. nuntium by its more prominent and less frequent annulations and from 8. caelamen by its continuous sharp, longitudinal striae and more elevated annulations. The Maryland Collection contains a single, small and broken specimen labeled simply Western Maryland, which apparently belongs to this species. It is marked by similar prominent annulations and about the same dis- tance apart, 6 mm. on this specimen, while the air-chambers are about 3 mm. apart, more frequent than the annulations and marked by continuous longitudinal striae. It agrees well with specimens in the ofiice of the State Paleontologist of New York which are labeled this species, as well as with a portion of one of the type specimens.* Later, additional specimens were collected from the localities named below. Occurrence. — ^Eomney FoRMATioi«r, Hamilton Member. Western Maryland; Emstville; W. Va. side Potomac Eiver about 3 miles south of Cumberland; on road 1 mile north of Eomney, W. Va. ( ?) . Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. • Pal. N. Y., vol. V, pt. ii, pi. 82, fig. 1. 316 Systematic Paleontology — Middle Devonian Spyeooeeas nuntium Hall Plate XLI, Pigs. 6-8 Orthoceras nuntium Hall, 1861, Descriptions of New Species of Fossils, etc., p. 51. Orthoceras nuntium Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 79, pi. viii, figs. 3, 4. Orthoceras nuntium Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 299, pi. xliii, figs. 4-10, 13, 14; pi. Ixxxii, figs. 14, 15. Orthoceras nuntium Grabau, 1899, Bull. Buffalo Soc. Nat. Sci., vol. vi, p. 290, fig. 225 on p. 289. Orthoceras (Spyroceras) nuntium Clarke, 1903, N. Y. State Mus., Bull. 65, p. 633. Spyroceras nuntium Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 64, fig. 1272. Description,. — Shell straight, regularly and rapidly enlarging from the apex; transverse section subcircular. Air-chambers regular, numerous, having a depth of 2 mm. where the tube has a diameter of 10 mm., and are of about the same frequency as the annulations. Septa smooth, with a concavity equal to more than the depth of the adjacent air-chambers; sutures straight and horizontal, essentially corresponding to the annula- tions; siphuncle subcentral, moniliform. Test very thin, rarely pre- served; tube ornamented with regular, numerous, horizontal annulations. Surface marked by regular, fine, thread-like, longitudinal striae, which are crossed by finer, less prominent lines of growth; the longitudinal striae are usually continuous, but are occasionally interrupted by the lines of growth, of which there are about twelve in the space of two mm. ; on the internal mold the striae are usually impressed, but they appear as if rounded and continuous, and do not present the sharp, threadlike character as on the interior. A large fragment has a length of 140 mm., and shows forty-two annulations; portions of smaller individuals show from four to six annulations in the length of ten mm., varying with the diameter of the tube. This species is distinguished from 8. crotdum by its more frequent and less prominent annulations, and by the somewhat coarser longitudinal striae ; while it differs from 8. caelamen in not hav- ing the longitudinal striae rounded and often interrupted by lamellose lines of growth. Maeylakd Geological Survey 317 There is a single broken specimen in the Maryland Collection which is 36 mm. in length, 17 mm. wide and shows six annulations which are about 3 mm. apartj not so strong and distant as those of S. crotalum, but similar to the figures of 8. nuntiwm. A bit of the test is preserved at one end showing the fine, thread-like longitudinal striae, which alternate slightly in size as is stated to be the case for at least some specimens of this species,^ with ten to twelve in a space of two mm., crossed by finer transverse striae. Occurrence. — Eomney Formation, Hamilton Member. W. Va. side Potomac Eiver 3 miles south of Cumberland. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History. Spyroceras clarkei n. sp. Plate XLI, Pigs. 9-11 Description. — An annulated broken, compressed specimen which has a total length of about 60 mm., and diameter of about 23 mm., showing three annulations on one side and five on the other, is referred to this genus. The annulations are broadly rounded, about 10 mm. vertically from the center of one to the center of the adjacent one and separated by a broad, rounded sinus. Surface marked by distinct, raised, uniform, con- tinuous longitudinal striae which are crossed by regular concentric striae of nearly the same strength, forming a slight node at the point of inter- section, both at about the same distance apart so that the surface is com- posed of squares or rectangles with a height and width of about 1 mm., inside of which on part of the surface are faint vertical and concentric striae which are perhaps due to crushing. This species is somewhat similar to Spyroceras geneva Clarke from the Onondaga limestone of New York; ' but it differs in having a more slender tube, much broader sinus between the annulations and longitudinal and concentric striae of nearly equal strength, instead of the longitudinal '■ Pal. N. Y., vol. V, pt. ii, pi. 43, explanation of fig. 7. ' lath An. Rep. State Geologist [N. Y.], 1894 [1895], p. 168, pi. 2, figs. 5-7. 318 Systematic Paleontology — Middle Devonian being much stronger as in iS^. geneva. In general appearance and surface markings it is very similar to some specimens of the Dictyospongidae and the •writer at first regarded it as a new species of the genus Ceratodidya and related to C. annvlata (Hall)/ The specimen, however, was later sent to Dr. J. M. Clarke, in whose honor the specific name is given, who referred it to the genus Bpyroceras and this identification is accepted by the writer. Dr. Clarke wrote the following note concerning this speci- men: "Notwithstanding the remarkable similarity between this speci- men and the typical forms of the dietyosponge, Ceratodictya (C. annu- lata and C. centeta) the characters of the exterior lead me to the con- viction that it is not a sponge but an Orthoceras. These features favor this view: the longitudinal ridges are too regularly continuous and equidistant and they are caught up slightly where crossed by the con- centric lines. Interstitial lines almost fail except where developed by compression. In a sponge these should be as evident as the major lines. The prevailing ornament in Orthoceras of the Dawsonoceras and Spyroceras types approaches very closely the reticulation of a dietyo- sponge; but compare with this specimen my Orthoceras (Spyroceras) geneva (Onondaga limestone) in 13th Eept. K. Y. Geologist." Occurrence. — Romney Formation, Hamilton Member. Ernstville. Collection. — Maryland Geological Survey. Suborder CYRTOCHOANITES Family PHRAGMOCERATIDAE Genus GOMPHOCERAS Sowerby Cf. GOMPHOCERAS PIN6UE Hall Plate XLII, Figs. 1, 3 Gomphoceras pingue Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 346, pi. xciv, fig. 9; pi. xcv, fig. 6. Gomphoceras pingue Clarke, 1903, N. Y. State Mus., Bull. 65, p. 593. Description. — Gomphoceras pingue was described by Hall as follows: " Shell small, gibbous, slightly arcuate ; transverse section very broadly *15tli An. Rep. State Geologist [N. Y.], vol. ii, 1898 [1899], p. 860, pi. 22, figs. 3-6. Maryland Geological Survey 319 oval or subcircular ; point of greatest gibbosity posterior to the middle of the living-chamber ; apical angle abont 30°. Living-chamber gibbous, with the sides convex, and sloping gradually to the aperture ; crenulated band not well defined, but the markings are preserved over the cast of the walls of the air-chambers as broad, shallow, longitudinal furrows. Air-chambers regular, having a depth of about 4 mm. ; septa smooth, moderately con- cave ; sutures, in uncompressed specimens, straight and horizontal. Test and surface markings unknown; internal mold smooth, with the excep- tion of the crenulations over the walls of the air-chambers; sutures but slightly impressed. A fragment embracing a portion of the living- chamber, with five attached air-chambers, has a length of 50 mm.; of which about 30 mm. pertain to the grand chamber, which has a greatest transverse diameter of 40 mm." The Maryland specimen is apparently part of a living-chamber with a length of about 72 mm. and width of 58 mm., which is slightly arcuate, quite convex, sides sloping and siphuncle eccentric. Occurrence. — Eomney Formation, Hamilton Member. Western Maryland. Collection. — ^Maryland Geological Survey. Order AMMONOIDEA Suborder MICROCAMPYLI Family BACTRITIDAE Genus BACTRITES Sandberger Bacteites aciculatus (Hall) Plate XLII, Fig. 4 Dentalium aciculatum Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 107. Ooleolus (Dentalium (?)) aciculatum Hall, 1879, Pal. N. Y., vol. v, pt. il, p. 190, pi. xxxli A, figs. 17, 18. Description. — "Form slender, elongate, cylindrical, tubular, very gradually attenuating from the base; surface striated (?). The speci- mens under examination are several fragments of longer tubes, but there 320 Systematic Paleontology — Middle Devonian are no entire examples. Some of these are very slightly curved while others are entirely straight, and it is possible that the curvature may be due to accident. From the specimens examined no satis'factory determina- tion of the surface markings can be made." Hall, 1879. The Maryland specimens are slender, gradually tapering and perfectly smooth, with the exception perhaps of one suture near the larger end of the specimen figured, the longer one with a length of 22 mm. The specimen was sent to Dr. J. M. Clarke who has written as follows: " With regard to the specimen called Coleolus aciculatus I might say that for myself I do not know what Coleolus really is. So far as my observa- tions of specimens of this object are concerned they seem to be forms of Bactrites. Coleolus adculum is certainly that, and I am inclined to think that when Professor Hall described C. aciculatum he confused the species with what he had previously described as 'Orthoceras adcvla' from the Genesee shale. Miller, I observe, cites C. aciculatus from the Marcellus and Portage; C. acicula from the Genesee. Now the type of Coleolus is C. tenuicincius, in which I have never seen any septa, but the species having the external aspect of this with full concentric orna- ment, mostly prove to be Bactrites. As to the identity of your specimen with Hall's Dentalium aciculatum I should have little question." ' Occurrence. — Eomney Formation, Onondaga Membee. W. Va. Cent. E. E. cut at 21st Bridge. Collection. — Maryland Geological Survey. Bactrites aciculum Hall Plate XXXVIII, Fig. 9; Plate XLII, Fig. 5 Orthoceras aciculum Hall, 1843, N. Y. Geol. Survey, Fourth Geol. Dist., p. 243. Coleolus aciculum Hall, 1879, Nat. Hist. N. Y. Pal., vol. v, pt. ii, p. 187; p. S2A, figs. 11-15 (16 ?). Bactrites aciculum, Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 104, pi. ix, fig. 3. Description. — " Fossil extremely elongate, cylindro-conical, having in the large specimens a diameter at the base (in its flattened condition) of ' Letter of March 28, 1903. Maryland Geological Survey 331 about 7 mm., with a length of more than 3 inches, becoming extremely slender and attenuate towards the apex. These fossils usually appear to have been subjected to maceration in the muddy sediment, and seldom preserve any indication of surface markings. There are rare examples, which present some evidence of obscure annulations or striae." Hall, 1879. This fossil occurs on the surface of slabs of dark or drab shale as flat- tened aeicular cones destitute of surface markings. Occurrence. — Romney Formation, Onondaga Member. Williams Eoad, 3y2 miles east of Cumberland. Collection. — ^U. S. National Museum. [E. M. Kindle.] Family NAUTILINIDAE Genus AGONIATITES Meek Agoniatites expansus (Vanuxem) Plate XLII, Fig. 6 Goniatites expansus Vanuxem, 1842, Geol. N. Y., pt. iii, p. 146, fig. 1 (non von Buch). Goniatites expansus Hall, 1860, Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 96, figs. 1, 2. Goniatites vanuxemi Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 434, pis. Ixvi-lxviii; pi. Ixix, figs. 3-6; pl. cix, figs. 7, 8. Goniatites vanuxemi Hall, 1888, Pal. N. Y., vol. v, pt. ii, Supplement, p. 39, pl. cxxvii, figs. 3-6. Agoniatites expansus Clarke, 1901, N. Y. State Mus., Bull. 49, pp. 124, 125. Agoniatites expansus Clarke, 1903, N. Y. State Mus., Bull. 65, p. 573. Agoniatites expansus Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 135, fig. 1388. Description. — Shell large, discoid, flattened on the sides and upon the periphery in its advanced stages of growth; volutions of the spire about three to four in specimens of smaller and medium size, and not determined in the larger ones; umbilicus large and open, exposing all the volutions of the spire. Living-chamber extremely large, occupying fully two- thirds of the last volution, with capacity at least four times as great as all the air-chambers together. Septa deeply concave, and with some exceptions, regularly increasing in distance toward the outer chamber, 21 322 Systematic Paleontology — Middle Deivonian in mature specimens they are ten or twelve mm. distant from each other, and in the extremely large specimens more than fifteen mm. distant ; their concavity greater than the depth of the air-chambers; siphuncle is well defined at the septa, close to the ventral side, and distinctly circidar in section. Test one to two mm. thick on the outer chamber of older indi- viduals, and about half as thick in the smaller ones ; the surface marked by strong, lamellose, curving striae, which in the young shells are crowded into fascicles, rising into ridges, and these curving annulations are some- times indicated, on the cast of the living-chamber of the young shell, by low undulations. The striae, on the lateral faces, make a curvature very nearly corresponding to the curvature of the septa; and in the young shells they malce an abrupt retral curve over the low saddle, thence to the middle of the periphery, where they are recurved, forming a deep sinus upon the ventrum ; the place of the saddle is indicated by a double revolv- ing groove, margined on each side by a low carina, and separated by a stronger similar one ; as the shell enlarges, the lateral of these two grooves first becomes obsolete, and finally also the other, leaving a simple obtuse angle along the line of the saddle, over which the striae in their retral curve are more conspicuous. The individuals of this species present a great range in size and proportions ; the smaller specimens do not exceed thirty mm. in their greatest dimensions, while many specimens have a greatest diameter of 150 to 200 mm. and one specimen has a diameter of over 300 mm. Fragments of a fairly large specimen were obtained in the lime- stone lentil in the West Virginia Central Eailroad cut at 21st Bridge, which are mostly smooth internal impressions and are scarcely well enough preserved for illustration. One fragment shows the inside of the shell and where it is exfoliated curving striae similar to those represented in figures of medium sized specimens of this species. The best specimens were shown Dr. J. M. Clarke who identified them as Agoniatites expansus (Vanuxem) and later in commenting upon a speci- men of Bactrites aciawlatus (Hall) embedded in a portion of the limestone which also contained a fragment of this shell he wrote : " Of additional interest to me is the fragment of large Goniatite on the reverse of this Maryland Geological Survey 333 specimen, which makes the rock look particularly like our Agoniatite limestone." The Agoniatite limestone is found in the lower part of the Mareellus shale in New York extending geographically from Schoharie County on the east to about the meridian of Phelps, Ontario County, on the west. Stratigraphically as described by Dr. Clarke it descends in the shale toward the west from a horizon in the east fifty feet above the summit of the Onondaga limestone until it reaches and probably enters that limestone.^ The occurrence of a similar lithologic limestone in Mary- land in the upper part of the black Onondaga shales, which also contains the characteristic Goniatite of the New York limestone — Agoniatites ex- pansus (Vanuxem) — is an interesting fact. Occurrence. — Eomney Formation, Onondaga Member. B. & 0. E. E. cut at 31st Bridge ; W. Ya. Cent. E .E. cut at 31st Bridge ; Williams Eoad, 3% miles southeast of Cumberland. Collections. — Maryland Geological Survey ; New York State Museum ; American Museum of Natural History. Suborder EURYCAMPYLE Family MAGNOSELLARIDAE Genus PARODICERAS Hyatt ^ Paeodioeras discoideum (Conrad) Plate XLII, Figs. 7, 8 Ooniatites discotdeus Hall, 1860, 13tli An. Rep. N. Y. State Cab. Nat. Hist., p. 97, figs. 4-6, p. 98. Qoniatites discoideus Hall, 1879, Nat. Hist. N. Y. Pal., vol. v, pt. 11, p. 441, pi. 71, figs. 1-13; pi. 74, figs. 4-5. Description. — " Shell depressed orbicular in the young state, becoming discoid in its advancing growth and varying conditions of preservation. In young shells the transverse and lateral diameters are about as 5 to 10, 11 to 20, and 13 to 24; in a medium-sized specimen, preserving its natural proportions, the two diameters are as 17 to 46. A specimen, which is perhaps somewhat compressed, has a lateral diameter of 60 mm., with a ' Bull. N. Y. state Mus., No. 49, 1901, p. 137. 334 Systematic Paleontology — Middle Devonian transverse diameter of 30 mm. The later faces curve rapidly in young shells, and in older ones are very gently curving toward the periphery, which is abruptly rounded. "Volutions about four, embraced within the outer one, having the umbilicus closed exteriorly, and with a slight depression, which does not expose the inner whorls; somewhat gradually expanding in the young shell and more rapidly in the older ones. Transverse section, semi- elliptical with the base, deeply concave from the inclosed preceding volu- tion. The increase in width of the last volution, in young, well-formed shells, is from 8 to 15 mm. In a large form it is from 14 to 38 mm., and in a specimen of 65 mm. in its greatest diameter, the increase in the last volution is from 35 to 40 mm., while the largest specimen measured, which is much compressed and somewhat distorted, gives 33 and 60 mm. as the diameters of the base of the last volution and that at the aperture. " Chamber of habitation very large, having an area four times as great, and a capacity eight or ten times as great as all the air-chambers. Aper- ture, in old shells, elongate-seniielliptical, with the base deeply indented by the embraced volution; toward the base the margin is laterally ex- panded, and distinctly auriculated at the baso^lateral angles; thence curv- ing rapidly forward, it is again depressed anterior to the middle of the lateral face, forming a shallow sinus; whence it advances on the ventro- lateral portions, and, abruptly curving backward, forms a deep sinus on the periphery. Air-chajnbers very shallow near the axis of the shell, continuing nearly parallel, and then becoming rapidly expanded toward the periphery, gradually increasing in depth with the increasing size of the volutions. " The septa, on each side, are closely arranged on the inner half of the volution, and first curve gently forward, and thence abruptly recurving on the middle of the lateral face, continue with a more gentle retral bend to the periphery, where they are more than three or four times as distant as at their origin. In their passage, they describe a broad and deep lateral lobe, which occupies the outer half of the volution; with a very shallow and scarcely marked saddle upon the peripheral border, and a very short and narrow, ventral lobe. In young shells the sides of the ventral lobe are Maryland Geological Survey 335 nearly parallel, and extend about one-third of the distance across the adjacent air-chamber. The width of the saddle is equal to the width of the lobe, and the depth of the lobe is equal to one and a half or two air- chambers. The sutures are distinctly marked upon the exterior of the cast by the thickened margins of the septa, which are imbricating toward the outer chamber, and leave a strong groove when weathered. " Siphuncle very small, close to the ventral side, and nearly coincident with the walls of the peripheral lobe. In one specimen, having its greatest lateral diameter of 28 mm., the width of the volution at the last septum is 7 mm., and the diameter of the siphuncle about 1 mm. on the convex side of the septum. In a specimen exposing the siphuncle between several of the septa, its form is evidently subconical, narrower at the concave face, and wider at the convex face of the septum. " The test is very thin, in young specimens being not more than .2 mm., and in older ones not more than .5 mm. The older shells are always extremely compressed. The surface is marked by fine, closely arranged striae, which at intervals are raised in fascicles, giving an undulated aspect, which is often more conspicuous in young than older shells. The striae become more conspicuous as they pass from the lateral faces over the borders of the periphery. There are other fine, gently undulating, concen- tric striae, which are confined to a small area around the umbilicus, giving a delicately ornamented surface. Some of the specimens show a pitted or punctated surface, of similar character to that observed on the shell of the recent Nautilus beyond the covering of the mantle. The principal striae make an abrupt retral bend upon the ventro-lateral margins, and describe a deep sinus upon the periphery. " The internal cast, in a large proportion of the specimens, is essentially smooth, being marked only by impressions of the striae of growth, and in a few examples by gentle undulations, which indicate the course of the stronger fascicles of the external striae. The marks of the undulating concentric striae around the umbilicus are rarely preserved in the casts of the interior, but the punctate marking is more frequently seen. Small individuals of this species have a lateral diameter of 10 mm., with a transverse diameter of 6 mm. The largest specimen measured, which is 326 Systematic Paleontology — Middle Devonian much compressed in the softer shales., has a greatest diameter of 95 mm. The prevailing forms are illustrated on plate 71. The natural rotundity of the young and medium-sized specimens is illustrated in figures 5, 6, 8, and 9 of the same plate. " This species differs conspicuously from the young of G. Yanuxemi by its closed umbilicus, and the usual absence of undulations or annulations upon the shell surface or upon the casts." Hall, 1897. This shell occurs rather rarely in the dark shales. The largest indi- vidual observed has a maximum breadth of 47 mm. Occurrence. — Romnet Formation, Onondaga Member. Williams Eoad, ^^2 miles southeast of Cumberland. Collection. — TJ. S. National Museum. [E. M. Kindle.] arthropodA Class CRUSTACEA Subclass TRILOBITA Order OPISTHOPARIA Family PROETIDAE . Genus CYPHASPIS Burmeister Cyphaspis cf. stephanophora Hall Plate XLII, Pig. 9 Cyphaspis stephanophora Hall, 1888, Pal. N. Y., vol. vll, p. 142, pi. xxiv, figs. 2-6. Description. — " Cephalon. Outline transversely semi-elliptical ; length to width as 1 to 1.7. Grenal angles produced into recurved spines which are longer than the axial length of the cephalon. Border spinose and thickened by doublure. Frontal area narrow, convex and appressed about the glabella, anteriorly depressed by abrupt curvature to the thickened, slightly reflexed anterior margin. "Facial Sutures, normal for the genus, originating on the occipital 'Contributed by Charles S. Prosser with the addition of Onondaga species by E. M. Kindle as indicated. Maryland Geological Survey 337 anmilation just within the genal angles, passing obliquely forward and inward to the eye-lobe, thence forward and outward to the anterior margin. " Glabella, extending three-fourths the length of the cephalon, sub- pyriform, convex, bounded by a strong sulcus which becomes shallow over the ocular lobes. Basal lobes pyriform ; baso-lateral furrows deep; antero- lateral impressions faintly discernible. " Cheeks elevated about the orbital node and sloping abruptly to the thickened margin. Palpebral lobes elevated ; visual surface not observed. " The Surface of the cephalon is ornamented by strong, scattered pus- tules which become obsolete upon the border and the genal spines. Upon the occipital ring is a single, strong, spiniform tubercle, generally accom- panied by a smaller one on either side. The anterior and lateral margins of the cephalon bear two rows of strong spines, one above the other ; those of the . upper row being the longer and having their bases upon the proximal surfaegi of the marginal rim. The proximal surface of this rim lies vertically upon the margins of the cheeks, ajid hence the spines which stand. perpendicular to its surface, lie in the horizontal plane; as it ap- proaches the frontal margin this rim becomes turned upward and slightly reflexed, so that towards the anterior extremity the spines of the upper row stand at an angle of nearly 45° to the horizontal. The spines of the lower row are shorter, lying in the horizontal plane on the frontal margin, and deflected below the horizontal plane on the genal margins. Of the spines there are about 18 in the upper and 16 in the lower row. " A single fragment of a thorax associated with a cephalon of this species shows a very wide and gently arched axis, 6 narrow and flattened segments each bearing a number of strong pustules, of which there are two longitudinal rows upon the pleurae, and for each segment of the axis 5 or 6 pustules which do not appear to be arranged in longitudinal rows. This appearance may, however, be due to the imperfection of the specimen. Length of cephalon, 4 mm.; width at the posterioj margin, 7 mm.; length to the extremity of the genal spines, 8 mm." Hall, 1888. Occurrence. — Eomney Formation, Onondaga Member. One and three-quarters south of Berkeley Springs, West Virginia. Collection. — U. S. N"ational Museum. [E. M. Kindle.] 338 Systematic Paleontology — ^Middle DEvoNLiN Order PROPARIA Family CALYMMENIDAE Genus HOMALONOTUS Koenig HoMALONOTUS DEKAYi (Green) Plate XLIII, Figs. 1-7 Dipleura Aekayi Green, 1832, Mon. Trilobites N. A., p. 79. Dipleura dekayi Vanuxem, 1842, Geol. N. Y., pt. iii, p. 150, fig. 1. Homalonotus dekayi Emmons, 1860, Man. Geol., p. 146, figs. 134, 135. Homalonotus dekayi Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 113. Homalonotus dekayi Hall and Clarke, 1888, Pal. N. Y., vol. vil, p. 7, pi. il, figs. 1-11; pi. iii, figs. 1-5; pi. iv, figs. 1-6; pi. v, figs. 1-10. Homalonotus dekayi Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Homalonotus (Dipleura) dekayi Clarke, 1903, N. Y. State Mus., Bull. 65, p. 712. Homalonotus dekayi Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 318, fig. 1631. Description. — General from elongate, linguiform, anterior and posterior extremities produced and subangulate; lateral margins nearly straight and approximating posteriorly; length to width about as two to one. Surface depressed-convex or flattened, obscurely trilobate, abruptly de- flected along the lateral margins. Cephalon broadly subtriangular in out- line, posterior side the longest; angles rounded; glabella subquadrang- ular, broadest behind; movable cheeks flattened and when normally pre- served abruptly deflected; eyes situated at the summit of strong, elevated nodes. Thorax broad, length equal to the width; surface depressed- convex; scarcely trilobate, lateral portions abruptly deflected; axis broad, making two-thirds the width of the body ; pleurae narrow, deflected along their median line. Pygidium subtriangular, anterior margin with a for- ward curve, lateral margins nearly straight, with an upward curve near the posterior extremity, which is produced into a subspatulate extension; surface convex, faintly trilobate; ten annulations on the axis and eight upon the pleurae, which are rarely visible upon the dorsal surface except in young individuals. The surface of the test on its more prominent portions marked by the openings of large vertical tubulipores, the edges Maetland Geological Sukvet 339 of which project in some specimens and in internal impressions frequently give the surface a pustulose appearance to the naked eye. The Maryland Collection contains two exfoliated specimens of pygidia of moderate size belonging to this species. Both clearly show casts of the tubulipores and one of them the upward subspatulate extension at its posterior end, the tip of the other being broken. The tubules of the Maryland specimens are apparently closer together and the openings of the tubulipores smaller than in the majority of New York specimens. The outline and other characters of the specimens agree closely with those of this species. Apparently the species is not common in Maryland and these two specimens are preserved in rather coarse arenaceous shales quite sim- ilar in lithologic appearance to shales in which they are most frequently found in central New York. Later, a few additional specimens of this species were found at other localities. Length of largest pygidium, the tip of which is gone, about 30 mm. ; width, 43 nun. Occurrence. — Eomnbt FoKMATioisr, Hamilton Membee. On road east of Pine Hill about 4 miles north of Oldtown; Williams Road, 3^ miles southeast of Cumberland; Williams Eoad i mile east of Queen City Hotel, Cumberland; on Hancock-Harrisonville Road about 2 miles north of Hancock; west of iron bridge over Town Creek northeast of Oldtown; on east side Warrior Mt. east of Rush. Collections. — ^Maryland Geological Survey; New York State Mupeum; American Museum of Natural History. Family PHACOPIDAE Genus PHACOPS Emmrich Phacops eana (Green) Plate XLIII, Figs. 8-13 Calymene bufo var. rana Green, 1832, Mon. Trilobites N. A., p. 42. Phacops lufo Emmons, 1860, Man. Gaol., p. 138, fig. 124 (6). Phacops rana Hall, 1861, Descriptions New Species of Fossils, etc., p. 55. Phacops rana Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 93. 330 Systematic Paleontology — Middle Devonian Phacops rana Meek and Worthen, 1868, Geol. Surv. 111., vol. iil, p. 447, pi. xi. figs. la-e. Phacops rana Nicholson, 1873, Pal. Prov. Ontario, p. 123, fig. 56a. Phacops rana Whitfield, 1882, Geol. Wis., vol. iv, p. 339, pi. 26, figs. 17-19. Phacops rana Hall and Clarke, 1888, Pal. N. Y., vol. vii, p. 19, pi. vii, figs. 1-11; pi. viii, figs. 1-18; pi. viii A, figs. 21-33. Phacops rana Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. Phacops rana Clarke, 1903, N. Y. State Mus., Bull. 65, p. 737. Phacops rana Clark and Mathews, 1906, Md. Geol. Surv., vol. vi, pi. xvii, fig. 9. Phacops rana Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 323, fig. 1638. Description. — General form elongate suboval; greatest width (measured at the posterior margin of the cephalon) to axial length as 1 to 2; the cephalon, thorax and pygidium are to one another in length as 1.5 to 3 to 1. Cephalon subsemicircular, the regularity of the outline interrupted by the slight protrusion of the glabella and the genal extremities, frontal margin obscure, concealed by the overhanging glabella; facial sutures rarely discernible; glabella large, gibbous, outline subpentagonal, greatest width anteriorly, posterior furrow extending clear across the glabella; cheeks abruptly sloping to the margin, narrowing anteriorly and reflected ventrally to form the doublure; eyes prominent, scarce reaching the height of the glabella in uncompressed specimens, visual area lunate, separated from the cheek by a strong, smooth sulcus, average number of lenses in normal adults is between forty and fifty for each eye. Thorax subquadrate, lateral margins slowly tapering, surface strongly trilobate; axis flattened at the margins, evenly convex in the middle, widest at the third or fourth segment, tapering very slowly to the ninth, and thence much more rapidly to the pygidium ; pleurae flat for about one- third their width from the axis and thence abruptly deflected to the margin, each segment bears a furrow which becomes obsolete at the fulcrum. Pygidium relatively small, regularly and evenly rounded margin the posterior part of which forms the are of a circle; axis composed of nine annulations, rapidly and evenly tapering from the last segment of the thorax, reaching an acute termination just within the posterior margin; pleurae seven in number, broad, depressed-convex, and sloping evenly to the posterior margin. Surface of the test ornamented with tubercles, which are largest and most closely set upon the glabella. Maryland Geological Survey 331 This widely distributed and abundant species is represented in Mary- land mainly by broken specimens, the cephalon and pygidium being the parts which are most frequently found. These were compared with authentic specimens of this species in the office of the State Paleontologist of New York, and found to agree closely in all essential characters. The species is found more commonly in Maryland in the argillaceous shales of the Hamilton, but also occasionally in the arenaceous shales. The species was reported by Hall and Clarke from the Hamilton shales at Cumberland, Md. (Pal. X. Y., vol. vii, p. 26). Length of nearly perfect cephalon, 15 mm.; width, 25 mm. Length of most nearly perfect pygidium, 9 mm. ; width, 15 mm. Occurrence. — Eomney Formation, Hamilton Member. Bast bank Evitts Creek below Wolfe Mill ; on National Eoad 14 mile west of Tonolo- way Eidge; Licldng Creek east of Warren Point; McCoys Ferry; south- west of McCoys Ferry; Ernstville; on road east of Pine Hill about 4 miles north of Oldtown. Collections. — Maryland Geological Survey; New York State Museum; American Museum of Natural History.. Phacops cristata Hall Plate XLIII, Figs. 13-15 Phacops cristata Hall, 1861, Desc. New Sp. Fos., p. 67. Phacops cristata Hall and Clarke, 1888, Nat. Hist. New York Paleontology, vol. vll, p. 14, pi. vi, figs. 1-31; 16-29; pi. vlilA, figs. 1-4. Phacops cristata Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 107, pi. x, figs. 6-8. Description. — ^This species is distinguished by the following features according to Hall. The annulations of the pygidium are dichotomous; termination of axis is obtuse, the axial row of spines extend as far as the pygidium, the glabella is strongly protuberant, tuberculations are numer- ous only on the glabella, the genal angles bear stout spines, there are 10 to 11 crenulations on each side of submarginal furrow of cephalon, corneal lenses number 23 to 45. This species and the related form P. cristata var. pipa are probably the most abundant representatives of the trilobites in this Onondaga 332 Systematic Paleontology — Middle Devonian fauna. Although P. cristata is readily distinguished from P. pipa by the axial row of spines and other less conspicuous differences in perfect speci- mens, the two are often difficult to discriminate in the fragmentary material representing them in the average collection. The glabella figured represents the largest individual observed, its length and breadth are respectively 18 and 24 mm. The genal spines, though not shown in the figure, are indicated by broken bases in the specimen. Occurrence. — Romnet Foemation, Onondaga Member. Twenty- first Bridge ; Williams Eoad, 31/2 miles southeast of Cumberland; Tonolo- way; Hanging Eock, West Virginia. Collections.— MsLTjlajnd Geological Survey; U. S. National Museum. [E. M. Kindle.] Phacops cristata var. pipa Hall Plate XLIII, Figs. 16, 17 Phacops cristata var. pipa Hall, 1888, Pal. N. Y., vol. vii, p. 18, pi. vliiA, figs. 5-18. Phacops cristata var. pipa Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 108, pi. X, figs. 9, 10. Description. — " The essential points of difference between this form and the normal Phacops cristata^ are the following: (a) greatly inferior size, (b) absence of the axial row of spines, (c) smaller spines at the genal angles, (d) fewer annulations upon the pygidium, (e) smaller num- ber of corneal lenses, varying, as ascertained from measurements of a large number of specimens, from 23 to 45 for each eye." Hall, 1888. The variety seems to be abundant and is very generally present in the calcareous shales and argillaceous limestones of the adjacent states of Pennsylvania and West Virginia. It has been observed at but one locality in Maryland. Occurrence. — Romney Formation, Onondaga Member. One mile east of Oldtown in cut of Western Maryland Railroad. Collection. — TJ. S. National Museum. [B. M. Kindle.] Maryland Geological Survey 333 Genus DALMANITES Barrande Dalmanites (Cryphaeds) boothi (Green) Plate XLIV, Figs. 1-4 Cryphaeiis ioothii Green, 1837, Am. Jour. Scl., vol. xxxil, p. 343 and figure. Dalmania bootMi Hall, 1861, Descriptions New Species of Fossils, etc., p. 63. balmania loothn Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 91. Dalmanites toothii Hall, 1876, Illustrations of Devonian Fossils, pi. xvi, figs. 1-6, 9-11, 13, 15, 16. Dalmanites (Gryphaeus) 'boothi Hall and Clarke, 1888, p. 42, pi. xvi, figs. 1-4; pi. xvi A, figs. 3-8. Dalmanites boothi Keyes, 1891, Johns Hopkins Univ. Giro., vol xi, p. 29. Dalmanites (Gryphaeus) boothi Clarke, 1903, N. Y. State Mus., Bull. 65, p. 683. Gryphaeus boothi Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, p. 329, figs. 1647a, b. Description. — General form snboval, laterally and posteriorly fimbriate ; length about one-half greater than the width; surface depressed-convex, distinctly trilobate; axis prominent, elevated. Cephalon relatively large; outline semielliptical, faintly produced on the frontal margin; length to width as 1 to 2; margin thickened by a broad doublure which is produced at the genal angles into broad, thin and blunt spines that norm- ally reach to the sixth thoracic segment; glabella elongate subpentagonal, length and width equal and nearly equal to length of the cephalon ; three pairs of transverse furrows conspicuous; eyes large, elevated, exceeding the height of the glabella; visual surface lunate with 206 lenses for each eye. Thorax length to width as 1 to 1.5 ; axis arched, widest at the fourth segment, tapering thence evenly to the pygidium ; pleurae flattened, gently deflected along the fulcrum. Pygidium subtriangular, depressed convex; axis tapering with slightly incurved margins, and ending abruptly just within the posterior border, with from ten to fourteen annulations; the pleurae each bear five sulcate annulations, the anterior limbs of which are flattened, thickened and produced beyond the margin as short, flat and closely set spines; a similar spine, but shorter and relatively broader, is produced in the axial line, thus making eleven spines in the pygidial fimbria. In the normal forms the entire surface is covered with granula- tions which become quite strong on the axial region of the glabella and 334 Systematic Paleontology — Middle Devonian thorax^ and the surface of the pygidial fimbria, where the granules be- come elongate and pustuliform, often crowded and more conspicuous than upon the surface of the shield itself. The representatives of this species in the Maryland Collection consist almost entirely of specimens of pygidia which have been found more abundantly in the thin argillaceous shales on the east bank of Evitts Creek just below "Wolfe Mill than at any other locality. One badly crushed specimen shows the larger portion of the thorax and the posterior part of the cephalon, while another shows the pygidium and one side of the thorax. The pygidial fimbria in all the specimens are broad, fiat, granu- lose and contiguous as in those of this species and not lanceolate and relatively narrow as in D. ioofhi, var. calUteles Green. They were also compared with authentic specimens of D. ho'othi in the ofQce of the New York State Paleontologist and found to be practically identical. It is to be remembered that the original specimens of D. ioothi were obtained from near Huntingdon, Huntingdon County, Pennsylvania (Am. Jour. Sci., vol. xxxii, 1837, p. 34-5). Length of pygidium, 10 mm.; width, 17 mm. Occurrence. — Eomney Formation, Hamilton Member. East bank Evitts Creek below Wolfe Mill ; on road about half way between Eonmey and Hanging Eock, W. Va. Collections. — ^Maryland Geological Survey; N"ew York State Museum; American Museum of ITatural History. Dalmanites marylandicus n. sp. Plate XLIV, Fig. 5 Description. — A single pygidium was found in the lower Hamilton shales at Ernstville, Md., which is considered distinct from other species of this genus, and shows the following characters: Pygidium subovate triangular in outline, conspicuously trilobed and composed of 33 or 34 annulations ; axis moderately convex, tapering gradually and extending as far as the posterior margin, marked by two rows of tubercles of which each segment bears two, one on each side of the middle and most convex Maryland Geological Suevbt 335 part of the axis ; pleurae composed of 18 annulations, nearly flat near the axis, thence regularly depressed toward the margin, about the middle of each segment is a furrow which begins near the axis and extends nearly to the margta, while the convex portions of the segments are marked by two somewhat irregularly arranged rows of tubercles, one on each side of the furrow; margin scarcely shown except at the posterior. extremity where it is apparently terminaied by two caudal spines, which are broad at their bases, separated by a rather greater distance than the width of the axis, and one showing apparently the bases of three or four small spines near its extremity. This pygidium is to be compared with those of Dalmanites (Coronura) aspectans (Con.) of the Onondaga limestone of Wew York, Ohio and the Falls of the Ohio; but is considerably smaller than average specimens of that species, while the axis is composed of a larger number of segments and is marked by two longitudinal rows of tubercles instead of five. Length of pygidium, 13 mm. ; width, 23 mm. Occurrence. — Eomnet Poemation, Hamilton Member. Ernstville Collection. — Maryland Greological Survey. Subclass EUCRUSTACEA Order OSTRACODA Family LEPERDITIIDAE Genus LEPERDITIA Renault Lepeeditia ? SUBEOTUNDA TJlrich Plate XLIV, Pig. 6 Leperditia ? suirotunda Ulricli, 1891, Jour. Cin. See. Nat. Hist., vol. xijl, p. 181, pi. xvi, figs, la, b, c. Leperditia ? cf. subrotunda Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 115, pi. ix, fig. 7. Description. — " Size of left valve : Length, 0.68 mm. ; thickness, 0.21 mm. Carapace small, short, rounded, uniformly convex, encircled, except at the strongly convex ventral edge, by a flattened border, widest in the 336 Systematic Paleontology — Middle Devonian posterodoTsal region. Dorsal edge scarcely straight, gently curving into the ends. Ventral overlap distinct. Surface smooth and even, without eye tubercle or muscle spot. The development of a flange at the dorsal border is a very unusual feature in this genus. L. sinuata Hall has nearly the same shape, but is withoiit a flange, and so far as known its valves do not overlap at the ventral margin. I am inclined to believe that species of this character ought to be arranged with Apardhites rather than Leperdi&a. Position and locality : Devonian Bryozoa bed. Palls of the Ohio. Eare." Ulrieh, 1891. A circular or subcircular ostracode occurs sparingly as casts of the shell at three or four localities represented by the collections. These agree with Ulrich's figures of L. subrotunda,, except that the projecting flattened border feature appears to be developed but slightly or not at all; the form here compared with L. s-uhrotunda may represent a closely related species. Occwrrence. — Eomney Pokmation, Onondaga Member. One and three-quarter miles south of Berkeley Springs, West Virginia. Collection. — U. S. National Museum. Family BEYRlCHIIDAE Genus BOLLIA Jones and Holl Bolma ungula Jones Plate XLIV, Pigs. 7, 8 Bollia ungula Jones, 1889, American Geologist, vol. iv, pp. 338-339, pi. opp. p. 242, figs. 10-13. Bollia ungula Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 113, pi. ix, flgs. 9,10. Description. — " Prof. Claypole's specimens are well preserA^ed casts in buff-colored, non-calcareous shales from the Marcellus limestone of Perry County, Pennsylvania (near New Bloomfield). There are several, and they vary from 1 to 2% mm. in length. The proportions of some of the best are given in the figures 10-13, magnified 15 diameters. In some Maryland Geological Survey ' 337 respects they resemble BoUia lata Hall ; ^ but they are larger, and the central curved ridge is much thinner at its curve, whereas in the specimens from New York State the curve is thicker just there, and is not so sym- metrical throughout as in the Pennsylvania specimens. Hence I prefer to regard the latter as specifically distinct, and to adopt Prof. Claypole's MS. specific name (having reference to the hoof -like ridge), than to refer them to Bollia lata. A hollow cast of the outside, and one presumably perfect valve give evidence of a smooth exterior. The slight variations in the shale and proportions of the curved sub- central ridge and of the marginal ridge are well shown in the figures 10- 13." Jones, 1889. Occu-irence. — ^Eomney Formation, Onondaga Member. Williams Eoad, 31/^ miles southeast of Cumberland; Tonoloway. Collection. — ^U. S. National Museum. Bollia obesa Ulrich Plate XLIV, Pig. 9 Bollia olesa Ulrich, 1891, Jour. Cincinnati Soc. Nat. Hist., vol. xiii, p. 189, pi. xiv, figs. 5a, b, c. Bollia oiesa Kindle, 1912, Bull. U. S. Geol. Surv., No. 508, p. 114, pi. ix, fig. 8. Description. — " Size of valve : Length, 1.52 mm. ; height, 0.98 mm. ; thickness, 0.5 mm. Carapace subpentagonal, ends nearly equal, strongly curved, back straight, short, dorsal angles obtuse, ventral edge produced in the middle. Marginal portion of valves thick, causing them to appear unusually ventricose. Horse-shoe ridge unsymmetrical, with bulbous ex- tremities, the anterior knob oval, and reaching the dorsal edge, the pos- terior one larger, more nearly round, and terminating a short distance within the dorsal margin. "This species is not likely to be mistaken for any other known to me. Though clearly a true BoUia, it is -very different in its general appearance from the associated B. ungvla, Jones. 'Paleontology of New York, vol. ii, 1852, p. 301, pi. 66a, figs. 10a, b, d (not c and e) , also some in British museum. I may here mention that I have to refer lata and symmetrica to Bollia, and spinosa to Aechima. 22 338 Ststematio Paleontology — ^Middle Devonian " Position and locality : Devonian Bryozoa bed, Falls of Ohio." TJlrich, 1891. This species is associated with B. ungula but is less abundant. Occurrence. — Komnet Poemation, Onondaga Member. Williams Road, 3% miles southwest of Cumberland ; Tonoloway. Collection. — U. S. Ifational Museum. THE UPPER DEVONIAN DEPOSITS OF MARYLAND BY CHARLES S. PROSSER AND CHARLES K. SWARTZ THE UPPER DEVONIAN DEPOSITS OF MARYLAND BY CHARLES S. PROSSEK. AND CHARLES K. SWARTZ IISTTEODUCTOEY' As stated under the description of the Middle DeTonian, the Devonian period was often separated in a general way into the lower, middle, and upper divisions. For the latter Prof. H. S. Williams proposed the name Keodevonian ' which in general included, in New York, the Tully limestone, Genesee shale. Portage, Chemung, and Catskill stages, the latter being a local facies of the Chemung, or Portage, Chemung and perhaps early Carboniferous, occurring in southern and southeastern New York. In 1840, Prof. James Hall named and described the following "groups" as succeeding the "upper Black shale" (Genesee shale) in the Genesee Valley, in the order named : Cashaqua shale, Gardeau or Lower Pucoidal group, and Portage or Upper Fucoidal group.' He also stated that " the two groups just described [Gardeau and Portage], occupy a thickness of more than 1000 feet, and are interposed between the Cashaqua shale and the Chemung group." * In succeeding accounts, the base of the Chemung formation has generally been considered as resting on top of the sand- stones which Professor Hall described as composing the Portage group; but the following statement is important, especially when the classi- fication of the rocks of this part of the Genesee Valley by Dr. J. M. Clarke, is considered. Professor Hall said, " Indeed, if we consider the Chemung group as commencing with the occurrence of its characteristic marine fossils, then several hundred feet more of rocks may be noticed * Contributed by Charles S. Prosser. ^ Jour. Geol., Vol. II, pp. 155, 157. »4tli Ann. Rep., Fourth Geol. Dist. [N. Y.] (Assembly Doc. No. 50, 1840), pp. 390, 391. *IUd.,v. 392. 342 The Upper Devonian Deposits of Maryland as intervening between the upper Portage rock and that group."' The following year Professor Hall reported on the geology of Erie County and described the terrains just mentioned under the headings of Cashaqua shale, Grardeau group and Portage group/ In Vanuxem's Pinal Eeport of the Third District the Cashaqua shale, Gardeau and Portage groups, and Sherburne flagstone and shale of the Annual Eeports were combined to form the Portage or Nunda group." Hall's Pinal Eeport of the Pourth District, published the following year, contained the same classification.' The term Nunda, from the former name of the township which had been changed to Portage, where the rocks of the " group " are finely shown on the banks of the Genesee Eiver, was soon abandoned although its reten- tion would have avoided confusion since Professor Hall first applied the name Portage to the mass of sandstones in the upper part of the "group." The rocks deposited during Portage time in the central and eastern parts of New York have local facies and have received special names. In the first place in the meridian of Canandaigua Lake Dr. J. M. Clarke found, on studying the faunas of the Cashaqua shales and Gardeau shales and flags, that they were closely related to that of the Genesee shale and he proposed the name Naples beds or shales for these two lower divisions of the Portage." In another paper published the same year Dr. Clarke stated that in Ontario County the Cashaqua shales and the Gardeau shales and sandstones are both lithologically and palasonto- logically a single group to which has been applied the name Naples shales.' Finally, in 1891, it was stated by Dr. Clarke that he used the term Naples beds for the subdivisions of the Portage which had been called the Cashaqua and Gardeau and to their faunal contents he applied the name Naples fauna.' In 1898, Dr. Clarke called attention to the fact that in the section west of Ontario County the heavy bedded Portage ^/6W., p. 392. = 5th An. Rep., ibid. (Assembly Doc. No. 150, 1841), pp. 165, 166. ' Geol. N. Y., Pt. Ill, 1842, p. 172. " ma., Pt. IV, p. 224. = Bull. tr. S. Geol. Surv., No. 16, 1885, p. 36, f. n. ° 4th Rep. State Geologist [N. Y.], p. 20, f. n. ' Amer. Geol., Vol. 8, p. 93. Maryland Geological Survey 343 sandstones " are overlaid by a considerable mass of flags and sands which continiie to carry a jSTaples fauna with some modifications, but embrace no typical Chemung species." * This upper zone carrying a Naples fauna and overlying the Portage sandstone is the one noted in 1840 by Professor Hall in the Genesee Valley to which in a section of this valley Dr. Clarke gave the name "Wiseoy shales and flags."' In the succeeding report appeared an extended account of " The Naples fauna (fauna with Manti- coceras intwmescens) in western New York " in which Dr. Clarke gave a history of the Portage group and this fauna." Later and more detailed stratigraphic work by Dr. J. M. Clarke and Mr. D. Dana Luther in western New York has resulted in a greater sub- division of the Upper Devonian rocks. A recent publication devoted to this subject is their " Geologic map of the Canandaigua and Naples quad- rangles" on which the several formations of these two quadrangles are very accurately represented. The rock formations represented as units of sedimentation " are given in the right-hand column of the following table, divisions of broader value constituting the other three columns : r Prattsburg. 'LHighpoint. Neodevomc . . . .. Chautauquan group. .Chemung beds. Senecan group. . . Ithaca beds. Portage beds. Genesee beds. /West hill. iGrimes. rHatch. Rhinestreet. Cashaqua, Parrlsh (lentil in Cashaqua). Middlesex. Standish. West river. Genundewa. > Genesee. Tully limestone TuUy." nsth An. Rep. State Geologist [N. Y.], p. 58. ''I&id., p. 62. neth An. Rep. State Geologist [N. Y.], 1899 [April, 1900], p. 41. Reprint issued in 1898. *N. Y. State Museum, Geologic map of the Canandaigua and Naples quad- rangles, April, 1904, p. 2. For descriptions of the above formations, see pp. 18-32. 344 The Upper Devonian Deposits oe Maryland The rock formations composing the Portage beds in the above table were also described by Dr. Clarke in another memoir published earlier in April than the one Just quoted in which he stated that " Throughout this interval oi about 600 feet the Naples fauna prevails, without evidence of encroachment of the eastern or Ithaca fauna." ' The following year in the description of the geology of the Watkins and Elmira quadrangles Dr. Clarke transferred the High Point sandstone from the Chautauquan to the Senecan, while the Chautauquan began with the Prattsburg shale succeeding which is the Chemung sandstone and shale." Spirifer disjunctus Sowerby occurs in the list of fossils from the Chemung sandstones ; ° Hall's original description of the " Chemung group " is quoted, following which Dr. Clarke stated that " It will be seen that the definition of this formation is derived from the very region we have here under consideration and embraces those rocks to which we are now applying the term in the original and restricted meaning." ' The above classification has recently been reviewed by Prof. H. S. Williams who wrote that " According to the list of species reported by them [Clarke and Luther] for the Watkins and Elmira quadrangles their West Hill flags and shales and High Point sandstone should both be included in the Chemung formation as here defined [in the Watkins-Catatonk folio]."" The above rather extended review of the use of the names Portage and Naples in their typical sections in western New York is given in order that the reader interested in stratigraphical geology may readily acquaint himself with the historical usage of the names which appear very fre- quently in this monograph in the description of the Upper Devonian rocks and fossils of Maryland. Again, east of the Naples section in the Ithaca region the Portage stage is represented by the Sherburne sandstone and Ithaca beds and the writer in 1903 proposed that these two members be united and ^ N. Y. State Museum, Mem. 6, p. 213. " N. Y. State Mus., Bull. 81, p. 4. ' Loc'cit., p. 24. ■* hoc. cit., p. 23. = Geol. Atlas U. S., Folio 169, Field Edition, 1909, p. 85. Maryland Geological Survey 345 called the TJnadilla formation/ while farther east along the Chenango Valley it is represented by the Sherburne sandstone, Ithaca beds and Oneonta sandstone. When followed eastward, sediments with the litho- logical characters of the Oneonta appear at lower and lower horizons in the Ithaca until the Ithaca fauna disappears. In a similar manner the Chemung fauna above the Oneonta sandstone is driven out until in the Catskill region of southeastern New York the Hamilton formation and fauna are succeeded by the Sherburne sandstone, which is followed by sediments not lithologically different from those of the Oneonta which pass without any break into the similar lithological deposits of the Catskill formation.'' Dana in his time division of the Devonian placed the upper or later portion in the Chemung and Catskill periods.' The Chemung period as defined in his earlier editions of the Manual of Geology was composed of the Portage and Chemung epochs, the Tully and Genesee being in- cluded in the Hamilton period, and the Catskill period composed of simply the Catskill epoch. In the last edition, however, the Upper Devonian consists simply of the Chemung period at the base of which was the Genesee shale while the conclusion, that the Catskill is a local formation representing a varying thickness of the Upper Devonian, was accepted and so the name disappeared from the chronological list.' Among the names proposed by Mr. Darton for the formations of central Appalachian Virginia and adopted by the United States Geological Sur- vey for the Polios of that region, the Jennings formation, called from Jennings gap and branch in western Augusta County, Virginia, agrees very closely with the Genesee, Portage, and Chemung formations of New York. The line of division between the Eomney and Jennings formations was not indicated very distinctly and it was said that they " intergrade through beds of passage." In reference to the correlation of the Jennings formation it was stated that " very few beds are f ossilif erous, and they are ' Amer. Geol., Vol. XXXII, 1903, p. 384. ^ For details of this region and the varying lithologic and faunal characters of the formations see Prosser In the 15th An. Rep. State Geol. [N. Y.], 1897 [1898], pp. 87-223 and 17th iMd., 1899 [1900], pp. 64-316. ' Proc. Am. Assoc. Adv. Science, Vol. ix, 1856, p. 14. * Man. Geol., 4th ed., 1895, pp. 576, 602. 346 The Upper Devonian Deposits op Maeyland mainly in the medial beds where Chemung and Portage forms occur com- prising Spirifera disjuncta, Spirifera mesocostalis, Streptorhynchus che- mungensis, Chonetes scitnla, and others," ' while Hampshire called from the eonnty of that name in northeastern West Virginia corresponds in a general way to the upper portion of the Catskill formation of southeastern 'New York. Finally, Clarke and Schuchert propose that the Upper De- vonian be divided into the Senecan and Chautauquan periods or groups; the Senecan composed of the Tally limestone, Genesee shale, and Portage beds which include the terms Naples beds, Ithaca beds and Oneonta beds as local facies of that stage, and the Chautauquan composed of the Che- mung beds of which the Catskill sandstone is given as a local facies." The Maryland Geological Survey adopted Jennings formation for the name of the division succeeding the Eomney for a reason similar to that given in explanation of the Eomney formation. The name Chemung was first used as the name of a stage, but Dana considered it as the name of a period composed of the Portage and Chemung epochs, so that it is in common use as the nanne of a stage or age, using the terms proposed by the International Congress of Geologists, as well as for the name of the higher division of series or epoch. Jennings was already in use by the Maryland Geological Survey before the publication of the names Senecan and Chautauquan by Clarke and Schuchert and, for convenience in mapping, it was also found better to regard it as one formation. The name Hampshire was used in the earlier publications of the Mary- land Geological Survey, instead of Catskill, because of the controversy over the limits of that formation in New York, and because the ques- tion had been raised whether, on account of the absence of fossils, it is possible to correlate the upper Devonian red rocks of Maryland and West Virginia with those of New York. Eecognizing the fact, however, that the Catskill formation in different parts of New York represents a different length of geological time, it is believed that the southern red deposits have the same general stratigraphic position and may be followed across Pennsylvania to Maryland. ' Am. Geol., Vol. x, 1892, p. 18. " Science, N. S., Vol. x, 1899, p. 876. Maryland Geological Survey 347 STRATIGBAPHIC AND PALEONTOLOGIC CHAEACTERISTICS' The Jennings Formation introductory At or near the base of the Jennings formation in Allegany County and apparently confined to it are black, fissile shales, with a thickness of about 90 feet, which weather to a gray color and readily turn to soil. In Wash- ington County the olive shales and thin sandstones of the succeeding division rest on top of the upper Eomney sandstones and the black shales have disappeared by thinning out to the eastward. The black shales con- tain fossils which occur in the Genesee shales of New York as for example : Buchiola retrostriata v. Buch, Pteroehaenia frwgilis (Hall), Styliolina fissurella Hall, Bactrites acicultis (Hall), and other species. Among the best exposures are those to be observed in the cut above Corriganville, by the side of the National Eoad 2y2 miles northeast of Cumberland and on Flintstone Creek in Gilpin. The black shale occurring at or near the base of the Jennings is believed to represent the same horizon at the several localities at which it has been noted in Allegany County. A characteristic Hamilton fauna is known to extend within at least 30 feet of the black shale, and perhaps to its base since the interval of 30 feet is covered, while similar recurring black shales were not noted in the superjacent beds of Portage age as is the case in the deposits of this stage in western New York. On account of its stratigraphie position it is thought that this black shale represents the reappearance of conditions in Maryland similar to those which existed in central and western New York while the Genesee shale was beiag deposited, but which were absent during that time in eastern New York and eastern Pennsylvania, and it has been provisionally correlated with the Genesee shale of New York. The time of its deposition may not have been precisely identical with that of the Genesee shale of New York; however, it is believed that the difference in time was not great. The next member of the Jennings formation consists mainly of greenish argillaceous and arenaceous shales alternating with thin sandstones of similar color all of which weather to a yellowish-green. The sandstones which usually vary in thickness from a fraction of an inch to a foot, * Contributed by Charles S. Prosser. 348 The Upper rtevoNiAN Deposits of Maryland though there are occasional strata 2 feet in thickness, occur throughout this part of the formation ; but as a rule are not thick enough to be of any economic importance. In Washington County brownish-red shales occur in the upper part of this division ; but in Allegany County reddish rocks make their first appearance in the succeeding member. Fossils are not common near its base although specimens of Buchiola retrostriaia v. Buch, Pterochaenia fragilis (Hall), Tornoceras uniagulare {Conra-d) , Badrites adcvlus (Hall) and some other species occur. A profuse fauna has been observed in the higher strata of this member by Dr. Swartz who correlates them with the Ithaca beds of Kew York. Its thickness is estimated at 1300 to 1600 feet. This division of the Jennings formation has been named the Woodmont member by Swartz and is regarded as representing the Sherburne and Ithaca stages of ISTew York. It is fairly well shown on the bank of Town Creek and the lower slope of Polish Mountain on both the National and Williams Roads and in the upper part of the section near Woodmont west of Tonoloway Station. The succeeding division, named the Parkhead member by Swartz and Stose, consists of shale and interbedded sandstones and conglomerates. It was shown to contain an abundant fauna of Hamilton affinities by Dr. Swartz who discusses it more fully elsewhere in this volume. Its thickness is 400 to 600 feet. The upper part of the Jennings formation consists of argillaceous and arenaceous shales alternating with beds of sandstone which are very often micaceous, while several layers of conglomerate occur in this mem- ber. These shales and sandstones are usually greenish or greenish-gray in color and weather to a yellowish-green; but there are not infrequent zones of brownish-red shales and sandstones. In certain layers fossils are common and the chaxacteristic species Spirifer disjunctus Sowerby of the Chemung stage occurs frequently and this together with the presence of other Chemung species, lithologic similarity and stratigraphic position indicates the correctness of the correlation of this division with the Chemung stage of New York. The writer correlated the beds between the top of the Genesee shale, or where this shale is absent the top of the Romney, and the lowest ones con- taining Spirifer disjunctus Sowerby with the Portage of New York. The Maryland Geological Sdevet 349 succeeding part of the Jennings formation he correlated with the Che- mung of 'New York. In the Jennings Kun section there is a 40 foot zone of sandstone and conglomerate shown in the highway cut about 550 feet below the top of the formation. In Garrett County the conglomerates are quite con- spicuously represented by loose blocks ; but are not often found in place. OnCj containing quite large fiat white quartz pebbles, is found frequently to the northeast of Oakland and in the vicinity of Mountain Lake Park. This conglomerate is light gray in color, slightly fossiliferous, con- tains numerous milkj' quartz pebbles, part of which at least are flat and lenticular in shape, but none of jasper were seen by the writer, while the jointing surfaces of the blocks cut directly across the pebbles making a smooth surface. Apparently the rock always breaks straight across the pebbles in a direction at right angles to their bedding, and the cementing material is dark, gritty, and somewhat ferruginous. Regarding the presence of jasper pebbles Dr. Martin has written as follows : " I have not noticed jasper pebbles in the Chemung near Corriganville [Jen- nings Eun section] . I have seen a few in the vicinity of Mountain Lake Park and Oakland and also to the south of Oakland. I do not remember seeing them elsewhere." ' It is clearly shown at several localities to the northeast of Oakland that this conglomeiate is succeeded by a considerable thickness of rocks containing abundant specimens of Spirifer disjunctus Sowerby, Atrypa liystrix Hall, Douvillina cayuta Hall, and other Che- mung species so that there can be no doubt that the stratigraphical posi- tion of this conglomerate is considerably below the top of the Chemung. In this region a higher conglomerate occurs about 50 feet below the base of heavy reds which are considered as forming the base of the Catskill forma- tion." This stratum, 6 inches more or less in thickness, occurs in the midst of yellowish-green shales and contains numerous quartz pebbles which are not so lenticular in shape as those in the lower conglomerate. On Pea Eidge, southeast of Avilton, in the northern part of the county a similar conglomerate occurs, containing small, mostly rounded quartz pebbles which do not break with a smooth fracture on the joint planes but ' Letter of January 12, 1904. '' See an alternative Interpretation by C. K. Swartz in this volume. 350 The Upper Devonian Deposits of Maryland either project from or drop out of the matrix so that its appearance is quite different from that of the lower, conspicuous conglomerate. In Bedford and Fulton counties in Pennsylvania to the north of Alle- gany County, Maryland, Professor Stevenson described two conglomerate layers in the Chemung separated by 950 feet of shales and sandstones which he designated from their stratigraphic positions the lower and upper conglomerates." ' The upper part of the Chemung is imperfectly shown in both Bedford and Pulton counties ; but Professor Stevenson in his "generalized section" for the latter county has given 800 feet of " shales with occasional beds of sandstone " as overlying the upper con- glomerate before the top of the Chemung is reached.'' Prom their stratigraphic position it is evident that the two conglomerates just described in Maryland do not represent the lower and upper conglomer- ates in Pennsylvania both of which contain iiat pebbles as described by Professor Stevenson. The upper one of Professor Stevenson, however, occurs near the stratigraphic position of the lower one just described in Maryland and there is some probability that these two are identical. This opinion is somewhat strengthened by Professor Stevenson's statement that in Bedford County the beds overlying the upper conglomerate are quite fossiliferous containing Spirifer disjunctus Sowerby, Strepto- rhynchus chemungense (Conrad), Orthis closely allied to 0. tioga Hall, and " great numbers of characteristic Chemung Lamellibranchs." ° Dr. I. C. White correlated the upper conglomerate of Stevenson with his Laekawaxen conglomerate found on the blufE of the Delaware River near the town of that name in northeastern Pennsylvania.* Although later, in describing the formations west of Cumberland, he stated that " The Chemung beds consist of olive shales, flaggy sandstones, and one massive conglomerate (Allegrippus) [the name which he gave to Stevenson's lower conglomerate'] near the top; thickness about 3500 feet."' Dr. Martin also wrote that the flat pebble conglomerate of Garrett County ' 2d Geol. Surv. Pa., T, 1882, p. 76. 'IMd.,V- 75. 'IMd.,v. 78. 'lUd., T", 1885, p. 90, f. n. p. 91, and section on p. 96. 'lUa., pp. 99, 101, 103. "Congrfis G6olg. Internat., Compte Rendu de la 5nie Ses., Washington, 1901 (1903), p. 282. Maryland Geological Survey 351 " suggests very strongly the Laekawaxen conglomerate of Pennsyl- vania " ; ' while Professor Claypole stated that " the two conglomerates, the Allegrippus and the Laekawaxen, .... figure conspicuously in the outcrops of the Chemung from Virginia to New York." " Professor Lesley, however, called attention to the fact that the Eeports for Blair, Center, Clinton, Lycoming, Union, Snyder, Mifflin, and Juniata counties situated in the line of strike of these formations to the northeast of Bedford, Fulton, and Huntingdon counties make no mention of these conglomerates. ' He also considered the one described by Dr. I. C. White at Bearing Eun, Columbia County, intermediate in location between those of the southern counties and the Laekawaxen conglomerate of Pike County, which Dr. White provisionally correlated with the latter con- glomerate,' and concluded that " Considering the solitary apparition of this Eocky [Eoaring] Eun conglomerate, as we may call it, and the large number of fish beds known to exist in Chemung and Catskill series, it seems to me a little hazardous to adopt unhesitatingly its identity with other fish-bed conglomerates in distant counties of the state. We must leave to future explorers the task of proving or disproving such facts." ° It appears to the writer that there is as yet insufficient evidence to warrant the correlation of Stevenson's upper conglomerate of Bedford, Fulton, and Huntingdon counties with the Laekawaxen conglomerate of northeastern Pennsylvania. This conclusion appears to be warranted when we consider the rather limited extent, in general, of deposits of this character and especially when it is noted that Dr. White stated that many of the pebbles of the Laekawaxen conglomerate are angular and exhibit " little evidence of water wear " " while the pebbles of Stevenson's upper conglomerate he described as " generally flat." ' • Md. Geol. Surv. Garrett Co., 1902, p. 87. ' Am. Geol., Vol. XXXII, 1903, p. 105. ' Geol. Surv. Pa. Sum. Desc. Geol. Pa., Vol. II, 1892, p. 1552. * 2d Geol. Surv. Pa., G', 1883, pp. 59, 303. " Loo. cit, p. 1553, footnote.* ' G«, p. 156. ' T", p. 93. In Professor Stevenson's description he stated that " The larger pebbles are flat" (T2, p. 76). 353 The Upper Devonian Deposits of Maryland In the northern part of Garrett County are numerous loose blocks of white quartz, flat pebble conglomerate, some of which contain jasper pebbles, as shown on the National Road about 5 miles from Frostburg on the Graham farm, on the Frostburg-Salisbury Eoad near the Baker house, and to the south of the National Eoad on Pea Eidge near Avilton. The pebbles in these blocks are evenly broken so that there is a smooth fracture similar to that of the 'flat pebble conglomerate in the Oakland region and the one found in place 1% miles south of Avilton opposite the house of Mr. John Eobinson. The jasper pebbles, however, are infrequent in the more southern localities just mentioned and the writer is not certain that the two conglomerates are identical. Professor Stevenson in the descrip- tion of his upper conglomerate of Bedford County mentioned rounded and flattened pebbles of white quartz,^ but apparently none of jasper; while Dr. I. C. White in describing what he considered as the same conglomerate in Huntingdon County distinctly called attention to " its red jasper ( ?) pebbles." ' Professor Stevenson also stated that the upper conglomerate in Bedford County had " films of quartz in the joints " ° which the writer believes is likewise true of the Garrett County conglomerate and Dr. Mar- tin has noted that the joints of the Maryland conglomerate " are frequently coated with drusy quartz." ' It is not improbable that further study may show that the flat pebble, jasper conglomerate of Garrett County is identical with Stevenson's upper conglomerate of Pennsylvania. The flat pebble, jasper conglomerate of northern Garrett County is named the Avilton conglomerate on account of its occurrence near the post-office of that name on Pea Eidge. The flat pebble, white quartz con- glomerate found farther south on Pea Eidge, frequently in the Oakland- Mountain Lake Park district and to the south of Mountain Lake Park and Oakland probably belongs to the same horizon although the writer was unable to demonstrate it to his satisfaction. These conglomerates appar- ently occur much below the top of the Jennings formation and their bould- ers as stated by Dr. Martin " are found along a more or less distinct line of ' T^ p. 79. ' T, p. 93. ' T^ p. 79. * Md. Geol. Surv., Garrett Co., p. 87. Maryland Geological Survey 353 hills parallel to and about half a mile from the outer and upper contact of the formation." * Succeeding the conglomerate in Jennings Eun are 550 feet of rocks that have been put in the Jennings formation in which Chemung fossils occur. These rocks consist largely of coarse grained, micaceous, greenish- gray and brownish-red sandstones alternating with shales. In Garrett County there are zones above the flat pebbled conglomerate in which abundant specimens of Chemung fossils occur, among which the charac- teristic species Spirifer disjunctus Sowerby is common. This part of the formation contains the most fossils and is one of the best collecting grounds for Chemung fossils in Maryland. The soil derived from the Jennings formation is yellowish in color. The thickness of the Jennings formation of Maryland, varies, according to the measurements of Swartz and Ohern, from 3400 to 4750 feet. It represents the Genesee shale and Portage and Chemung stages of 'New York and Ko. VIII, e, f, and g of Pennsylvania. DISTRIBUTION OF THE JENNINGS FORMATION The most eastern Jennings rocks in Maryland are found just west of the eastern belt of the Licking Creek area of the Romney formation and extend westward for 4 miles to Pigskin Eidge. Kear the middle of this area on the Potomac Eiver is Millstone which furnishes an appropriate name for this area of the Jennings. To the west of Timber Ridge, includ- ing the valley of the Great Tonoloway Creek, and extending nearly to . Hancock is a belt of the Jennings formation about I14 miles in breadth. In the western part of Washington County to the west of the Tonolo- way area of the Eomney formation a belt of the Jennings formation varying from three-fourths to nearly 1 mile in breadth crosses the state in a parallel direction to that of the Eomney area just mentioned. West of Sideling Hill is another belt of the Jennings formation, about I14 miles wide on the Maryland-Pennsylvania state line, in which part of the valley of Sideling Hill Creek has been excavated, and the greater part of this area lies to the west of this creek in the eastern part of Allegany ' Md. Geol. Surv., Garrett Co., p. 87. 23 354 The Upper Devonian Deposits of Mabtland County. This may be called the Sideling Hill Creek area of the Jennings formation. In Allegany County the Jennings occupies the center of the Pawpaw anticline and outcrops in a wide area extending from the east slope of Grreen Ridge to the west side of Polish Mountain. It also forms a broad belt east of and parallel to the Alleghany Front. In Garrett County it occupies the center of the Oakland anticline and is exposed in a small area west of Accident. Exposures in Washington County Exposure East of Millstone. — Under the description of the Middle De- vonian, exposures of the Upper Eomney have been described on the Na- tional Eoad to the southeast of Millstone and about one-half mile west of Licking Creek. That part of the section closes with massive grayish sandstone, alternating with shales and is regarded as near the top of the Romney. The exposures are somewhat infrequent, accompanied by rolls and changes in the dip so that no attempt was made to measure the thickness of the rocks in this section. No. 1. Succeeding the Romney to the westward is the Jennings formation, the first exposures of which are not far beyond the last one described under the Romney. These rocks consist of rather mealy, mica- ceous, arenaceous to argillaceous shales, some of which are thin and buff. ISTo fossils were found. Some of the harder blocks resemble in lithologic appearance the Woodmont member of the Jennings formation to which it is believed they belong. No. 2. On the William B. Jones farm about 2 miles east of Millstone from the excavation for a well were obtained brownish-red sandstones with olive shales and thin sandstone. Some of the sandstones contain fossils, as Camarotoechia and segments of large Crinoid stems. The sand- stones are quite reddish and these rocks apparently belong in the lower part of the Chemung stage of the Jennings formation. No. S. In a small quarry, which is no longer worked, one-half mile east of Millstone are red micaceous and gray sandstones alternating with olive and red argillaceous shales. There is also an occasional stratum Maryland Geological Sdkvey 355 of eornstone or a calcareous layer containing pebbles. In one of these strata in the lower part of the quarry are a few poorly preseryed fossils. The dip is 20° S., 15° E. This quarry was opened for flagstones without success but it would yield dimension stone for foundations and similar purposes. To the west of the quarry along the hillside the rocks are mainly red argillaceous shales, but there are some greenish shales and sandstones alternating with the red rocks. No. Jf. Outcrops in the cliff to the west of the house of George Pelton composed largely of red argillaceous pencil shale with thin sand- stone layers in the upper part. In this part of the zone is a slightly calcareous layer in which Spirifer mesastricdis Hall is abundant and there are a few other species the most abundant one of which is Ambo- coelia umbonata (Conrad). Farther toward the west the sandstones are more prominent, one massive stratum, near which a few fossils were found, being over 6 feet thick. There are also numerous pieces of coarse grit varying to conglomerate. The upper part of this zone is very red. In the red rocks to the east of the house no fossils were found. The thickness of this zone is estimated as about 500 feet. No. 5. A little farther west and with continuous exposures from No. 4 is an excavation where shale is obtained for the highway. At the top of No. 4 is a zone of yellowish shale, some of it partly mottled, in which there are fossils, as for example Ambocoelia umbonata (Conrad), Chonetes, and several species of pelecypods. These shales are mostly soft and argil- laceous and below them are brownish to somewhat reddish ones as well as buff and some that are decidedly olive in tint. In the shales along the road in ascending the slope to the west, no fossils were found. This zone was estimated as 275 feet in thickness, the lower part of which is composed mostly of buff shales. A little farther west are buff, argillaceous shales, somewhat micaceous but non-fossiliferous. There are also layers of sandstone one of which is massive, of fairly greenish-gray color, very hard and about 7 feet in thickness. From numbers 4 and 5 of this section east of Millstone the following species as determined by Dr. Clarke were collected : Ambocoelia umbonata 356 The Upper Devonian Deposits oe Maryland (Conrad), Atrypa hystrix Hall, Choneies sp., Ohonetes lepidifornds Clarke, Cyrtina hamiltonensis Hall, Spirifer mesastrialis Hall. No. 6. By the side of the road in Millstone are thin, olive, micaceous shales alternating with thin bedded, olive sandstones all of which are in the Woodmont member of the Jennings formation. No fossils were found in these rocks. The dip is about 40° S., 10° E. No. 7. In the western part of Millstone is a blocky sandstone, near the axis of the anticlinal fold, which belongs in the Hamilton stage of the Eomney formation. The rocks of zone No. 7 were described under the section of the Eomney at Millstone. No. 8. By the side of the road to the west of Millstone and just east of the first creek west of that village, are olive, thin bedded shales alter- nating with thin sandstones. In the excavation immediately east of the creek is a band of brownish-red shale similar to that described in the Upper Chemung in the outcrops east of Millstone. One of the layers con- tains a large and long Crinoid stem and this was the only fossil found at this locality. The red shale is about 6 feet in thickness and some of the olive shales are fairly thick and quite arenaceous. Prom this locality to the vicinity of Hancock, the rocks are not well exposed but they belong in the Jennings formation with the exception of the Catskill belt from Pig- skin Eidge to the western slope of Timber Eidge. The important thing to note in the lithological characters of this section is the early appearance of bands of red shale as compared with the section to be described in Allegany County. In the more western sections the red rocks made their first appearance well up in the Chemung and above a fauna composed of a number of characteristic species of that stage; while east of Han- cock they occur below the Chemung. This earlier appearance of the conditions toward the east favorable for the deposition of the red rocks agrees with their occurrence in southern New York, where in the eastern part they begin as a continuous mass of red and green rocks fully as early in time as in this section, while along the southern border half-way across the state they are not seen until near the close of tlie Chemimg stage. Exposure hetween To7iolou.'ay Ridge and Sideling Hill. — There is a ledge of quite massive greenish-gray sandstone on the National Eoad about Maetland Geological Survey 357 4 miles west of Hancock which is supposed to mark the top of the Eomney formation. No. 1. Then after passing a covered interval of a few feet, olive shales of the Woodmont member of the Jennings, with an occasional sandstone 3 or 3 inches in thickness, begin. These shales stand at a very high angle and only the loose pieces on the surface can be examined. A little farther west the shales are shown to better advantage by the side of the road in front of the house of Mr. Banner Hess, 4 miles west of Hancock. There are but few fossils simply fragments of Pteroehaenia fragilis (Hall), Styliolina fissurella (Hall), Bactrit&s adculus (Hall) and two or three fragments of Goniatites having been found. There are also the usual marks of the trails of animals in the smooth shales. That part of the section in which the transition from the Eomney to the Jennings occurs is covered ; still the interval is not great and it appears from the examination of the section in the eastern part of Hancock that the Genesee shale is not present. The sandstones in the upper part of the Romney are evidence of shallower water than that in which the greater part of the formation was deposited and perhaps in Washington County the deposit of the Genesee shale pinched out. In the northeastern continuation of this belt in Fulton County, Pa., Professor Stevenson reported Genesee shale " on the west side of Tonoloway Ridge in Bethel Township " and also in the continuation of the Hancock belt " on Tonoloway Creek near the northern edge of Thompson Township," Ptilton County.'' No. 2. N'ot far west of Mr. Hess' house, by the side of the road, are slightly coarser fossiliferous and somewhat arenaceous shales containing specimens of Spirifer mucronatus (Conrad) var. posterns Hall and Clarke, Pro&actella, and crinoid segments. Some of these shales are slightly brownish but most of them, at least when weathered, are of a buff to olive color. Interstratified with the shales are shaly to thin bedded sandstones. The dip in places is over 70° but there are small rolls so that it is not uni- form. In the upper part of this zone are brownish argillaceous shales and at the top a brownish massive sandstone, some 4 feet in thickness. ' 'P. p. 82. j 358 The Upper Devonian Deposits of Maetland No. S. Above the sandstones are buff to olive shales in which are fossils as Productella and Schizophoria striatula (Schlot.), and brownish argillaceous shales interstratified with the olive ones. Toward the upper part of this zone there are some quite massive sandstones at the base of which is one 4 feet thick, then shales occur capped by another sandstone 10 feet in thickness. Next there is a band of mostly red argillaceous shale containing some reddish compact sandstone the layers of which vary in thickness from 6 inches to 1 foot. Kear the top is a stratum of olive blocky shale. No. Jf.. Succeeding the belt of red shale is a fairly massive sand- stone followed by buff argillaceous and very compact shale which splits into quite thick layers. These are much stained vn& bright red blotches on the weathered surfaces. Farther up the road are thin bedded, olive, argillaceous shales which form the greater part of this zone and extend to the school-house. No fossils were found by the writer but a few specimens were reported by Eowe. From numbers 3-4 of this section Clarke has identified the following species : Atrypa hystrix Hall, Cyrtina hamiltonensis Hall, Schizophoria striatula (Schlot.), Spirifer marcyi var. superstes Clarke, Spirifer mucronatiis var. posterus Hall and Clarke, Bellerophon nactoides Clarke. No. 5. The shales of this zone are mostly buff in color but they are not well shown along the road. Some distance above the school-house there are reddish fissile shales which are not very thick. The Upper Chemung is covered along the National Eoad so that the transition from the Jennings to the Catskill formation is not shown. From collection? made by Rowe in the vicinity of the school-house mentioned above, Clarke has identified the following species: Leptodesma ncuviforme Hall, Liopteria higsbyi Hal], Nucula cf. corhuliformis Hall. No. 6. The Catskill formation is well shown by the side of the road just west of the church and is composed of red shale and sandstones with some layers of greenish sandstone. From the church well toward the top of Sideling Hill are numerous exposures of red argillaceous shales and red sandstones as well as some greenish-gray, massive sandstones and greenish shales all belonging in the Catskill formation, while the hill is capped by Pocono sandstone. Maryland Geological Survey 359 Exposures in Allegany County Exposure West of Sideling Greek. — After crossing the crest of Sideling Hill there are outcrops of Pocono sandstone on the western side In which, not far below the summit, is a small opening for coal. Lower are numer- ous outcrops of the red shales and sandstones of the Catskill formation and a thick band of red argillaceous shale is shown just east of the Side- ling Creek bridge. One mile west of the creek is a band of somewhat calcareous sandstone in which are fossils mainly Spirifer viesacastalis Hall, Spirifer mesastricUis Hall, and Spirifer disjuncius Sowerby asso- ciated with Sphenotus contractus Hall and a few other pelecypods. This rock weathers to a rusty-brown rottenstone due to the leach- ing of the calcareous material. Immediately below the zone of fossils is a red sandstone stratum beneath which are red argillaceous shales. The dip at this locality is 13° IST., 70° W. The rocks of this zone belong in the Upper Chemung and it is to be noted that these fossils occur above red rock. As has already been indicated the red rocks in western Maryland occur at different horizons so that it would be im- possible to separate formations by the first appearance of red rocks. A better means of classification is that made by the last appearance of fossils considering the rocks below such a horizon as of Chemung age. In this case in the upper part of the Chemung or Jennings formation there will be found bands of red rock which in the wratern part of the state are confined to the Chemung member of the Jennings formation but in Washington County appears as early as the Parkhead member. Prom collections made in the vicinity of Sideling Hill Creek Dr. J. M. Clarke has identified the following species: Favosites sp., Heliophyllum scrutarium Clarke, Spirorbis gyrus Clarke, Ambocoelia urribonata (Con- rad), Productella lach/rymosa (Conrad), var., Spirifer mesastrialis Hall, Sphenotus contractus Hall, Bellerophon sp. Exposure Northwest of Little Orleans. — The rocks in the vicinity of Little Orleans belong in the Jennings and Catsldll formations. The road to the northwest of Little Orleans runs along Fifteen Mile Creek for some distance and then climbs a steep hill. The rocks of the lower Jennings formation are exposed in Fifteen Mile Creek, in the vicinity of Little 360 The Upper Devonian Deposits op Maryland Orleans. The lower rocks are olive shales interstratified with some rather massive greenish-gray sandstone. The higher rocks contain some fossils as Ambocoelia umbonaia, (COnrad), and Atrypa reticularis (Linne). The rocks at this fossiliferous horizon are largely argillaceous shales which weather to an olive or hvS. color. Toward the top of the hill in the shales and some slightly coarser layers are fossils tiiough at no place are they abundant. Exposure on Oreen Ridge. — This section follows the National Road along which there are fair outcrops up the western slope of Green Ridge. The base of the section begins near the lower part of the hill to the east of Fifteen Mile Creek. No. 1. The lowest rocks are olive to buff, smooth, argillaceous shales with layers of greenish-gray sandstone not more than 6 to 8 inches in thickness. These shales and sandstones belong in the Woodmont member of the Jennings formation. Higher is the first zone of fossils near the top of one of the thicker layers in which are specimens of Camarotoeohia sp., but the fossils are fragmentary. At this part of the section the lithologie characters remain about the same as in the lower exposure. No. 2. Lithological appearance of the rocks about the same as in No. 1 but no fossils were found. No. S. A zone of somewhat crumbly and mealy shales in layers of which there are numerous specimens of Camwrotoechia, sp., with a few of Spirifer mesacostalis Hall. This zone is about 5 feet in thickness. No. J).. Olive shales interbedded with thin sandstone; fossils rare. This zone extends up to the base of the lowest brownish shales. No. 6. At the base of this zone are brownish argillaceous shales but most of the rocks are olive to buff shales alternating with thin sandstone. No fossils Were found in this zone, which occurs on the highway below the farm house. From the top of this zone for some distance the rocks are concealed (No. 6). No. 7. The rocks of this zone are composed of shales and thin sand- stone to arenaceous, coarse, blocky shales. They weather to a brownish or buff color with patches and streaks of rather bright red due to weather- ing of the iron contained in the rock. The base of this zone begins a short distance above the farm house and in a thin sandstone layer are Maryland Geological Survey 361 numerous specimens of Spirifer with a very high hinge area probably Spirifer marciji var. superstes Clarke associated with Spirifer disjwnctus Sowerby, and numerous specimens of Ambocoelia umbonata (Conrad). Some of this sandstone is almost pinkish in color and all of it is much stained and blotched with red patches. The sandstone is fairly hard but the shales in this zone are mostly olive and fissile. No. 8. Some distance above the stratum containing the numerous specimens of Spirifers are brownish argillaceous shales and thin arena- ceous layers. The succeeding rocks are mostly olive to buif shales and thin sandstone with an occasional layer of brown shale or sandstone. No. 9. Almost at the top of Green Ridge is a ledge of brownish-red sandstone and just above are arenaceous shales to mealy sandstone in which fossils occur; as Spirifers, Lyriopeden tricostatv^ (Vanuxem), Sphenotus contractus Hall and other pelecypods. In one block con- taining a specimen of Spirifer is a white quartz pebble, while on the surface are quite large blocks of conglomerate which apparently formerly capped the hill. It will be seen in the description of the sections on Polish Mountain that blocks of a similar conglomerate occur near its summit. The summits of these mountains were undoubtedly originally covered by this Chemung conglomerate which has been nearly removed by erosion. At first it was supposed to form the top of the Jennings formation but in the section west of Cumberland in Jennings Eun it is shown that succeeding a similar conglomerate are several hundred feet of rock which still carry Chemung fossils. In the upper part of that zone there are bands of red shales and sandstone of considerable thickness but in the olive shales alternating with the reds are fossils. The higher rocks, either clear red shales and sandstone or somewhat greenish in color and without fossils, are in the Catskill formation. Evidently Dr. O'Harra considered the conglomerate blocks found on Green Eidge as identical with the one in Jennings Eun for he wrote that " It [ Jeimings Eun conglomerate] is not well shown on Green Eidge, although there is abundant evidence of its presence, but along the eastern flank of Town Hill [a parallel ridge a short distance east of Green Ridge] it appears to be of considerable thickness." ^ * Allegany Co., p. 107. 363 The Upper Devonian Deposits of Maryland Dr. J. M. Clarke has identified the following species from the col- lections made on Green Kidge: Ambocoelia umbonata (Conrad), Oama- rotoechia contracta Hall, Liorhynchus cf. midticosta Hall, Spi/rifer marcyi var. superstes Clarke, Spirifer mesastrialis Hall, Tropldoleptus cwrinaius (Conrad), Lyriopecten tricostattis (Vannxem), Cypricardella gregaria Hall, Palaeoneilo constricta (Conrad), Sphenotus contractus Hall, Ten- taculites discissus Clarke. Exposure on National Road on Polish Mountain. — ^Under the Eomney formation a section was described beginning at the top of the Oriskany sandstone to the west of Gilpin and extending, probably, to the top of the formation. A ledge of coarse shale to thin sandstone occurs in the eastern part of the hamlet which was considered to be near the top of the Eomney, while from that horizon the rocks are covered east to Town Creek on the bank of which the Woodmont member of the Jennings formation is shown. No. 1. On the bank of Flintstone Creek, however, just south of Gilpin are bluish shales containing an abundant Hamilton fauna. Then the rocks are covered for an interval when black, fissile shales (No. 3) of the G«nesee are exposed. These shales are about opposite the old tannery only a few rods above the junction of Flintstone and Town creeks; and the lowest of them, which are rather bluish in color, are more arenaceous than those seen at the other localities but they contain about the same fauna. At the top of the exposure the shales are more argillaceous and quite carbonaceous and also contain more fossils both in number of speci- mens and species. The dip at this locality is about 30° S. of E. and some 75 feet of shales are exposed. From the black shales of this locality Dr. J. M. Clarke has identifed the following species: Buchiola retrostriata v. Buch, Lunulicardium crinitum Clarke, Paracardium doris Hall, Pterochaenia fragilis (Hall), Styliolina fissurella (Hall). No. S. On the eastern bank of Town Creek at the Kational Bead bridge are olive to greenish fine argillaceous shales which alternate with thin bedded sandstones from 3 inches to a foot in thickness. Fossils are rare but Pterochaenia fragilis (Hall) and Buchiola livondae Clarke were found. About 100 feet of rock is exposed in this outcrop with a dip of 30° Maryland Geological Survey 363 E. and strike N. 33°. Toward the top the shales are more bluish and, in slightly irregular layers of bluish to greenish shales are some fossils as BucMola retrostriata v. Buch, Pterochaenia fragilis (Hall), and a small Orthoceras. In the upper part of the cut there is a sandstone stratum over 2 feet in thickness with thinner sandstones above, followed by olive shales. The sandstone weathers to a dark brown color on the edges of the outcrop and the shales, frequently, to a yellowish-brown. These rocks are very similar in lithological characters to many exposures of the Portage stage in central, or the Sherburne sandstone in eastern New York. They are referred to the lower part of the Woodmont which forms the lower member of the Jennings formation in Maryland. About 4% miles nortli of this localiiy in Southampton Township, Bedford County, Pa., Professor Stevenson described " laminated brown to olive shales " on the road from McLewees' Gap across Polish Mountain which he stated " may be regarded as Portage." " From the Woodmont as exposed from Town Creek along the National Eoad to the second turn on the lower part of Polish Moimtain Dr. J. M. Clarke has identified the following species: Buchiola conversa Clarke, Buchiola livoniae Clarke, Buchiola retrostriata v. Buch, Pterochaenia fragilis (Hall), StylioUna fissurella (Hall), Bactrites adculiis (Hall), Orthoceras filosum Clarke, Probeloceras lutheri ( ?) Clarke. No. 5. On the National Eoad at the second turn east of Town Creek near the lower part of the western slope of Polish Mountain are fine, olive, argillaceous shales with an occasional thin sandstone stratum. These shales are moderately fossiliferous, containing Ghonetes lepidi- formis Clarke, Camarotoechia eximia Hall, Leptodesma, and some other species, and breaking into very thin pieces soon crush into powder on the road, although they are used for road material. Up the mountain beyond this point are shales and thin sandstones in which fossils occur infre- quently, but about 100 yards above the turn specimens of a small Spirifer and large Camarotoechia were found. By the roadside above the second turn is a similar exposure of olive shales with an occasional thin sandstone. Some of these shales are ' 1', p. 205. 364 The Upper Devonian Deposits op Maryland blocky and contain, though rarely, a few fossils. About 600 feet above the second turn there are fossils in rather blocky shales which are brownish-gray in color, break into irregular pieces, and a little coarser than most of those in this section. Specimens of Tropidoleptus carinatus (Conrad) occur and a few other species. The lithologic characters of this band are more like the Eomney than is generally the case in the Jennings formation and the fauna is perhaps a recurrent one of that formation. No. 7. At the third turn on the road are greenish shales alternating with thin sandstones and near the base is a sandstone of greenish-gray color 3 feet in thickness. Some of the thin, blocky sandstone layers contain fossils and two specimens of Spirifer disjunctus Sowerby were found as well as others of Liorhynchv^ mesacostcde Hall, Ambocoelia. umbonata (Conrad), Cypricardella and layers composed of small crinoid segments. This zone is very similar in appearance to many in the Chemung of southwestern 'New York to which stage it is referred. The presence of Spirifer disjunctus Sowerby a characteristic species of the Chemung stage is regarded as proving the correctness of this correlation. Some of the thin sandstones are quite micaceous and split into rather smooth layers. A little higher in green argillaceous shales is a slightly irregular layer in which are numerous specimens of Ambocoelia umbonata (Con- rad). The exposed rocks from Town Creek up the lower part of Polish Mountain are mainly greenish argillaceous and arenaceous shales alter- nating with thin sandstones of similar color. There is no sharp line separating the rocks which are referred to the Woodmont and Parkhead and those of the Chemung; but a gradual transition from the lower to the upper members. Rocks containing Spirifer disjunctus Sowerby are referred to the Chemung stage and the line of separation between the Chemung and Parkhead is considered as below this zone. The average dip of the rocks is 39°. No. 8. A little below the fifth turn on the road in somewhat blocky shales, fossils are rare but a few small pelecypods were found. At the sixth turn on the road are line olive non-fossiliferous argillaceous shales. Maryland Geological Survey 365 No. 9. A little above the sixth turn are olive shales in which an occasional fossil, as Ambocoelia umbonaia (Conrad) occurs, while a little higher in some rather lumpy shales are quite a few fossils as Spirifer dis- junctus Sowerby, Spirifer mesacostalis Hall, Productella lachrymosa (Conrad), and pelecypods. These rocks are mostly green to olive shales with thin bands of arenaceous shale or sandstone. There is not much variaition in the lithological appearance of the rocks, and fossils occur only in occasional layers. No. 10. Between the seventh and eighth turns on the road, about opposite a spring which occurs in a run on the lower side, are somewhat coarser layers, and on thin sandstones are excellent specimens of Camw- rotoechia contracta Hall associated with specimens of Spirifer mesa- costalis Hall. The rocks above at the eighth turn are very argillaceous olive shales which break into pencil shales. No. 11. Just below the ninth turn, in thin sandstone layers are numerous specimens of Ambocoelia umbonata (Conrad) and Spirifer dis- junctus Sowerby together with several other species. The rocks are com- posed of thin sandstones which alternate with the shales and axe about the same in general appearance as the f ossilif erous layers in the Chemung of southern New York. No. 12. Near the top of the mountain the shales weather to quite a brownish or rusly color. In some of the layers of thin sandstone a broad form of Spirifer disjunctus Sowerby occurs. Quartz crystals were found in a piece of shale while very near the summit of the mountain are layers of thin bedded, rather bluish sandstone with a dip of 15° to 17° B. Loose pieces of conglomerate and grit occur on the side of the mountain near its top and on the crest. All of the pieces found were loose and the conglomerate was not seen in place, although it undoubtedly capped the mountain originally. In small runs to the south of the National Road are the greenish shales and sandstones of the Chemung and no indication of a conglomerate ledge was seen. The blocks are not numerous and it is probable that their horizon, stratigraphically, is considerably above the highest ex- posures on the National Eoad. Some of the blocks on the joint planes 366 The Upper Devonian Deposits op Maryland have a smooth fracture, breaking directly across the quartz pebbles, while others have an irregular, rough surface. 'No jasper pebbles were seen in the blocks and they do not closely resemble the conglomerate that occurs in the vicinity of Oakland and Mountain Lake Park in Garrett County. They do, however, more closely resemble the conglomerate found on Pea Eidge at Mr. John Eobinson's in the eastern part of Garrett County. It is evident that Dr. O'Harra correlated these conglomerate blocks with the one of Jennings Eun since he stated that " Eemnants of the same conglomerate [Jennings Eun] are seen along the top of Polish Moun- tain."^ Pour and one-third miles farther north in Pennsylvania, Pro- fessor Stevenson gave the following description of loose conglomerate blocks found on Polish Mountain: " Fragments of the Chemung Conglomerate lie plentifully along the crest of the ridge, but none was seen in place " There is some possibility that the conglomerate seen on the crest of Polish Mountain may belong to the lower one, as the shales seen in the valley bear little resemblance to those overlying the Upper Conglomerate; and, moreover, contain many layers with Ambocoelia gregaria and im- pressions of erinoid stems, such as ordinarily characterize the shales holding the Lower Conglomerate."' The Chemung rocks consist largely of greenish, argillaceous and arenaceous shales with bands of greenish to greenish-gray sandstone. The average dip of the Chemung on Polish Mountain is about 30° and the distance from its base to the top of the point south of the National Eoad one-half mile. An estimate of the thickness of the Chemung ex- posed on the upper part of this mountain gave 1000 feet. Farther to the northeast Professor Stevenson in his "generalized section for Pulton County," Pa., gave the thickness of the " Portage flags " as 1400 feet and the Chemung as 2330 feet, making a thickness of 3620 feet to which is to be added the Genesee shale which Professor Stevenson estimated to have a thickness of 200 ± feet near Saxton° in the northeastern part of Bedford County making a total thickness of ' Allegany County, p. 107. ^ T^ p. 205. » T^ p. 82. Maryland Geological Survey 367 about 3830 feet for the rocks which in Maryland are referred to the Jennings formation.' The Jennings formation of Polish Mountain may be followed northeasterly across the eastern pat't of Bedford County to Professor Stevenson's section " on the Huntingdon and Broad Top Eailroadj beginning in Saxton" which gave a thickness of "almost 3400 feet"' to which is to be added the 300 ± feet of Genesee shale" malcing a total thickness of almost 3600 feet. From the specimens collected in the Jennings rocks on the western slope of Polish Mountain Dr. J. M. Clarke has identified the following species: Ambocoelia umbonata (Conrad), Atrypa hystrix Hall, Atrypa reticularis, (Linne), Camarotoechia contracta Hall, Camarotoechia exirma Hall, Ghonetes hpidiformis Clarke, Crania sp., Cryptonella cf. eudora Hall, Dalmanella sp., Douvillina cayuta Hall, Liorhynchus mesacostale Hall, Oriiculoidea ef. media Hall, Productella lachrymosa (Conrad), Productella lachrymosa (Conrad) var., Productella speciosa Hall, Spvrifer disjunctus Sowerby, Spirifer marcyi Hall, var. superstes Clarke, Spirifer mesacostaiis Hall, Spirifer mesastriaJis Hall, Tropidolept'iis ca/rinMus (Conrad), Nucidites sp., Bchuchertella chemungensis (Conrad), Murchi- sorda ecclesia Clarke, Tentaculites discissus Clarke. Exposure on Williams Road on Polish Mountain. — This section begins at the intersection of the Williams Road and Town Creek and then follows the road to the top of Polish Mountain, crossing the same zones of the Jennings formation as the section along the National Eoad and nearly parallel with it but about 2 miles farther south. The road winds back and forth to such an extent that no effort was made to measure the thickness of the rock but there are various well -exposed zones of the Jennings formation which extend from the bank of Town Creek to the summit of the mountain. No. 2. In the cliff on the eastern bank of Town Creek just below the highway bridge are smooth, argillaceous mainly light olive to bluish, sparingly fossiliferous shales changing to thin sandstones. A few speci- ' r, p. 75. = 76i(?., p. 78. ' nid., p. 82. 368 The TJppee Devonian Deposits oe Maetland mens of Buchiola retrostriaia v. Buch and Bactrites adculus (Hall) were found in theni and some trails of animals. The rocks are of the Woodmont member and from the lower part of the Jennings formation. The cliil is from 75 to 80 feet in height and the dip apparently between 37° and 28° nearly ea^t. No. 3. The lower part of Polish Mountain along Williams Eoad is composed of thin, olive, argillaceous shales with some thin sandstone layers as shown on its western side. In the midst of the shales forming this zone is a buff to olive layer of mealy sandstone 2 or 3 inches in thickness in which are numerous erinoid segments and shells as for example Spmfer disjunctus Sowerby, Spirifer mesastrialis Hall, Spirifer mesacostalis Hall, Atrypa reticularis -(Liane) , ProducteUa, Chonetes, and a few other species. This layer apparently contains about the first of the Chemung fauna, for fossils were not found below and the rocks above for some distance are also barren, smooth, olive shales with olive quite micaceous sandstones 6 inches or more in thickness. No. J/.. This is another thin layer containing a few fossils. The stratum is an olive, mealy sandstone several inches in thickness in which are undoubted specimens of Spirifer disjunctics Sowerby and Spi- rifer mesastrialis Hall. The association of these two species of Spirifer found in zones No. 3 and No. 4 is interesting because in New York such occurrence is rather infrequent. Atrypa reticularis (Linne), Crin- oid segments and a few other fossils were found. Loose on the surface of the mountain at this locality are frequent blocks of brownish-red sandstone. Brownish-red arenaceous shales and thin micaceous sand- stones of similar color interstratified with buff to olive argillaceous shales appear in place at the side of the road only a few feet above the top of the fossiliferous layer of zone No. 4. No. 5. Eeddish fine argillaceous shale by roadside. The color is perhaps more of a brownish-red and not so bright as in the lowest bands of red shale occurring farther west in Garrett County. Above are shales of olive color which weather to a buff. No. 6. A stratum of quite heavy, compact grayish sandstone which shatters on weathering but still forms a fairly conspicuous ledge by the Maryland Geological Survey 369 side of the road. Below is a considerable thickness of olive argillaceous shale between this sandstone and the lower argillaceous red shales. Specimens of Spvrifer mesacostalis Hall occur in the more shaly sand- stone. A few loose pieces of conglomerate were noticed on the surface. No. 7. Olive argillaceous shale occurs at the fork of the road, where one turns to the south, and forms the greater part of the rock along the road for some distance below the fork. One piece was found which con- tained specimens of Ambocoelia umbonata (Conrad). The blocks of conglomerate are more common along the side of the road from this part of the section to the summit of the mountain although most of the pieces are small. No. 8. Thin layers of mealy sandstone containing abundant speci- mens of Spirifer mesacostalis Hall which occurs only a short distance above the fork in the road. The layer is in the midst of olive to buff argillaceous shales and is about 3 inches thick. The Spirifers com- pose a considerable part of this layer and there are also specimens of quite a large species of Eolopea. The specimens of Holopea marylcmdica Clarke, Holopea rowei Clarke, and Macrochilina pulchella Clarke which were described by Dr. J. M. Clarke and the locality given as " road over Polish Mountain east of Eush " were from this section and perhaps this zone. No. 9. Two bands of red shale cross the road above which are fine, olive, argillaceous shales in which are thin layers containing specimens of Spirifer mesacostalis Hall, Ambocoelia umbonata (Conrad), Productella and pelecypods. Large blocks of massive coarse grained sandstone, grayish in color but weathering to brownish-gray occur along the road and on the mountain slope. It is probable that this sandstone occurs in place at about this horizon although a ledge was not seen. No. 10. Olive shales occur above the loose sandstone, and one block from this horizon contains large numbers of Spirifer mesacostalis Hall. There are also thin, gray sandstones, 6 inches or more in thickness inter- stratified with the shales. This zone is but a short distance below the summit of the mountain. Loose on the top of the mountain near the four corners are numerous small blocks of quartz pebble conglomerate which 24 370 The Upper Devonian Deposits oe Makyland apparently once capped Polish Mountain as was stated in the description of the ITational Eoad section of this mountain and the same or a similar one, Green Eidge, on the east. This conglomerate does not represent the top of the Jennings formation as is shown by the sections in the western part of Allegany Connty as well as those of Garrett County. On Polish Mountain are also blocks of loose sandstone containing large numbers of specimens of Ambocoelia. ISTear the summit and on top of the mountain are numerous blocks of this Ambocoelia sandstone some of which are 6 inches in thickness. Exposure East of Cumberland. — By the side of the National Road 2^2 miles northeast of Cumberland, to the west of Evitts Creek and Wolfe Mill, are excellent outcrops of the Genesee shale at the base of the Jennings formation. The shale which is very fine, fissile, black in color on a fresh outcrop but weathering to a gray and readily turning into soil, begins some distance above the valley and is exposed along the roadside to the top of the small hill. This is one of the best localities noted in the county for studying the Genesee shale which seems to be the only county in Maryland in which the shale occurs. Fossils are common, perhaps the most abundant species is Buchiola livomae Clarke. E"ext in order of abundance are Pterochaenia fragilis (Hall), Buchiola retrostriata v. Buch, Styliolina fissurella (Hall), and Probeloceras lutheri Clarke ( ?) . This locality is readily accessible from Cumberland and is an excellent place for studying the black, fissile shales at the base of the Jennings formation which the writer has correlated with the Genesee shales of New York. The complete list of species found at this locality, as determined by Dr. J. M. Clarke, is as follows: Buchiola livoniae Clarke, Buchiola retrostriata v. Buch, Lunulicardium crinitum Clarke, Paracardium doris Hall, Paa-acardium delicatulum Clarke, Pterochaenia fragilis (Hall), Styliolina fissurella (Hall), Bactrites aciculus (Hall), Probeloceras lutheri Clarke (?). On the Williams Eoad, but a short distance southeast of Cumberland, are fossiliferous shales of the upper part of the Hamilton stage of the Eomney formation containing specimens of Trapidoleptus carinatus Maryland Geological Suevet 371 (Conrad), Spirifer mucronatus (Conrad), Palaeoneilo emarginata (Con- rad), and other Hamilton species. Succeeding the Eomney formation are finer argillaceous shales which split into very thin layers. In the shales axe specimens of calcareous concretions which have been broken and the cracks filled with calcite so that except in regard to size they considerably resemble the septaria of the Genesee shale in New York. The shales contain some fossils as BucMola retrostriata v. Buch, Bactriies acictdus (Hall), and a few other species and are in the lowest part of the Jennings formation which is referred to the Genesee shale. As has already been mentioned the stratigraphy of the outcrops on this part of the road is somewhat complicated by faulting and folding. From these shales on the Williams Road and McKays Hill southeast of Cumberland, Dr. J. M. Clarke has determined the following species: Buchiola Kvoniae Clarke, Buchiola retrostriata v. Buch, Paracardium doris Hall, Pterochaenia fragilis (Hall), StyliolUia fissurella (Hall), Bactrites aciculus (Hall), Probeloceras lutheri Clarke, Tornoceras uni- angulare (Conrad). Farther east on the road and still higher in the Jennings formation the shales are olive in color and fossils are infrequent. This portion of the formation is correlated with the Portage stage in New York. Exposure on Jennings Bun. — Jennings Run, in the northern part of the county, a tributary of Wills Creek, has cut a deep trench through the eastern face of the Alleghany Front in which part of the formations of the Upper Devonian and Carboniferous are well shown. The lower part of its course is across the Romney formation all of which is covered except its top which is also true for the greater part of the middle portion of the Jennings formation, while several succeeding formations are quite well shown ia the narrow part of the gorge. In the section above Corrigan- ville, the upper part of the Romney is shown as has already been described under that formation, but the remaining part of the section was only briefly mentioned. This is an important locality for studying the forma- tions under consideration and the various exposed zones will now be described in detail. 372 The Upper Devonian Deposits of Maryland Total Thick- thick- ness. nes8. No. 1. At the eastern end of the road cut are shales and sand- stones of the upper part of the Romney formation, 147 feet shown. No. 2. Covered portion 30 30 No. 3. Thin black argillaceous shales splitting into very thin pieces which are even and smooth, and weathering to a slightly ■brownish tint are excellently shown in this cut, which In many respects is the best exposure of Genesee shale known In Maryland. The shales are quite fosslllferous as for example, Styllolina fis- surella (Hall) is abundant in certain layers while Buchiola retro- striata v. Buch and Pterochaenia fragilis (Hall) are not un- common. This exposure of shale is quite similar to many in the typical outcrops of the Genesee shale in central New York with which it is correlated. The contact between the Genesee and Wood- mont Is clearly shown and at the top of the black Genesee shales the rocks become coarser In texture and thin sandstones occur alter- nating with shales. The line of division is drawn where the thin sandstones appear, a little to the east of the sycamore tree near the middle of the upper part of the cut. Within 5 feet there are bands of sandstone 2 to 3 inches in thickness alternating with the shales, and the lithological appearance of the rock is unmistakably that of the Woodmont stage. This is the best exposure of the contact of the Genesee shale and Woodmont shale known in Maryland. From these black shales Dr. J. M. Clarke has identified the following spe- cies: Buchiola retrostriata v. Buch, Lunulicardiv,m cymbula Clarke, Faracardiwn doris Hall, Pterochaenia fragilis (Hall), Styliolina flssurella (Hall), Bactrites aciculus (Hall), Proieloceras lutheri Clarke ( ?), Tornoceras uniangulare (Conrad) 73 103 To the northeast of this exposure Professor Stevenson reported two outcrops of the Genesee shale in Napier Township In the west- ern part of Bedford County, Pennsylvania.' No. 4. On a fresh fracture the thin shales have a rather bluish color and alternate with thin sandstones of similar color, both of which weather to a greenish tint and here and there are iron- stained. In the upper part of this zone the sandstones are thicker than in the lower portion; one being 9 inches and several others nearly as thick 38 141 No. 5. Prominent massive bluish-gray sandstone, which weath- ers to a greenish tint, 2 feet, 9 inches in thickness. This is the most prominent stratum in the upper part of the cut and may be readily located 2+ 143-1- No. 6. The shales above are bluish argillaceous and arenaceous, and a little higher mainly greenish shales occur alternating with thin sandstones. The greater part of this upper portion Is in the field at a short distance from the road. These rocks are all in the ' T^', p. 82. Maryland Geological Survey 373 Total Thick- thick- ness, ness. Woodmont member of the Jennings formation. Dip at top of Gene- see shales 77°, on the massive sandstone 85°, and in the upper part of the section from 84° to 86° 190-f 333-f No. 7. Rocks mostly covered. Thickness estimated as about 2740 feet 2740 3073 No. 8. Exposures in the highway cut about 1% miles west of Corriganville and directly below a small railroad bridge. In the lower part are brownish-red, micaceous sandstones and argillaceous shales and higher are greenish and yellowish shales and sand- stones varying in thickness from an inch to 1 foot 112 3185 No. 9. Mostly very massive thick bedded grayish quartzose sandstone alternating with layers of conglomerate. Some of the largest pebbles are in the upper layers at the western end of the cut although these layers are mainly a brownish-gray coarse grit containing an occasional pebble; but other layers near the center of the mass contain more numerous quartz pebbles and form a con- glomerate. The pebbles are mainly white quartz, rounded or flat- tened in shape and of various sizes up to an inch or more in diam- eter. Some of the sandstone layers contain Chemung pelecypods and Dr. Rowe found a single specimen of Spirifer disjunctus Sowerby, while specimens of small TentacuUtes and crinoid seg- ments occur. Near the western end of the cut on the surface of thin sandstone layers are specimens of Sphenotus contractus Hall. This conglomerate at one time was considered to mark the upper limit of the Jennings formation; but later investigations have shown that it is better to draw the line of division at a horizon several hundred feet higher. It was also considered as occurring near the horizon of the conglomerate which has been noted on top of Green Ridge and Polish Mountain as well as the prominent one in Garrett County which in a general way is probably true, although it is hardly proven that they occur at strictly the same horizon; but they do occur In the upper part of the formation within several hundred feet of its top. The rocks at this locality are quite similar in lithological appearance to many exposures of the upper Chemung in southern and southwestern New York 40 3225 Dr. O'Harra gave the thickness of this zone in Jennings Run as 35 feet and stated that, " It is well marked by a line of hills along the eastern slope of Allegany Front and near the southern end of this line of hills 4% feet of the bed is shown." ' About 7% miles northeast of Jennings Run, in Gladden's Run west of Palo Alto, Bedford County, Pa., Professor Stevenson found a con- glomerate which from the context^ he evidently regarded as the ' Allegany Co., p. 107. 'V, p. 79, where the list of localities of the lower conglomerate in the county is given. 374 The Upper Devonian- Deposits of Maryland Total Thick- thick- ness, ness. one which he called the Upper Chemung and stated that, " The exposure of this rock in place is incomplete, but great masses of conglomerate are strewn thickly over the surface." ' The occur- rence of the Upper Chemung conglomerate at the locality just cited, only 7% miles northeast of the Jennings Run conglomerate and in the direct line of strike supports the opinion that they are identical. In Dr. White's section along the Potomac River to the northwest of Keyser where the same belt of the Jennings formation crosses the river he described two layers of conglomerate in the Chemung about 900 feet apart. The upper one is given as 400 feet below the top of the Chemung and 2 feet in thickness and is described as " composed of very thin, flat, rounded quartz pebbles, in a matrix of coarse rotten sand with numerous fossil shells imbedded " while the lower one is given as 40 feet thick and consisting of " a gray, hard sandstone, containing numerous layers filled with flatfish, white quartz pebbles." ^ The interval of 900 feet between these two conglomerates agrees closely with that of 950 feet given by Professor Stevenson as the thickness of the rocks between his lower and upper Chemung conglomerates in Fulton County, Penn- sylvania.^ The horizontal distance was obtained in part from pacing and also by counting railroad ties parallel to the direction of the section from which was estimated 3225 feet for the thickness of the rocks from the base of the Jennings formation to the top of this con- glomerate. Dr. Rowe made the horizontal distance by pacing 3236 feet which with an average dip of 77° gave a thickness of 3140 feet from the base of the Jennings to the top of this conglomerate. No. 10. For a distance of about 630 feet along the highway are partial exposures of coarse grained micaceous, greenish-gray and brownish-red sandstones alternating with shales. The average dip is about 62° and at the top of the Chemung it is 57° The greenish to yellowish sandstones contain some rather poorly preserved Chemung fossils, as for example Spirifer disjunctus Sowerby and Spirifer mesacostalis Hall (?) together with Grammy sia elliptica Hall and Sphenotiis contractus Hall. The last of the fossils were poorly preserved and occurred after a considerable thickness of brownish-red rocks had been passed. On Dr. Rowe's section the horizontal distance from the top of the conglomerate to the upper horizon of fossils was 612 feet which with an average dip of 68° gave a thickness of 570 feet for this upper zone of the Chemung. . 555 37S0 'IMd., p. 99. ' Proc. Amer. Phil. Soc, Vol. XIX, 1882, p. 443. ' 2d Geol. Surv., Pa., T^ p. 75. Maetland Geological Sukvkt 375 The thickness of the Jennings formation in this section has been estimated several times and by different observers from vrhich it appears that 3800 feet is not far from the formation's thickness in Jennings Run. Dr. O'Harra gave the thickness of the zone in the Jennings overlying the conglomerate of Jennings Run as " about 650 feet " " and stated that the thickness of the entire formation along Jennings Run " is thought to be between 3500 and 4000 feet."' Professor Stevenson estimated the thickness of the Portage and Chemung rocks near Saxton in the north- eastern part of Bedford County, Pa., as " almost 3400 feet " ' to which is to be added the 200 ± feet of Genesee shale' making a total thickness for the rocks representing the Jennings formation of about 3600 feet. It will be observed that the thickness obtained by Professor Stevenson in both Bedford and Pulton counties agrees very closely with the results in Jennings Run. It is somewhat difficult to decide upon the line of division between the Jennings and Catskill and perhaps in some respects a merging of the colors representing the two formations at their junction would be the more satisfaetory way to map them. The lowest appearance of red or brownish-red rocks, which has been used in some instances as the line of division ia areal work, is a very variable horizon as has been shown in the accounts of various sections in Washington and Allegany counties. The horizon of the highest fossils which has been taken for the line of division between the two formations is about 550 feet above the grit and con- glomerate which has already been described as exposed in the Jennings Run highway cut. In regard to the lithology of the rocks there are plenty of dark red to brownish-red sandstones and shales below the last fossils but it is noticeable that above this horizon the rocks are of a brighter red color and for nearly a thousand feet consist almost entirely of red shales and sandstones. ' Allegany Co., p. 107. 'IUd.,x>. 108. » T^ p. 78. *Ibia., p. 82. 376 The Upper Devonian Deposits of Maryland The conglomerate or grit has also been called the top of the Jennings formation which indicates that there was a change in the depth of water and so a physical modification ; but it is not certain that all these conglom- erates occur at precisely the same horizon. It is known that in Garrett County there are at least two and probably other horizons. At least the Chemung fauna continues above the conglomerates both in the western part of Allegany County and G-arrett County and since this shows that the rocks succeeding a conglomerate for a thickness of about 550 feet are of Chemung age it appears better to class this upper division in the Jennings formation. Succeeding this horizon the rocks are mainly red shales and sandstones which belong in the CatsMll formation. The first of the reds begins considerably lower in most of the sections but as long as Chemung fossils occur in considerable abundance the rocks have been classed in the Jennings formation. It will be seen from the above statements that there is a gradual change in lithological appearance between the Jennings and CatsMU formations so that it is difiScult in this particular to draw a sharp line of division between them. Again there is probably some difllerence of position in the horizons at which the last Chemung fossils were collected; but upon the whole it is thought that this method of division is the most satisfactory one that can be used in separating these formations. Exposure on BraddocJc Run. — Four miles or more south of Jennings Eun the Allegany Front is deeply cut by Braddock Eun in which gorge in the cuts of the two railroads which follow it, are frequent exposures of the same formations shown in Jennings Eun. That portion of the Allegany Front to the north of Braddock Eun is known as Pine\' Mountain, and to the south is Dans Mountain which when seen from the east is the most conspicuous mountain slope in western Maryland. Unfortunately for the geologist it is well timbered and the slope mostly covered so that the several formations composing it are largely mantled. There are from the crest line of both Piney and Dans mountains magnificent views of the country to the south and east, and one of the most favorable and popular localities is known as Dans Eock on Dans Mountain 5 miles southeast of Frostburg. Maryland Geological Survey 377 In the first cut on the Georges Creek and Cumberland Eailroad west of the Winchester Eoad station are greenish shales belonging in the Wood- mont member of the Jennings formation. East of this cut the inter- mediate rocks between the Woodmont member of the Jennings and the Marcellus shales at the base of the Eomney formation are largely con- cealed. No fossils were found by the writer in the shales of this first rail- road cut. In two or three of the following cuts, to the west, are some red shales; but a considerable part of the rock is a friable, mealy sandstone with red streaks and blotches in which fossils are quite rare. These sandstones alternate with greenish to olive shales which are very argillaceous and similar ra lithological appearance to those of the first cut. Another cut in the upper part of the Jennings formation shows bands of red shales, of considerable thickness, in its western part and loose blocks of conglomerate occur which probably came from a stratum near this horizon. The other rocks are mainly olive clay shales and thin bedded sandstones, some of the latter being rather coarse grained, friable, and buff to yellowish in color. In the somewhat mealy sandstones the writer f oimd occasionally poorly preserved fossils as, for example, Spirifer, Camor rotoechia, and pelecypods. These fossils occur both above and below the red shales. In some of the olive shales are a few specimens of pelecypods. Near the western end of the trestle the rocks are considered to belong in the Catskill formation which continues to the vicinity of the east- em end of the longer tunnel where the base of the Pocono sandstone is reached. There are covered intervals so that the entire thickness of the Catskill formation is not shown, still this railroad affords a good locality for becoming acquainted with the rocks composing it. Exposures in Garrett County. Exposure in Savage River Valley. — ^The valley of Savage River was examined for some miles north of the mouth of Crabtree Creek ; but it is not a very favorable locality for the study of the Jennings formation. For some distance above the mouth of the creek the rocks are mostly concealed, except on the eastern steep bank of the river. About one-third of a mile above the mouth of Bear Pen Run are grayish to greenish-gray arenaceous 378 The Upper Devonian Deposits of Maryland shales some of which are coarse and bloeky. Smooth, thin shales also occur which are slightly reddish in color and all of these rocks are shown on the banks of the stream. In the grayish shales are some fossils as Douvillina cwyuta Hall with small pelecypods; but the fossils are not common. The dip at this locality is between 13° and 14° S. E., and the rocks belong in the Chemung stage of the Jennings formation. Dr. J. M. Clarke identified the following species from this locality: Ohonetes sdtulus Hall, Douvillina cayuta Hall, and Spirifer mesastrialis Hall. Lower on the creek, not far up the highway from the river, are quite massive, very hard and compact, greenish-gray sandstones having a tendency to form flagstones. On some of the layers are conspicuous ripple marks which indicate shallow water during their deposition. Loose blocks of conglomerate also occur at this place and there are some shaly arena- ceous layers. No fossils were found in place in these sandstones ; but in a loose block from about this horizon specimens of Actinopteria were seen. Exposure on National Road. — In the northern part of Garrett County one of the favorable localities for an examination of the Jennings and Catskill formations is along the ISTational Eoad. It is to be noted that the word favorable in this connection means as far as Garrett County is concerned for it may be stated that there are, in general, very few even fair exposures of the Jennings formation in the county. The Catskill is shown to better advantage; still, on account of the absence of fairly continuous sections it becomes a matter of difficulty to give precisely the stratigraphic composition and thickness of either of the formations. This is particularly true of the Jennings formation and will be fully appre- ciated by one who, being familiar with it in Maryland, has studied the admirable exposures of the Chemung formation in southern New York. By the side of the road east of Mr. Michel's and west of the chapel are outcrops of olive argillaceous shales with some thin mealy sandstones containing a few fossils as Spirifer disjunctus Sowerby, Atrypa hystrix Hall, Productella speciosa Hall, Pterinea chemungensis Conrad, and MurcTiisonia sp., while a large number of pelecypods occur in the thicker layers of this exposure. These rocks alternate with red argil-. Maryland Geological Survey 379 laceous shales and thin brownish-red sandstones. Fossils are not abund- ant, being found only in the thicker layers. This exposure is in the upper part of the Chemung stage. The dip is N". W., and it is on the western side of the anticlinal fold. At the side of the road are loose stones from Mr. T. L. Layman's farm, mainly sandstones a few of which are somewhat calcareous and these contain in certain layers numerous fossils. On weathering the blocks are quite yellowish-brown from the small amount of iron they contain. Among the fossils are Dowvillina Oircvata Hall, Chonetes scitulus Hall, Dictyop'hyton, a large number of pelecypods and Loxonema terebrum Hall. On top of a hill just east of Mr. Layman's and about 7% miles east of Grantsville buff shales occur and thin sandstones in which are a few fossils; but the fossils are rare and do not form layers in the rock. Kear the top of the hill are shales varying from brownish-red, argillaceous to those that are thin and arenaceous. The dip is 3° to the east. Both these zones are between the sixth and seventh mile posts west of Pi'Ofitburg. From the collections made on the ISTational Road 6 miles west of Frostburg, Dr. J. M. Clarke has reported the following species : Chonetes scitulus Hall, Schuchertella chemungensis (Conrad), Spirifer disjunctus Sowerby. Eeported from 5 to 7 miles west of Frostburg : Atrypa hystrix Hall, Actinopteria cf. epsilon Hall, Leptodesma lichas Hall, Leptodesma longispinum Hall, Lyriopecten tricostatus (Vanuxem), Orthonychia pros- seri Clarke, Turio coronula Clarke. From a few miles west of Frostburg were listed : Cypricardella sp., Gypricardella nitidula Clarke. In addition the following species were reported but without statement as to the distance west of Frostburg at which they were found : Atrypa reticularis (Linne), Bouvillina cayuta Hall, Douvillina cayuta, var. graciliora Clarke. Near the top of the first hill east of the sixth mile post west of Frostburg the rocks are mainly olive, very argillaceous shales. There is an occasional sandy layer in which are pelecypods. OHe of these blocks shows ripple marks very nicely; while the shales where they were dug out for the road are nearly horizontal. Directly over the summit of the hill, on the eastern side, the rocks in place are mostly 380 The Upper Devonian Deposits of Maryland coarser areBaceous shales, in which few fossils occur, varying to thin sandstones although there is some of the clear argillaceous shale. The dip is to the east. By the side of the road on each side of the crest of this ridge, in the piles of stone drawn from the adjacent fields, are numerous blocks of flat pebble, jasper conglomerate some of which are large, and one meas- uring 14 inches shows that the stratum reached at least that thickness. Mr. Frank C. Graham, who owns the fanu on the northern side of the road to the east of the ridge, stated that in his field he had found blocks which required two men to lift. Still he has never found a solid ledge of the rock in plowing or other work on his farm, which statement is also made by the farmers on the opposite side of the road as well as by others on whose land loose blocks of the conglomerate were found in northern Garrett County. The blocks are particularly numerous in Mr. Graham's field about opposite the house of Mr. Huey McMan and they also occur ahundantly on the western part of Mr. McMan's farm as well as on that of the one to the west owned by James Carey. This ridge, the second one to the west of Mr. Johnson's, is to the west of the fifth mile post from Frostburg. On account of the infrequency of the blocks on the lower part of this ridge and the large number near the summit it appears that the stratum crosses the road at this locality with the general strike of the rocks of this region as is shown by the blocks of the same conglomerate near Mr. Baker's on the road from Johnson's to Salisbury which is to the northeast of the National Eoad blocks. The color of the matrix of these conglomerate blocks is very generally a rusty brown in which are imbedded numerous white quartz pebbles of varying size and shape. Many of them, however, are distinctly flat and in the joints of the rock have broken with an even, smooth fracture showing that they were held very firmly in the matrix. This is true regarding the small pebbles as well as those of larger size, so that the jointed face of the rock is perfectly smooth, sometimes covered by a thin film of quartz, and there are no projecting pebbles. This is not true, however, in breaJdng the weathered blocks by hand, for in this case there are fre- quently projecting ends of pebbles while many of the fractures instead of Maryland Geological Survey 381 being smooth are somewhat rough. This conglomerate has been likened in general appearance to " peanut taffy " which as a comparison is not especially far-fetched. In addition to the white quartz pebbles there are occasional jasper ones some of which are one-half an inch across, and a few of rose quartz. Some of the flat pebble conglomerates in the upper Chemung of southwestern New York, as for example the Panama con- glomerate of Chautauqua County, contain jasper pebbles so that it is interesting to find them here. This conglomerate closely resembles the one in the upper Chemung in the vicinity of Mountain Lake Park and Oakland, and it appears probable that these blocks represent the northeastern extension of that stratum. The blocks of this conglomerate found on the hill west of Avilton, on the National Eoad and the Salisbury Eoad show that in northern Garrett County it is fully as prominent as in the vicinity of Oakland and Moun- tain Lake Park. Immediately east of the fifth mile post west of Prostburg red argil- laceous shales and thin brownish-red sajidstones occur. A little farther east are thin bedded greenish sandstones and shales. Some of these sandstones contain specimens of Spirifer disjunctus Sowerby, and Atrypa hystrix Hall. Specimens of the latter are comm.on and similar to those which appear abundantly near Deer Park except that at this locality there are not such good exposures for collecting. There are a few other fossils but it is not a good collecting place for the rocks are mostly covered by soil. Most of the rocks weather to a yellowish-brown color and some become fairly rotten, while others of a greenish color are much harder and remain firm. The dip is strongly to the east. Near the bottom of the hill are outcrops of olive to buff shales and thin sandstones. In one of the layers of sandstone are large numbers of crinoid stems. Red argillaceous shales succeed the buff ones in which some of the layers are 1 inch thick. The dip is 42° about S. 60° E. In the field to the south of the road and across the run at the foot of this hill are rather common blocks of a flat pebble conglomerate which also breaks with a smooth fracture across the pebbles ; but the writer is not sure whether they are from the one described to the west or not. Associated 382 The Upper Devonian Deposits of Maryland with these blocks are others containing clay pebbles as well as those of quartz that do not break with a smooth fracture. Possibly both kinds of blocks are from conglomerates occurring very near the top of the Jennings formation. In conjunction with the conglomerate blocks are numerous ones of reddish sandstone and it is thought that the Catskill formation begins in the lower part of this ridge. On the northern side of the road are numerous blocks of brownish-red sandstone and an occasional brownish-gray block containing Chemung fossils, mostly pele- cypodsj but no blocks of conglomerate were noticed. Exposure on Salisbury Boad. — On the Prostburg-Salisbury Eoad, which leaves the National Eoad on the ridge northwest of Mr. Johnson's is red Catskill soil continuing to the base of the first northwestern slope. At this point there are loose blocks of conglomerate which do- not break smoothly across the pebbles and probably come from a thin conglomerate stratum at about the top of the Jennings. On the second slope are loose, some- what porous, conglomerate blocks of a rather brownish-gray color bearing no resemblance to the conspicuous flat pebble conglomerate. At this point are brownish-red sandstones and greenish shales and sandstones in some of which are Chemung fossils, as Productella and a few other brachiopods. In the second hollow, however, and in the fields, opposite the house of Philip Baker, are numerous loose blocks of the flat pebble, jasper con- glomerate. This locality is about 1% miles northwest of Mr. Johnson's, 514 miles from Prostburg and 1 mile south of the Pennsylvania line. One of the blocks measured 10 inches which shows that it came from a stratum of considerable thickness. There are numerous pebbles of white quartz of fair size, an occasional one from 1 to 1% inches across, some of rose quartz and a number of jasper. In the lines of jointing these flat, lenticular pebbles are broken with an even fracture making a perfectly smooth surface of rock. The pebbles neither project nor by falling out make pits, so that the plane of the break is as smooth as if the rock were composed of amorphous material. The fracture is so smooth that it may be said to be almost flinty. The matrix is grayish to brownish-gray but much rust stained in many of the blocks from weathering. Maryland Geological Survey 383 This conglomerate in lithologic appearance, manner of breaking, and shape of pebbles resembles fairly well the conspicuous one on the ridges near Mountain Lake Park and Oakland. As already stated it is in the line of strike with the very similar conglomerate described on the National Eoad and still farther southwest near Avilton To the northeast of this belt, as far as the writer is aware, there is no detailed description of the Upper Devonian rocks in the southeastern part of Somerset County, Pennsylvania. If the line of strike of the Jennings, however, is followed northeasterly across Somerset County, as shown on the various geologic maps of this portion of Pennsylvania, it will lead to the exposure of the Chemung conglomerate described by Professor Stevenson in Juniata Township in the western part of Bedford County. Professor Stevenson called this "the great conglomerate of the Chemung"' and evidently considered it as representing the one which he named the Upper Chemung conglomerate and reported it as entering the county from Somerset County on the western side of the Savage Mountain anticline. This indicates the possible identity of the flat, jasper pebble conglomerate of Garrett County and Stevenson's Upper Chemung conglomerate of Penn- sylvania and it is to be remembered that Dr. I. C. White in his descrip- tion of what he regarded as the same conglomerate in Huntingdon County called attention to the presence of the " red Jasper (?) pebbles." ' Numerous loose blocks of, apparently, the same conglomerate occur northwest of Mr. Baker's on the western slope of the hill toward Piney Eun. It was also noted on the western side of the anticline on the hill some distance to the northwest of Piney Eun, and near the state line the Hampshire formation is reached. Exposure on Pea Ridge. — To the south of the National Eoad and west of Savage Eiver is an elevated region known as Pea Eidge, near the northern part of which is the post-office of Avilton. On the western, southern, and eastern sides of this ridee the streams have cut deep and very narrow valleys. This is especially characteristic of the country to the southwest of the ridge and in the region of the Elbow on the Savage Eiver. From ' T^ p. 119. ' V, p. 93. 384 The Upper Devonian Deposits oe Maryland the southern part of Pea Eidge there are fine views of the narrow valleys, steep slopes and peaks to the southward. To the north-northwest of Pea Eidge and Avilton is Walnut Hill which is on the western side of the Devonian anticlinal axis and is composed of the Catskill formation. On the road crossing Walnut Hill from Avilton to Piney Grove the top of the Catskill formation is near the top of Eed Eidge and its base is 1 mile northwest of Avilton near McKen- zie's store. On the ridge just east of the store are loose blocks of con- glomerate in the road in one piece of which a fragment of a fossil was noticed. The rocks in place are brownish-red, rather arenaceous shales near the dividing line of the Catskill and Jennings formations. The blocks of conglomerate resemble, lithologieally, the one which has been noticed in several localities very near the top of the Jennings formation, and the yellow soil of the Jennings covers the hill to the eastward. On the road to the southeast are occasional slight exposures of greenish shales and sandstones of the Jennings formation. On top of the hill just northwest of Avilton are numerous loose blocks of the flat pebble, jasper conglomerate. , The field to the south of the road is well covered with numerous blocks of it and also a brownish sand- stone which weathers to a very light gray color. The pebbles of this conglomerate on the faces of the blocks are broken evenly so that there is a smooth fracture and the rock in its lithologic appearance closely resembles the conglomerates described on the National Eoad near Mc- Man's and Graham's and on the Salisbury Eoad at Baker's. On account of the conspicuous presence of these blocks in the immediate vicinity of Avilton the name Avilton conglomerate is proposed for this zone of flat, jasper pebble conglomerate in the Upper Jennings of northern Garrett County. The conglomerate described to the northeast on the National Eoad near McMan's and Graham's and on the Salisbury Eoad at Baker's is undoubtedly identical. The white quartz, flat pebble conglomerate described to the south of Avilton on Pea Eidge and the numerous blocks of a similar one found in the Mountain Lake Park-Oakland region and to the south of those towns is correlated provisionally with the Avilton conglomerate. MARYLAND GEOLOGICAL SURVEY. MIDDLE AND UPPER DEVONIAN, PLATE III. Fig. I. — VIEW showing Jennings topography near little Orleans. Fig. 2.— view showing rectilinear jointing in the sandy shale of the JENNINGS FORMATION NEAR STOTLERS CROSSROADS. Mahyland Geological Survey 385 On the Pea Eidge Eoad lYz miles south of Avilton, opposite the house of Mr. John Robinson, is an interesting exposure of a massive con- glomerate rock in place and this is the only known locality in northern Garrett County in which this occurs. It becomes, therefore, a place of con- siderable interest. The ledge is shown by the side of the highway, just west of the house, where it is dipping at a rate of from 34° to 39° S., 60° E. A little lower are numerous large blocks of the conglomerate which on long exposure have weathered to a very light gray color. The rock passes from a quite coarse pebble conglomerate through a grit into a coarse quartzose sandstone. In fact much of the rock really varies from a grit to a fine pebbled conglomerate; but is almost entirely composed of the coarse material like a fine pebble deposit on a recent sea beach. The color on recent unweathered fractures of the rock is rather a rusty brown; but the outside of the blocks on long exposure bleach to a very light gray or almost white. Some of the rock shows layers of pebbles through a coarse sandstone, while some of it is a sandstone containing an occasional pebble. The stratum by the roadside is mainly a sandstone varying to a grit and shows a thickness of at least 3 feet. One block of the conglomerate on the stone crop had a thickness of 20 inches. There are in parts of the rock quite large, flat, white quartz pebbles which have broken with a smooth fracture on the joint surfaces. No jasper pebbles, however, were found and in that particular it does not agree with the Avilton conglomerate. It does, however, resemble quite closely the conglomerate in the upper part of the Jennings formation in Jennings Eun. This ledge is on the eastern side of the anticlinal fold and in the line of the strike about N. 35° E. At the second turn of the road to the northeast of Mr. Robinson's are numerous loose blocks of the conglomerate. Before reaching the first road turning east there are outcrops of green- ish Jennings shales which are dipping sharply eastward, and in blocks of loose greenish sandstone on top of the ridge near the corner are specimens of pelecypods. On this eastern road some distance below the summit of the hill is a zone of greenish to greenish-gray micaceous sandstone and olive argillaceous shale in which is a yellowish-gray con- 25 386 The Upper Devonian Deposits of Maryland glotaerate. The pebbles are quite small, mostly rounded quartz but they are neither flat nor very numerous and do not break with a smooth fracture. They either project from or drop out of the matrix so that in appearance it differs from that of the conglomerates described from a lower horizon in the formation. This horizon is considered as nearly, if not quite, at the top of the Jennings formation, at which position a similar conglomerate has been noticed in several other localities. Exposure on Green Glade Bun. — Seven miles northeast of Oakland a road passing over Green Glade Eun from the southeast to the northwest crosses the belt of the Jennings formation and, although on the opposite side of the glade there are scarcely any exposures, outcrops occur on the hills on each side of the run. No. 1. Exposures on the north and south road to the east of Green Glade Eun and between the road leading to Altamont and the one to Swanton. The outcrops are mostly very argillaceous olive shales stained brown which weather to a rather yellowish color and readily decompose into soil. There are but few arenaceous layers and no fossils were found. No. 2. Outcrops by the side of the road up the hill to the west of Green Glade Eun as far as Maryland Park Place consisting of olive to yellowdsh-green argillaceous shales with some thin layers of sandstone on which are a few poorly preserved fossils as Spirifer disjunctus Sowerby and Chonetes scitulus Hall but these species are not abundant. The rocks dip eastward but they are probably on the western side of the axis and it is a reversed dip as is shown on the upper Deer Park Eoad north- east of Oakland. On the Geological Map of the Piedmont Folio this exposure is near the upper part of the Jennings formation. To the east of the run some red argillaceous shales were noticed by the roadside. No. S. By the road on the western side of the first hill to the west of Green Glade Eun the rocks are dipping northwest and are composed of micaceous greenish thiu sandstones and arenaceous somewhat rusty shales. These sandstones contain some pelecypods and a few poorly preserved specimens of Spirifer disjunctus Sowerby. The fossils, however, are not abundant and on the road a little to the east and below this fossiliferous Maryland Geological Survey 387 sandstone are red argillaceous shales while to the west and above the fossils is a band of red sandstone. This localiiy is about at the line of division between the Jennings and Catskill formations as represented on the Geological Map of the Piedmont Folio. From zones ISTos. 3 and 3 of this section Clarke has identified the fol- lowing species : Chonetes sciivlus Hall, Douvillina arcuata Hall, Dou- villina cayuta Hall, Schuchertella chemungensis (Conrad), Spirifer dis- junctus Sowerby, Loxonema terebra Hall, MurcJdsonia ( ?) sp. The rocks along the road after turning to the north are mainly red shales belonging in the Catskill formation. Shales occur by the highway on the hill to the southeast of ISTorth Glade Eun which, buff in color, meal}' in texture and quite micaceous, alternate Tvith red argillaceous and arenaceous shales. 'No fossils were found. The dip is to the northwest and the outcrop is on the western side of the anticlinal axis. On the road turning north at North Glade are greenish micaceous are- naceous shales varying to thin sandstones. Ko fossils were found in rocks in place but in some of the loose blocks were plenty of Crinoid segments. Above this outcrop are red argillaceous shales. On the road from I^orth Glade to Swanton, which crosses the Jennings formation, no fossils were found and very few exposures of rock occur. From the turn, 1% miles west of Swanton, red shales of the Catskill formation occur along that road toward the town. Exposure from Ness Lick Bun to Alta/mont. — The Jennings and Cats- kill rocks of the anticlinal fold which crosses Garrett County from the northeast to the southwest do not form' any conspicuous clifEs or ledges in the vicinity of Oakland and Deer Park, still there are, perhaps, the most satisfactory outcrops of the formations in the southern part of the county to be found along the several highways between these two towns. This is especially true as far as the Jennings formation is concerned and although there is not a continuously exposed section for any great distance yet a very fair idea of its composition may be obtained. The exposures are some of the Chemung stage of the Jennings and afford the best collecting to be found in this formation in Maryland. The 388 The Upper Devonian- Deposits of Maryland characteristic Chemung species Spirifer disjunctus Sowerby is common and in places there are beautifully preserved specimens. There is more or less reversal of dip in these outcrops, so that none of them are favor- able for determining the thickness of the rocks. One of these sections follows the road northeast from Mountain Lake Park, crosses Ness Lick Eun, then the hill by the Mitchell house and continues to Altamont. Just after crossing the -western branch of Ness Lick Eun, to the north of Mountain Lake Park, above the point at which the upper Deer Park Eoad from Oakland pins the Mountain Lake Park Eoad, are olive argillaceous shales in the gutters by the side of the road and plenty of loose, argillaceous, greenish sandstones. In some of these pieces are fossils, the most common of which is Ambocoelia umbonata (Conrad), Cyrtina sp. was also found. The soft argillaceous shales weather into clay. There is an occasional piece of quartz conglomerate but the pebbles are quite small. The rocks are exposed in the gutters almost to the top of the hill and are mostly olive to yellowish-green shales. Some of the layers are slightly reddish and others vary from a light gray to almost white. Near the base of the ridge just west of the Ness Lick Eun branch, at the locality just described, are quite large blocks of grayish conglom- erate containing some flat white quartz pebbles. Some of these blocks occur in the gutter on the upper Deer Park Eoad but a short distance above its junction -with the Mountain Lake Park Eoad while to the north of it they have the appearance of a broken down ledge. Blocks of conglomerate occur to the south of the locality just described on the road from Hotel Dennett in the northwestern part of Mountain Lake Park to Oakland. There are also large blocks of conglomerate on the western side of the small draw not far west of Hotel Dennett appar- ently the same as those just described to the west of Ness Lick Eun. Prom the blocks found at other local ties about on the line of strike with this one it appears that there is a stratum of this conglomerate in the Chemung rocks on the western side of the anticlinal axis which is light gray in color and contains numerous quartz pebbles part of which at least are flat, and on the jointing surfaces of the blocks are broken directly Maryland Geological Survey 389 across so that there is a smooth surface. A similar conglomerate has been found at a number of localities in the vicinity of Oakland and Moimtain Lake Park as well as to the south of these towns. To the northeast of the two localities just described, on the hill crossed by the Mountain Lake Park and Altamont Eoad, which forms the divide between the branch and Ness Lick Eun, are large loose blocks of conglom- erate. This locality is on the western side of the axis but, on account of a roll in the rocks, the shales on this ridge, by the side of the road, show a dip to the south of east. Again on the first road turning to the northwest toward Hoop Pole Eidge there are blocks of conglomerate on the ridge directly west of the crossing over Ness Lick Eun which are not large but are, apparently, near the horizon of a conglomerate stratum. Above is a brownish-red, thin bedded sandstone. The base of nearly continuous reds occurs on this road 2800 feet to the northwest and outcrops of thin bedded sandstone which are 340 feet below the base of these reds give an average dip of 55° N., 40° W. If the dip remained the same for the entire horizontal distance it would make this conglomerate 3300 feet below the heavy reds at the base of the Catskill formation while even a dip of 45° would give a thickness of 1960 feet. It is probable, however, that there are rolls in the rocks or that the dip is less for part of the distance so that this estim.ate of the thickness is considerably too great. But, 45 feet below the base of the heavy reds on this road is a second conglomerate which is shown in the ditch at the side of the road and there are fairly large blocks of it in the field. The stratum measures from 5 to 7 inches in thickness and it occurs in the midst of yellowish-green shales. There are numerous quartz pebbles in the matrix which are not so lenticular in shape as those in the lower conglomerate and the weathered blocks of the rock are stained a rusty brown color. The average dip of the shales just above this conglomerate is 59° K, 50° W. and the strike is N. 40° E. The Oakland-Altamont Eoad crosses a ridge about 1 mile northeast of the road leading to Hoop Pole Eidge, above described, which is the third ridge west of the Mitchell house. The top of this ridge is covered 390 The Upper Devonian Deposits op Maryland with numerous quite large blocks of rock varying in texture from a coarse sandstone to a conglomerate. Some of the sandstone blocks contain layers of pebbles and the others vary from those in which part of the pebbles are more than an inch in diameter to a conglomerate composed of small ones. The pebbles, which are largely white quartz, somewhat len- ticular in shape, break with a smooth fracture on the joint surfaces. It is evident from the presence of these numerous and large blocks that this ridge was formerly capped by this conglomerate and sandstone. The soil by the roadside up the ridge contains large numbers of white quartz pebbles which have been derived from the decomposition of this rock. In appearance this conglomerate considerably resembles the one described on Pea Eidge in the northern part of Garrett County at Mr. John Eobinson's and, to some extent, the flat pebbled conglomerates in the Chemung of southwestern New York. To the west of the road is a considerably higher point on the slope of which are quite large blocks of sandstone containing numerous specimens of a few species of Chemung fossils : Atrypa hystrix Hall and Douvillina cayuta Hall are especially abundant but other species are associated with them. The conglomerate and sandstones are on the western side of the anticlinal axis where the dip is westerly and as the fossiliferous sandstones are on the ridge to the west of and higher than the conglomerate there is no question but that they occur at a stratigraphicaUy higher position than it. The fauna of the sandstones is very similar' to that found at several localities in the vicinity of Deer Park and mostly on the eastern side of the anticlinal axis. Directly above the four corners along the side of the Altamont Eoad to the north of Deer Park are exposures of olive shales alternating with thin layers of calcareous sandstones containing fossils. In some of these layers specimens of Ambocoelia umbonata (Conrad) are very abundant forming a large part of the rock. There are other layers which contain specimens of Leptostrophia perplana (Conrad), var. nervosa Hall, Cho- netes sdtvJiis Hall and Atrypa hystrix Hall. ISTear the top of the hill are numerous blocks filled with specimens of Leptostrophia perplana var. nervosa Hall indicating that they are, apparently, above the zone in which Ambocoelia umbonata (Conrad) occurs so abundantly. Maryland Geological Suevey 391 There are exposures on the side of the road west of the Mitchell house 2 miles west of Altamont and on what is known as the Williams farm. In the road ditch on the western side of the hill are numerous pieces of olive to buff shaly sandstone containing abundant specimens of Lepto- stropMa perpJana var. nervosa Hall and some other species. Some of the thinner and rather harder layers contain pelecypods. Near the top of the hill in some rather sandy shales are numerous specimens of Chonetes scitulus Hall. There are also argillaceous shales shown by the side of the road and it is evident that all of these rocks occur in place at this locality. On the small hill to the west are loose blocks of sandstone, part of which are also fossiliferous, and a few blocks of flat pebble conglomerate. The dip of the rocks on this hill is to the east. The road across the Williams farm was formerly a good locality for collecting fossils but they are now partially exhausted. The species which occurred, though not numerous, were represented by a good many speci- mens. On top of the hill at the Mitchell house are numerous, unfos- siliferous, loose blocks of fairly fine grained, buff to brownish sandstone. This hill is a high point for this region and there is a good view of the mountain peaks to the southwest and northeast. East of the junction of the Deer Park and Swanton and Altamont roads, about 1 mile west of Altamont, red argillaceous shales are exposed by the road side. To the west of the corners and east of the school-house greenish-gray sandstones are shown but no fossils were found in any of these rocks. On the ridge directly east of the school-house where the road starts down the grade is a thin ledge of conglomerate. The pebbles of this stratum are not conspicuously flattened and, like the one described on the road toward the Hoop Pole Eidge, it probably belongs near the top of the Jennings. Exposures North of Deer Park. — Other good localities for examining the upper part of the Jennings formation are on the two highways north of Deer Park. Probably the exposure of some 60 feet on the road north- east of Deer Park toward Altamont is the greatest thickness of any one outcrop; the rocks are fossiliferous and it is a good locality for collecting. 393 The Upper Devonian Deposits of Maryland An exposure occurs on the northeast side of the highway from Deer Park to Altamont in descending the hill toward the small mn. The rocks are shown in place and consist of olive shales and thin gray sandstones which alternate with three zones of red argillaceous shales, the middle one being partly arenaceous and about 5 feet thick. There are certain layers of the rock which contain large numbers of Spirifer disjunctus Sowerby, Productella lachrymosa Hall, and other fossils. The lowest reds are at the base of the small hill so that all the specimens of fossils occur above red shales. This exposure, which is mapped on the geological map of the Piedmont Folio as at the base of the Catskill formation, is clearly in the Chemung after the appearance of the red shales and is a favorable one for studying the Chemung fauna. About 60 feet of rocks are exposed, the greater part of which consist of olive colored, argillaceous, blocky shales. Along the highway to the north of Deer Park axe some exposures of Chemung rocks but they are mostly concealed. In the stone walls are numerous pieces of rather flat, thin bedded sandstone containing fossils which evidently came from the adjacent fields. Some of the rocks are not fossiliferous and others only contain layers of Crinoid segments. These rocks are about west of the locality which has just been described to the northeast of Deer Park. Farther north on the road from Deer Park sta- tion loose pieces of sandstone which contain large numbers of Douvillina cayuta Hall and some specimens of Camarotoechia occur by the side of the highway and in the field. In Garrett County Dowvillina coAfuta Hall and Leptosirophia perplana (Conrad), var. nervosa Hall are, apparently, the first abundant species in the Chemung fauna. On the road to the south was a little red shale which, probably, occurs below the fossiliferous layers. From the collections made in the vicinity of Deer Park, mainly from the exposure by the roadside just northeast of the village and from the side of the road running north from Deer Park station and the adjacent fields. Dr. J. M. Clarke has identified the following fauna, which is one of the most extensive found in the Chemung rocks of Maryland : Ambo- coelia umbonata (Conrad), Chonetes scitulus Hall, Douvillina ammta Maryland Geological Survey 393 Hall, Douvillina cayuta Hall, Douvillina cayuta gradliora Clarke, Lepto- strophia perplana nervosa Hall, Schuchertella chemung&nds (Conrad), Productella spedosa Hall, Schizophoria striakda, var. marylandica Clarke, Spirifer disjunctus Sowerby, Leptodesma agassizi Hall, Lep- todesma lichas Hall, Leptodesma longispinum Hall, Oypricardella mary- landica Clarke, Oypricardella rdtidula Clarke, Pcdaeoneilo constricta (ConraA) , PaJaeoneilo filosa (Conrad) , Pierinea nodocosta Clarke, Schizo- dus chemungensis var. quadrangularis Hall, Sphenotus contrachis Hall, Murchisonia ecdesia Clarke, Palaeotrodhus praecursor Clarke, Tentacu- lites discissus Clarke. On the ridge to the west of the road leading north from Deer Park station which is crossed by the upper one from Deer Park to Mountain Lake Park, are numerous large blocks of conglomerate. These blocks are on the western side of the ridge facing Ness Lick Run and in lithological appearance are similar to those which occur on the other side of the run. To the south on the same side of the lidge are numerous blocks of flat pebble conglomerate by the side of the lower or new road from Deer Park to Mountain Lake Park. The blocks are more conspicuous near the top of the ridge and on the upper part of its western slope. The late Mr. Eobert H. Gordon reported that to the south of this road on his grounds the conglomerate was shown in place in excavating for a building. This line of blocks on the lidge to the east of N"ess Lick Eun seems to show a con- tinuous stratum of the conglomerate, which is apparently on the eastern side of the anticlinal axis. Exposure Northeast of Oakland. — The section giving the greatest nearly continuous exposure and thickness of the Jennings and Catskill forma- tions is that on the upper Deer Park Eoad beginning about 2 miles northeast of Oakland and following the road southwest into the edge of the town. The lower rocks contain plenty of Chemung fossils ; then there is a considerable thickness with alternation of red and olive colored rocks, finally terminated by about all clear red shales and sandstones of the Catskill formation. No. 1. Exposures above thin sandstones and shales on the upper Deer Park Eoad 2 miles northeast of Oakland. In some of the layers are 394 The Upper Devonian Deposits of Maryland mimerous specimens of Douvillina cayuta Hall, similar to those on the road north of Deer Park, and a few other species were noticed. A few thin bands of red shales were seen alternating with the bnff shale and the zone is near the transition from the clear olive shales to the alternation of red and olive shales. To the east of this zone are the blocks of the flat pebble conglomerate as shown on this road directly west of the branch of Ness Lick Eun. As far as shown at this locality the rocks are all dipping westward so that the fossiliferous horizon is, stratigraphically, considerably above that of the conglomerate. No. 2. Directly above the house and bend in the highway, and a little farther west than the fossiliferous zone described above are buS to greenish thin sandstones which become hard on weathering and contaia fine specimens of Spirifer disjwnctiis Sowerby and Atrypa hystrix HaU with some other fossils especially Schizophoria striatula, var. mary- landica Clarke; but the first two species are the abundant ones of this zone which is near the top of the ridge about three-fourths of a mile west of the intersection of this road and the one north of Mountaia Lake Park. The section is similar to those north of Deer Park and shows in its lower part the zone with abundant specimens of Douvillina cayuta Hall and higher, the one with abundant specimens of Spirifer disjunctus Sowerby. The rock is stained here and there with red and yellowish spots. The blocks containing fossils extend to the top of the hill at the eastern edge of the woods and loose in the field just east of the woods are quite large blocks of greenish-gray sandstone, weathering to a rusty color, in which are some fossils though not nearly as many as there are a little lower on the highway. These blocks, however, still contain specimens of Spirifer disjunctus Sowerby and the rocks to the top of this ridge clearly belong in the Chemung stage of the Jennings formation. No. S. On the western side of the hill the rocks are not continuously exposed to the valley of the small run but for part of the distance they dip to the southeast, showing a reversal of the dip, and this renders it difficult to make any careful estimate of their thickness. There are outcrops of olive, argillaceous shales and sandy layers with thin bands of red shale. In some of the blocks fossils were found, as, for example, Maryland Geological Survey 395 very broad specimens of Spirifer disjunctus Sowerby, Atrypa hystrix Hall, Productella and the type specimen of Palaeaster clarki Clarke. From these three zones on the road northeast of Oakland Dr. J. M. Clarke has described the folio-wing fauna: Palaeaster cla/rhi Clarke, Am- bocoelia wnbonata (Conrad), Atrypa hystrix Hall, Atrypa reticularis (Linn6), Chonetes scitulus Hall, Cyrtina hamiltonensis Hall, Douvillina cayuta Hall, Douvillina cayuta var. graciliora Clarke, Leptostrophia per- plana var. nenosa Hall, Schuchertella chemungensis (Conrad), Schizo- phoria striatula, var. marylandica Clarke, Spirifer disjunctus Sowerby, Leptodesma longispinum Hall, Pterinea nodocosta Clarke. No. 4- Exposures on the eastern slope of the hill to the west of the run where the dip is northwest and the rocks consist principally of olive shales, thin bedded greenish sandstones, a cornstone and some red shales. Small blocks of quartz pebble conglomerate occur loose in the field and the thin stratum was found in place by the side of the road. This conglom- erate is similar to the thin one foimd to the northeast on the road toward Hoop Pole Ridge. Not much higher are red shales and sandstones near the farmhouse. The only fossils seen were segments of crinoid stems. No. 5. On the western slope of this hill toward the second run, and east of the road fork near Oakland are greenish shales varying to thin bedded sandstones near the top of the ridge. Lower are mainly red , shales and sandstones which extend to the bottom of the hill. The sandstones are thin bedded and in n, stratum of greenish sandstone near the base of the section of nearly continuous red rocks a fragment of a fish scale was found. These rocks, apparently, belong in the Catskill formation although on the opposite side of the run a few fossils were found. It is not perfectly clear, however, that this is a continuous section and the fossiliferous layer, perhaps, is not above the zone of red rock. No. 6. On the eastern slope of the hill after crossing the small run west of the old mill are, mainly, greenish, coarse grained, micaceous sandstones in the lower part of which a few fossils were found as, for example, Camarotoechia and pelecypods. Higher, sandstones alternate with greenish shales while still higher are reddish rocks. On top of 396 The Upper Devonian Deposits of Mabtland the ridge in the edge of Oakland the rocks consist entirely of red argil- laceous shales. This section along the road from Oakland toward Deer Park is an excellent one for studying both the lithological characters and fauna of the Jennings and Catskill formations. Exposures on Trout Run. — Mountain Lake Park on an east and west line is near the middle of the Jennings belt which, to the south of the Little Youghiogheny River, extends southwesterly into West Virginia. The Jennings formation is flanked on each side by the Catskill formation, in the same manner as from Mountain Lake Park northeast to Pennsyl- vania. On the Jennings area well toward the West Virginia line are the two localities known as Sunnyside and Eed House. About south of Mountain Lake Park is Trout Eun, the lower course of which is a sluggish stream, flowing through glades, without exposures of rocks. On the ridges, however, on each side of the run are at first loose blocks of stone and then ledges in place. No. 1. On the ridges along Trout Eun are plenty of loose blocks of the Jennings conglomerate and grit rock frequently mentioned in the sections on the northern side of the river. On the ridge directly south of the first Trout Eun crossing are numerous large blocks of this conglom- erate and grit which must have, formerly, capped it. Under the con- glomer'ate, apparently, are olive, mealy sandstones. The soil along the highway contains numerous specimens of white quartz pebbles which have come from^ the decomposition of the conglomerate. A part of this ■ coarser rock is similar to a typical coarse grit while other pieces contain large numbers of quite large pebbles which are smooth showing that they are water worn. Some of the white quartz pebbles are quite flat, suggest- ing somewhat the flat pebbled conglomerates of the upper Chemung in southwestern New York. There are also large clay pebbles which on weathering leave holes in the rock resembling slightly the impressions of fossil shells. The only fossils found, however, were impressions of wood. No. 3. On the highway 3 miles south of Mountain Lake Park and near the top of the second hill south of Trout Eun, reddish shales show in the gutters by the roadside. This is on the farm now owned by Mr. Beckman, known as the " old Billy White place." Loose by the side of Maryland Geological Survey 397 the highway are numerous pieces of sandstones containing abundant fos- sils as, for example, Spirifer disjunctus Sowerby, Atrypa hystrix Hall, and peleeypods. There are also dark red sandstones which contain numerous specimens of peleeypods similar to Actinopteria, together with a few Brachiopods. These fossiliferous rocks are stratigraphically above the conglomerate which was described on top of the first ridge. Some of the fossiliferous sandstone is a greenish color, very hard before weathering and, apparently, calcareous. This is about at the line of division between the Catskill and Jennings formations as represented on the Geological Map of the Piedmont Folio. No. Jf. On the third ridge to the south of Trout Run, just after crossing a small stream but before reaching the highway turning to the west, are buff, coarse, mealy shales at the base of the hill. Higher are red argillaceous shales and still above these, but loose on the road, are blocks of buff to greenish sandstone containing Chemung fossils, as Spirifer disjunctus Sowerby and some other species, most of which are peleeypods. From the above-mentioned outcrops in the Trout Run region Dr. J. M. Clarke has identified the following species : Atrypa hystrix Hall, Atrypa , reticularis (Linne), Douvillima cayuta Hall, Productella hystricula Hall, Productella lachrymosa (Conrad), Spirifer disjun,ctus Sowerby, MurcM- sonia sp^ MurcMsorda ecclesia Clarke. Exposures on Cherry CreeJc. — Farther southwest Cherry Creek flows northwesterly across the Jennings and Catskill formations ; but for the greater part of the distance across the Jennings the country is flat with few outcrops. In the upper part of its course, however, on the foot hills of Backbone Mountain are exposures by the side of the highway but the other rocks are largely covered by talus. Along the side of the highway to the south of the east fork of Cherry Creek are olive to buff shales and sandstones. Interstratified with these rocks are some reddish argillaceous shales. In the olive shales and in layers of the sandstones are numerous specimens of Chemung fossils as Atrypa hystrix Hall, Chonetes scitulus Hall, Leptostrophia perplana var. nervosa Hall, Schuchertella che- mungensis (Conrad), Schizophoria striatula, var. marylandica Clarke, Spirifer disjunctus Sowerby. 398 The Upper Devonian Deposits of Maryland This fauna is similar ta that on the Williams farm 3 miles west of Altamont. There are some of the very argillaceous shales in which fos- sils rarely occur. This zone is at the base of the Catskill formation as represented on the Piedmont Folio and, probably, is stratigraphically higher than the Chemung conglomerate. There are red shales alternating with olive by the side of the road after crossing the upper part of Cherry Creek not far north of Bownan's Corners. Only a few specimens of imperfectly preserved pelecypods were found in some of the thicker sandy layers. The dip is heavy between south and southeast. Exposure at Bed House. — ^Perhaps the best section of the Jennings formation in the southwestern part of Garrett County is the outcrop on the IsTorthwestem Pike from Bownan's Comers west toward Eed House. Catskill rocks are shown on the pike to the east of the Corners and on the lower part of the western slope of Backbone Mountain. The iirst fossils were found west of the Corners. Bownan's Corners are formed by the junction of the road from the north with the pike which is the one along which the outcrops described for the upper part of Cherry Creek occur. No. 1. Shales and thin sandstones by the roadside a short distance west of Bownan's Comers. The first rocks are brownish-red to rgd argil- laceous shales and thin sandstones, alternating with olive shales; but farther west on the road they are all olive argillaceous shales, some of the layers of which are quite porous. This part of the Jennings formation seems to correspond with the " ochre division " of Rogers as described in his Annual Eeports of Virginia. In the mealy layers fossils are quite abundant as, for example, specimens of Spirifer disjunctvs Sowerby, Atrypa hystrix Hall, Douvillina cayuta Hall, and especially the variety of this species described by Dr. J. M. Clarke under the name of gradliora which is abundant, together with some pelecypods. Above the red shales some that are yellowish have bright red blotches and in the coarser of these layers are specimens of Spirifer disjunctus Sowerby and other fossils. No. 2. On the hill at the four corners southwest of Sunnyside are olive shales and thin sandstones by the side of the l-oad but no fossils Maryland Geological Survey 399 were found. The dip has changed at this locality and is steeply toward the northwest showing that the rocks are on the western side of the anticlinal axis. The lithological appearance of these rocks is similar to that of the more unfossiliferous layers of the Chemung stage of the Jennings formation. Prom exposures, however, about 2 miles south of Oakland specimens of Douvillina arcuata Hall, Strophonella cf. reversa Hall, Productus {Mwrginifera) hallanus Walcott, and Leptodesma rogersi Hall were collected. Blocks of the white quartz, flat pebble conglomerate occur at several localities between Sunnyside and Oakland. The Catskill Poemation introductory In Barton's account of the Devonian formations of central Vir- ginia he says that " The Hampshire formation has yielded only a few plant remains which throw no light on the equivalency of the formation, but no doubt it comprised the representatives of the Catskill in their en- tirety or in greater part." ' As stated by Darton fossils are rare in this formation as is the case in the corresponding one in Pennsylvania and New York ; but the lithologic appearance and stratigraphie position agree, in general, with those of the Catskill formation which has been shown to be a local one in New York scarcely represented in the southwestern part of the state while in the southeastern or Catskill Mountain region it has replaced all of the Chemung and the greater part of the Portage of western New York. It has been further shown that to the east of the Susquehanna Eiver, in New York, the red rocks at first are interstratified with those which contain Chemung fossils, while farther east the red and greenish shales and sandstones replace all the rocks with the lithologic characters of the Chemung and its fauna disappears. Below the Chemung and in the midst of what corresponds to the Portage stage of western New York is another mass of red and greenish shales and sandstones, called the Oneonta formation which extends west of the Chenango Valley. > Amer. Geol., Vol. x, 1892, p. 18. 400 The Upper Devon-iak Deposits of Maryland In Delaware County the upper reds of the Oneonta and the lower of the Catskill unite and, in the Catskill Mountain region, extend downward into what is called the Sherburne sandstones which represent the lower part of the Portage stage of western New York. In Pennsylvania, on following this mass of red rocks to the southwest it is found that they gradually begin later and that the faunas of the Portage and Chemung stages reappear as is the case in the southern part of western Few York/ In the lower part of the Catskill formation the rocks consist of brownish-red sandstones alternating with thick bands of red argillaceous shale, while there are occasional thin bands of greenish shale. In these rocks the red sandstones predominate and in some regions make good farming lands, as about Accident in Garrett County. In the upper part of the formation there is a greater thickness of greenish-gray sandstone and shale, alternating with red rocks of similar lithological composition. The greenish-gray rocks increase in amount from the middle to the top of the formation, while near the top the reddish sandstones have more of a brownish tinge than those of the middle and lower part of the formation. The sandstones are conspicuously micaceous, cross-bedded structure is not infrequent and in some localties there is a rapid horizontal change from sandstone to shale deposits or the reverse. The soil formed by the decomposition of the Catskill rocks is of brick-red color contrasting sharply with the yellowish soils of the subjacent Jennings or the super- jacent Poeono formations. Fossils are very rare in this formation, the only shells found being some very imperfectly preserved pelecypods from the Baltimore and Ohio Eailroad above Prankville and in the railroad cut just east of Altamont; while worm trails and borings have been found at several localities. Some of the best places for studying this formation are in Jennings Eun above Corriganville where nearly its entire thickness is shown ; along the road down Wamick Eun northwest of Lonaconing and along the Baltimore and Ohio Eailroad above Prank- ville. In Washington County the Catskill is about 3800 feet thick.' In ^17th An. Rep. State Geol. [N. Y.], in which the writer has discussed this question. " Pawpaw-Hancock Folio U. S. Geol. Surv., 1912, p. 13. MARYLAND GEOLOGICAL SURVEY. MIDDLE AND UPPER^DEVONIAN, PLATE IV. Fig. I. — ^viEW showing the woodmont shales on town creek, east of gilpin. Fig. 2. — ^viEW showing the contact of the genesee and woodmont west of corriganville. Maryland Geological Survey 401 Jennings Eun it covers about 2000 feet and the result of several measure- ments indicates that the formation is between 1900 and 2000 feet in thickness. In the eajstem part of Garrett County Dr. Martin stated that "The thickness of the formation varies from 1800 to 2300 feet" but decreases toward the west and in the western area " is about 1200 or 1400 feet."' The Catskill formation represents at least part of the Catskill formation of N"ew York and No. IX of Pennsylvania. DISTRIBUTION OF THE CATSKILL FORMATION Prom Pigskin to Timber Eidge a belt of the Catskill formation, varying from IV2 to 1% miles in width, crosses th.e state from the northeast to the southwest. A belt of the Catskill formation crosses the state, east of Sideling Hill, varying from a mile to 1^ miles in breadth, extending well up the slope. The upper part of Sideling Hill is composed of the Pocono formation while on the western slope is ajiother parallel belt of the Catskill formation, about a mile in breadth, crossing the state and, for part of its distance, extending as far west as Sideling Hill Creek. These two belts may be called the Sideling Hill Catskill areas. Finally, the extreme northwestern corner of Washington County is covered by the Catskill formation, which belongs in the belt of this formation situated just west and parallel to the Sideling Hill Creek area of the Jennings formation. In Allegany County the Catskill forms a broad belt on each side of Town Hill and oiitcrops in a linear area on the east slope of the Alleghany Front. In Garrett County it flanks the Jennings on both sides of the Oakland anticline and outcrops in a large elliptical area in the center of the Accident anticline, near Accident. Exposures in Allegany County. Exposure on Jennings Run. — The cuttings for the highway from the top of the Chemung up Jennings Eun afford an excellent series of exposures of '■ Garrett Co., p. 89. 26 403 The Uppbe Devonian Deposits oe Maetland the Catskill formation. This is one of the best exposures of the formation in Maryland and nearly all its layers are shown in a contimions section. The dip varies from 62° at the base of the formation to about 30° at its top which is near the farm house at the upper end of the narrow part of the gorge. The lower rocks of the Catskill formation, immediately succeeding the zone with Chemung fossils at the top of the Jennings formation, are brownish-red to red sandstones alternating with thick bands of red argillaceous shale. The lower half of the formation consists of nearly all red sandstones and shales, sandstones predominating, and there are but few bands of rather thin greenish shales. In the upper half of the formation coarse greenish-gray sandstones appear in the lower part in rather thin bands alternating with the reddish rocks; but in the upper portion there are thick zones of both greenish-gray sandstones and shales. Some of the reddish sandstones also are more of a brownish-red color near the top of the formation. All of the sandstones, as a rule, are very micaceous and there is considerable cross-bedding. In general, it is to be noted that in this section the reds, below the fossiliferous zone at the top of the Jennings formation have a rather brownish tinge; then the lower part of the Catskill is composed of quite red sandstones and shales, while in the upper half of the formation there are zones of green- ish-gray sandstone and shales of considerable thickness with brownish- red sandstones near the top. The Catskill formation at this locality was measured, from the base upward, by Dr. Eowe who estimated the thickness of the section in three divisions as follows : lorizontal distance. Average dip. Thickness. 1097 62° 965 83S 54° 679 753 31° 391 Total 2688 Total 2035 Dr. O'Harra gave the thickness of the Catskill for this section as 1900 feet.' The above thickness agrees very well with that of the Catskill to the west of Hyndman, Bedford County, Pa., which is about 10 miles ' Allegany Co., p. 109. Maryland Geological Survey 403 northeast of Jennings Eun, where it was determined by Professor Steven- son as 1980 feet.' Dr. White in his section along the Potomac River gave the thickness of the Catskill as 1300 feet.' Exposure on Braddoch Eun. — The Catskill is exposed in the cuts of the Cumberland and Pennsylvania R. E. west of Allegany Grove. No. 1. An estimate of the thickness of the Catskill formation was made which was measured by zones. The first one is from the western end of the trestle to the eastern end of the second cut; the horizontal distance is 900 feet, determined by counting the rails as in all the zones, but the general direction is IST. 10° E. so that the distance for measuring the thickness is only about 378 feet. The dip is 60° which gives a thickness of 327 feet for this zone. No. 2. Extends from the east end of the above cut to the eastern end of the tunnel in the Catskill. The dip at the east end of the cut is 60° to 63°, average 61°, and at the western end 71°, making an average dip, for the cut, of 66°. Horizontal distance 510 feet which would give a thickness of 464 feet but on account of a heavy curve in this zone this would be an overestimate. The general direction, however, from the base of this zone to the top of the formation is nearly at right angles to the strike. The rocks are red shales and sandstones, except at the eastern end where there are some greenish-gray sandstones. No. 3. The Catskill tunnel, dip at eastern end 63°, at western end 64°, average dip for tunnel 63° ; horizontal distance 390 feet, giving a thickness of 347 feet for the tunnel. No. 4. From the western to the eastern end of the cut is 430 feet horizontal. Dip in cut 53°, making an average dip of 58° and giving a thickness of 357 feet for the zone. The rocks at the western end of the tunnel are largely brownish-red sandstones which are quite massive. No. 5. This zone runs from the eastern end of the first cut east of the Pocono tunnel to the grayish Pocono sandstones at the eastern end of the tunnel. The rocks consist largely of red argillaceous shales alter- nating with quite massive, brownish-red, micaceous sandstone. In the ^ r\ 1882, pp. 73, 103. ^ Proc. Amer. Phil. Soc, Vol. XIX, 1882, p. 443. 404 The Uppek Devonian Deposits op Maktland red shales are occasional thin bands of bluish to greenish shale from a fraction of an inch to an inch or more in thickness ; while at the western end of the cut are some greenish-gray rather shaly sandstones. The average dip of the Pocono sandstones at the eastern end of the cut is 50° which gives an average dip for this zone of 51°. Horizontal distance is 1066 feet which gives 833 feet for the thickness of the zone. The sum of these five zones gives 3327 feet as the thickness of the Catskill for- mation. This, however, is too great for there are some curves on the road and the horizontal distance is not a straight line. From the base of the second zone, the distance was paced to the base of the Pocono sandstone, avoiding as much as possible the curves in the road, and this gave a horizontal distance of 3175 feet ; while the distance determined from the railroad rails is 2386 feet. The average dip for this distance is 593^° which would give a thicloiess of 1870 feet which, plus the 327 feet of the first zone makes a thickness of 3197 feet for the formation. This is only 163 feet greater than the thickness obtained for the Catskill formation in Jennings Run and is probably not seriously in error. Exposures in Garrett County Exposures at Franhmlle and Crabtree CreeJc. — Prankville is a station on the Baltimore and Ohio Railroad 8 miles northwest of Piedmont. The railroad follows the western side of Back Bone Mountain up Crabtree Creek until the divide between the creek and the Little Youghiogheny River is reached in the vicinity of Altamont where the highest point of the Baltimore and Ohio Railroad, 3630 feet A. T., occurs and between Frankville and this locality there are numerous cuts on the railroad, affording an excellent opportunity for the examination of the Catskill formation. The prevailing color of the rocks along the track for 3 miles above Frankville is red, and they consist mainly of shales and sandstones, the shales predominating. There are, however, in places some pure argil- laceous shales of olive color which weather to a slightly buff tint and some that are rather arenaceous. In one of these zones, perhaps one-half mile above Frankville, part of a pelecypod shell was found. There is also occasionally a calcareous stratum which is a sort of cornstone. The Maryland Geological Survey 405 various railroad cuts show excellently the irregular nature of the bedding in these rocks, for the sandstones often appear as lenses which replace for a distance of several rods a thickness of from 10 to 20 feet of red shales. On the other side the shales will then reappear, and the sandstones are, apparently, evidence of strong currents which eroded channels in the soft shales that were later filled by sands. If this interpretation be correct these sandstone lenses are fine examples of channel filling. The rocks in some of the cuts are mainly sandstone with a thickness of 35 feet; but as a rule there is a greater amount of red shale which is often banded by olive colored zones. Some of the sandstones are of a greenish- gray color. These rocks are in the upper portion of the Catskill formation. Two miles above Prankville in the bed of Crabtree Creek which is about 115 feet lower than the railroad track, are red sandstones. On the path up the bank is, apparently, a great deal of red argillaceous shale while in the railroad cut opposite this locality the sandstone is mostly greenish-gray in color and in it is a calcareous stratum or breccia. Spring Lick Creek enters Crabtree Creek from the north and near the top of the hill on the road up Spring Lick is a ledge of faintly reddish sandstone. This stratum is about 740 feet above Crabtree Creek and 3% miles from Frankville. The road from Crabtree Creek follows Spring Lick Eun to the top of the mountain about 41/2 miles from Frankville. On the lower part of the mountain are red shales and sand- stones with some beds of coarse gray sandstone, all belonging in the Catskill formation; but about two-thirds of the distance from the bottom are coarse bluish-gray sandstones containing an occasional speci- men of Grammysia. Higher, an occasional poorly preserved Spirifer was found; and well towards the top of the mountain in much decomposed buff colored argillaceous sandstones are fine specimens of Spirifer dis- jurvctus Sowerby, Productella, Camaroioechia, Schuchertella, and pele- cypods. Olive shales occur along the roadside on the summit of the mountain and no fossils were found. The top of the mountain is 880 feet above Crabtree Creek and the rocks belong in the Jennings formation. On the eastern bank of Savage Eiver some distance below Bear Pen Eun and opposite a school-house is a conspicuous cliff in the lower part of 406 The Upper Devonian Deposits of Maeylakd which are bluish to greenish-gray arenaceous shales and massive very com- pact greenish-gray sandstones. Higher are red micaceous sandstones. On the surface of the layers are numerous ripple marks, raindrop impressions and a great variety of mud flows, cracks and, perhaps, the trails of animals. These markings show very clearly the shallowness of the water when the rocks were deposited which are probably in the Catskill formation. A little below the above-mentioned cliff are massive, mica- ceous red sandstones which extend down the river to the vicinity of C^abtree station. These red rocks are of course in the Catskill formation. Exposures on the National Road West of Frostburg. — The exposure be- gins on Red Ridge to the east of Piney Grove probably somewhat east of the road summit, although the exact position is not fixed because the con- tact with the Pocono sandstone is concealed. On the lower part of this ridge to the west of Two Mile Run are a few thin bands of yellowish-green shale but the rocks are mostly red shales, some of which are quite arena- ceous. The soil and road are decidedly red from the disintegration of these shales, and they are typical exposures of the Catskill formation some- what below its top. The dip is 20° N"., 65° W. The hill to the east of Two Mile Run is composed almost entirely of the Catskill red rocks ; the soil is red and there are occasional outcrops by the roadside. Not far east of Mr. Thomas Prost's house is a band of greenish-gray sandstone and reddish sandstone above it. The dip is between 34° and 36° N., 55° W. At the eighth mile post west of Prostburg the dip is 27° N., 55° W. and strike is N., 35° E. The base of the Catskill is toward the crest of the ridge and a dip of 33° N"., 60° W. was noted. Small loose blocks of flat pebble conglomerate were picked up at this locality and some of them were broken across smoothly. On the summit of the ridge are greenish shales and sandstones which are in the Jennings although on the eastern side of the ridge, not far west of Mr. Wm. Michel's house, are zones of red shale a number of feet in thickness and the soil is reddish. The limits of the Catskill are not sufficiently well defined to make possible any very accurate estimate of its thickness. Its horizontal out- crop, however, was called 1% miles, the direction about 45° from the Maryland Geological Survey 407 true dip and the average of the several determinations of dip 23° which, after correcting and solving, gives a thickness of 2010 feet which being very near that of the formation indicates that about its true limits were talcen. The contact of the Jennings and Catskill formations is not shown on this eastern limb of the anticline on the National Eoad; but it is thought that the base of the Catskill formation is reached in the lower part of the western slope of the first ridge west of Mr. Thomas Johnson's house, about 4% miles northwest of Frostburg. In the upper part of the ridge the rocks are mostly reddish shales and thin bedded sandstones with some thin bands of greenish shales and sandstones. The soil is colored as red as that produced by the Catskill formation. The dip varies from 20° to 22° to the east. On the eastern slope of the ridge directly above Mr. Johnson's the shales and sandstones are a much brighter red than the rocks in the upper part of the formation on the western slope of Little Savage Mountain. It is believed to be generally the case in western Maryland that the lower and middle parts of the formation are a brighter red than the upper portion. For some distance the rocks are mostly concealed but from the chapel on the western slope of Little Savage Mountain to its summit there are frequent outcrops of the upper part of the Catskill formation. Just above the chapel is a zone of gTcenish-gray, coarse grained, very micaceous sandstone suc- ceeded by brownish-red rather coarse argillaceous shale. Then, after a covered interval, there is a zone of greenish-gray, micaceous sandstone and greenish shale; but it is much broken and hardly forms a ledge. Higher, are brownish-red, thin bedded sandstones capped by brownish-red arenaceous shales. Then there is another brownish-red, micaceous sand- stone zone, massive and irregularly bedded with a dip of 22° S., 75° E. Following this are red to brownish-red, micaceous, arenaceous shales which run into thin bedded sandstones. Then, near the crest of the mountain, is a conspicuous zone of greenish-gray sandstone and greenish argillaceous shale having a dip of 25° with a horizontal distance of 270 feet, making it 113 feet in thickness. This, or a similar zone of greenish- gray rock has been noted in a number of sections near the top of the 408 The Upper Devonian Deposits of Maryland Catskill formation. On the crest of Little Savage Mountain imme- diately succeeding in stratigraphic order the greenish zone just described is one of brownish-red, very micaceous sandstone in which some small openings have been made on each side of the road. It is a fairly heavy bedded sandstone but with a more or less cross-bedded structure. The average dip of these beds to the north of the road is about 35° S., 60° E. On the south side of the road at the summit is a ledge of brownish- gray, very micaceous sandstone in which there is a small excavation. Some of the layers are brownish-red and others grayish and the surface of most of them is very irregular. The dip of these layers varies from 25° to 27° S., 55° E. ; while in the road at the comer are dips varying from 24° to 28°. Just to the east of the crest and a few feet above the brownish-red, micaceous sandstone is a stratum of mottled, brownish-red and greenish sandstone. This is the highest stratum shown on the road which could be included in the Catskill. The thickness of this brown- ish-red and mottled zone at the top of the Catskill is 14 feet. An estimate of the thickness of the Catskill of this section (No. I) was made by pacing the distance from a point near the foot of the first ridge west of Mr. Johnson's to the crest of Little Savage Mountain, in a direction about at right angles to the strike and averaging the various observed dips which gave a thickness of nearly 1900 feet. Exposure on Road over Four Mile Ridge. — ^On the steep hillside, 1 mile south of Avilton, are intemipted outcrops of the lower part of the Catskill formation which consists largely of blocky brownish-red sandstone alternating with red shale; some of the lower sandstones are in thin layers and cross-bedded. The dip is between 18° and 19° S., 70° E. In the bed of Savage Eiver thin bedded, brownish-red sandstones show a dip of 17°. In the lower part of Four Mile Eidge are conspicuous ledges of brownish-red sandstone, somewhat cross-bedded, alternating with red, rather blocky shales. This zone is well shown along the highway up the ridge and the dip varies from 18° to 20° eastward with a strike IST. 35° E. There are various exposures of the red shales and sand- stones farther up the road with dips varying from 20° to 24° and a strike of N. 35° E. The upper part of the Catskill formation is partly concealed ; Maryland Geological Survey 409 but its top is reached near the summit of Four Mile Eidge on the road to Lonaconing. The horizontal distance, measured on the map, across the Savage Kiver is but 1 mile between the top and bottom of the Catskill formation which on averaging the dip, would give a thickness of about 1700 feet for the formation. It is probable, however, that the horizontal distance is underestimated. The red shales and sandstones of the Catskill formation are also well shown to the southwest of the above locality on the road from Savage Eiver up Wamick Eun nearly to the top of Elbow Mountain. At the western end of the Baltimore and. Ohio Eailroad cut just east of Altamont station are red shales and sandstones. A little farther east are greenish, coarse grained sandstones and shales in which a few im- perfectly preserved pelecypods were found. The dip is between 16° and 17° S. E. This cut as shown on the Geological Map of the Piedmont Folio is near the top of the Catskill and it is apparently the zone of greenish rocks in the upper part of that formation. The occurrence here of a few very imperfectly preserved fossils becomes important. The lithological character of the rocks in the upper part of the Catskill shows that there was a somewhat gradual change from the conditions under which they were deposited to those of the Pocono. The greater part of the Catskill is simply an alternation of red shales and sandstones with zones of greenish rock in the lower and upper part of the reds. The Chemung fauna survived for some time after the conditions were such that thick masses of brownish-red to red rocks were being deposited, but most of the fossils are found in zones of rock which in lithological characters more closely resemble those of the ordinary Chemung than the Catskill. It is possible that other localities of the greenish rocks in the upper Catskill will furnish fossils and these will probably be confined to those forms capable of life under very adverse conditions as for example the comparatively few species of pelecypods and fishes which have been found in the Oneonta and Catskill formations of New York and Pennsylvania. 410 The Upper Devonian Deposits of Maryland CORRELATION OF THE UPPER DEVONIAN ' The Upper Devonian strata of Maryland consists of two types of sedi- ments, a lower marine type termed the Jennings formation, and an upper continental type called the Catskill formation. These formations will be considered in the order of their deposition. The Jennings Formation introductory Nature of the Problem. — The Jennings formation consists of inter- bedded shales and sandstones 4000 to 4800 feet thick in Maryland, the study of which presents great difficulties. This is due in part to the great variability in the composition of the sediments. Sandstones and shales succeed each other at frequent intervals in vertical sequence, while beds of sandstone that appear very massive at one locality may pass into a series of sandstones and shales in a short distance on the strike and these again into shales, or vice versa, rendering it very difficult to discover persistent horizons in them. Although fossils are profuse in some strata they are rare in others, wide intervals being nearly barren, necessitating a careful search for the fossiliferous horizons. Finally, the beds are intri- cately folded in the Appalachian structure, while the areas in which the Jennings outcrops, are separated by others in which the strata have been removed by erosion. These features, in addition to the problems pre- sented by the contained faunas, unite to render the study of this forma- tion most difficult. Method of Solution. — -The foregoing facts have rendered it neces- sary to make a detailed study of the sections of the Jennings throughout the State.^ The method has been to investigate the sections exposed in each of the detached areas of Jennings in Maryland and in adjoining ' Contributed by Charles K. Swartz. ^ Professor Prosser, who studied the Upper Devonian before the investiga- tions of the writer were undertaken, describes a number of these sections elsewhere in this volume. The author is greatly indebted to him for the privilege of examining his results in advance of their publication. Maryland Geological Survey 411 parts of Pennsylvania and West Virginia, in order to establish a series of persistent lithological and faunal horizons, and then to correlate the divisions so established with the strata of other regions. The subject will be discussed under the headings: Lithological and faunal subdivisions, Correlation. LITHOLOGICAL AND FAUNAL SUBDIVISIONS An examination of the local sections shows that the Jennings formation of Maryland is divisible into four members which are distinct both lithologically and faunally. The members are further subdivided into a number of lithological divisions, and faunal zones as shown in the following table: Jennings formation. Chemung sandstone mem'ber. Splrlfer dlsjunctus fauna. Upper sandstone and shale. CamarotoBchia eximia zone. In the central part of the area these beds comprise three divisions. Beds of recurrent Jennings type with a marine fauna. Palaeanatina angusta zone. Red beds of Catskill type. Beds of Jennings type with a marine fauna. Upper Chemung conglomerate. Middle sandstone and shales. Lower Chemung conglomerate, Tropidoleptus carinatus zone. Lower sandstone and shale, Dalmanella tioga zone in west. Parkhead sandstone memher. Recurrent Tropidoleptus carinatus fauna. Shale beds. Conglomeratic sandstone beds. Cyclonemina multistriata zone. Camarotoechia congregata var. parkheadensis zone. Liorhynchus mesacostale zone. Woodmont shale member. Beds containing Ithaca fauna. (Spirifer mucronatus var. posterus fauna). Liorhynchus globuliforme zone. Cladochonus-Reticularia iKvis zone. Beds containing the Naples fauna (Buchiola speciosa fauna). Genesee Hack shale member. Genesee Black Slmle Member Character and Thickness. — The Genesee member consists of fissile, black, argillaceous shale, characterized by breaking into large fiat sheets 412 The Upper Devonian Deposits op Maryland which weather into thin fragile flalces with parallel sides. The shale is quite carbonaceous and becomes chocolate brown upon prolonged weath- ering.. Many exposures of considerable thickness exhibit a system of well-developed joints, which intersect nearly at right angles to the bed- ding, a feature frequently seen in the Genesee formation of N'ew York. This member is 90 to 100 feet thick west of Wills Mountain. It di- minishes in thickness and finally disappears eastward, the most easterly exposure observed being on the flanks of the anticline forming Strafford Eidge, east of Oldtown. Fauna.- — The Genesee shales abound in individuals of a few species. The fossils are chiefly minute pelecypods associated with pteropods and goniatites. The following species occur in this member according to the identifications of Dr. J. M. Clarke : Buchiola retrostriata, Buchiola con- versa, Budhiola livonice, Pterochania fragilis, Lwrmlicardium, encrinitum Styliolina fss^irella, Pharetrella tenebrosa, Tornoceras uniangulare, Pro- leloceras lutheri, Bactrites aciculus, Orthoceras filosum. Eomney-Genesee Boundary. — The boundary between the Genesee and Eomney is well defined both lithologically and topographically. A massive sandstone occurs either at, or a short distance below the top of the Eomney, while the shale of the upper part of that formation breaks into fragments of very irregular shape which weather to a yellowish or greenish color, contrasting sharply with the smooth fissile brown, or black platy fragments of the Genesee. The Genesee usually occupies a valley developed between the upper sandstone of the Eomney and the hard resistant olive-green shale of the Woodmont shale member. Woodmont Shale Memher Character and Thickness. — ^The Woodmont shale member receives its name from Woodmont Station, Washington County, % mile east of which it is well exposed in the cut of the Western Maryland Eailroad. This station is situated about % of a mile west of Tonoloway Eidge which is opposite Great Cacapon, West Virginia. It is also finely exposed at many places on the banks of Town Creek. It overlies the Genesee shale member conformably or in the absence of the latter, the Eomney Maryland Geological Survey 413 formation. It consists of alternating courses of olive-green shale and thin, fine-grained, flaggj' sandstone, with an occasional more massive sandstone. The shale is usually fissile and breaks into smooth thin frag- ments with parallel sides, contrasting strongly in this respect with the very irregular fragments produced by the weathering of the underlying Romney. Some of the upper beds are more arenaceous and fracture irregularly. Upon weathering the shale becomes greenish or yellowish. A few beds have a decided reddish-brown color. The sandstone is pre- vailingly micaceous and usually becomes fissile upon weathering, breaking into platy fragments. Occasionally a sandstone is more massive and breaks into larger, irregular fragments. The surface of the shale often exhibits " dimpling " and indistinct wave markings. The strata of this member usually occupy the lower slopes of the ridges formed by the more resistant sandstone of the Parkhead member. The thickness varies from 1600 feet in the eastern sections to 1300 or 1300 feet in the sections west of Green Ridge. Subdivisions. — The Woodmont member consists of two divisions, the beds containing the Naples fauna and the beds containing the Ithaca fauna. Beds Contwining the Naples Fauna. — ^The beds containing the Naples fauna form the lower division of the Woodmont member. They consist of olive-green, hard, fissile, argillaceous shale, alternating with numerous courses of thin, fine-grained, flaggy sandstones. The lower beds are often largely formed of olive-green shale. The thickne^ varies from 500 to 600 feet in the eastern sections, to 1200 to 1300 feet west of Green Ridge. These beds contain a fauna which resembles, in many respects, that of the Genesee member. The species are chiefly small, delicate-shelled pelecypods and goniatites. Fossils are more abundant in the lower strata, though many beds are nearly barren. The following s.pecies occur in this division according to the identifica- tions of Dr. J. M. Clarke: Buehiola retrostriata, Pterochwnia fragilis, Tornoceras uniangulare, Bactrites aciculus. 414 The Upper Devonian Deposits of Maryland Beds Contcdninff the Ithaca Fauna. — The beds coDtaining the Ithaca fauna so closely resemble those of the underlying division lithologically, that it has not proven practicable to separate them upon the map of the re- gion. In general the shale tends to be somewhat softer than that of the lower division and some beds break with a more irregular fracture, while the proportion of sandstone is somewhat smaller. In a single section in Thompson Township, Fulton County, Pennsylvania, in the extreme north- eastern part of the area studied, the upper limit of the Woodmont member has been so drawn as to include several conglomeratic sandstones. No conglomerates have been observed in this member west of that point. Bast of Sideling Hill the top of the division is frequently formed by a bright red bed which, in its lithological features, closely resembles sedi- ments of the Catskill formation. Some of the lower beds have also a reddish tone. The Ithaca fauna ranges through a thickness of 1000 to 1100 feet in the vicinity of Hancock. Farther west the fauna becomes more re- stricted and iinally vanishes west of Green Eidge where it is replaced by the Naples fauna in the same strata that contained the Ithaca fauna farther east. The Ithaca fauna differs greatly from that contained in the underlying beds. Brachiopods occur in profusion, while many large pelecypods of entirely different genera from those found in the Naples fauna are pres- ent. A list of the species observed in these beds is given in the table of distribution. The beds containing the Ithaca fauna may be subdivided into two faunal zones, a lower termed the Cladochonus-Beticvlaria Icevis zone and an upper, the Liorhynchus globuliforme zone. Genesee- Woodmont Boundary. — When the Genesee is present the lower limit of the Woodmont member is defined by the contrast between the olive-green color of the Woodmont shale and the black or brown color of the Genesee shale. The transition from the Genesee to the Woodmont is, however, not very abrupt, so that the precise plane of division is not always determinable, some of the beds being more or less transitional at many places. Maryland Geological Suevey 415 In the absence of the Genesee, the Woodmont is readily discriminated from the underlying Eomney by the marked difference in the shape of the fragments produced by weathering, the Eomney yielding pieces of very irregular shape, while the Woodmont yields smooth thin plates whose two larger surfaces are nearly parallel. The abundance of brachiopods in the Eomney and their almost entire absence from the lower beds of the Woodmont member is another decisive difference. Parkhead Sandstone Member Character and Thickness. — The Parkhead sandstone member re- ceives its name from Parkhead, Washington County, Maryland, a station on the Western Maryland Eailroad, 7 miles east of Hancock, where its strata are well exposed. It consists of shale interbedded with massive, frequently conglomeratic sandstones. Certain beds of the latter are highly fossiliferous at many places. The shale is more arenaceous than that of the Woodmont member and tends to break more irregularly. When freshly exposed the strata vary in color from gray to olive-green, while some beds are nearly black. Upon weathering they usually become yellowish or buff in color. The thickness varies from 400 feet in the eastern exposures to 800 feet west of Green Eidge. Fauna. — The fauna of the Parkhead member has strongly pronounced affinities with the Hamilton fauna. Among the more diagnostic species found in it are Tropidoleptus carinatus, Camarotceclua congregata var. parkheadensis and Spirifer (Delthyris) mesacostcdis, while 8. marcyi var. superstes and Rhipidomella vannxemi, etc., are also abundant in the more westerly sections. Three faunal zones may be distinguished in this division. These are, in ascending order: The Liorhynchus mesacostale zone, the Camwroioe- chia congregata zone and the Cydonemina muUistriata zone. The Liorhynchus mesacostale zone is chiefly developed in the western sections. It is fovmd at the base of the member in somewhat shaly beds that lie below the more massive sandstones. Among the more diagnostic species are Liorhynchus mesacostale, Leptodesma naviforme, and several species of the genus Lingula. The Camarotcechia congregata zone is char- 416 The Uppee Devonian Deposits of Maryland acterized by a very profuse development of Camarotoechia congregata var. pcorkheadensis, Tropidoleptus carinatus, and Spirifer {Delthyns)mesacos- talis. The Cyclonemina muUistriata zone contains a great profusion of fossils of many genera, including many gastropods. The range of the species observed in these zones is shown in the chart of columnar sections. (See pocket in cover.) Subdivisions. — The Parkhead sandstone member is divisible into two parts, a lower containing conglomeratic sandstones and an upper con- sisting more largely of shale. Conglomeratic Sandstone Beds. — ^This division constitutes the larger part of the Parkhead member. It usually contains conglomeratic sand- stones at three horizons in the eastern part of the area — at its base, near its middle and at its top respectively. The sandstones are not argillace- ous, as are many in the Woodmont member. They are often bluish black when fresh, becoming buff colored upon weathering and, in places, are tinged yellow and red by iron. They usually break into large irregu- lar pieces. The lower sandstone is, as a rule, highly fossiliferous, abounding in CamarotoBchia congregata var. parhheadensis and containing also a pro- fusion of Tropidoleptus carinatus at many places. The upper conglom- eratic sandstone is unusually massive near Parkhead, where it is finely exposed in the cut of the Western Maryland Eailroad, west of the station. The Parkhead member usually forms a pronounced ridge, the crest of which is commonly occupied by the middle conglomerate. The beds of sandstone lose their conglomeratic character and become reduced in volume toward the west. "West of Wills Mountain they are largely replaced by shales so that this member can scarcely be dis- tinguished from the underlying Woodmont in that region. The sandstone division is about 400 feet thick in the eastern sections. Its limits are less clearly defined west of Washington County. The upper part of the Parkhead member consists largely of shale with some interbedded sandstone. It contains few fossils to indicate its re- lations. It lies, however, below the horizon at which the first appearance of the Spirifer disjunctus fauna has been observed. The shale beds have been MARYLAND GEOLOGICAL SURVEY. MIDDLE AND UPPER DEVONIAN, PLATE V. Fig. I. — VIEW showing the catskill formation on Jennings run road i mile east OF BARRELVILLE. Fig. 2. — VIEW showing the lower part of the catskill formation ON JENNINGS RUN. 416 The Uppek Devonian Deposits of Maryland acterized by a very profuse development of Camarotoschia congregata var. pcorkheadensis, Tropidoleptus carinatus, and Spirifer {Delthyris)mesacos- tcdis. The Cyclonemina multistriata zone contains a great profusion of fossils of many genera, including many gastropods. The range of the species observed in these zones is shown in the chart of columnar sections. (See pocket in cover.) Subdivisions. — The Parkhead sandstone member is divisible into two parts, a lower containing conglomeratic sandstones and an upper con- sisting more largely of shale. Conglomeratic Sandstone Beds. — This division constitutes the larger part of the Parkhead member. It usually contains conglomeratic sand- stones at three horizons in the eastern part of the area — at its base, near its middle and at its top respectively. The sandstones are not argillace- ous, as are many in the Woodmont member. They are often bluish black when fresh, becoming buff colored upon weathering and, in places, are tinged yellow and red by iron. They usually break into large irregu- lar pieces. The lower sandstone is, as a rule, highly fossiliferous, abounding in Camarotoechia congregata var. parkheadensis and containing also a pro- fusion of Tropidoleptus ca/rinaius at many places. The upper conglom- eratic sandstone is unusually massive near Parkhead, where it is finely exposed in the cut of the Western Maryland Eailroad, west of the station. The Parkhead member usually forms a pronounced ridge, the crest of which is commonly occupied by the middle conglomerate. The beds of sandstone lose their conglomeratic character and become reduced in volume toward the west. West of Wills Mountain they are largely replaced by shales so that this member can scarcely be dis- tinguished from the underlying Woodmont in that region. The sandstone division is about 400 feet thick in the eastern sections. Its limits are less clearly defined west of Washington County. The upper part of the Parkhead member consists largely of shale with some interbedded sandstone. It contains few fossils to indicate its re- lations. It lies, however, below the horizon at which the first appearance of the Spirifer disjunctus fauna has been observed. The shale beds have been MARYLAND GEOLOGICAL SURVEY. MIDDLE AND UPPER DEVONIAN, PLATE V. Fig. I. — VIEW showing the catskill formation on jennings run road i mile east OF barrelville. Fig. 2. — ^VIEW showing the lower part of the catskill formation on JENNINGS RUN. Maryland Geological Survey 417 included in the Chemung on the geological map of Washington County, because of the ease of drawing the base of the Chemung at the top of the upper Parkhead conglomerate, elsewhere they have been included in the Parkhead member. The thickness of this division varies from 300 to 400 feet. Woodmont-Parkhead Boundary. — The boundary between the Wood- mont and Parkhead members is usually rather distinct, though at places it is very difficult to determine its exact position. Massive sandstones usually develop at the base of the Parkhead, which are conglomeratic in the eastern sections, although thick sandstones may also occur in some places in the upper part of the Woodmont member. The lower sandstones of the Parkhead can be distinguished at many localities by being bluish- black when freshly exposed. Upon weathering they become butl-colored and break into large, irregularly shaped pieces, in contrast with the Woodmont sandstones which usually break into flat platy pieces, due to the presence of clay. The shale of the Parkhead is, as a whole, more arenaceous and tends to break more irregularly than the Woodmont shale. At many places in Washington County a bright red band forms the top of the Woodmont member. The distinctive feature, however, is the occurrence of a great profusion of fossils in the basal sandstones of the Parkhead, among the most abundant species being Camarotoschia congre- gata var. parhheadensis, Tropidoleptus carinatvs, Spirifer (Delthyris) mesacostcdis and, in the western sections, Spirifer marcyi var. superstes. At places these fossils are so abundajit as to render the rock almost a eoquina. The lowest fossiliferous beds of the Parkhead are usually found on the slope of the ridge facing the subjacent strata. Chemung Sandstone Member Character and Thickness.— The Chemung sandstone member over- lies the Parkhead member with which it is so intimately connected by transitional beds as to render their discrimination difficult. It consists of alternating shale sandstone and conglomerates, the percentage of sand- stone generally increasing toward the top of the formation. The shale 27 418 The Upper Devonian Deposits of Maryland is usually more arenaceous than that of the underlying members and hence breaks more frequently into irregular pieces, while the sandstone is not argillaceous and is rarely fissfile. The beds are variously colored, gray, olive-green, yellow, and brown being common tints. Upon weather- ing many beds become yellowish or brown and are often stained by iron. Eed or brownish-red beds are of frequent occurrence, the percentage of red strata increasing toward the top of the member. These beds occur at successively lower and lower horizons toward the east until in the sec- tions east of Millstone, they appear near the base of the member. Conglomerates occur at many horizons in the Chemung clearly indi- cating its littoral character. A comparison of the different sections shows that there are two more persistent zones of conglomerates east of Wills Mountain although it must be noted that other conglomerates are present, and may readily be confused with them. These conglomerates are not single beds but zones of massive sandstones some of which are usually conglomeratic. They are recognizable topographically by the fact that the upper zone tends to form the crest of a high ridge, when at a distance from larger streams, while the lower zone tends to form a -minor ridge on the flanks of the larger. In the more easterly sections the Catskill strata descend so close to the upper conglomerate as to obscure these re- lations. Again, the lower conglomerate may be the stronger ridge-maker locally. The thickness of this member varies from 2000 to 3300 feet. Fauna. — ^The Chemung member contains a distinct fauna, the most characteristic species of which is Spirifer disjunctus. Associated with the latter and scarcely less diagnostic, are various species of the genera Dahnanella and Douvillina. The latter are, however, more restricted in geographical distribution and vertical range. Many other species cited in the table of distribution are also restricted to this member, but are more limited in range and distribution and hence less important for purposes of correlation. Subdivisions. — The upper and lower conglomerates divide the Che- mung member into five parts, which are here termed the lower shale and sandstone beds, the lower conglomerate, the middle shale and sandstone Maryland Geological Survey 419 beds, the upper conglomerate, and the upper shale and sandstone beds respectively. The upper beds are in turn subdivided into three parts. The following table indicates the sequence and f aunal zones west of Side- ling Hill. Chemung member. Upper shale and sandstone beds. Camarotoechia eximia zone. Beds of Jennings type. Palseanatina angusta zone. Red beds of Catsklll type. Beds of Jennings type. Upper conglomeratic sandstone beds. Middle shale and sandstone beds. Lower conglomeratic sandstone beds. Tropidoleptus carinatus zone. Lower shale and sandstone beds. Dalmanella tioga zone west of Wills Mountain. A third persistent conglomerate occurs between the lower and upper conglomerates in the sections west of Wills Mountain, whose relation to the conglomerates of the eastern section is not apparent. The character- istics of these divisions will now be briefly considered. Lower shale and sandstone teds, Dalmanella tioga zone west of Wills Mountam. These beds consist of shale and interbedded massive sand- stones. In the syncline west of Warrior Mountain many of the strata are very red, suggesting the red bed that occurs in a similar position in the section on Williams Eoad, Polish Mountain. East of Wills Mountain, the beds of this division contain a number of species that pass up int-o them from the Parkhead member, among which gastropods are very prominent. (See table of distribution.) West of Wills Mountain the lower beds are characterized by a profuse development of Dalmanella tioga, which species has not as yet been observed in Maryland either at higher horizons or east of Wills Mountain. Lower Conglomeratic Sandstone Beds. — Tropidoleptus carinatus Zone. A massive conglomeratic sandstone appears in most of the sections east of Wills Mountain about 600 feet above the base of the Chemung member, which probably represents one horizon. This is shown by the fact that it contains a recurrence of the Tropidoleptus carinatus fauna and also by its nearly constant altitude (600 feet) above the base of the Chemung. The conglomerate contains flat pebbles often of a large size, some of 420 The Upper Devonian Deposits of Maryland which are jasper. A similar massive sandstone, containing the Tropido- leptus carinatns fauna, occurs about 300 feet above the base of the Che- mung west of Wills Mountain. While it may represent the same horizon, it is not possible to affirm this confidently, because of the differences in the sections east and west of Wills Mountain. Among the most important species occurring in these beds are Tropi- doleptus carinatus, Spirifer marcyi var. superstes, Rhipidomella vanuxemi and other species of Hamilton affinities, a complete list^ of which is given in the table of distribution. The recurrence of a fauna of pro- nounced Hamilton affinities above the base of the Chemung is of much interest. Middle STiale and Sandstone Beds. — The preceding division is over- lain by shales and interbedded sandstones. West of Wills Mountain a very massive gray and brown conglomeratic sandstone occurs between the upper and lower conglomerates. It is not improbable that it is in the middle of this division, though its relation is not assured. A list of the species observed in this division is given in the table of distribution. No distinctive features have been recognized in this fauna. Upper Conglomeratic Sandstone Beds. — A zone of massive conglomer- atic sandstones occurs in the sections east of Wills Mountain, about 800 feet above the lower conglomerate. No distinctive fauna has been ob- sen-ed in it, but the constancy with which the conglomerates appear at about the same horizon, and the fact that they are always very massive and ridge-forming, leads to the conclusion that they probably constitute one horizon. West of Wills Mountain a similar, very massive, ridge- forming conglomerate occurs 500 to 800 feet below the top of the Jen- nings and probably represents the same horizon. The upper conglomerate contains flat quartz pebbles, which are often large. Some jasper pebbles are also found in it. The cement is so firm that the rock usually breaks across the pebbles the fractured faces of which present a polished appearance. An attempt has been made to dis- ' In the Woodmont section the Tropldoleptus fauna occurs 54 feet above what appears to be the lower conglomerate. Whether the fauna is higher than usual or the conglomerate is at a lower horizon in that section Is not known. Maryland Geological Suevey 431 tinguish the upper conglomerate by the lithologieal features named. The distinction does not appear to be assured, however, since the lower con- glomerate contains similar flat pebbles, some of which are also jasper. Upper Shale and Sandstone Beds. Camarotcechia eximia Zone. — East of the Oakland anticline many of the strata of this division contain much iron hydrate and are discolored by iron stains. Associated with this feature are distinct faunal peculiarities. The fossils are often small and depauperate, while species of restricted range appear. This may be called the Camarotcechia eximia zone from the profuse occurrence of that species in it. Red beds occur in the midst of this division in the region west of Sideling Hill dividing it into three parts as given in the preceding table. In the Oakland anticline the conditions seem quite difEerent, little ferruginous material being present in these beds, while they are highly fossiliferous and the species are not depauperate. The stratigraphy of that region has, however, not been worked out in detail because of the imperfect character of the exposures. Chemung-Pahkhead Boundary. — It is very diiBcult to determine this boundary with precision, owing to the close lithologieal resemblance of these members. The base of the Chemung is generally marked litho- logically by a distinct increase in the percentage of sandstone, the lower beds of the Chemung usually containing heavy sandstones although this feature is not constant. In some localities red strata appear a little above this horizon. In Washington County the base of the Chemung was drawn, for convenience in mapping, at the top of the upper conglomerate of the Parkhead member. The only assured criterion for the separation of the Chemung and Parkhead is the incoming with the Chemung of the Spiri- fer disjunetus fauna, the most distinctive members of which are Spirifer disjunctus and species of the genera Douvillina and Dalmanella. CatsMU-Chemung Boundary. Barren red sediments of Catskill type alternate with lighter-colored, fossiliferous sediments of Jennings type in the upper part of the Jennings. Such alternations become quite frequent toward the upper limit of the 422 The Upper Devonian Deposits op Maryland formation, often rendering it very difficult to fix upon a precise boundary between the Jennings and Catskill. In the area west of Sideling Hill a thick red bed which resembles Catskill sediments in all respects, makes its appearance about 4000 feet above the base of the Jennings, and is in turn overlain by deposits of Jennings type carrying Chemung fossils. Persistent Catskill sediments reappear 4700 to 4800 feet above the base of the Jennings. Eastward the Catskill thickens and the red strata ap- pear lower and lower in the section. The relations believed to exist are illustrated in the following diagram: West Sideling Hill East Sediments of Catskill Sediments of Jennings _^_— type ^^ *yP« In view of the foregoing facts the question arises, What is the upper limit of the Jennings formation? It is well known that the Chemung and Catskill are not successive formations but are, to a considerable extent, of the same age, representing two phases of sediments deposited at the same time but under different conditions, the Catskill phase accumulating more largely in the east, while the Chemung phase has its larger development farther west. It is hence impossible to discrimi- nate them upon the basis of age. It is manifest that Catskill and Jennings conditions alternated in the same region, due probably to oscillations of level, so that sediments of Jennings and Catskill type intertongue re- peatedly, the Catskill beds thickening eastward and the Chemung beds thickening westward. The line of division between the Catskill and Chemung is hence arbi- trary to a large degree and expresses the opinion of the observer. The method used in discriminating these formations in Maryland has been to draw the top of the Chemung at the upper limit of abundant marine fossils, which is also in general at the base of the more persistent red beds. This is the most trustworthy and hence the most satisfactory method to employ in this area, in the opinion of the writer, since the highest marine fauna is of undoubted Chemung type. Maryland Geological Sdevby 433 correlation with new tork The Upper Devonian of this country was first studied with care in the state of Kew York, from which area many of the formational names were derived. Continued investigation has rendered our knowledge of the Devonian of that state more accurate and detailed than that of any otlier region in America. The correlation of the Jennings with the Upper Devonian of New York will therefore be considered firsthand after this its relation to corresponding strata in Pennsylvania. The correlation with the Upper Devonian of West Virginia is considered in the discussion of the local sections. The Jennings formation is intimately related to the marine Upper De- vonian of Few York. This will be seen best by considering the correla- tion of the various members of the Jennings with the corresponding strata of Xew York. Genesee Shale Member.- — A list of species that occur in the Genesee shale member has been given on a preceding page. Among the most abundant forms are: Buchiola retrostriata, Pterochcenia fragilis, Styli- olina fisswrella, and various goniatites. Two of the species are new. All of the remainder are found in the Genesee of New York in which StyliolifM fisswrella, PUrochaenia fragilis and species of Buchiola are abundant. The strata of this member are similar lithologically to those of the Genesee of New York, both being black, carbonaceous shales, while they occupy a like stratigraphic position. Both also attain their maximum thickness in the west and become thinner and disappear eastwards. The close resemblance of these strata in fauna, lithology, stratigraphic position, and geographic distribution, fully justifies their correlation with the Genesee formation of New York as has been published by Prosser. WooDMONT Shale Member. — ^The Woodmont shale member has been shown to consist of two divisions. The lower of these contains the Naples fauna and is equivalent to the Sherburne of New York. The upper con- tains the Ithaca fauna and is equivalent to the Ithaca of that state. 434 The Upper Devonian Deposits of Maryland These divisions are paleontological in the Maryland region and are mapped as a unit, since they have not been differentiated lithologically. It is not ilnprobable, however, that they may be discriminated in the future when the names Sherburne and Ithaca would be appropriate be- cause of their close resemblance to those members of the Portage forma- tion of New York. Beds Containing the Naples Fauna. — A list of the species observed in this zone in Maryland has been given on a preceding page. All are characteristic of the Naples fauna which occurs in the Sherburne mem- ber of the Portage of New York. Fossils are rare in these beds in both areas. The Maryland strata also resemble the Sherburne beds lithologically, consisting of alternating fissile, olive-green shale and flaggy sandstones, while they occupy a like stratigraphic position in both states. The vertical range of the faunas is similar in both sections. The resem- blance of this division to the Sherburne of New York is thus so close as to indicate their essential identity. Beds Containing the Ithaca Fauna. — The upper division of the Wood- mont member closely resembles the underlying strata lithologically, but contains a very distinct fauna characterized at most localities by the abundant occurrence of Spirifer mucronatus var. posterus, Productella speciosa, Pugnax ptignus var. altus, Schizophoria striatula, Cyrtina hamiltonensis, and Liorhynchus globidiforme. The table of distribution lists the species observed in this zone in Maryland and gives their occur- rence elsewhere. Seven of these species, Spinfer mucronatus var. posterus, Productella speciosa, Cyrtina hamiltonensis, Atrypa reticularis, Spirifer mesistrialis, Actinopteria cf. hoydi, and Palceoneilo constricta are placed by Williams among the dominant species of the Ithaca fauna.^ Pugnax pmgnus var. altus and Schizophoria striatula are also prominent members of that fauna. One of the species, Pterinea chemungensis, is said by Williams ' ^ Bull. U. S. Geol. Survey, No. 210, p. 74, 1903. = Journal of Geology, vol. xv, p. 98, 1907. Maryland Geological Survey 425 to be characteristic of the Chemung in New York. Clarke/ however, cites it from the Ithaca of New York, while Williams and Kindle ' identify it in the Ithaca fauna at Catawissa, Pennsylvania. Its occur- rence below the range of the Chemung fauna in Maryland is well estab- lished. Liorhynchus glohuliforme is assigned by Williams' to a higher horizon in New York, but is quoted from the Ithaca fauna of east-central New York, by Clarke." The fauna includes thirty species, of which three are new. Of the previously described forms, twenty-two or 73 per cent, occur in the Ithaca fauna of New York or Pennsylvania. Four not found in the Ithaca fauna of those states occur in the Hamilton of New York, while but one species, Grwmmysia, communis, has not been hitherto reported in horizons below the Chemung. Thus all but one of the previously described species are found in the Hamilton or Ithaca of New York or Pennsylvania. These facts fully justify the correlation of this fauna with the Ithaca fauna of New York. It has already been shown that the Ithaca fauna of Maryland possesses a considerable vertical range in the eastern sections but becomes more restricted and finally vanishes in the west, where it is replaced by the Naples fauna. In this respect it also resembles the Ithaca fauna of New York. The beds containing this fauna consist more largely of shales than do the underlying strata in either Maryland or in New York. Cladochonus-Reticularia Icevis Zone. — The lower zone of the Ithaca of Maryland has been designated the Cladochonus-Reticularia Icevis zone from its most characteristic species, Cladochonv^ humilis and Beticularia Iwvis. All the species of the zone, save two new species, occur in the Ithaca of New York and nearly all in central New York. A species of Cladoehonus, which is not improbably the same as one found in Maryland, is common in the lower portion of the Ithaca beds at Ithaca, New York. Reticularria Icevis occurs at two horizons at Ithaca, one near the base and ' Bull. N. Y. State Museum, iSTo. 82, p. 62, 1905. ' Bull. U. S. Geol. Survey, No. 244, p. 77, 1905. ' Folio No. 169, U. S. Geol. Survey, p. 6, 1909. * Ithaca fauna of Central New York, Bull. N. Y. State Museum, No. 82, p. 64, 1905. 426 The Upper Devonian Deposits of Maryland one near the top of the Ithaca beds. This zone may correspond to the beds containing the Ithaca fauna in central New York. It does not seem possible to correlate these horizons precisely at present, although the oc- currence of these species in Maryland is of interest. Liorhynchus glohuliforme Zone. — H. S. Williams has described a fauna from east-central Kew York to which he has applied the name Liorhynchus glohuliforme fauna from the abundant development of that species in it. He says that " the Ithaca fauna as a whole may be called the Spirifer pennatus var. posterus fauna which on passing eastward is separated into three distinctive paleontological zones, the ff Paracyclas lirata zone, H' Spirifer mesastrialis zone, H* Liorhynchv^ glohuliforme zone." ^ He further states that the latter zone occupies a higher strati- graphic position than does the Ithaca fauna of central New York, cor- relating the beds containing it with the basal strata of the Enfield mem- ber of the Portage of New York. He thus manifestly regards the Lior- hynchus glohuliforme fauna as a later phase of the Ithaca fauna which is restricted to east-central New York. Many characteristic species of the Ithaca fauna of central New York are present in it including Spirifer mucronatus var. posterus, Pugnax piignus var. alius, Schizoplioria stri- atula, Productella speciosa, Cyriina hamiltonensis, Stropheodonta demissa, and Leptostrophia interstrialis. It contains, however, Spirifer {DeWiyris) mesacostalis which makes its first appearance in the Ithaca region in the Tropidoleptus fauna overlying the Ithaca beds. The Liorhynchus glohuliforme faun^ of Maryland occupies the upper part of the Ithaca beds and bears a marked resemblance to the fauna of the same name in New York as shown by its stratigraphic position and by its dominant species and is probably to be correlated with that fauna; but differs, both in its purer Ithacan character, and in lying below the zone of Spirifer (Delthyris) mesacostalis. The latter species makes its first appearance in the overlying Tropidoleptus carinatus fauna in Mary- land, as it does in central New York. These facts suggest that the Liorhynchus glohuliforme fauna of Maryland may occupy a somewhat lower stratigraphic position in Maryland than in east-central New York. ' Folio 169, U. S. Geol. Survey, 1909, p. 6. Maryland Geological Survey 437 The fauna of this zone also bears some resemblance to that found in the higher beds containing the Ithaca fauna at Catawissa, Pennsylvania.' This is shown by the presence of Pterinea chemungensis and Edeno- desma hirostratum at both localities. The latter species is confined to the Liorhynchus gldbuliforme zone in Maryland. Although many species of the Ithaca fauna occur in the Hamilton formation, it is interesting to note that it contains many forms of dif- ferent origin, including some of its more important members. Among these are Spirifer mesastrialis, Productella spedosa, Liorhynchus glohuli- forme, Pugnax pugnus var. alius, and Schizophoria striatula. While there are Hamilton elements in the fauna, it cannot piroperly be called a recur- rent Hamilton fauna in a strict sense and differs greatly from the assem- blage next to be described. Parkhead Sandstone Member. — Among the most important and characteristic species of this member are : Tropidoleptus avrinatus, Spiri- fer (Delthyris) mesacostalis, S. marcyi var. superstes, Camarotceohia, congregata var. parhheadensis, Rhipidomella vanrucemi, Cyriina hamil- tonensiSj Cypricwrdella iellistriata, Liopieria higsiyi, Coleolus tenuidnc- tus, Cydonemina mvJtistriata, and Pleurotomaria capillaria, all of which occur in the Hamilton, save Cydonemina muUistriata, a new species. One of the most abundant species is Tropidoleptus carinatus, which is the most characteristic member of the Hamilton fauna, according to Williams, who terms that fauna the Tropidoleptus carinatus fauna."" An examination of the table of distribution, in which all the species of this member are listed, shows that the entire assemblage possesses a pronounced Hamilton aspect, about 66 per cent of its species occurring in the Hamilton formation of Few York. That it is, however, later than the Hamilton is shown by the modification of some of the species, as, for example, Spirifer marcyi, which is present as a mutation, and also by the presence of a considerable number of species of later age. The fauna is manifestly a recurrent Hamilton fauna with an addition of later species. ' Kindle and Williams. Bull. U. S. Geo]. Survey, No. 244, p. 77, 1905. " Bull. U. S. Geol. Survey, No. 210, 1903. p. 50. 438 The Upper Devonian Deposits of Maryland A similar recurrence of fauna characterized by the Tropidoleptits cari- natus overlies the Liorhynchus glohuliforme zone in ISTew York, where, according to Williams,'' it contains Tropidohptws carinatus, Spirifer marcyi, Spirifer (Delthyris) mescwostdlis, Productella lachrymosa, Bhipi- domella varmxemi, Cypricardella iellistriata, Pleurotommia capillaria, and other species found in the Parkhead fauna of Maryland. The re- currence of similar faunas in the same relative position in New York and Maryland is a most interesting fact and furnishes striking evidence of the essential similarity of the conditions in New York and Maryland in Upper Devonian time. The Parkhead fauna, like that of the Enfield member of the Portage of New York, occurs in sediments that become increasingly arenaceous eastward, where they are similar to the Chemung sediments. The fauna vanishes westward in both areas. The similarity in composition, lith- ology, stratigraphic sequence, and geographic distribution leaves little doubt that the Parkhead fauna is the same as the recurrent Tropidolep- tus carinatus fauna of the Enfield member of Williams. In the Enfield member, however, the Naples fauna recurs above the Tropidoleptus carinatus fauna,, a feature not observed in the Parkhead of Maryland, so that the upper limits of the two members may not be the same. For the present, therefore, the term Parkhead is applied to this member instead of Enfield, although the beds containing the recurrent Tropidoleptus carinatus fauna are probably of the same age in both areas. Chemung Member. — Different values have been attached to the term Chemung by different observers, rendering necessary a definition of its significance as here employed. The marine Upper Devonian strata lying above the Genesee, exhibit different facies in eastern and western New York. In the western part of that state the lower strata consist of inter- bedded shale and flaggy sandstones and contain very few brachiopods. They are overlain by more arenaceous sediments rich in brachiopods. Farther east sandstones develop at successively lower and lower horizons > Folio No. 169, U. S. Geol. Survey, 1909, p. 6. Maryland Geological Survey 439 while many brachiopods appear both within and below them. Vanuxem ' drew the base of the Chemung at the base of the more arenaceous sedi- ments and called the brachiopod-rich horizon below the Chemung the Ithaca, while the brachiopod-poor shale beneath the Ithaca was named the Portage or Nunda. Hall ' drew the base of the Chemung of central New York at the base of the brachiopod-rich fauna including Vanuxem's Ithaca and Chemung in his Chemung, as shown by his use of that term in the systematic volumes of the Paleontology of New York. It was later shown by Williams^ that the Naples fauna recurs above the Ithaca, a result which led to the separation of the Ithaca from the Chemung and its inclusion in the Portage group. Williams later ' defined the Chemung formation as the strata through which the Spirifer disjunctus fauna prevails. In 1897 Clarke' showed that the Chemung fauna makes its first ap- pearance in the Genesee River section, above the Wiscoy shale which overlies the Portage (Nunda) sandstone, while in the Naples section, further east, it appears at a lower horizon, being found in the Portage sandstone. In 1905 ° Clarke accordingly proposed to restrict the term Chemung to strata of the age of those bearing the Chemung fauna at the type locality and which lie above the horizon of the Wiscoy (Pratts- burg) shale, excluding the latter from the Chemung. Williams' has since proposed to employ the term Chemung in a dual sense, calling the sediments containing the Spirifer disjunctus fauna, " the faunal Chemung " and the arenaceous sediments of which it is a part, "the lithological Chemung." The usage of the various authors, as applied to these sediments in cen- tral New York, except that of Clarke, is shown approximately in the fol- ' Geology Third District, Geology of New York, p. 179, 1842. ' Palaeontology of New York, vols, iv, v, vii. Refers Ithaca fossils to Che- mung. = Bull. U. S. Geol. Survey, No. 3, 1884, p. 20, also Bull. No. 41, 1887, pp. 81-82. * Bull. U. S. Geol. Survey, No. 210, 1903, p. 82. = Rep. N. Y. State Geologist for 1896, p. 33, 1899. ° Bull. N. Y. State Museum, No. 81, 1905, p. 20. ■ Folio U. S. Geol. Survey, No. 169, 1909, p. 12. 430 The Upper Devonian Deposits of Maryland lowing table. Clarke's section is from the Watkins-Blmira quadrangles in which the sequence of the beds below the Chemung differs from that in central New York. Divisions HaU Vanuxem Williams 19071 1909 Beds containing the Spirif er dis junctus fauna Chemung Chemung Chemung Chemung 13 Chemung Beds containing the Naples and Tropi- doleptus carinatus fauna a Enfleld o Enfield Prattsburg Beds containing the Ithaca fauna Ithaca Ithaca Ithaca Senecan Beds containing the Naples fauna Portage Portage Sherburne Sherburne Genesee Genesee Genesee Genespe Genesee Genesee It will thus be seen that the terra Chemimg has had a very lax usage. The lower limit of the formation has not only been placed at different horizons by the different authors, but has also probably been drawn obliquely across strata of the same age by all but Clarke. The upper limits of the Chemung is equally lacking in precision. It is known that it descends obliquely across strata of the same age towards the east, owing to the earlier development of Catskill conditions there. It is hence probable that, however defined, the Chemung will embrace different units east and west so that it is questionable whether the term meets the needs of scientific nomenclature.' As employed in the present discussion, the base of the Chemung is drawn in Maryland at the base of the Spirifer disjunctus fauna and its upper limit at the upper limit of the observed marine fauna of the Upper Devonian, since these afford the most precise limits for correlation. ^ Journal of Geology, vol. xiv, 1906, p. 579. ' Bull. N. Y. State Museum, No. 87, 1905, p. 20. = See remarks by J. M. Clarke in Bull. N. Y. State Museum, No. 87, 1905, p. 20. Maryland Geological Survey 431 It is, however, questionable whether it would not be better to define the Chemung simply as the arenaceous phase of the marine Upper De- vonian including the Chemung and Parkhead members as here defined. In that case it would have very different limits in different areas and be without definite time value, resembling in this respect the term Catskill. This usage has not been followed, however, in the present case. The most diagnostic species of the Chemung of New York are Spirifer disjunctus and species of the genera Dalmanella and Douvillina, the Chemung fauna having been called the Spirifer disjunctus fauna by Williams.'' These are also important members of the Chemung of Maryland and are associated with many other species restricted to the Chemung in Kew York and in Maryland. The number of species and va- rieties identified in the Chemung of Maryland is 101, of which 34 are new. Of the 77 species formerly described, 60, or 78 per cent, occur also in the Chemung of New York. A list of the species occurring in these beds is given in the table showing the distribution of species, in which their vertical range and occurrence in other areas are indicated. The lithological character of the Chemung sediments is the same in both areas and the development of arenaceous sediments below the range of the Chemung faunas is the eastern sections in Maryland is in harmony with the same condition in New York. Moreover, the beds occupy a simi- lar relation to the underlying Portage and overlying Catskill. These facts clearly establish the Chemung age of this member. A conspicuous feature of the Maiyland fauna is the abundant occur- rence of species of Dalmanella and Douvillina west of Wills Mountain, and the almost entire absence of the former genus and the rarity of the latter genus east of that mountain. Williams notes ' a similar restriction of the species of Dalmanella to western and central New York. The lower shale and sandstone beds correspond in their stratigraphic position to the Cayuta member of the Chemung of New York. They contain certain species which are reported by Williams ' from that member ' Bull. U. S. Geol. Survey, No. 210, 1903, p. 83. ' Proceedings of the U. S. National Museum, vol. xxxiv, pp. 35-64. ' Polio of the U, S. Geol. Survey, No. 169, 1909, p. 6. 433 The Upper Devoxian Deposits of Maryland only, in eastern and central New York. These include Bucanopsis mcera, Loxonema styliolum, Sandhergergoceras chemungensis, and Manticoceras patersoni. They also resemble the Cayuta member in being much more fossiliferous than the overlying strata. The lower shale and sandstone beds are succeeded by a massive conglom- eratic sandstone containing the Tropidoleptus carinatus fauna at many places. There is also a similar recurrence of the Tropidoleptus carinatus fauna at the top of the Cayuta member of New York. In Maryland this fauna has been observed chiefly in the central part of the area and contains the following species, all of which occur in the corresponding zone in New York: Tropidoleptus carinatus, Spirifer marcyi var. superstes, Rhipido- mella vanuxemi, Camarotcechia contracta, Amboccelia umbonata, Spirifer mesacostalis. The recurrence of a fauna of Hamilton type above the base of the Chemung, in a position similar to that in which it occurs in New York is of great interest and still further indicates the similarity of the conditions under which sedimentation took place in both areas and the probable equivalency of these horizons. A recurrence of the Tropidoleptus carinatus fauna corresponding to its recurrence near the base of the Che- mung in New York has not been assuredly observed in Maryland. The Spirifer disjunctus fauna has, however, been found at the base of a section exposed in the axis of a small anticline, situated a short distance east of the house of Mr. Cheney 2.3 miles northeast of Pratt, on the road leading to Pifteenmile Creek. An abundant development of the Tropidoleptus carinatus fauna may be seen on the hilltop a little over 100 feet higher stratigraphically, which strongly suggests the fauna in the upper zone of the Parkhead, while the undoubted upper Tropidoleptus carinatus fauna of the Chemung is seen in different associations in a conglomerate on the hills to the west. It is hence possible that the Spirifer disjunctus fauna may occur below the top of what has been considered the Parkhead mem- ber in this locality, in which case the upper zone of that member may represent the lower recurrence of the Tropidoleptus carinatus fauna in the Chemung of New York. The stratigraphic relations are, however, too obscure at this place to permit confident conclusions, while the Spiriffer Maeyland Geological Survey 433 disjunctus fauna has not been noted in a corresponding position in any of the studied sections, where the stratigraphic relations are clear. These facts suggest a possible lower range of Spirifer disjunctus in the western sections of Maryland analogous to the lower range of that species in eastern New York described by Clarke. The middle shale and sandstone beds occupy a position similar to that of the Wellsburg member of the Chemung of New York, which they also resemble in being more arenaceous than the underlying strata in the eastern and central sections, and in containing fewer fossils. They are, however, more fossiliferous in the Oaldand area (15 species having been observed in this division east of the Oakland area 3 of which are new). All but one of the previously described species occur in the Wellsburg member in New York. Most of these species have a considerable strati- graphic range so that they have little value for exact correlation and the equivalency of these horizons is not necessarily established. The upper conglomerate occupies a position suggesting that of the con- glomerate terminating the Wellsburg member in New York. It is, how- ever, not possible to correlate them by faunal features and their identity is not established. The upper shale and sandstone beds are replaced by Catskill sediments in central and eastern New York so that it is not possible to institute com- parison between the upper shale and sandstone bed and the strata of that region. Athyris angelica occurs near the top of the Jennings in Maryland and is also found in New York in the Cuba sandstone and overlying beds of the Olean quadrangle' in western New York where it appears to be high in the Chemung. Species of Palceanatina also occur in the fer- ruginous upper beds of the Chemung in New York as in Maryland. The following table shows the relation of the marine Upper Devonian strata of eastern Allegany County, Maryland, to those of central New York. 'Bull, of the N. Y. State Museum, No. 69, 1903, p. 992. 28 434 The Upper Devonian Deposits op Maryland Mabyland Chemung sandstone member. Ferruginous shale and sandstone beds. Palaeanatina angusta zone at top. Upper Chemung conglomerate. Middle sandstone and shale, 800 feet thick. Lower Chemung conglomerate, containing the upper recurrent Tropidoleptus carinatus fauna. Lower shale and sandstone beds, 600 feet thick. Parkhead member. Parkhead sandstone member con- taining the recurrent Tropido- leptus carinatus fauna. Beds more arenaceous eastward. Woodmont shale member. Beds containing Ithaca fauna. Liorhynchus globuliforme zone. Cladochonus-Reticularia Isevis zone. Beds containing Naples fauna. Alternating shale and flagstone. Genesee black shale member. Absent eastward. Genesee fauna. New Yoek^ Chemung formation. Absent. Fall creek conglomerate. Corre- lation doubtful. Wellsburg member, sandstone and shale 600 feet thick. Zone containing upper recurrent Tropidoleptus carinatus fauna. Cayuta member, shale and sand- stone 600 feet thick. Portage formation. Enfield member. Containing the recurrent Tropidoleptus carina- tus fauna. Beds more arena- ceous eastward. Ithaca shale member. Liorhynchus globuliforme zone of Ithaca fauna of eastern New York. Ithaca fauna of central New York. Sherburne member. Containing Naples fauna. Alternating shales and flagstones. Genesee black shale formation. Absent eastward. Genesee fauna. CORRELATION WITH PENNSYLVANIA The Upper Devonian of Pennsylvania has not been studied as fully as that of New York, the criteria available for correlation being chiefly lithological and, hence, attended with much -uncertainty. The essential identity of the Upper Devonian deposits of New York and Maryland renders it probable that the sediments of this age in Pennsylvania were laid down under substantially the same conditions. Confident correla- tion, however, must await fuller paleontological proof than is now possessed. ^Williams, H. S., Devonian Section at Ithaca, N. Y. Journal of Geology, vol. xiv, 1906, p. 579. Maryland Geological Suevey 435 It has long been recognized by geologists engaged in the study of the Upper Devonian of Pennsylvania that it represents in a general way the Genesee, Portage, Chemung, and Catskill formations of New York. The limits of the formations were drawn, however, at very different horizons by different students. I. C. White/ who made an extended study of these strata in Pennsylvania, recognized the presence of two conglomer- ates which he correlated throughout most of the state by means of their stratigraphic position and lithological characters. He called the upper of these the Lackawaxen conglomerate from a locality on the Delaware Kiver, and stated that it is formed of flat pebbles, some of which are jasper. He named the lower the AUegrippus conglomerate from Alle- grippus, Huntingdon County, Pennsylvania. The section exposed in Huntingdon County, Pennsylvania, was interpreted as follows by White : ' Catskill Formation Thickness Non-marine beds 2525 Hauns Bridge beds (marine fossils) 1000 Lackawaxen conglomerate (3650 feet above base of Upper Devonian). Strata below conglomerate, witb a fish bed at base 100 CATSKILL-CHEMUNG TRANSITION BEDS Containing some bright-red sediments 700 Chemung Formation Arenaceous sediments, containing the AUegrippus conglomerate 2700 feet above the base of Upper Devonian 1550 Portage flags 1100 Genesee formation 200 The base of the Catskill of Huntingdon County is made by White to correspond, as far as possible, with the base of the Catskill as de- termined by him on the Delaware Eiver. The fact that the section studied by White in Huntingdon County is on the strike of the Jennings strata west of Green Eidge in Maryland and the close agreement of his •measurements with those of the Jennings in the latter area renders it not improbable that the base of White's Chemung occupies approximately the position of the base of the Parkhead sandstone member of Maryland, that the AUegrippus conglomerate which occurs 2700 feet above the base ' Rept. 2d Geol. Survey, Fa., vol. T3, 1885, p. 102. 'Ibid. 436 The Uppek Devonian Deposits of Maryland of the Genesee in Huntingdon County is the same as the Lower Chemung conglomerate, occurring 3600 to 3700 feet ahove the base of the Jennings in Maryland, and that the Lackawaxen conglomerate occurring 3659 feet above the base of the section in Pennsylvania is the same as the Upper Chemung conglomerate occurring 3400-3500 feet above the base of the Jennings. In that event the Hauns Bridge beds probably represent the upper sandstone and shale beds of the Chemung of Maryland which are 1200 to 1400 feet thick in the central part of the area, while his non-marine Catskill beds would be the Catskill of this State. This com- parison is only tentative in the absence of adequate faunal evidence. J. J. Stevenson discussed the Upper Devonian of the eastern United States in his Vice-Presidential address delivered before the American Association for the Advancement of Science in 1891.'' In this paper he states that there are two conglomerates in the Chemung traceable from Tennessee to New York and correlates them throughout that entire area by their lithological character and stratigraphic position. The following section which is situated immediately north of the Mary- land-Pennsylvania state line, in Pulton County, Pennsylvania, is given by Stevenson in his report on the geology of Bedford and Pulton counties." Catskhx Foemation Red non-marine sediments. Chemung Formation Shale beds with marine fossils iSOO Upper conglomerate, 2810 feet ahove base of Portage 10 Shale and sandstone 950 Lower conglomerate, 1850 feet above base of Portage 10 Shale 450 Total thickness of Chemung 2220 Portage formation 1400 Total 3620 • Proc. A. A. A. S., 1891, vol. xl, p. 219, and Amer. Geol., vol. ix, 1892, p. 6. This paper is quoted in full by Lesley in the Final Rept., 2d Geol. Survey Pa., 1892, vol. ii, pp. 1405-1433. = Rept. 2d Geol. Survey Pa., vol. T2, 1882, p. 75. Maryland Geological Survey 437 Stevenson correlates his upper conglomerate with White's Lackawaxen conglomerate. A section measured by the author in Thompson Township, Fulton County, Pennsylvania, renders it probable that Stevenson's upper con- glomerate occupies approximately the position of White's AUegrippus conglomerate, in Fulton County, while his lower conglomerate is probably Town Creek AUegRny Co.. Md. Huntingdon Co., Pa. Swartz White. Tbompson Twp. Fulton Co., Pa. Swartz Fulton Co., Pa. Stevenson i 1 LOWER ' CONGLC CONGLOMERATE- i ■ I svt rcow "■'CON 'I CONGLOMERATE Fig. 2. — Diagram showing the correlation of Marine Upper Devonian of Maryland and Pennsylvania. the upper conglomerate of the Parkhead sandstone member, illustrating the difficulty of correlating the strata over large areas by the use of the congloinerates. The relation of the Maryland section to those of White and Stevenson is suggested tentatively in the preceding diagram, although fuller paleon- tological data are needed before confident conclusions can be drawn. 438 The Uppbe Devokian Deposits oe Maryland The Catskill Formation The Catskill formation of Maryland is nearly barren, no fossils other than underterminable vegetable fragments and a few poorly preserved pelecypods having been found in it. It closely resembles the Catskill of New York in its lithological character, in the absence of marine fossils, and in its increasing thickness eastward, where it replaces the upper Chemung sediments. The similarity in lithological character, conditions of sedimentation, geographical distribution, and its continuity with the Catskill of Penn- sylvania and ISTew York fully justify its correlation with them. The range of the fossils of the Upper Devonian of Marjdand is given in the subjoined table which also shows their occurrence in the Ithaca fauna at Catawissa, Pa.,^ and in the Upper Devonian of central New York.^ The range of the species in Maryland is also shown in greater detail upon the chart of columnar sections (contained in pocket) in which the species are indicated by the numerals prefixed to their names in the table. 1 Kindle and Williams, Bull. V. S. Geol. Survey, No. 244, 1905, p. 78. ^ The occurrence of species in the Liorhynchiis gloliuUforme zone and in the Ithaca of Central N. Y. cited In columns referred to Williams, is from Folio of the U. S. Geol. Survey, No. 169, 1909, p. 6. The occurrence in Ithaca fauna of Central N. Y. cited in column referred to Clarke is from Bull., N. Y. State Museum, No. 82, 1905, p. 55. Maryland Geological Survey 439 Geological Range of XJprEE Db:vonian Fauna in Maryland Pennsylvania and New York SPECIES Maryland -•1 s Oh s New York 0) a; s g w 1 s fa O Jennings Formation d o "■4J a s 1 1 B K § E a Portage Format'n .2 s bo i o 1 o Woodmont Member Xi s 1) S Ph Chemung Member a s s ■e Ithaca Member 1 1 1 Ithaca Fauna Area east of Oakland 0) T3 i 9i o ■St to iJ] Iz; pa Oh t P g 1 t— ( New York 1 s 1 B a i ■s 1 S e o Jennings Formation 1 P g e a> s lU p Portage Format'n 1 1 5 Woodmont Member 1 Chemung; Member 1 fa P P Ithaca Member 0) ■i P 1 CO 4i ft Ithaca Fauna Area east of Oakland T3 1 Centr'l N. Y. 3 1 CO p ■g p I" § CO 1 t 1 3 V s a faD P ■g 1 3 1 .a 0} C 1 1 S 0) 1 i V 3 1 1 13 ■s i 0} 1 g 1 u S !S H Oh cd C ed fa New York O B & i S O a B o P3 Jennings Formation c o "S o fa g '1 cd Ell O fa Portage Format'n g s S. a p 1 Q) i C5 Woodmont Member 1 s ea •a Chemung Member 1 a 0) E3 •e Ithaca Member -a "at a fa fa s 1 Ithaca Fauna Area east cf Oakland c o Centr'l N. Y. 1 o 1 to 1 1 ■g o 'h3 c o N m > 1 t § 1 3 o N E 8 1 1 3 g el to 'O -a ai V ni A 3 1 s o 'hD IS o .o u 0) 3 1 c ■s •a 1 1 0) o 1 Ri 1 1 T3 0) 1 § g ■c i 1 0) 6 MOLLUSCA— PELECYPODA.— Ck>iitinued. Gosselletia sp Actinopteria cf. epsilon Hall # * * * * * * * * * * § 'ii ■^ » ■i » "i * * # • * '* « * * 1 '* * « « • Ptychopteria sp Ptychodesma 1 sp Schizodus cheniungensis (Conrad) 1 Sohizodus chemung^enais var. quadrangnlaris H. Sohizodus ohemi Clarke & Swartz Schizodus oherni var Sohizodus frostburgenais Clarke & Swartz Schizodus trigonalis Clarke & Swartz Avieulopecten cf. cancellatus Hall Aviculopecten ? sp Lyriopecten tricostatus (Vanuxem) Modiomorpha subangrulata Hall var Goniophora truncata Hall Goniophora glauca Hall Oypiricardella bellistriata (Conrad) Cypricardella nnarylandica Clarke & Swartz C^ricardella marylandica 1 var. (very small) . C^Tiricardella gregaria (Hall) C^ricardella gregraria var C^Tiricardella nitidula Clarke & Swartz C^ricardella cumberlandias Clarke & Swartz.. Cypricardella crasaa Clarke and Swartz (ST>rioardella sp Oypricardinia elegans Clarke & Swartz Cypricardinia elegans var. angusta C. & S Paracyelas marylandica Clarke & Swartz Paracyclas sp MOLLUSCA— GASTROPODA. Pleurotomaria sp Pleurotomaria (Gyroma) capillaria Conrad Murchisonia sp Hormatoma bistriata Clarke & Swartz Ectomaria marylandica Clarke & Swartz Ectomaria ecclesiEE Clarke & Swartz Bellerophon nacfoides Clarke & Swartz Bellerophon clarki Clarke & Swartz t = abundant, t = common, § = rare, || = very rare, H = related form, •• = compare. The numbers preceding the names of the fossils refer to the occurrences of these species as shown upon the chart of columnar sections of the Jennings Formation of Maryland (in pocket of this volume). » - "i ..uiuuiiia. Maryland Geological Survey 443 Geological Range of Upper Devonian Fauna in Maryland, Pennsylvania and New Yokk. — Continued. SPECIES Maryland 1 s a, S 3 V Kew York t4 S'clonemina multistriata Clarke & Swartz Turbo coronula CJlarke & Swartz Trochonema (Gyronema) liratum (Hall) Trochonema (Gyronema) sp Macroohilina pulchella Clarke & Swartz Loxonema hamlltoniae Hall Lozonema terebrum Hall Loxonema styliolum Hall Lozonema ? glabrum Clarke & Swartz Trachydomia pnecursor (Clarke) Holopea rowei darke & Swartz Holopea maiylandica Clarke & Swartz Holopea humills Clarke & Swartz Holopea ? sp Orthonyohia prosscri Clarke & Swartz Orthonychia unguiculata Clarke & Swartz Orthonychia sp Platyceras marylandieum Clarke & Swartz Platyceras compressum Clarke & Swartz Platyceras sp Diaphorostoma lineatum (Conrad) MOIJ.USCA— PTEROPODA. * « * * t * * # * # '» * * '■'■ i '? * J- Tentaculites descissus Clarke & Swartz Tentaculites spiculus Hall Ooleolus tenuicinctus Hall Hyolithes aclis Hall MOLLUSCA— CEPHALOPODA. Orthoceraa consortale Hall Orthoceras ef. demum Hall ' ' t = abundant, } = common, § = rare, 11= very rare, H = related form, »* = compare. The numbers preceding the names of the fossils refer to the occurrences of these species as shown upon the chart of columnar sections of the Jennings Fommtion of Maryland (in pocket of this volume). 444 The Upper Devonian Deposits of Maryland Geological Range of Uppek Devonian Fauna in Maryland, J>bnnstlvania and New Yoek. — Continued. 197 198 199 200 201 202 203 SPECIES Maryland ■«1 I Si g 1 NEW YOBK s i a a o S 1 o § 1 Jennings Formation 1 1 1 o o 1 c Portage Format 'n o Is t V i Woodmont Member -a 1 Chemung Member 1 ELI S g 1 m Ithaca Member a; g Ithaca Fauna Area east of Oakland 1 5 Centr'l N. Y. 0) g K o 1 ■fel 1 s .& o 3 1 g ! s c o •g 1 V o 9 1 1 o 'h3 CO 0) c o 1 c % 0) o s o o u 1 13 (U .a o § 1 -s 3 13) 1 u> cu g 13 0) s Pi P« e 4) 1 p § .2 1 CD o MOLLUSOA-CEPHALOPODA.-Oontinued. Baetrites aciculua (Hall) Mantioooeras patersoni (Hall) Probelooeras lutheri CSarke 1 Tomooeras uniangulaie (CJonrad) Sandbergeroceras chemungeiiBis (Vanuxem) . . . . ARTHROPODA— CRUSTACEA. Phacopa rana (Green) VERTEBRA.TA— PISCES. Grlyptaspia castmani Clarke & Swartz * * • * # .. .. * ■c « ■? • * « * * ? « « * '» t = abundant, % = common, § = rare, 1| = very rare, It = related form, ** = compare. The numbers preceding the names of the fossils refer to the occurrences of these species as shown upon the chart of columnar sections of the Jennings Formation of Maryland (in pocket of this volume). Maryland Geological Survey 445 LOCAL SECTIONS OF THE UPPEE DEVONIAN ' THE JENNINGS FORMATION The Jennings formation outcrops in a number of narrow areas, the longer axes of which trend northeast and southwest, parallel to the Ap- palachian Mountains. At least one and where possible several sections have been studied in each area.^ Marked differences exist between the strata east and west of Wills Mountain. In the following discussion, therefore, the sections east of Wills Mountain have been grouped in one division and those west of Wills Mountain in another. The various sections of each area are brought together, while the areas are considered in order from east to west.' Sections East of Wills Mountain I. Section East of Millstone * An extended section of the Jennings is exposed east of the village of Millstone, beginning at the Eomney-Jennings contact in the village and extending eastward along the National Eoad and in the cuts of the Western Maryland Eailroad which parallels that road, for a distance of 6500 feet. It ends at the axis of the syncline in which the strata are con- tained. The lower part of the section is partially concealed and is so complicated by minor folds that the measurements of it are not deemed trustworthy and hence are not employed in the discussion. A bed occurring 2706 feet east of the beginning of the section and abounding in Camaratmchia congregata var. panlcheadensis is taken as a datum plane and is placed at an altitude of 1600 feet above the base of the Jennings, ' Contributed by Charles K. Swartz. ' Graphic sections are shown on pi. vi (in pocket at end of volume) . •The writer is greatly indebted to D. W. Ohern, T. P. Maynard, and J. T. Singewald, Jr., for assistance in the study of the sections described in this chapter. The sections in large part were first measured, described, and the fossils collected by Ohern and Maynard. The critical points were then studied in detail by the writer, who alone is responsible for the conclusions presented. * Measured by pacing. The strike, of rocks is taken as N. 35° Ei through- out the entire calculation. 446 The TJppee Devonian Deposits of Maryland which is approximately the elevation at which the same bed occurs in the section west of Berkeley Springs, West Virginia, where the lower strata are well exposed and free from minor folding. The identity of the beds at both places is established by the sequence and by the contained faunas. This is the most easterly section in Maryland and is admirably exposed. Jennings Fobmation , , , « _^ an ■3i°° f III Productella speciosa, Spirifer mesastriaUs common, S. mucronatus var. posterus, Nucula corhuUformis Palmo- neilo hrevis, BellerpTion sp. small resembles clarki 110 At the beginning of the section are found: Cyrtina ham- iltonensis, Liorhynchus glohuUforme abundant, Pugnax pugnus var. alius, Spirifer mucronatus var. posterus The lower part of the section is so complicated by minor folding that the measurements of it are deemed untrustworthy and are not employed. The bed containing CamarotoecMa congregata var. parkheadensis, oc- curring 1526 feet from the beginning of the section, is selected as a datum plane and is placed 1600 feet above the base of the Jennings, approximately at the horizon at which it occurs in the section east of Berkeley Springs. The Liorhynchus glolidiforme zone of the Ithaca fauna is very fossiliferous at this locality. A conspicuous feature of the section is the brilliant red bed of Catskill-like sediments that occurs just below the CamarotcecMa congregata var. parhheadensis bed and which is found in the same position in many of the sections as far west as Tonolo- way. Sections were measured in the Hancock area at Berkeley Springs, Hancock, on the Hancock-Harrisonville road and in Thompson Township, Fulton County, Pennsylvania. III. Section East of Berkeley Springs ^ The section described is exposed on the Yellow Springs Eun road, east of Berkeley Springs, West Virginia, beginning at the Eomney-Jen- nings contact, just west of the house of Mr. Ruppenhals, one-half mile east of the village and extending eastward 3284 feet. It is admirably exposed, free from minor folds, rich in fossils and is the most satisfactory section for the correlation of the lower strata of the Jennings observed in the eastern part of the area studied. ' Measured by tape. Maryland Geological Survey 455 SS go oS M Jennings Formation '° ° & ""-S'S Chemung Sandstone Memher h*mo I v^^ Road N. 49° W. 1 11 Si I S*i Concealed. Spirifer mesastrialis abundant at top 3284 130 2158 Road N. 25° W. Concealed 3084 130 2028 ParTchead Sandstone Member Concealed. A massive brown conglomeratic sandstone at top 15 feet thick. Dip 37° B 2844 27 1898 House 2784 Concealed 2784 102 1871 Concealed. A massive gray sandstone at top 12 feet thick containing Camarotoechia congregata var. parlcheadensis, Tropidoleptus carinaius, Spirifer {Delthyris) mesacostalis. 2554 75.2 1769 Fork of road 2384 Road N. 63° W. Concealed in part, exposing some fissile olive-green shale. N. 18° E. 40° E 2384 127.5 1694 Massive greenish-gray sandstone. In fragments found on hillside north of road vyere found CawMrotoschia con- gregata var. parlcheadensis, abundant, C. congregata var. with deeper sinus, suggesting contracta, Spirifer {Delthy- ris) mesacostalis, CypricardeUa gregaria var., Cylconemina multistriata. Thickness of sandstone approximate 2214 12 1566 Woodmont Shale Member BEDS CONTAINING ITHACA FAUNA Very red shale having a bed of green sandstone 18 inches thick at bottom 2194 Fissile olive-green shale ■ 2144 Olive-green shale breaking irregularly 2079 Fissile olive-green shale 2069 Red shale 2019 Concealed 1989 Green sandstone 1974 Fissile brown shale 1954 Massive brown sandstone 1914 Red shale 1909 Red shale containing at top Productella speciosa abun- dant, Schimophoria striatula, Spirifer mucronatus var. pos- terns abundant 1889 Fissile green shale 1869 30 1554 39 1524 6 1485 30. 1479 18 1449 9 1431 12 1422 24 1410 3 1386 12 1383 12 1371 43.6 1359 456 The Upper Devonian Deposits oe Maryland o aS S 3 So .a S'3 „n ^ ■■S'°o) Fissile red shale 1809 11 1316 Olive-green shale containing thin beds of green sand- stone. Shale rusty l'?94 ^9 1305 Olive'green shale of varied physical character 1699 72.7 1236 Hackly green shale and a few thin beds of brown shale containing the following fossils at top: Cyrtina Tiamilton- ensis abundant, LiorJiynchus gloiuUforme, Productella speciosa abundant, Pugnax pugnus var. alius abundant, Spirifer mueronatus var. posterus 1599 69.1 1163 N. 20° W. 50° E. Brown shale and sandstone 1504 13.5 1094 Hackly green shale containing at top N. 15° E. 40° E. LiorJiynchus gloliuliforme, Productella speciosa abundant, Pugnax pugnus var. alius, ScUieopTioria siriaiula, Spirifer mucronaius var. posterus, crinoid rings 1482 6 1080 Green shale breaking irregularly containing Productella speciosa common and Spirifer mucronaius var. posterus, Palceoneilo irevis ? 1472 10.5 1074 Green hackly arenaceous shale, containing Productella speciosa abundant at top. N. 15° E. 40° B 1455 6 1064 Green hackly shale and thin beds of fine-grained green sandstone. At top occur Pugnax pugnus var. alius, Lin- gula spatulata, Liorhynchus gloiuliforme, Schizophoria siriaiula, Productella speciosa, Spirifer mucronaius var. posterus. N. 25° E. 60° E 1445 47.5 1058 Green shale, very fissile at bottom, becoming gradually more hackly above, containing Spirifer mucronaius var. posterus at top 1390 185 1010 Road N. 80° W. Green shale of varied character containing Oladochonus humilis abundant at top 1120 39 825 Hackly green shale, one bed chocolate-colored, con- taining the following fossils at top of unit: Airypa reticu- laris, Schizophoria siriaiula common 1065 14.1 786 Arenaceous green shale breaking irregularly 1045 17.5 772 Green shale breaking irregularly containing the follow- ing fossils at the top: Oladochonus humilis, Airypa reticu- laris, Productella speciosa, Reticularia Iwvis, Spirifer mucronaius var. posterus 1020 10.5 755 Maryland Geological Survey 457 S V 32 89 43 *K'rt'§ QJ O 744 §;|^ Hill Fissile green shale 1005 Fissile olive-green shale and thin beds of green sand- stone, N. 5° E. 45° E. Containing the following fossils at top of unit: Atrypa reticularis abundant, Lingula spatulata, LiorJiynchus globuliforme common, Reticularia Iwvis abun- dant, Spirifer mucronatus var. posterns, Stropheodonta demissa common 960 BEDS CONTAINING NAPLES FAUNA Road N. 85° W. Concealed 840 Ravine 79O Concealed 790 48.5 590 Largely concealed. The bank along the road indicates strata possessing the same general character as the fol- lowing unit, save that sandstone beds are more numerous. Dip 45° B. New house on the north side of road 720 712 623 243 532 Road N. 80° W. Fissile olive-green shale interbedded with thin layers of flaggy sandstone, bearing crinoid segments at top. N. 20° E. 45° B 370 126 • 289 Fissile olive-green shale. N. 23° E. 50° 220 74.3 163 Largely concealed. N. 23° E. 50° E 120 88.5 88 Romney-Jennings contact RoMNET Formation Massive sandstone. The occurrence of a zone of Reticularia Icevis in the lower part of the Ithaca fauna is of special interest hecause of the restricted range of that species in New York, while the overlying lAorhynchus glohuliforme zone is well developed. The conglomerate containing Camarotwchia congregata var. parkheadensis, which forms the base of the Parkhead, is found in numerous fragments on the hillside and is underlain by the conspicuous red band that frequently occurs in this position in eastern Maryland. 458 The Upper Devonian Deposits of Maryland lY. Section on National Road East of Hancock " The Jennings is exposed on the Kational Road east of Hancock. The lower part of the section is concealed in part and is also complicated by minor folds, as shown by the measurements and by the geological structure of the area, so that earlier students were led to false estimates of the thickness of these strata. The section described begins at the Eomney-Jennings contact, 200 feet east of the center of the bridge over Little Run east of Hancock, and ex- tends 6737 feet eastward to the Jennings-Catskill contact. Catskill Fokmation Red shale and sandstone. Jennings Formation a^^ Chemung Sandstone Memter g" ^s Road N. 77° B. 2^$i^ I 2^| Jennings-Catskill contact 6737 3989 Concealed 6737 161 3989 Toll-gate house near fork of road 6537 Concealed 5537 ^g^ gggg Yellow shale, poorly exposed, fossiliferous near the top. . 6337 95 3667 Dark-red shale 6217 15 3572 Brown shale, weathering yellow green 6197 15 3557 Dark-red shale ; ; 6177 8 3542 Road N. 59° W. Argillaceous yellow and green shale 6167 15 3534 Arenaceous chocolate-red shale N. 5° E. 52° B 6147 7 3519 Argillaceous chocolate-brown sandstone 6137 21 3512 Chocolate-red shale g]^j2 17 3491 Dark-yellow shale .".".'.'.".'.'.'.' 6092 34 3474 Dark-purple sandstone 6052 1 3450 Arenaceous shale 6051 25 3449 Dark-purple sandstone 602i 1 3424 Chocolate-brown shale '.'.'.'.'.'.'.'.'.'..'. 6020 17 3423 Argillaceous sandstone and arenaceous shale N. 5° E. 70° E. containing at top Spirifer mesastrialis abundant 6000 4 3406 ' Measured by pacing. Maryland Geological Survey 459 §•88. -won ■-■S'S Road S. 47° E. siSgl a-3'Bs.a Concealed, massive conglomeratic sandstone at top, 20 feet thick 5995 322 3402 Concealed. Massive gray sandstone at top. N. 7° B. 60° E 5565 150 3080 Road S. 50° E. Concealed to east end of bridge over creek. Massive con- glomeratic sandstone at about 4800 feet from beginning of section (2627 feet above base of Jennings) seen in creek bed 5365 401 2930 Concealed. Spirifer disjunctus found on slope of hill west of creek, altitude about 2275 feet above base of Jen- nings 4815 301 2529 Road N. 17° E. Argillaceous shale and some sandstone N. 17° E. 60°.' At 4185 horizontally (2223 vertically) Amiocoelia umbonata abundant, Chonetes scitulus, Spirifer mesastrialis, Oy- ronema liratum, Ortfioceras cf. demum 4465 10 2228 Road N. 75° E. Largely concealed. Argillaceous sandstone and shale. Chonetes scitulus '. 3895 254 2218 Parkhead Sandstone Member. Argillaceous sandstone and shale. A conglomeratic sand- stone near top 3565 123 1974 Sandstone and shale. A conglomeratic sandstone vyith large virhite pebbles at base of unit 3405 23 1851 Yellow sandy shale, more argillaceous above, breaking irregularly and weathering to a reddish tint. N. 7° E. 56= B 3375 177 1828 Yellow arenaceous shale and sandstone. Some dark-red sandstone 3145 51 1651 Yellow, fine-grained conglomeratic sandstone containing CamarotaecMa congregate var. parhheadensis abundant, C. eximia, Spirifer (Delthyris) mesacostalis, Tropidoleptus carwfltMs 'n. 7° E. 40° E 3077 1 1600 460 The Upper Devonian Deposits or Maryland 30 1564 1525 4 1525 60 Woodmont Sliale Member l^g's g '§'i~ BEDS CONTAINING ITHACA TA-QNA gS.SSf 3 S„ I Dark-red argillaceous sandstone, several thin beds of yel- lowish-green shale. Yellow sandstone interbedded in upper 15 feet. N. 5° E. 30° B. Lingula ligea was found loose on road, probably from this unit 3075 35 1599 Argillaceous yellow shale breaking very irregularly and weathering yellowish-brown. N. 25° E. 30° E 3000 Axis of minor anticline 2920 Same as preceding beds 2920 Yellow and red sandstone and shales 2910 Concealed in part. Fragments of dark-yellow conglom- eratic sandstone, same as at 3077 horizontally, loose on hill- side 2770 50 Loose fragments of conglomeratic sandstone, same as at 3077 horizontally, containing Gamarotcechia congregata var. parkheadensis in abundance. N. 15° E. 40° E 2680 1600 Reddish-brown fine-grained sandstone and yellow shale . . 2680 50 1600 Concealed 2590 276 1550 Coarse arenaceous shale. At the top of this unit back of the third of four similar houses occur Liorhynchus glot- uUforme, Spirifer mucronatus var. posterus abundant. Be- tween 2020 and 2180 were found Cortina hamiltonensis common, Lingula spatulata, L. ligea, Liorhynchus gtobidli- forme abundant, Productella speciosa, Spirifer mesastrialis, S. mucronatus var. posterus abundant, Nucula coriuli- formis, Palceoneilo irevis 2180 43 1274 Road N. 85° E. Coarse arenaceous shale, second of four similar houses opposite top of unit. N. 15° E. 60° E. At top was found Froductella speciosa, Spirifer mucronatus var. posterus abundant 2120 82 1231 Coarse arenaceous shale breaking irregularly. At top of this unit, behind the first of four similar houses, occur Productella speciosa and Spirifer mucronatus var. posterus abundant 2020 155 1149 Yellow arenaceous shale containing at top Cladochonus humilis, Productella speciosa, Pugnax pugnus var. altus ?, Spirifer mucronatus var. posterus ? N. 9° E. 70° E 1850 59 994 Yellow argillaceous shale. At top occur Reticularia IcBvis 1, Spirifer mucronatus YOT. posterus. N. 7° E. 56° E 1785 166 935 Axis small anticline. No deduction made for folding. . . 1580 Light-colored argillaceous shale, weathering to a reddish- brown tone, some chocolate-colored shale 1580 81 769 Maryland Geological Survey 461 2 i o'g •a cj g - m cj :S-Q a) Road S. 83° E. 1 § § g-S ^ _ Concealed 1480 16 688 Ravine 1450 About 300 feet northeast of the road, on the strike of the rock, there were found in the shale behind a barn the fol- lowing fossils: CladocJionus humilis, Atrypa reticularis common, ProOuctella speoiosa abundant, Pugnax pugnus var. alius, SoMzophoria striatula abundant, Beticularia Imvis .abundant, Spirifer mucronatus var. posterus, Strophe- odonta dem-issa. The vertical altitude at which these forms occur is approximately 690 feet. Concealed. Minor folding probably occurs in this interval 1450 351 672 BEDS CONTAINING NAPLES FAUNA Largely concealed. In part olive-green shales and inter- bedded flaggy sandstone. Beds vary arenaceous at top. N. 7° E. 37° B 480 106 321 Ravine 300 Concealed 300 19 215 Olive-green fissile shale with interbedded flaggy sand- stone 270 26 196 Same as above containing at the top Buchiola speciosa fauna. N. 8° E. 40° E 230 64 170 Same as above containing Buchiola speciosa fauna. N. 16° E. 55° E 130 74 106 Concealed 40 32 32 Romney-Jennings contact RoMNEY Formation Very massive sandstone. Though not well exposed, this is one of the first sections of the lower Jennings that was carefully studied in Maryland. The Camarotoechia congregata var. parkheadensis bed, forming the base of the Parkhead member, is selected as a datum plane and placed 1600 feet above the base of the Jennings, tbis being approximately the position at which the same bed occurs at Berkeley Springs, West Virginia. Among the most con- spicuous features of the section is the Cladochomis-Beticularia Imvis zone, which occurs near the base of the beds containing the Ithaca fauna (690 462 Thk TJppek Devonian Deposits of Maryland to 1000 feet vertically) and is a horizon of importance for correlation with the Few York section. The Liorhynchus glohvliforme zone is ■well developed above this (1000 to 1600 feet vertically). The conglomerate at the base of the Parkhead is finely exposed and abounds in Camarotoe- chia congregata var. parlcheadensis. It is underlain by a red bed which suggests the Catskill lithologieally, and shows that Catskill conditions had probably already begun in some adjacent area. The Parkhead contains three conglomeratic zones, above which the beds consist more largely of shale. These are in turn overlain by more arenaceous beds of the Che- mung seen on the west bank of Great Tonoloway Creek east of the turn of the road, in which the Spirifer disjunctus fauna makes its appearance. V. Section on HancocTc-Harrisonville Road ' This section is exposed on the Hancock-Harrisonville road, which leads eastward from Cove Eidge, not quite one-half mile north of the Maryland- Pennsylvania State line. It is located in Fulton County, Pa., about 2 miles northeast of Hancock. The section begins at the Eomney-Jennings contact and extends eastward 1505 feet. It affords a good exposure of the lower strata of the Jennings. Jennings Formation , , . _ „ », •5^2 « ° S 5 p WooSmont Shale Member _ a-" & o'*'! 3 ° *** w s BEDS CONTAINING ITHACA FAUNA §~ B S c ■g'fS Road N. 85° E. oS-Sl'S S ^^l Ravine 1505 Shale breaking into irregular fragments 1505 87.3 1104 Fissile olive-green shale 1385 29.1 1017 Hackly olive-green shale, containing at the top Atrypa reticularis 1345 43.3 ggg Coarse olive-green shale breaking irregularly, containing at the top Atrypa reticularis abundant, Productella spec- iosa, Pugnax pugnus var. alius, Schizophoria striatula, Spirifer mucronatus var. posterus. N. 17° E. 60° E 1280 62 944 Green shale fissile at bottom, breaking irregularly at top. Thin beds of sandstone N. 22° E. 55° B., containing at the top Atrypa reticularis abundant, Productella spec- iosa abundant, Pugnax pugnus var. alius, ScMzopJioria striatula, Spirifer mucronatus var. posterus, Stropheodonia demissa, Leptosirophia interstrialis 1213 156.7 882 ' Measured by pacing. Maryland Geological Survey 463 •§■35 Olive-green shale. Some beds of sandstone. Some red beds. N. 15° E. 56= E. Containing at the top Claaochonus humths abundant, Atrypa reticularis, Pugnax pugnus var. alius, ScMzophoria striatula abundant, Spirifer mucronatus yav. posterns 995 ^^ g ^^g BEDS CONTAINING NAPLES FAUNA Olive-green shale with beds of fine-grained flaggy sand- stone. N. 12= E. 50° E. Some beds of shale covered with bright-red rust 885 265.6 640 Second-class road to left 520 Road N. 95° E. Daxk olive-green fissile shale N. 20° E. 40° 520 65.2 374 Road N. 80° E. Dark olive-green fissile shale N. 20° E. 47° E 415 133 309 Olive-green fissile shale 230 15.3 176 Fissile dark shale. N. 11° E. 50° E. At top occur Buchiola sp., PterocJiwnia sp 210 160.8 161 Romney- Jennings contact RoMNBY Formation Massive sandstone. VI. Section in Thompson Township, Fulton County, Pennsylvania^ The section extends along a road leading from Great Tonoloway Creek to Timber Eidge, about 1.9 miles north of the Marylajad-Pennsylvania line. It begins a short distance northeast of the point at which the road enters the area embraced in the Hancock quadrangle of the U. S. Geologi- cal Survey and ends 833 feet east of the intersection of this road with another road leading north and south on top of the first ridge east of the Great Tonoloway Creek. ' Measured from to 3036 by pacing, from 3036 to top by tape. 464 The Uppbk Devonian Deposits oe Maryland CATSKILL FOBMATION ^ S" §" o""! 3 g " 0) o " Strata above 3869 horizontally are prevailingly red. |t.S^ I ||? Road S. 85° W. i||.|| | fj Light-green shale 3869 10.5 Red shale 3851 18 Light-green sandy shale 3821 6.5 Road S. 58° W. Concealed 3811 18 Red shale. N. 18° E. 43° E 3761 8.5 Yellow-green sandstone, 4 inches thick 3737 0.5 Red shale 3736 1 Green shale 3734 5 Road N. 95° W. Map altitude 700 feet Yellowish-brown shale 3720 10.5 Light-green shale, sandy below. N. 18° B. 43° E 3701 4 Red shale. Thin green band near bottom 3694 14 Road N. 80° W. Red sandstone N. 18° B. 43° E 3669 2 Green sandy shale 3666 3 Red sandy shale 3661 11.5 Thickness of Catskill described 113 Jennings Formation Chemung Sandstone Meniber Jennings-Catskill Contact 3462 3837 Green shale, sandy near bottom, Camarotcechia sp., etc., at top N. 18° E. 45° E 3642 22.5 3837 Road N. 46° W. Red shale and thin bedded shaly sandstone 3616 Light green shale, sandstone near bottom 3607 Green sandstone N. 15° E. 44° E 3602 Green shale. Camarotcechia sp., etc 3601 Red shale and thin sandstone 3590 Red sandstone 3579 Green shale 3577 Red shale, 6 inches of red sandstone in middle 3570 5 3814 3 3809 0.5 3806 6 3806 5 3800 1 3795 3.5 3794 3.5 3790 Maryland Geological Survey 465 Green arenaceous shale and sandstone 3563i 5 3787 Red arenaceous shale and sandstone 3554 7.5 3782 Red sandstone 3540 0.5 3774 Red shale and thin sandstone 3539 12 3774 Green shale 3517 1 3762 Red and green shale 3515 4 3761 Green sandstone 3508 1 3757 Red shale 3507 7 3756 Concealed 3494 24 3749 Yellow shaly sandstone, CwmarotoecMa. sp 3448 2 3725 Red sandy shale. Base of red band. N. 15° B. 42° B 3443 32 3723 Road N. 32° W. Map altitude 720 feet Yellow to yellowish-green arenaceous shale 3381 34 3691 Red to yellowish-green shale 3310 14 3657 Road N. 85° W. Concealed 3280 37 3643 Road S. 77° W. Map altitude 740 feet. Green and brown, thin-bedded sandstone N. 15° E. 55° E. 3226 9 3606 Red shale 3213 7 3597 Concealed 3203 11 3590 Red arenaceous shale, sandstone below 3187 11 3579 Thin-bedded shaly green sandstone 3171 10 3568 Thin-bedded shaly red sandstone 3156 2 3558 Concealed 3153 11 3556 Thin-bedded shaly brown sandstone N. 15° B. 58° B 3138 11 3545 Yellowish-green arenaceous shale 3122 1 3534 Red shale 3121 8 3533 Thin-bedded red shaly sandstone. Dip 58° E 3109 32 3525 Concealed 3062 17 3493 Road S. 85° E. Map altitude 790 feet Cross roads on top of ridge 3036 Concealed '. 3036 128 3476 Brown and green arenaceous shale. Mostly concealed . . 2896 73 3348 Brown arenaceous shale, some brown sandstone 2816 54 3275 Grayish-green sandstone 2756 7 3221 Brown shale breaking irregularly. Dip 65° B 2734 23 3201 30 §■>! ■R'S? s CJ i»n S •1 Pi 37 3178 9 3141 11 3132 15 3121 39 3106 466 The Upper Devonian Deposits op Maryland »0'" Id -. B"s ° Road N. 55° E. Map altitude 780 feet |||.|| Interbedded yellow, green, and brown arenaceous shale. . 2709 Thin-bedded brown sandstone, some interbedded brown 2649 arenaceous shale Brown arenaceous shale ^"^'^ Green sandstone. Some brown sandstone on top 2614 Green and brown hackly shale 2609 Road N. 85° B. Brown and green shale breaking irregularly. Dip 50° . . . 2539 58 3067 Brown arenaceous shale with 2 feet massive yellowish- green sandstone at top carrying abundant crlnoid rings. . . 2469 33 3009 Road S. 75° E. Map altitude 720 feet Concealed. Dip 55° E 2429 132 2976 Road N. 45° E. Map altitude 730 feet Brown arenaceous shale. Some interbedded green arena- ceous shale 2279 47 2844 Yellowish-green arenaceous shale 2179 9 2797 Brown arenaceous shale breaking irregularly 2159 10 2788 Road N. 35° B. Map altitude 690 feet Yellowish-green argillaceous shale. Some thin-bedded green sandstone 2139 60 2778 Road N. 60° E. Green argillaceous shale 1959 30 2718 Road N. 85° B. Brown and green arenaceous shale, 18 inches green sand- stone at top. Dip 50° E 1909 16 2688 Brown arenaceous shale, some green arenaceous shale near top. Green sandstone 1 inch thick at top 1889 12 2672 Yellow and green argillaceous shale 1874 70 2660 Conglomerate sandstone and some interbedded shale forming hilltop. Sandstone in three beds 1784 11 2590 Yellowish-green argillaceous shale 1770 21 2579 Maryland Geological Survey 467 i a o > SP -M o a m 44 255.8 17 2514 8 2507 17 2499 12 2472 11 2460 23 2449 14 2426 3 2412 18 2409 Road S. 60° E. lilsf Yellowish-green argillaceous shale. Some interhedded green sandstone. Dip 50° B 1774 Green sandstone, interbedded yellowish-green shale 1684 Yellowish-green argillaceous shale 1664 Reddish-brown arenaceous shale. Thin-bedded brown sandstone at top. This unit is almost bright-red 1654 Massive red-brown sandstone 1634 Road S. 35° E. Map altitude 630 feet Massive red-brown sandstone 1620 Yellow shale 1604 Red shale 1571 Massive sandstone 1551 Yellow and reddish-brown shale 1546 Road S. 37° E. Reddish and yellowish-green arenaceous shale. Some thin beds brown and green sandstone 1520 163 2391 Reddish-brown arenaceous shale : . 1290 18 2228 Yellowish-green argillaceous shale. Dip 55° E 1265 21 2210 Road S. 57° E. Map altitude 620 feet Yellowish-green, somewhat fissile arenaceous shale 1235 106 2089 Concealed 115 134 2083 Interbedded brown sandstone and shale. Greenish- yellow arenaceous shale at top 965 37 1949 ParkUead Sandstone Meonher Interbedded sandstone and shale. Coarse conglomeratic sandstone at top 925 Thin-bedded reddish-brown sandstone. Dip 70° E 885 Yellowish-green arenaceous shale, breaking somewhat irregularly 875 Limit of Hancock quadrangle. Map altitude 580 feet 825 Thin-bedded grayish-green sandstone 775 Yellowish-green arenaceous shale breaking somewhat ir- regularly 765 Conglomeratic grayish-green sandstone, very massive... 725 Yellowish-green arenaceous shale, breaking somewhat irregularly, some green sandstone 715 125 1725 34 1912 9 1878 90 1869 9 1779 36 1770 9 1734 468 The Upper Devonian Deposits oe Maeyland 2j a) 0*3 o > 2? ■30°° ■s'S c iiJS^ .S S S _ m o .-S-n o Road S. 60° E. '§11 1" I Shale. Conglomeratic sandstone at top containing Camor rotoBoJiia congregata var. parkJieadensis abundant 575 4 1600 Woodmont Shale Memher BEDS CONTAINING ITHACA FAUNA Reddish-brown and green shale 570 37 1596 Thin-bedded yellowish-green sandstone and arenaceous yellowish-green shale 530 23 1559 Yellowish-green arenaceous shale 505 50 1536 Yellowish-green arenaceous shale with coarse-grained conglomerate at top 7 inches thick 450 36 1486 Yellowish-green arenaceous shale. At top of this unit a fine-grained conglomerate 18 inches thick. Dip 60° E 410 150 1450 Road S. 55° E. Concealed. A conglomerate 1 inch thick at top. Ithaca fauna near base including Liorhynchus gloiuUforme, Pro- ductella speciosa, Pugnax pugnus var. aUus, Spirifer mucro- natus var. posterus 240 213 1300 Beginning of section at a second-class road leading to south 825 feet northwest of limits of Hancock quadrangle. . 1087 This section was studied chiefly for its lithological features. It pre- sents an excellent exposure of the strata near the Jennings-Catskill contact, the alternation of sediments of Jennings and Catskill type oc- curring near the top of the Jennings formation being well shown. It also exhibits the topographic features of the Chemung admirably, the sandstones occupying the horizon of the upper conglomerate forming tlie chief ridge, while the lower conglomerate forms a smaller ridge on the flanks of the larger. An unusual feature is the development of conglom- erates in strata that correspond to the Woodmont member in sections farther west. YII. Section East of Woodmont Station ' One of the best sections of the lower Jennings in the State is seen between Woodmont and Tonoloway stations, nearly opposite Great Caca- ' Measured by tape. Maryland Geological Survey 469 pon. West Virginia. -This is the locality from -which the Woodmont member is named. The strata, which stand nearly vertical, are exposed in the cuts of the Western Maryland Eailroad, where there is an uninter- rupted section of the lower 1400 feet, rivalling the section at Berkeley Springs, West Virginia, in its excellence. The section is somewhat thinner than usual, due probably to the compression of the strata in the west limb of the anticline, a feature frequently seen in Appalachian folds. It begins at the Eomney- Jennings contact west of Tonoloway Station, and extends westward along the railroad 1391 feet, from which point it is continued on the hillside north of the railroad. rt o ^ Jennings Foemation Chemung Sandstone Member o-Smo | .S^"^ ■r o B Section Exposed on Hillside g g.g g 3 S Ravine 2281 Concealed 2281 97 2249 Schoolhouse 2181 Concealed 2181 485 2152 Concealed, N. 23° E. 77° W. At top occurs Amioccelia umbonata abundant, Spirifer disjunctus. Crinoid rings . . . 1681 72 1667 Parkhead Sandstone Member Concealed. A sandstone at top 1601 Massive brown sandstone 1487 Concealed 1460 Concealed. Massive brown sandstone at top, 6 feet thick, bearing Camarotoechia congregata var. parkhead- ensis, Tropidoleptus carinatus 1391 Concealed. Brown sandstone at top 1370 Concealed. Conglomerate 1 foot thick at top. Dip Si' W 1354 56 1348 Concealed. Conglomerate at top, 8 inches thick, contain- ing Camarotcechia congregata var. parkheadensis abundant 1298 7 1292 Top of section on railroad 1291 1285 Massive green sandstone containing at top Camarotwchia, congregata var. parkheadensis, C. congregata var. with deeper sinus suggesting contracta, C. eximia, Cypricardella tenuistriata 1291 25 1285 112 1595 29 1483 69 1454 21 1385 16 1364 S'ga ■s-s-y u ■S'Sr^ u .■s-°S Eh <'S3 .05 1260 33 1155 36 1122 19 1086 470 The Upper Devonian Deposits of Maetland •d"^ en ■slot Woodmont Shale Member b-Smo |g.S-" BEDS CONTAINING ITHACA FAUNA I 6 S o'f Green fissile shale 1266 Brown fissile shale. Dip 87° W 1161 Green fissile shale 1128 Brown and green concretionary sandstone 1092 Green smooth shale, containing at top Bryosoa, Chonetes lepidiformis ?, Cyrtina Jiamiltonensis, Liorhynchus globuli- forme, Productella speciosa abundant, ScMzophoria stria- ttila common, Spirifer mucronatus var. posterus abundant, Actinopteria cf. boydi, cf. Palwoneilo irevis 1073 35.5 1067 Concretionary sandstone grading into green shale. At top are found Crytina hamiltonensis common, Liorhynchus gloiuUforme common, Productella speciosa abundant, Schizophoria striatula, Spirifer mucronatus var. posterus abundant, Palwoneilo brevis, Ectenodesma birostratum. At 1030 horizontally (1020 vertically) were found Cyrtina hamiltonensis, Liorhynchus globitliforme abundant, Pro- ductella speciosa, Pugnax pugnus var. altus, Spirifer mucro- natus var. posterus 1038 Olive-green shale and concretionary sandstone 1011 Red shale 943 Olive-green fissile shale. Dip 90° W 923 Olive-green shale. At top were found Productella spec- iosa, Spirifer mucronatus var. posterus. Dip. 83° W. At 735 horizontally (728 vertically). Pugnax pugnus var. altus was found 782 65.3 776 Olive-green shale, some interbedded sandstone. At top occur Productella speciosa, Spirifer WMcronatus var. pos- terus, Palwoneilo constriota, P. brevis. At 520 horizontally (515 vertically) occurs Atrypa reticularis 716 239 710 BEDS CONTAINING NAPLES FAUNA Green shale and flaggy sandstone 477 Concealed 4]^2 Road leading north 295 Olive-green fissile shale and bands of flaggy sandstone. . 295 Olive-green shale weathering to an ashen-white 278 Olive-green fissile shale with bands of flaggy olive-green sandstone. Dip 84° W. increasing to 90° W. at top of unit 269 Olive-green flssile shale 46 Romney-Jennings contact 27 1032 68 1005 20 937 141 917 65 471 117 406 17 289 8.5 272 220 264 44 44 Maryland Gkological Sdrvey 471 RoMNET Formation gcBg-a 3 2 | Sandstone and some interbedded shale -which, break irregularly 32 Massive sandstone. The lithologieal features of the lower Jennings are well displayed. The basal beds contain the Naples fauna, while the Ithaca fauna makes its appearance 520 feet above the base of the Jennings, and ranges up to the beds containing Camarotcechia congregata var. parhheadensis. The Liorhynchits glohuliforme zone contains a profusion of fossils, rendering this one of the best localities in the State for collecting Ithaca fossils. YIII. Section on National Road West of Tonoloway Ridge^ This section is situated five and one-half miles northeast of the pre- ceding and its lower part embraces the same strata. It is exposed along the National Road, beginning at the Romney-Jennings contact about one mile west of the Tonoloway Eidge, and extending westward 4003 feet. The upper strata are not well exposed, the section being important chiefly because it affords a good exposure of the lower Jennings. Jennings Formation ""-"a Z^'t Chemung Sandstone Member c't^soo S •§•§5 RoadN. 35° W. gUgl I 2^1 Largely concealed. Fossils at top 4002 143 3692 Road leading south. Approximate position of upper con- glomerate of Chemung 3882 3549 Red shale 3822 67.5 3549 Red sandstone 3752 7 3481 Red shale. Beds of red sandstone. Some green shale .. . 3745 135 3474 Red shale breaking irregularly 3605 14.5 3339 Red and green sandstone 3590 29 3325 Red shale breaking irregularly 3560 38.5 3296 Concealed 3520 38.5 3257 ^Measured by pacing. Thickness calculated using average strike N. 24° E., average dip 79" W. 473 The Upper Devonian Deposits of Maryland ftga "^-'rf'S 1 i^J> H SS-?-^ J 5 so Canal. S. 60° E. gSlg'S S S~| Canal lock 5958 Concealed 5958 Ravine 5556.3 Brown sandstone with some green sandstone 5556.3 Brown shale breaking irregularly with an occasional bed of brown sandstone 5523.3 Jejstnings Formation Chemung Sandstone Member Jennings-Catskill contact 5213 4543 Green sandstone 5213 14 4 4543 Brown sandstone 5197 3 ^gie 4533 Thin-bedded green sandstone with some beds of massive green sandstone 5183 3 4g g 4521 Brown and green shale breaking irregularly 5132.3 25.3 4475 Thin-bedded brown sandstone 5104.3 23.5 4449 Thin-bedded brown sandstone with interbedded brown and green shale breaking irregularly 5078.3 47.1 4426 Heavy-bedded brown sandstone with interbedded thick beds of brown sandstone N. 30° E. 65° E 5026.3 51.6 4379 Thin-bedded green sandstone 4959 3 14 8 4327 Reddish-brown sandstone with occasional hackly beds of brown shale. N. 30° E. 45° E 4948.3 25.8 4312 ' Measured by tape. Maryland Geological Survey 483 iSH — =»■ o o " a °„,^-" a poJo N OJ-g 4« -C.D Brown hackly sliale predominating with gray and brown interbedded sandstone 4911.3 86.5 4287 Thin-bedded green sandstone with interbedded green shale 4798.8 22.2 4200 Heavy-bedded brown sandstone with an occasional bed of green sandstone N. 30° E. 50° E 4769.8 48.2 4178 Massive gray sandstone 4706.8 17.2 4130 Brilliant red band of flaggy sandstone at the bottom and red shale breaking irregularly at the top 4687.3 18.5 4113 Interbedded hackly brown and green shale with thin beds of flaggy grayish-green sandstone 4666.2 27.2 4094 Brown sandstone, heavy-bedded at the bottom, thin- bedded towards the top. N. 30° E. 62° E 4635.2 11.4 4067 Gray sandstone lower 10 feet massive, upper 30 feet thin-bedded 4622.2 35.2 4055 Interbedded green and brown shale breaking irregularly 4582.2 36.1 4020 Brown and green shale breaking Irregularly with some Interbedded brown sandstone 4541.2 13.2 3984 Brilliant red hackly shale 4526.2 12.3 3971 Green and brown shale breaking Irregularly with inter- bedded grayish-green and some brown sandstone 4512.3 125 3959 Brown sandstone 4370.2 2.6 3833 Brown shale breaking irregularly. Strike N. 30° E 4367.2 5.2 3833 Thin-bedded gray flaggy sandstone 4361.2 63.7 3826 Brown hackly shale at the bottom with thin beds of green hackly shale in middle of unit and gray sandstone at top. N. 27° E. 62° B 4288.6 36.8 3762 Green and reddish-brown arenaceous shale with thin bed of gray sandstone at top 4246.8 11.1 3725 Massive brown sandstone 4233.6 6.8 3714 Hackly green arenaceous shale with an occasional thin bed of grayish-green sandstone 4225.6 9.4 3707 Hackly interbedded brown and green arenaceous shale Interbedded with grayish-green sandstone and some brown sandstone. N. 25° E. 60° B 4214.6 81.5 3698 Grayish-brown shale breaking Irregularly 4120 7.9 3616 Brown sandstone with interbedded brown shale breaking irregularly 4111 7 3608 Red and green shale breaking Irregularly with Inter- bedded thin and heavy beds of brown and grayish-green sandstone. Dip 62° E "03 65.2 3601 Heavy and thin-bedded gray sandstone coarse-grained and carrying small pebbles. N. 30° E. 55° E.- 4029 12.2 3536 484 The Upper Devonian Deposits of Maryland ^ B O^ ^5 " ""' c -S i u a r^ <■■ l-Sll .a ?•= ^'2 ■o«§ s; Bo A a 'a 5*9 5-0 Massive flaggy sandstone and interbedded shale 3759.5 15 2636 Fissile green shale and interbedded sandstone 3738 31 2621 Red sandstone 3690 1.9 2590 Fissile olive-green shale and beds of sandstone. Dip 45° E 3687 92.5 2588 Coarse olive-green shale. In a sandstone at top occur Spirifer disjunctus abundant, Cypricardella cf. mary- landica small, Cypricardella sp., Palceoneilo sp., cf. Schizo- dus Chemung ensis, S. oherni ?, Bucqnopsis mmra 3545 21.7 2496 Coarse green fissile shale and Interbedded sandstone. Dip 48° E 3513 23.8 2474 Spring and ravine 3478 Coarse green fissile shale and bands of sandstone. At the top in coarse arenaceous shale are found Spirifer mesas- trialis abundant 3478 59.2 2450 Dark-green fissile shale and bands of sandstone. Dip 55° E. At top in sandstone are found LeptostropUia perplana var. alternata abundant, Palceoneilo perplana, cf. Schizodus oherni, Bucanopsis mwra 3398 75.3 2391 Concealed 3298 88 2316 Ravine 3173 Concealed on railroad. On hillside are beds much the same as in underlying unit. At top of this unit on hillside are found ArnbocmXia iimbonata, Chonetes scitulus, Cyr- Una hamiltonensis, Spirifer disjunctus abundant, S. mesas- trialis common, S. (Delthyris) mesacostalis 1, Schizodus oherni common, Cyclonemina multistriata, Cyclonema con- cinnum, Cyclonemina crenulistriata abundant, C. crenulv- striata var. obsolescens, Loxonema styliolum abundant, L. terebrum, Nucula corbuliformis, Palceoneilo plana, Pterinea chemungensis, Schizodus trigonalis, Cypricardella crassa 1 abundant, Bellerphon clarki, Loxonema ? glairum, Holopea parva, Ectomaria marylandica. These species are limited to a narrow horizon 3173 105.7 2228 Concealed on railroad. On hillside are seen yellow fissile shale, green where not weathered, and some sandstones. At top of this unit are found Ambocaelia umbonata, Lep- tostrophia perplana var. alternata, Spirifer disjunctus abundant, S. mesastrialis, Cyclonemina crenulistriata, Lox- onema terebrum. cf. Cypricardella crassa, C. tenuistriata. This is the lowest occurence of Spirifer disjunctus ob- served in this section 3023 52.8 2122 500 The Upper Devonian Deposits of Maryland ■aioi i O Road N. 40° E. Map altitude 890 | ill's g g^| Green fissile shale. At top in a shale occurs the Buchiola speciosa fauna (PterochcBnia, etc.) 1690 39 625 Road N. 60° E. Green fissile shale. Dip 28° E. At top occurs the Buch- iola speciosa fauna 1530 50 586 Concealed. Dip 28° B 1400 460.5 536 Road S. 79° E. Map altitude 740 Concealed 200 76.5 76.5 Romney-Jennings contact is concealed. Position approxi- mate The great profusion of fossils in the Parkhead memher and the occur- rence of bright-red strata just above the base of the Chemung member are interesting features of the foregoing section. XVIII. Section on National Road, Polish Mountain^ The Jennings is well exposed on the National Eoad on the western slope of Polish Mountain. The section begins at the Eomney-Jennings contact, 450 feet west of the center of the bridge over Town Creek and extends to the cross roads on the top of the mountain. It is continued above this point on the road leading to the southwest on Polish Mountain. Jennings Formation Chemung Sandstone Member •3-°S -2 Be Concealed. A conglomeratic sandstone near top of moun- tain 75 3375 Concealed. A massive conglomeratic sandstone crosses the road which leads southwest from National Road. Its outcrop is 1740 from National Road and its map altitude 1560 feet. The interval from it to crossroad largely con- cealed. The remainder of the section is on the National ^"^^ 10565 200 3300 ' Measured in 1907 by pacing. Revised from instrumental surveys of High- way Division, Md. Geol. Survey. Corrected altitudes are from latter survey. Maktland Geological Survey 513 li-all g ^?i Crossroad at top of mountain, 1380 altitude. Map alti- tude 1372 8825 3119 Road N. 55° E, Shale breaking irregularly, beds of heavy sandstone, N. 20° E. 18° E., and N. 40° B. 17° E. At top of mountain, N. 32° E. 14° E 8825 83 3119 Fissile and hackly green shale and some sandstone. At top Spirifer mesastrialis in a bed of sandstone, probably 6 feet thick. Dip 18° E 8440 87 3036 Fissile green shale and beds of sandstone. At top a band of sandstone occurs containing Camarotwchia sp., Atrypa spinosa, Spirifer disjimctus, 8. {Delthyris) mesa- costalis 8220 20 2449 Fissile green shale. At top occur CamarotcecMa con- tracta, Spirifer (Delthyris) mesaoostalis abundant, S. mesastrialis, Loxonema styliolitm, Pterinea chemungensis . 8175 28 2929 Splintery shale breaking irregularly. N. 30° E. 15° E. . . 8098 61 2901 Road N. 55° B. Map altitude 1298 Green arenaceous shale breaking irregularly. N. 32° B. 22° E 7911 68 2840 Road N. 85° B. Altitude 1278. Map altitude 1275 Hackly and splintery green shale. N. 29° B. 17° B 7669 58 2772 Green shale breaking irregularly. At top occur Pterinea shemungensis "!, Liopteria sp. \a,Tge near L. higsbyi 7504 18 2714 Road N.-S. Altitude 1256. Map altitude 1240 Going down stratigraphically. Green shale breaking ir- regularly, N. 22° B. 15° E 7449 10 2696 Going down stratigraphically. Hackly green shale. At bottom occurs BchucJiertella chemungensis abundant, Dou- villina cayuta ?, Zaphrentis marylandica abundant, Z. che- mungensis abundant, Spirifer {Delthyris) mesacostalis common, S. mesastrialis abundant, Atrypa spinosa, Pterinea chemungensis, Camarotwchia contracta. Dip 16° E 7314 8 2706 Concealed. Going down stratigraphically. N. 27° E 14= E 7231 6 2714 33 514 The Upper Devonian Deposits of Maktland Road N. 65° "W. Altitude 1239. Map altitude 1240 S g.g gl | 2^ I Mostly concealed. Some fissile shale, bands of sandstone 7137 69 272fl Second sharp turn around head of ravine. Mostly con- cealed. N. 35° B. 14° E 6929 54 2797 Shale breaking irregularly. Dip 20° B 6763 94 2597 Road N. 45° "W. Map altitude 1220. Altitude 1183 Splintery and hackly shale. About 10 feet vertical from bottom a brown sandstone probably 10 feet thick. At the top of this unit in argillaceous shale occur Amboccelia um- honata, Grammysia suharcuata. N. 6° B. 13° B. and N. 36° E. 20° B 6545 82 2503 Road N. 60° E. Map altitude 1150. Altitude 1162 Largely splintery shale 6337 31 2421 Road N. 60° E. Altitude 1155. Map altitudfi 1150 Concealed 6212 52 2390 Road N. 50° "W. Altitude 1148. Map altitude 1140 Fissile shale and flaggy sandstone. Dip 23° E 6087 106 2338 Fissile shale and flaggy sandstone 5858 47 2232 Shale breaking irregularly and sandstone. At top Spirir fer disjunctus, Produotella lachrymosa. Dip 20° B 5744 26 2185 Fissile green shale, massive sandstone near base. At top Spirifer (DeltJiyris) mesacostalis. N. 28° B. 18° B 5681 85 2159 Road N. 85° B. Altitude 1099. Map altitude 1100 Fissile green shale bands and sandstone 5536 20 2104 Concealed 5484 68 2084 Road N. 75° W. Altitude 1078. Map altitude 1090 Fissile green shale with bands of sandstone. At top in hackly green shale occur Spirifer disjimctm, 8. (Delthy- ris) mesacostalis, Productella sp. Dip 25° E 5328 137 2016 Second-class road to southeast 30 feet from next turn. Road N. 11° E. Altitude 1056. Map altitude 1070 Going down stratigraphically. Fissile green shale, bands of sandstone. N. 25° E. 31° B 5047 32 1879 Maryland Geological Survey 515 Road N. 23° W. Altitude 1031. Map altitude 1080 S gl g| | S | Fissile green shale and bands of sandstone. Dip 30° E. Going down stratigraphieally 4704 46 1911 Fissile green shale. Going down stratigraphieally. At hottom Ambocoslia umionata. Dip 25° E 4548 40 1957 Road N. 50° E. Altitude 1002. Map altitude 1070 Concealed. Ravine. Sharp turn to left in ascending mountain. N. 21° E. 25° E 4361 28 1997 Road N. 50° W. Altitude 995. Map altitude 1060 Green fissile shale. Dip 23° B 4236 12 1969 Parkhead Sandstone Member Green fissile shale 89 1957 Massive sandstone. N. 27° E. 30° B 4007 5 1868 Largely concealed. Green shale and sandstone showing in places. Dip 30° B 3997 238 1625 Shale breaking into irregular pieces and concretionary sandstone. A massive sandstone at 3520 horizontal. N. 27° E. 35° E 3571 65 1625 Fissile green shale. At top occur CamarotcecMa congre- gata var. parkJieadensis, Spirifer (Delthyris) mesascostalis, 8. marcyi var. superstes, Cyclonemina multistriata, Pha- cops rana. Dip average 35° 3467 134 1560 Road N. 77° W. Altitude 909. Map altitude 920 Fissile green shale. At bottom in a sandstone occurs Camarotwchia congregata var. parkJieadensis, Spirifer mar- cyi var. superstes, Tropidoleptus carinatus, Leptodesma naviforme, Bellerophon clarki, Lioptera Mgshyi ?, Palw- oneilo irevis ? 3259 230 1426 Woodmont Shale Member Fissile green shale 2937 71 1196 Road N. 45° B. Altitude 869. Map altitude 880 Fissile green shale. Average dip 31° 2812 53 1125 Road N. 10° E. Altitude 853. Map altitude 870 Largely fissile green shale. Ascending stratigraphieally. N. 29° B. 30° B 2594 20 1072 516 The Upper Devonian Deposits op Maryland ■■3-^!i° °|.S a o ° *^ « i) •S So - M U .-S'^ «J Road N. 55° W. Altitude 821. Map altitude 860 ||-S|| g ^-gj Stone bridge 2220 1092 Concealed. Dip 30° E 220 735 1092 Black and green fissile shale. Buchiola speciosa fauna. Dip 30° B. At 760 occurs Cyclonema sp. resembles con- cinnum 760 161 357 Road N. 79° W. Altitude 770 Town Creek 450 196 Concealed. Dip 30° E. Genesee shale in interval 450 196 196 Romney-Jennings contact. 450 feet west of center of bridge over Town Creek - XIX. Section near Round, West Virginia The Jennings occupies a syncline west of Warrior Mountain, which deepens south of the Potomac Eiver. The lower Chemung conglomerate is exposed on top of a hill west of the home of Mr. J. Will Smith, the locality- being on the county line between Mineral and Hampshire counties, 2% miles in an airline southwest of Eound, West Virginia. The section is of interest because of the abundant development of the recurrent Tropido- leptus carinatus fauna in the lower Chemung conglomerate. The follow- ing species were collected in these beds : Ambocodia umhonata abundant, Camarotoschia congregata var. pa/rkheadensis, Bhipidomella vanuxemi, Spirifer marcyi var. superstes, Tropidoleptiis carinatus abundant. The underlying rocks are exposed in a ravine that descends in a northeasterly direction from the home of Mr. Smith, along an old road leading to Green Spring. The lower part of the Chemung consists largely of strata having a deep-red color, below which the Parkhead member is seen in the ravine. XX. Section on Williams Road East of Gumierland '■ The lower Jennings is admirably exposed on the Williams Eoad west of Mt. Hermon Church, 31/^ miles east of Cumberland. The section begins at the Romney-Jennings contact and extends 1908 feet to the west. The measurements were made on the old road and do not apply to the new road constructed in 1911, which follows another course. ^ Measured by tape. Maryland Geological Survey 517 Jennings Formation ■= " „ *^S-S ParTchead Sandstone Member I* at i ""i^ Road N. 80° W. I a f g-S -a S S Shale chiefly dark and bands of flaggy sandstone. At the top occur Chonetes scitulus common, Productella navi- celUformis common, Spirifer marcyi var. superstes abun- dant, Tropidoleptus carinatus abundant, Liopteria Ugsiyi, Orthoceras sp igog 72.9 1466 Fissile shale, green below, grading into black above. At top occur Camarotmchia congregata large, Lingula oherni abundant, Liorfiynchus mesascostalis abundant, Orbicvr loidea cf. media, RMpidomella vanuxemi, Spirifer (Del- thyris) mesacostalis ?, cf. Ptychodesma sp., Leptodesma naviforme 1812 76 1393 Road N. 22° W. Woodmont Shale Member BEDS CONTAINING NAPLES FAUNA Green fissile and splintery shale 1712 21.2 1317 Sandstone with shale partings. Dip 50° W 1662 7.6 1296 Shale and flaggy sandstone 1644 13.6 1288 Concealed 1599 26.3 1274 Road N. 55° E. Concealed 1549 44 1248 Fissile olive-green shale and flaggy sandstone 1479 31.4 1204 Fissile olive-green shale weathering to ashen-white 1429 47.2 1173 Road N. 55° W. Fissile olive-green shale weathering to ashen-white 1354 43.2 1125 Fissile olive-green shale 1304 39.7 1082 Green shale breaking irregularly. Dip 70° W 1258 43.2 1043 Road N. 95° W. Concealed 1208 40.4 999 Road N. 70° W. Fissile green shale. N. 12° E. 65° W 1161 131.3 959 Road N. 95° W. Green fissile shale 1014 127.7 828 Green fissile shale bearing at top Pieroc?iemia sp 864 34 700 518 The TJppee Devonian Deposits of Maryland Road N. 30° W. ||.S.|| 2 ^^| Green fissile shale. Dip 70° W 824 124.5 666 Green fissile shale bearing at top the Buchiola speciosa fauna 651 21 541 Green fissile shale bearing at top Buchiola speciosa fauna. Dip 67° W 621 52 520 Road N. 45° W. Green fissile shale hearing Goniatites at top. Dip 67° W. 547 62.6 468 Shale and shaly sandstone bearing BucMola speciosa fauna at top 471 33.3 406 Green fissile shale. N. 20° B. 50° W. bearing BucMola speciosa fauna throughout 423 34.4 373 Road N. 80° B. Concealed 373 30 338 Fissile green shale. N. 15° B. 61° W 335 32.2 308 Road N. 75° W. Green fissile shale bearing at top Buchiola speciosa fauna. N. 15° B. 70° W 294 186 276 Oenesee Black Shale Member Black shale bearing Genesee fauna. (Thickness approxi- mate) 100 90 90 Romney-Jennings contact RoiMNET Formation Yellowish-green shale weathering into irregular frag- ments 56 Massive sandstone. The Ithaca fauna was not observed, the Naples fauna appearing to range throughout the Woodmont member. The Liorhynclius mesacostcde zone is well developed at the base of the Parkhead member. An interest- ing feature is the profusion of Spirifer marcyi var. superstes in the Park- Maryland Geological Survey 519 head member, a form found abundantly in the western sections, but occur- ring less frequently in the east. A number of excellent exposures of the Jennings are to be seen in the Cumberland syncline, south of the Potomac Kiver in West Virginia. The best of these are along Eocky Eun on the Baltimore and Ohio Eailroad cut-ofiE, and on Turners Eun Eoad east of Knobly, seven miles southwest of Cumberland. At the former locality at the base of the Parkhead occur Chonetes scitulus, Cyrtina hamiltonensis, RMpidomella vanuxemi, Schizo- phoria striatuLa, Spirifer marcyi var. superstes abundant, Tropidoleptus carinaticSj Cyclon&mina mulUsiriatd, Pleurotomaria (Gyroma) capil- laria ? At the same horizon at the latter locality occur Chonetes scitulus, Spirifer marcyi var. superstes, Spirifer (Delthyris) mesacostalis. Sections West of Wills Mountain The sections of the Jennings exposed west of Wills Mountedn difEer both lithologically and faunally from those east of Wills Mountain. Among the conspicuous differences observed are the lesser thickness of the formation, the larger development of shale in the lower beds, render- ing the Parkhead member scarcely distinct, the occurrence of conglomer- ates in the middle of the Chemung, and the absence of the red band so prominent in the upper part of the Chemung in many of the eastern sections. The sections are exposed in two areas, the Keyser area and the Oak- land anticline. The sections in the Keyser area will be considered in the order of their location from the northeast to the southwest. XXI. Section at EUersUe, Pennsylvania^ The lower Jennings is exposed in a ravine north of and parallel to the tramway from EUerslie to the fire-clay mine on Little Allegany Mountain. The section begins at the Eomney-Jennings contact and extends westward 1911 feet. '■ Measured by pacing. 520 Ti-TE Upper Devonian Deposits of Makyland |ig= til Jennings Formation %. " a ^.-Sa S S . = JO Direction of run N. 40° W. S Sag's 3 5 5.SSt _ Concealed. At bottom of this concealed unit in thin- bedded gray sandstone were found Amiocwlia umbonata, Atrypa spinosa, cf. Graniella sp., Dalmanella tioga common, Douvillina cayuta, Schuchertella chemungensis, Spirifer mesastrialis, Leptodesma longispinum small, L. sp., Pteri- nea chemungensis abundant 1911 16 1524 Direction of run N. 20° W. Concealed 1893 11 1508 Interbedded arenaceous green shale and gray sandstone. At 1847 horizontally (1474 vertically) occur AmbocosUa umionata abundant, Atrypa spinosa abundant, Graniella hamiltoniw, Dalmanella carinata, D. tioga abundant Chonetes sp., Douvillina cayuta common, Productella lach- rymosa var marylandica ?, P. lachrymosa var. approaching speciosa common, Schizophoria striatula common, Spirifer disjunctus abundant, S. {Delthyris) mesacostalis, Schucher- tella chemungensis abundant, Pterinea chemungensis abundant 1878 37 1497 Direction of run due W. Thin-bedded green arenaceous shale 1828 14 1460 Direction of run N. 50° W. Heavy-bedded grayish-green sandstone 1811 5 1446 Largely concealed, with some thin bands of grayish- green sandstone at bottom 1806 57 1441 Thin-bedded grayish-green sandstone and interbedded arenaceous green shale. At 1680 horizontally (1316 verti- cally) occur Cladochonus humilis, Atrypa hystrix, A. spinosa, Dalmanella tioga abundant, Douvillina cayuta, Schuchertella chemungensis abundant, Productella lachry- mosa var. approaching speciosa, Spirifer disjunctus abun- dant, Pterinea chemungensis abundant, Pleurotomaria sp. 1749 125 1384 Direction of run N. 45° W. Concealed 1620 83 1259 Maryland Geological Survey 521 l^s-s I'll 'O' CO ^^ 2 .S ParTchead Sandstone Member 'S S § g'S •§ •■S S Concealed I533 2I 1176 Thin-bedded gray sandstone 1512 4 1155 Gray sandstone in beds 6 to 8 inches thick 1508 3 1151 Concealed 1505 37 1148 A second-class road crosses here 1467 Concealed 1467 63 1111 Direction of run N. 75° W. Thin-bedded gray sandstone 1393 18 1048 Concealed 1375 31 1030 Direction of run S. 35° W. Thin-bedded fissile green arenaceous shale and inter- bedded green sandstone 2 to 4 inches thick 1343 12 999 Concealed 1254 12 987 Direction of run N. 55° W. Fissile green arenaceous shale with interbedded thin bands of gray flaggy sandstone; shale weathering some- what hackly 1163 45 975 Direction of run N. 45° W. Green arenaceous shale with some interbedded green flaggy sandstone near the bottom 1118 29 930 Thin-bedded flaggy bluish-green sandstone and some Interbedded green arenaceous shale 1088 19 901 Direction of run N. 55° W. Thin-bedded arenaceous green shale and interbedded bluish-green flaggy sandstone. Sandstone more prominent near the top where beds become 6 inches to 1 foot thick. N. 27° B. 90° E 1068 69 882 Woodmont Shale Member BEDS CONTAINING NAPLES FAUNA Thin-bedded fissile green shale and interbedded thin sandstone. Partially concealed 998 48 813 Direction of run N. 85° W. Thin-bedded olive-green shale and interbedded bands of green sandstone. Partially concealed 948 46 765 532 The Upper Devonian Deposits of Maryland CO V v^ o Direction of run N. 75° W. 'li-Sfl I 3 flj O Thin-bedded green shale and interhedded grayish-green sandstone 898 57 719 Thin-hedded green shale. N. 27° B. 80° W 838 38 662 Grayish-green shale with interhedded thin gray sand- stone in courses, 1 foot thick near bottom of unit 798 21 624 Concealed 776 27 603 Direction of run N. 65° W. Dark bluish-black and green fissile shale and occasional bands of sandstone 2 to 3 Inches thick. Dip 90° 748 48 576 Direction of run due W. Olive-green fissile shale 648 49 528 Direction of run S. 45° W. Fissile green shale becoming more argillaceous towards the top, containing the Buchiola speciosa fauna. Upper 75 feet bluish-black fissile shale. Dip. 90° W 590 33 479 Direction of run S. 72° W. Olive-green fissile shale with occasional bands of blue sandstone 481 32 446 Direction of run N. 50° W. Olive-green fissile shale with occasional bands of blue sandstone 431 17 414 Olive-green fissile shale with occasional thin bands of bluish sandstone. N. 30° B. 90° W 413 48 397 Direction of run N. 85° W. Bluish-green fissile shale with an occasional band of sandstone near the bottom. Containing the Buchiola speciosa fauna 353 45 349 Direction of run N. 45° W. Fissile bluish-green shale, in some places becoming al- most black, resembling the Genesee, with thin bands of blue sandstone 2 to 3 inches thick. N. 27° E. 90° W 313 47 303 Olive-green thin-bedded shale with a few thin beds of blue sandstone 2 to 3 inches thick 263 44 256 Maryland Geological Sdkvey 533 Direction of run N. 85° W. 'fell 1 1 3 H^i Olive-green thin-bedded shale with a few thin beds of blue sandstone 2 to 3 inches thick 217 62 212 Direction of run N. 55° W. Olive green fissile shale with a few thin beds of bluish- green sandstone 2 to 3 inches thick. N. 27° B. 78° W 154 15 150 Massive dark-gray sandstone 139 3 135 Thin-bedded fissile olive-green shale with some thin beds of bluish-green sandstone 1 to 3 inches thick 136 31 132 0-enesee Black Shale Member Very fissile black shale carrying Genesee fauna from top to bottom. N. 25° E. 78° W 104 101 101 Romney-Jennings contact The thickness of the lower members is seen to be much less than in the eastern sections, the Chemung fauna appearing 1350 to 1300 feet above the base of the Jennings. Particularly noticeable is the profusion of Ddlmanella tioga in the lower Chemung, in contrast with the almost entire absence of this genus in the sections east of Wills Mountain. XXII. Section on Jennings Run Road The upper Chemung conglomerate and the overlying strata are well exposed on the road leading from Cumberland to Barrelville along Jen- nings Kun. (This section is described by Prosser, supra.) XXIII. Section near Allegany drove ' A section embracing nearly the entire Jennings is exposed in the cuts of the Cumberland and Pennsylvania Eailroad southwest of Allegany Grove. The section begins at the center of the trestle work over the Winchester Eoad, which leads southwest to Cresaptown, and extends westward 3433 feet, ending at the east end of the first tunnel. ' Measured by pacing. 524 The Upper Devonian' Deposits of Maeyland t^s" -211 SSo oil CaTSKILL FOBMATION c-^^Sio S ■S-a'^ Railroad N. 35° W. 'S « § gf I S ? East end of tunnel 3433 Interbedded red and green sandstone and red shale. Dip 62° W 3433 33.2 Red arenaceous shale and some thin-bedded green sand- stone 3393 24.9 Reddish-brown arenaceous shale and some green shale.. 3363 29.2 Jennings Formation Chemung Sandstone Member Jennings-Catskill contact 3328 2984 Green hackly shale. Dip 72° W 3328 16.6 2984 Concealed in part. Arenaceous green shale and brown sandstone fragments. At 3292 horizontally' (2957 verti- cally) occur Cam,arotcechia oontracta abundant, Spirifer disjunctus abundant, Leptodesma sp. At 3268 horizontally (2941 vertically) occur AtJiyris angelica, Camarotwchia oontracta abundant, C. eximia common, Spirifer disjunctus abundant 3308 Grayish-green and brown sandstone. Dip 48° W 3258 Arenaceous green shale and thin-bedded green and brown sandstone 3248 Fissile shale and thin beds of sandstone 3198 Massive grayish-green sandstone 3178 Grayish-brown sandstone and a little interbedded shale. . 3171 Massive conglomerate 3159 Green and brown interbedded shale with a bed of thin- bedded sandstone at the top 3157 64 2867 Concealed. A massive conglomerate sandstone occurs at 2990 horizontally (2756 vertically). About 2800 ver- tically occur Spirifer disjunctus, Grammysia elliptica, Lep- todesma sp 3062 94.5 2804 Railroad N. 59° W. Concealed 2922 199.2 2710 Second-class road crosses railroad 2722 2510 Green and brown arenaceous shale with several beds of brown sandstone 1 foot thick. Loose fragments of con- glomerate on hillside on strike of top of this unit. Ap- proximate position of upper Chemung conglomerate 2510 to 2520 2722 90.6 2510 Brown sandstone 2632 3.9 2420 32.5 2967 6.5 2935 33.7 2928 13.4 2894 4.6 2881 8 2876 1 2868 ftsa •h'm ^ V onata abundant, Camarotcechia sp., Spirifer (Delthyris) mesacostalis abun- dant. About 1250 vertically occur AmhocwHa umbonata abundant, Spirifer [Delthyris) mesacostalis abundant. At bottom occur Amhoccelia unvbonata abundant, Spirifer [Delthyris) mesacostalis abundant 1390 155 1310 Parkhead Sandstone Mem.'ber Concealed. 19 feet of thick yellowish-green argillaceous shale forms top of this unit on upper railroad 1224 126.9 1155 Maryland Geological Survey 527 ■o " ■" g.S a^o. -■2 3 "iltjo ^ *^'^ ■Hoc — m o SJ'^tt) bcflS'o ■a -^^ * K+J bflS^ B ■< s.£» Olive-green shale and thin beds of sandstone, all weather- ing yellow. Dip 73° W. At about 950 vertically was found Atrypa spinosa, Grammysia suharcuata 1089 166 1028 Argillaceous green shale and thin beds of sandstone be- low, thicker bed of sandstone above. All weathering yel- low. Containing in cut on upper railroad at a horizon near top of this unit Camarotcechia congregata var. parkhead- ensis, Gyrtina hamiltonensis, Liorhynchus mesacostale abundant, Schuchertella chemMngensis, Productella lachry- mosa ?, Spirifer (Deltfiyris) m-esacostalis ?, Pterinea che- mungensis 914 124.5 862 East end of first cut west of Winchester bridge 782 738 Woodmont Shale Member Concealed. Fissile olive-green shale, exposed on upper railroad 782 37.5 738 Olive-green and yellow shale and thin beds of ilaggy sandstone 742 225.7 701 Yellow shale breaking somewhat irregularly. At the top of this unit were found loose Amhocalia umlonata, Ghonetes sp. It is doubtful whether these fossils were in place 502 30 475 Railroad N. 73° W. Olive-green shale and thin bands of greenish sandstone, all weathering yellow. At top of this unit GamorotoecJiia sp. was found loose, but it is doubtful whether it was in place 470 311.7 445 Concealed 140 133 133 Center of trestle over Winchester road. Approximate position of the Romney-Jennings contact ROMNEY FOEMATION The presence of the Parkhead. member is shown by the occurrence of a number of its characteristic species an.d by a slight development of sand- stone, which may represent approximately the upper conglomerate of that member. The percentage of sandstone is, however, so slight as 528 The Uppek Devonian Deposits op Maryland scarcely to distinguish this portion of the section from the strata of the Woodmont shale member. The Chemung fauna appears 1350 to 1300 feet above the base of the section. An important feature of this section is the recurrence of the Tropidoleptus fauna 1670 feet west of the be- ginning of the section. The fauna was not seen in the section but was collected on the strike of this horizon V2 ^^^ southwest of the section where the following species were observed : AmbocoBlia urribonata, Spirifer marcyi var. superstes, Spirifer (Delthyris) mesacostaUs and Tropidolep- tus carinatus. XXIV. Section near Keyser, West Virginia The upper beds of the Chemung are finely exposed on the Keyser- Piedmont Eoad south of the Baltimore and Ohio Railroad 1% miles west of Keyser, West Virginia. The most conspicuous feature of the section is the occurrence of conglomerates at many horizons in the upper part of the Chemung, as shown by the following section. Catskhx Foemation Red shale and sandstone. A gray sandstone 5 feet thick occurs 78 feet horizontally (50 feet vertically) above base. Ji2f KINGS Foemation "^ "q. ""J§ Chemung Sandstone Member a-Stso i ■S'S'^ Road N. 71° W. |||g-S | S^| Sandstone and shale. Gray prevails, some beds red. Fossils at 2312 horizontally (2870 vertically) 2390 218.6 2920 Sandstone and shale. Dip at top 40° W 2050 75.5 2707 Signal tower. Mile post on B. & 0. R. R. marked B. 203 W. 176 1942 Sandstone and shale 1942 31.1 2626 Road N. 68° W. Sandstone and shale. N. 32° E. 50° W 1900 95.5 2595 Sandstone and some shale. A conglomerate 3 feet thick at top containing flat pebbles (Upper Chemung Conglomerate) 1776 22.9 2500 ' Measured by tape. Maryland Geological Survey 529 iis"s ti « o o-t B gag's 3 s^g bnale and sandstone 1747 15.6 2477 Shale and sandstone. A fine-grained conglomerate 2 feet thick at top 1726 Shales. A conglomerate 2 feet thick at top 1714 Sandstone 1709 Shale. A -sandstone 3 feet thick at bottom. N. 33° E. 52° W 1696 Shale 1675 Sandstone. A conglomerate at top 1583 Shale and sandstone 1543 Shale and sandstone. Slightly conglomeratic at top 1472 Shale and sandstone. Slightly conglomeratic at top 1453 Conglomerate 1421 Sandstone 1413 Chiefly shales • 1371 Coarse sandstone with interbedded shales, a few pebbles at top 1325 Chiefly shale 1306 Sandstone. N. 28° E. 53° W 1242.3 Shale 1240.8 Fine-grained conglomerate 1239 Shale 1235 Concealed 1180 Concealed in part. At the top of this interval is a massive green and gray sandstone 20 feet thick, overlain by a massive brown and gray conglomeratic sandstone 14.6 feet thick, containing flattened pebbles, seen on the hillside south of road. N. 43° E. 58° W 700 153 1614 Massive brown and gray conglomeratic sandstone 20.6 feet thick containing round and flat pebbles, seen on hillside south of road. N. 31° E. 60° W. 520 20.6 1461 Turn of wagon road, 1942 feet east of signal tower, oppo- site mile-post 203 of B. & 0. R. R The Jennings is exposed thronghout the center of the Oakland anti- cline. Most of the exposures, however, are of such a character that it is impossible to make satisfactory stratigraphie measurements of them so that while abounding in fossils, the stratigraphy of this part of the Jen- nings is but poorly known. 34 9.5 2461 4 2452 19.3 2448 15.6 2428 73.6 2413 32 2339 56.8 2307 15.2 2250 25.6 2235 6.4 2210 33.6 2203 36.8 2170 15.2 2133 60 2118 1.2 2058 1.5 2056 3.2 2055 44.6 2052 393.6 2007 530 The Upper Devonian Deposits op Maryland XXT. Section on Middle Fork ^ The best section observed in the Oakland area is on the Middle Pork of the Savage Eiver 2 miles on an air line northwest of Floyd Station on the Baltimore and Ohio Eailroad, from which point this section is best reached. It begins on the county road leading from Prankville (Floyd), 300 feet east of the point where the road crosses Middle Fork northeast of Chestnut Knob. It ends in the center of the anticline at the mouth of the first ran that enters Middle Fork from the northeast east of Black- hawk Eun. The base of the Chemung member is not exposed in this section. liso til -3 B qP, « o * CATSKILI, FOEMATION "l-Siillo I SS'^ S»-§^ I 11° Road N. 75° W. ■§ill'i 3 Si Section begins on county road 300 feet east of point where it crosses Middle Fork o Red sandstone (concealed in part). A massive gray- sandstone perhaps 20 feet thick occurs at top bearing a band of conglomerate, fragments of which are found on hill north of road. N. 32° E. 16° E 300 74 95.6 Road crosses stream. Section is continued beyond this point along Middle Fork Run. Altitude 1640 300 95.6 Direction of run due north. Concealed. In part red sandstone and shale 520 45 119 Concealed 680 32 151 Red arenaceous shale with one band of gray-green sand- stone near bottom 1 foot 4 inches thick, N. 42° E. 16° B. . 880 38 189 Jennings Foemation Chemung Sandstone Memier Largely concealed 1020 28 217 Direction of run N. 35° W. Largely concealed 112o 29 245 Thin-bedded gray sandstone. N. 45° E. 17° E 1260 30 276 Concealed 1370 50 326 Gray thin-bedded sandstone, N. 32° E. 19° E., N. 28° E. ^^° ^ 1550 25 351 ^ Measured by pacing. Maryland Geological Survey 531 ro o) y** AS? ?n i «>■§■* .3 S£° Thin-bedded gray-green sandstone, heavy bed at top containing fossils. N. 48° E. 16° E 1720 40 391 At 1920 to 1960 massive sandstone 11 feet thick. N. 36° E. 16° E. 1960. Dip 37° E. At 2000 a sandstone 2 feet thick. Dip. 21° E 2240 123 514 Direction of run N. 75° W. Concealed 2300 15 529 Catsklll-Jennings contact as given on map in Grantsville- Accident folio 2300 529 Thin-bedded brown sandstone. N. 35° E. 16° E. at 2320. . 2350 13 542 Concealed. N. 30° E. 18° E 2390 11 553 Interbedded brown and gray arenaceous shale and sand- stone. N. 25° E. 19° E 2490 32 585 Concealed 2540 14 599 Direction of run N. 35° W. Concealed. The road crosses stream at 2820 2910 72 671 Thin-bedded gray and brown sandstone. N. 30° E. 15° E. and N. 36° E. 16° E 3100 42 713 Concealed 3290 42 755 Direction of run N. 53° W. Concealed 3590 67 822 Direction of run N. 68° W. Concealed 3700 34 856 Heavy brown sandstone. Brown arenaceous shale at top. Dip 14° E 3720 5 861 Concealed 3960 37 898 Massive gray conglomeratic sandstone. N. 39° E. 10° E. . 3975 2 900 Massive grayish-brown sandstone. N. 31° B. 10° E 4065 14 914 Thin-bedded gray sandstone, interbedded brown shale and gray arenaceous shale. Dip 10° E 4215 23 937 Concealed 4355 22 959 Gray thin-bedded sandstone. 10°E 4395 6 965 Concealed. Dip 10° E 4455 9 974 Thin-bedded gray sandstone. Dip 13° E 4490 6 980 532 The Upper Devonian Deposits of Maryland (Q a> : n O o c -w _^ p (i> o Direction of run N. 89° W. Iglsl I 2„l Thin-bedded gray sandstone, some interbedded arenaceous shale at bottom. N. 21° E. 10° E., N. 21° E. 12° E., N. 25° E. 10° E 4635 21 1001 Grayish-brown sandstone. Some interbedded arenaceous shale. Sandstones thin-bedded. Heavy beds at top and bottom 4835 29 1030 Concealed 5055 14 1044 Alternating thin and heavy beds of brown sanustone with some interbedded brown shale. N. 27° E. 6° E., N. 12° E. 5° E. Dip 5° E 5235 12 1056 Concealed. A conglomerate at approximately 5325 Loose fragments probably in place on hillside. The upper Chemung conglomerate. Altitude 1720 on map 5325 6 1062 Concealed 5610 38 1100 Direction of run N. 69° W. Concealed 5735 Concealed. Old saw mill 5835 Concealed 5895 Thin-bedded gray sandstone. Dip 8° E 5935 Heavy-bedded brown sandstone with interbedded brown thin-bedded sandstone. Gray hackly shale at top. Dip 7° E 5995 6 1150 Interbedded brown sandstone and gray hackly shale. Dip 5° E 6165 14 1164 Thin-bedded brown sandstone. A few heavier beds. Dip 12° E 6285 Fifty feet from top. Dip 23° E. Concealed 6585 Thin-bedded brown sandstone. Dip 55° E 6605 Concealed. Dip 40° E. 40 feet from top 6655 Heavy thin-bedded brown flaggy sandstone. Dip 10° E. . 6695 Concealed 6760 Direction of run N. 11° W. Altitude 1750 on map Concealed. Massive sandstone 2 feet thick opposite house. Dip 6° E 6795 House 6795 Thin-bedded gray sandstone. Dip 6° E 6825 Concealed 6925 Thin-bedded gray sandstone and interbedded gray-green arenaceous shale. Dip 16° E. Dip 12° E 6955 18 1319 Thin-bedded brown sandstone and interbedded brown shale breaking into pieces. Dip 24° E 7075 5 1324 18 1118 14 1132 8 1140 4 1144 22 1185 42 1228 16 1224 31 1275 5 1280 8 1288 2 1290 1290 1 1291 10 1301 Maryland Geological Survey 533 S OJ-S"^ ,y s QJ o 'C20-"S " .■S'°o) Sgcg'S 2 - g Concealed 7115 4 1328 Massive brown sandstone. Dip 3° E 7122 1 1329 Concealed 7202 8 1337 Massive and thin-bedded brown flaggy sandstone. Dip 15° E 7372 26 1363 Concealed. At 7770 Dip 70° E 7840 46 1409 Direction of run N. 35° W. Concealed. Dip 85° W. at 7850 8072 31 1440 Grayish-green sandstone anticline. Dip 3° E. 3° W. 10° E 8202 10 1450 Largely concealed 8402 26 1476 Concealed. A massive sandstone and shale about 10 feet thick about 75 feet above base of the unit. Dip 20° E 9170 101 1577 Direction of run N. 19° W. Concealed 9202 4 1581 Grayish-green thin-bedded sandstone with thin-bedded brown sandstone at bottom, average dip taken 9° B. 18° E. Dips 24° E., 14° E., 8° E., 0° E., 8° "W 9442 23 1604 Largely concealed 9522 9 1613 Thin-bedded gray sandstone. Dip 40° E 9562 19 1632 Concealed 9582 3 1635 Heavy-bedded gray-green sandstone. Dip 8° E 9592 1 1636 Concealed ' 9742 17 1653 Thin-bedded grayish-green sandstone and interbedded grayish-green arenaceous shale with a few heavy beds of sandstone. Dips 2° E., 5° E., 7° E., 15° W. Average dip 18° E 10112 81 1734 Green and brown thin-bedded flaggy sandstone and inter- bedded brown and green hackly shale 10312 10 1744 End of section at ravine from north. Center of anticline. Altitude 1840 10312 1744 This section has not been studied faunally. It affords, however, a valuable estimate of the thickness of the strata in this area. Conglom- erates occur at three horizons. The lower of these is not well seen in the section but is conspicuous on top of the hill at the center of the anti- cline about 750 feet vertically above the point where the section ends. 534 The Upper Devonian Deposits of Maryland This is the most conspicuoTis conglomerate in the Oakland anticline and develops a series of knobs where it outcrops. It has been described by Prosser as the Avilton conglomerate and is probably the same as the upper conglomerate of the preceding sections. A less conspicuous conglomeratic sandstone occurs 163 feet vertically above the preceding. A third con- glomeratic sandstone occurs at the top of the section 900 feet above the lower conglomerate and develops a conspicuous series of hills in the region. It is underlain by red strata of Catskill type. The Jennings-Catskill contact was placed by Prosser 50 feet above the upper conglomerate in this section. The writer prefers to place it at the base of the red stratum found beneath the upper conglomerate because of the Catskill-like character and considerable thickness of the red stratum, the slight thickness of the upper gray beds associated with -the con- glomerate, and the absence of observed marine fossils above the horizon suggested. Similar gray beds are not infrequent in the lower part of the Catskill in the eastern sections. SYSTEMATIC PALEONTOLOGY OF THE UPPER DEVONIAN DEPOSITS OF MARYLAND BY JOHN M. CLARKE AND CHARLES K. SWARTZ SYSTEMATIC PALEONTOLOGY UPPER DEVONIAN COBLENTEEATA John M. Clarke and C. K. Swaetz. ECHINODERMATA John M. Clarke and C. K. Swaetz. VERMES John M. Clarke and C. K. Swaetz. MOLLUSCOIDBA. BEACHIOPODA John M. Clarke and C. K. Swaetz. MOLLUSCA. PELECYPODA John M. Clarke and C. K. Swaetz. GASTROPODA John M. Clarke and C. K. Swaetz. CEPHALOPODA John M, Claeke and C. K. Swaetz. ARTHROPODA. TRILOBITA John M. Clarke and C. K. Swaetz. OSTRACODA John M. Clarke and C. K. Swartz. VERTEBRATA. PISCES Charles K. Swaetz. COELENTERATA Class ANTHOZOA Subclass TETRACORALLA Family ZAPHRENTIDAE Genus ZAPHRENTIS Rafinesque Zapheentis maetlandicus n. sp. Plate XLV, Figs. 1, 2 Description. — Corallite simple, slightly curved, conical, diameter in- creasing a little more rapidly toward apex. Exterior showing indistinct septal furrows and slight irregular annular constrictions. Calyx shallow in proportion to length of corallite, width usually exceeding depth; its bottom wide, often flat, sides erect, edges thin. Septa about 80 in larger specimens, alternating in length, usually but not always reaching center, appearing as ridges upon bottom of calyx. Fossette deep, on con- vex side of calyx. Tabulae unknown. Length of corallite 55 mm. ; diameter of calyx 27 mm. This species differs from Z. ahemungensis in (1) larger size, (3) more distant septa, (3) calyx proportionally much shallower. It is known only by casts of calyx and exterior, hence its generic position is not assured. Although its interior structure is not known, the perfect pres- ervation of the interior of its calyx renders it worthy of a specific name. Occurrence. — Jennings F'oemation, Chemung Membee. National Eoad on Polish Mountain, 2706,^ abundant. Collection. — Maryland Geological Survey. * The numbers after localities indicate the stratigraphic altitude above the base of the Jennings formation. 540 Systematic Paleontology — Uppee Devonian Zapheentis chemungensis n. sp. Plate XLV, Figs. 3-6 Description. — Corallite simple, eonieai, curved. Exterior bearing shal- low annular constrictions placed at irregular distances, striated longi- tudinally by septal furrows. Calyx very deep in proportion to length of corallite, occupying much of interior of corallite; its bottom concave, sides spreading, edges thin. Septa about 60 to 65, alternating in length, the longer reaching center of calyx. Septal fossette deep, situated on convex side, containing a long cardinal septum. Length of corallite about 20 mm. ; diameter of calyx 17 mm. This species differs from Z. marylanddca in (1) smaller size. (3) closer septa, (3) great depth of calyx. This species is known only by casts of its exterior and calyx, so that its generic position is not assured. While it seems hazardous to erect a new species in the genus Zaphrentis upon such material yet the perfect preservation of the casts of the calyx renders it desirable to have some specific name by which the form may be distinguished. Occurrence. — ^Jennings Formation, Chemung Member. National Eoad on Polish Mountain, 3706, abundant. Collection. — ^Maryland Geological Survey. Family CYATHOPHYLLIDAE Genus HELIOPHYLLUM Hal! Hbliophyllum sceutaeium n. sp. Plate XLV, Figs. 7, 8 Description. — Corallum small, frequently budding; individual coral- lites rather short, slender, cupshaped; surface highly rugose, irregular. Calyx moderately deep, bearing numerous septa, those of all orders bearing the lateral carinations and the denticulate edges which char- acterize the genus HeUophyllum. Several specimens of this coral occur as casts in the same decomposed sandstone as that bearing the Pavosites described next following. Our Maryland Geological Survey 541 characterization of them is therefore restricted to exterior features, but the species is recognizable from its small and easily branching corallum. Species of Heliophyllum occur elsewhere in the Chemung fauna but forms of the expression of H. scrutarium are not known to the writer. Length of corallite 10-20 mm.; diameter 8-10 mm. Occurrence. — Jennings Foemation, Chemung ? Member. On Side- ling Hill Creek, Allegany County. Collection. — ^Maryland Geological Survey. Subclass HEXACOROLLA Order MADREPORIA Suborder TABU LATA Family FAVOSITIDAE Genus FAVOSITES Lamarck Favosites sp. Plate XLV, Fig. 9 Description. — Fragments of a rather slender branching form of Fdv- osites occur as casts in the sandstone and consequently only the aspect of their exterior is evident. As corals are unusual in sediments of this age these specimens are worthy of note inasmuch as the characters shown suffice to permit their recognition when found elsewhere. In general the specimens may be compared to the branching middle Devonian species Favosites arbusculus Hall (Hamilton, New York), but the stock and branches are more slender. This stock is essentially cylindric, tapers very slowly, undulates in growth and branches with irregularity. The cell apertures are oblique, polygonal and almost devoid of interstitial cellules. Diameter of corallum 6-8 mm.; diameter of corallites about 1 mrii. Occurrence. — Jennings Formation, Chemung ? Member. On Side- ling Hill Creek, Allegany County. Collection. — ^Maryland Geological Survey. 542 Systematic Paleontology — Upper Devonian Family AULOPORIDAE Genus AULOPORA Goldfuss AuLOPOEA EEPENS KnoiT & Walch Plate XLV, Figs. 10, 11 MelUporites repens Knorr et Walch, 1775, Rec. des mon. catastr. t. iii, p. 157, sup. pi. vl, fig. 1. Aulopora serpens Goldfuss, 1829, Petref. Germ., vol. 1, p. 82, pi. xxlx, fig. 1. Aulopora repens Mllne-Bdwards and Halme, 1857, Polyp. Foss. des Terr. Pal., p. 312. Aulopora serpens Rominger, 1876, Geol. Surv. Mich., vol. iii, p. 87, pi. xxxiii, fig. 2. Aulopora serpens Cleland, 1911, Bull, xxi, Wisconsin Geol. Surv., p. 34, pi. ii, flg. 4. Description. — Corallum tabular, prostrate ; branching from buds which originate below calyx; dichotomous, or branches anastomosing to produce a loose meshwork. Branches funnel-shaped, attached throughout their length to other organisms, especially to brachiopods. Calyx funnel- shaped, directed upwards. Tabulse and septa absent. Diameter of branches at calyx 2 mm.; at base 1 mm.; length of branches 3-5 mm. This appears to be the same species as one which occurs in the Hamil- ton formation of New York and which has usually been described as Aulopora serpens Goldfuss. Its identity with the European species, how- ever, is open to question. Occurrence. — Jennings Toemation, Paekhead Member. 3% miles southeast of Cumberland. Collection. — ^Maryland Geological Survey. Genus CLADOCHONUS McCoy Cladoohonds humilis n. sp. Plate XLVI, Figs. 1, 3 Description. — Corallum tubular, prostrate, branching diehotomously. Branches ascending, funnel-shaped, gradually increasing in diameter from origin to calyx. Interior of tube set with delicate spinules which are arranged in lines in some parts, in others irregularly disposed. Tabulae and septa none. Exterior showing delicate transverse strise. Maryland Geological Survey 543 Diameter of branches at calyx 3 mm.; at base 1 mm.; length of branches 5-7 mm. This genus differs from Aviopora in that the branches are not attached inferiorly to other objects but are in large part free. This is probably the same species as one usually described as Cladodhonus sp. which occurs in the Ithaca of New York. Very abundant in the Ithaca fauna, rare in the Chemung of Maryland. Occurrence. — Jennings Formation, Chemung Member. EUerslie, 1316. WooDMONT Member, Ithaca Fauna. Hancock 690, 994; Han- cock-Harrisonville Eoad, 2 miles northeast of Hancock, 736, abundant; Berkeley Springs, West Virginia, 755, 825, abundant. Collection. — Maryland Geological Survey. ECHINODERMATA Class ASTEROIDEA Subclass ENCRINASTERIAE Genus PALAEASTER Hall Pal^aster clarki n. sp.* Plate XLVI, Figs. 3, 4 Description. — This species is represented in the collections by a single specimen afEording a pretty sharp cast of both sides of a very regular and complete individual. In general structure and appearance the species is quite similar, especially on the oral surface, to Pcdceaster euchwris Hall of the sandy Hamilton shales of central New York, but the latter is a much larger form. The disk is small, rays long and slender, thecal plates all prominently developed. The ambulacral surfaces are represented only by a narrow linear depression beneath which the ambulacral plates are concealed. These depressions are bordered by thickened and somewhat elevated quadrangular or pentangular adambulacra. The marginal plates are in * Thus named, as a supererogatory tribute to Prof. W. B. Clark. 544 Systematic Paleontology — Upper Devonian single rows, much thickened, with generally quadrangular outline and convex surface, each projecting on the margin of the ray. At each axilla is a single pear-shaped plate with its apex outward, these plates being the largest in the individual. The abaetinal surface is tessellated by rows of strong convex plates of similar size to the marginal plates. Of these there are three rows, a median row of narrow oval ones between the ends of which are interlocked the edges of the much larger plates of the lateral rows which are highly convex and thickened in the center and greatly depressed to the sutures. Thus each plate has a cushioned sur- face. Between the ends of each plate of the middle row are two minute accessory plates lying in the angles at which the lateral plates enter. At the base of each ray and upon the disk is a single large plate whose surface rises into a high clavate node. Between each two of these is one of less height. The central portion of the aboral area is destroyed and no trace of madrepore is seen. The width of this specimen from tip to tip is 33 mm. Occurrence. — Jennings Formation, Chemung Member. Yellow sandstone on the road northeast of Oakland, Garrett County, where it is associated with Spirifer disjunctus. Collection. — Maryland Geological Survey. VERMES Class ANNELIDA Subclass CHAETOPODA Order POLYCHAETA Suborder TUBICOLA Genus SPIRORBIS Lamarck Spirorbis gyrus n. sp. Plate XLVI, Fig. 5 Description. — Tube closely coiled, attached by one side of all the whorls, the final whorls not becoming lax. Volutions 3-3, ascending on Maryland Geological Survey 545 the free surface. On the early whorls the upper outer edge is angulated and bears a row of sharp oblique tubercles, but in final growth this angulation disappears and rounded tubercles are irregularly scattered over the whole surface. The species bears much resemblance to 8p. angulatus Hall (15th Ann. Eept. N. Y. State Cab. Nat. Hist, p. 112, 1862) from the Hamilton shales of New York, but while that species is tubercled the growth is often irregular and the later whorls are lax and free. Diameter 4 mm. Occurrence. — Jennings Formation, Chemung ? Member. On Side- ling Hill Creek, Allegany County. Collection. — Maryland Geological Survey. Spirorbis sp. Description. — Casts of a small Spirorbis have been observed in the Parkhead that do not show exterior ornamentation. Their condition does not permit confident specific determination. Occurrence. — Jennings Pormation, Parkhead Member. Two miles north of mouth of Town Creek, 1723. Collection. — Maryland Geological Survey. INCERTAE SAEDIS Genus PTERIDICHNITES n. gen. Fern-like imprints consisting of two rows of small pits bordered by a narrow elevated margin and separated by narrow transverse ridges. Pits nearly equidimensional. The nature of these objects is problematical. They are probably tracks of crustaceans or possibly of annelids. The tracks suggest those referred to the genus Nereitcs, but are not sinuous. (From Pteris a fern, ichnos a track.) Ptbridichnites biseriatus n. sp. Plate XL VI, Fig. 6 Description. — Imprints consisting of two parallel grooves with raised borders, divided by narrow transverse ridges into shallow, nearly square 35 546 Systematic Paleontology — Uppee Devonian or slightly rounded pits, which commonly alternate in position. The median ridge dividing the two grooves is not straight but is crenulated by slight inflections directed toward the transverse ridges. Length and width of pits snbeqnal. The impressions usually become faint toward their ends and are often curved. Width of track about 4 mm., diameter of pits about 2 mm. Tracks are several centimeters long. Similar tracks are abundant in the beds containing the Naples fauna in New York. Occurrence. — Jennings Foemation, Woodmont Membee, Naples Fauna. Tonoloway. Collection. — Maryland Geological Survey. MOLLUSCOIDEA CLASS BRACHIOPODA Order ATREMATA Superfamily LINGULACEA Family LINGULIDAE Genus LINGULA Bruguiere LiNGULA OHEENI U. Sp. Plate XLVII, Figs. 1-5 Description. — Shell ovate-elliptical, slightly convex; width two-thirds to three-fourths length, greatest width slightly anterior to middle of valve. Cardinal slopes rounded, sides diverging slightly to a point in front of middle, anterior margin rounded. The shape of the cardinal margin is variable, in some cases forming an acute angle or in others being truncate. Surface marked by fine concentric striae. A fine im- pressed line extends from center of umbo a part of the length of the valve in some individuals. Shell substance thin. Length of larger individuals 8 to 12 mm. ; width 6 to 9 mm. This species resembles L. delia of the Hamilton of New York, but is smaller, proportionally wider, its cardinal slopes not abrupt. It differs Maryland Geological Survey 547 from L. ligea and L. melie in its more ovate form. Associated with the larger shells are many smaller individuals which are considered the young of this species. They are less ovate, not being much if any wider in front, a feature shown to be characteristic of the young individuals by the concentric lines on the older shells. This species is locally abundant in the western sections at the base of the Parkhead member. Occurrence. — Jennings PoRMAnoN, Parkhead Member. Williams Road east of Cumberland, 1393, abundant; 2% miles southeast of Cum- berland ; road 1 mile north of Eocky Run, "West Virginia. Collection. — ^Maryland Geological Survey. LiNGULA LIGEA Hall Plate XLVII, Pigs. 6, 7 Lingula ligea Hall, 1860, 13th Rept. N. Y. State Cab. Nat. Hist., p. 76. Lingula ligea Hall, 1867, Pal. of N. Y., vol. iv, p. 7, pi. i, fig. 2. Lingula ligea var. Hall, 1867, Pal. of N. Y., vol. iv, p. 8, pi. ii, fig. 8. Lingula ligea Grabau and Shimer, 1909, N. Amer. Index Fos. vol. i, p. 197, fig. 229. Description. — " Shell narrow elliptical; length equal to twice the width; sides regularly curving; extremities subequal ; margins of the valves thick- ened. Surface marked by iine concentric striae, and by a few obscure or obsolete radiating strise. The more convex valve shows, along the inner margin, a narrow shallow groove as if the edge of the opposite valve closed just within its margin." Hall, 1867. The variety is described as "larger, the sides somewhat straighter; while the cardinal extremity is not so rounded, and slopes in nearly a right line on each side of the beak." ' The individuals observed corres- pond well with the form described by Hall as Lingula ligea var. save that they are somewhat smaller. Occurrence. — Jennings Formation, Ithaca Fauna. Hancock, 1149 to 1374 rare, 1564 to 1599 ? abundant. The latter specimens were found loose on the road. They occur in red sandstone similar to that forming '■ Pal. of N. Y., vol. iv, p. 8. 548 Systematic Paleontology — Upper Devonian the red bed between 1564 and 1599 from which they probably come. Their exact horizon is not assured. Collection. — Maryland Geological Survey. LiNGULA SPATULATA Vanuxem Plate XLVII, Fig. 8 Lingula spatulata Vanuxem, 1842, Geol. of N. Y., Kept. Third Dist., p. 168, flg. 3. Lingula spatulata Hall, 1867, Pal. of N. Y., vol. iv, p. 13, pi. i, flg. 1. Lingula spatulata Grabau and Shimer, 1909, N. Amer. Index Fos. vol. i, p. 197, flg. 231. Description. — " Shell small, subspatulate or subelliptical, moderately convex, attenuate towards the beak, the ventral valve being more acute; greatest width across the middle of the shell; length (which is scarcely three-tenths of an inch) about twice as great as the width. Surface marked by fine concentric strisi, and, in the exfoliated shell, by faint radiating striffi." Hall, 1867. Length 3 mm. width .6 mm. This is a characteristic species of the Ithaca fauna of New York. It is distinguished by its small size and spatulate shape. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Hancock, 1149 to 1274; Berkeley Springs, West Virginia, 1058. Collection. — Maryland Geological SiTrvey. LiNGtJLA sp. ? Description. — -A small species of this genus having the elongate slender form of L. spatulata Hall ' of the Genesee fauna of New York has been found at a single locality, but the specimens are insufficient for exact identification or for illustration. Occurrence. — Jennings Formation, Woodmont Member, Naples Fauna. In the soft olive shales of the lower part of the section on National Eoad, Polish Mountain. Collection. — Maryland Geological Survey. ' Paleontology of New York, vol. iv, p. 13, pi. i, fig. 1. Maryland Geological Survey 549 Order NEOTREMATA Superfamily DISCINACEA Family DISCINIDAE Genus ORBICULOIDEA d'Orbigny OrBICULOIDEA cf. MEDIA (Hall) Plate XLVII, Pigs. 9, 10 Discina media Hall, 1863, 16th Rept. N. Y. State Cab. Nat. Hist., p. 27. Discina media Hall, 1867, Pal. of N. Y., vol. iv, p. 20, pi. ii, figs. 25-29. Orliculoidea media Hall and Clarke, 1892, Pal. of N. Y., vol. vlli, pt. i, pi. iv, figs. 15-17. Description. — -Shell subelliptieal to subcircular. Small. Dorsal valve low conical, umbo excentric, small, acute. Surface with concentric strise. Interior of dorsal valve and ventral valve not observed. The shell figured is somewhat crushed, causing the umbo to appear more nearly central than it is, and the outline more elliptical than it should be. This species of which but two individuals have been observed, suggests 0. media which occurs both in the Hamilton and Upper Chemung faunas of Isew York. More material is needed to permit confident identiiieation. Length 7 mm.; width 8 mm. Occurrence. — Jennings Formation, Parkhead Member. Williams Eoad, east of Cumberland, 1393; National Eoad on Polish Mountain in soft olive shale with Ghonetes lepidiformis. Woodmont Member, Ith- aca Fauna. Pifteenmile Creek, 1 mile above mouth, 1446. Collection. — Maryland Geological Survey. Superfamily CR AN I ACE A Family CRANIIDAE Genus CRANIELLA CEhlert. CrANIELLA HAMILTONIiE Hall' Plate XLVII, Figs. 11-13 Description. — Shell transverse conical. Umbo subcentral. Dorsal valve quite convex. Adductor muscular scars pronounced, close together ' For synonymy see page 131. 550 Systematic Paleontology — Uppee Devonian' beneath umbo. Posterior muscular scars more widely separated, indis- tinct in cast observed. Large C-shaped vascular markings near margin. Exterior not observed. Shell substance punctate. Width 16 mm.; length (antero-posterior diameter) 12 mm.; height 7 mm. The east of the interior of a single valve has been observed. While unusually convex it agrees with this species in other respects. The C- shaped markings of the vascular sinus, characteristic of the genus Crani- ella, are observable upon the cast though not shown in the drawing. Occurrence. — Jennings Formation, Pakkhead Member. Williams Eoad, Polish Mountain, 1660. Collection. — Maryland Geological Survey. Craniella ? sp. Description. — Shell low conical, subcircular or slightly transverse. Umbo excentric, near posterior margin. Dorsal valve quite convex from umbo to anterior margin, less so to lateral margin, slightly concave to posterior margin. Height of valve variable, about one-fourth diameter or less. Interior of valve shows a pair of indistinct scars beneath umbo for attachment of anterior adductor muscles. Shell substance punctate. Ventral valve not observed. Diameter 15 to 20 mm. ; height 3 to 4 mm. The identification of these specimens is not assured, the interior not being sufficiently well preserved to permit of confident generic determina- tion. It is not improbable that the species is C. Jiamiltomce though much less convex than the other Maryland individuals referred to that species. Occurrence. — Jennings Formation, Chemung Member. EUerslie, Pennsylvania, 1474, 1508. Collection. — Maryland Geological Survey. Genus CRANIA Retz Crania sp. Description. — A single dorsal or upper valve of this genus has been observed and is insufficient for specific identification. The genus is like- wise but sparingly represented in the Chemung fauna elsewhere. Maeyland Geological Survey 551 Occurrence. — Jennings Formation, Chemung ? Member. West slope of Polish Mountain on National Road. Collection. — ^Maryland Geological Survey. Order PROTREMATA Superfamily STROPHOMENACEA Family STROPHOMENIDAE Genus STROPHEODONTA Hall Steopheodonta demissa (Conrad) ' Plate XLVII, Pig. 14 Description. — ^Well-characterized specimens of this species occur not rarely in the Ithaca fauna. A single individual is recorded from the Chemung. Length 25 mm.; width 30 mm. Occurrence. — Jennings Formation, Chemung Member. Oakland- Altamont Eoad. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1388; Little Orleans, 1446; Pifteenmile Creek, 1 mile above Little Orleans, 1446 ; Hancock, 672 ; Hancock-Harris- Eonville Eoad, 882; Berkeley Springs, West Virginia, 712, common; YeUow Springs, West Virginia. Collection. — Maryland Geological Survey. Steopheodonta maynardi n. sp. Plate XLVII, Pigs. 15-18 Description. — Shell large semielliptical, planoconvex, cardinal extremi- ties long mucronate, hinge-line much longer than width of shell. Ventral valve convex, point of greatest convexity near umbo; surface curving regularly toward front, concave toward cardinal angles. Dorsal valve nearly plane, bearing low radiating fold-like plications. Area narrow, hinge-line crenulated. Surface bears numerous striae, the direction of ' For synonymy and description see page 136. 552 Systematic Paleontology — Upper Devonian which differ on cardinal extremities of ventral valve from those on re- mainder of shell. Interior of ventral valve with diverging flabelliform scars for diductor muscles, the surface of which is plicate. Adductor muscular scars dis- tinct, divided by an impressed line. Interior of dorsal valve pustulose with well-marked scars for attachment of adductor muscles and a forked cardinal process which is seen in cast as two circular pits. Length 35 mm.; width 75 mm. Occva-rence. — Jennings Foemation, Chemung Member. Town Creek, 3398. Collection. — Maryland Geological Survey. Genus LEPTOSTROPHIA Hall and Clarke Leptostrophia peeplana vae. nervosa (Hall) Plate XLVIII, Figs. 1-4 Strophomena nervosa Hall, 1843, Geol. of N. Y., Rept. 4th Dist., p. 266, fig. 1. StropTieodonta perplana var. nervosa Hall, 1867, Pal. of N. Y., vol. iv, p. 13, pi. xix, figs. 13-16. Leptostrophia perplana var. nervosa Hall and Clarke, 1892, Pal. of N. Y. vol. viii, pt. i, p. 15, figs. 14, 15, 17. Deseription. — Shell very depressed, siTbplane, gently convexo-concave in the umbonal region. Surface covered with fine radial strise which are irregularly thickened and give the surface a rough and scraggy ap- pearance. These plications are normally of different orders of size, between each two of equal size there being 3-5 of lesser size, a mode of arrangement of surface markings which is a very ancient feature among these brachiopods. Individuals of this variety show a tendency to irregu- lar thickening of the plications at early growth stages, but in the occasional individual in which it is not well displayed at maturity there is a notable irregularity in the course of the striae. The hinge is denticulate and the deltidium very narrow, almost or wholly closed. On the interior the ventral valve presents very broad flabellate muscle scars surrounded by a papillose pallial surface. In the Maryland Geological Suevey 553 dorsal valve the cardinal process is strong and deeply bifurcate, sup- ported by thick divergent and papillose ridges which bound the obscurely defined muscle impressions. These shells attain considerable dimensions, are frequently extended on the hinge-line, and show no internal characters which are not normal to the species itself. The species Leptostrophia perplana is one of the flat stropheodontids that makes its appearance early in the Devonian, becoming quite abundant in the Hamilton stage and also occurring with normal characters in the Chemung of New York. Length 30-35 mm.; width 35-40 mm. Occurrence. — Jennings Formation, Chemung Member. National Eoad west of Tonoloway Eidge. This shell seems not to be widely dis- tributed but has been found abundantly in the vicinity of Oakland, Cherry Creek, near Mitchell House on Altamont Eoad and Deer Park, Garret County. Collection. — Maryland Geological Survey. Leptostrophia perplana var. alteenata n. var. Plate XL VIII, Figs. 5, 6 Description. — This variety resembles L. perplana var. nervosa in having nodose strise and in its muscular scars. It differs from that variety in having alternating coarse and fine strise and is frequently smaller than the usual size of var. nervosa. It resembles L. interstrialis in possessing alternating coarse and fine strise but differs in the more strongly nodose character of the strise. It seems to be a transitional form connecting these two species. Length 11 mm. ; width 16 mm. Occurrence. — Jennings Formation, Chemung Member. Section on National Eoad west of Frostburg; Trout Eun near Mountain Lake Park; Williams Eoad on Polish Mountain, 2042 abundant; Town Creek, 2122, 2391 abundant. Collection. — Maryland Geological Survey. 554 Systematic Paleontology — ^TJppee Devonian Leptostrophia inteesteialis (Vanuxem) Plate XLVIII, Fig. 7 Strophomena interstrialis Vanuxem (non Phillips), 1842, Geol. N. Y., Kept. 3d Dlst, p. 174, fig. 1. StropJieodonta mucronata Hall (non Conrad), 1867, Pal. N. Y., vol. iv, p. Ill, pi. XV, figs. 13, 14. Stropheodonta interstrialis Schuchert, 1897, Bull. U. S. Cteol. Survey, No. 87. p. 423. Description. — " Shell semiovalj the proportions of length and breadth varying considerably, the hinge-line often extended beyond the width of the shell. The ventral valve is very depressed-convex, and the dorsal valve nearly flat. The area of the ventral valve is extremely narrow, and the inner margin crenulated for about half its length. The surface is marked by distant sharp elevated striae, with the interspaces occupied by numerous finer undulating stria. The muscular impressions are faintly marked; those of the occlusor muscles occupy a minute space near the apex of the cast; and the divaricator muscular impressions are elongate and spreading, and partially limited by an oblique pustulose ridge on each side, in form and character like those in S. perplana, but less strongly defined. The cardinal process of the dorsal valve is slender, and supported at its base by an oblique ridge on each side, between which the muscular markings are faintly impressed." Hall, 1867. Length 15 mm. ; width 23 mm. The individuals observed are smaller than those figured by Hall, their coarser strise are also somewhat nodose while the finer strise are slightly undulating. They resemble L. perplana var. alternata from which they differ in smaller size and in having straighter and less nodose strise. They occur also at a lower horizon. The resemblance to L. perplana var. alter- nata is so close in some cases, however, that the separation of this variety from that species is not fully assured. Occv/rrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Hancock-Harrisonville Road, 880; Millstone, 795. Collection. — Maryland Geological Survey. Maryland Geological Survey 555 Genus DOUVILLINA CEhlert Douvillina oayuta (Hall) Plate XLVIII, Pigs. 8-17; Plate XLIX, Pigs. 1, 3 Strophodonta cayuta Hall, 1867, Paleontology of New York, vol. iv, p. 110, pi. xix, flgs. 1-5. Douvillina cayuta Hall and Clarke, 1892, iMd., vol. viii, pt. 1, pi. xv, figs. 18, 19. Description. — Shell gently convexo-concave in the umbonal region, abruptly deflected toward the front, usually somewhat extended on the hinge ; surface with quite regularly alternating surface strise ; the denticu- lated hinge-line is fully developed on both valves and the deltidium wholly obliterated in the mature condition. The internal casts of the ventral valve show the short but highly pronounced divaricator muscular scars elevated upon a shelly thickening turned up at its anterior edge. Some of these also show at the sides of this scar broad granulated or striated ovarian areas while the pallial area may carry impressions of brachial or irregular sinuses. The brachial valve carries a strong bifur- cate cardinal process and is at once to be recognized by the elevated di- vergent edges of the muscular fulcrum separating the anterior and posterior adductor scars and beneath projecting edges of which the former are sequestered. The species sometimes attains quite commanding proportions and may vary notably in the extension of the cardinal area. This peculiar shell is one of the most abundant of the Maryland Chemung fossils. At certain localities it occurs in masses and almost to the exclusion of other organisms. This abundance is in very marked con- trast to its occurrence in more northerly localities of the Appalachians, for in New York the shell is seldom abundant and above the lower beds of the series in the western central region it is comparatively rare. Some specimens from section on Oakland-Altamont Eoad difEer from the others in having strisB somewhat fasciculate and in possessing a slightly angular median fold. It is useful to separate from the species a small shell of persis- tent habit which differs from the somewhat variable specific form in features to be directly pointed out. While in New York shells referred 556 Systematic Paleontology — Uppeh Devonian to the species at present include forms of small size in the middle and upper horizons of the Chemung it is not certain that such small shells are of the same local type as these here termed var. gradliorw. Length 25 mm. ; width 45 mm. This species occurs profusely west of Wills Mountain, rarely east of that locality. Occurrence. — Jennings Formation, Chemung Member. National Road west of Prostburg; Oakland- Altamont Eoad; Oakland-Eedhouse Eoad; Trout Eun near Mountain Lake Park; Deer Park; Green Glade Eun; Bear Eun (Savage Eiver) ; Allegany Grove, 1750, 2000, 2020 abundant, 2050, 2076 abundant, 2111, 2307; Ellerslie, Pennsylvania, 13 16, 1174 common, 1508; National Eoad on Polish Mountain, 2706 ?; Town Creek, 3584, 3942. Collection. — Maryland Geological Survey. DOUVILLINA CAYUTA VAR. GRACILIORA n. Var. Plate XLIX, Pigs, 3-13 Description. — The prevalent size of this small variety is shown on several crowded slabs where all the individuals are of about the same pro- portions and maintain diminutive dimensions while presenting in their full development the characters of D. cayuta. These shells are more convex than the larger form, the pallial region descending abruptly from about the middle part of the ventral valve, while behind the ridge of this curvature the umbonal region is quite flat. The surface stri^ distinctly alternate in size, the cardinal area is fully denticulated and closed except for a very narrow deltidium. Sometimes the shell is extended on the hinge. The small New York expression of D. cayuta has the same characters as those here mentioned but has not been specially studied. It is seldom if ever as abundant as var. graciliora in Maryland. Length 9 mm.; width, 13 mm. Occurrence.— Jennings Formation, Chemung Member. Section on road from Oakland to Altamont; Eedhouse abundant; Deer Park; National Eoad west of Prostburg. Collection. — Maryland Geological Survey. Maryland Geological Survey 557 DOUVILLINA ARCUATA (Hall) Plate XLIX, Figs. 14-17 Strophodonta arcuata Hall, 1858, Geol. of Iowa, p. 492, pi. ill, figs. 1, 2. Description. — This little species, iirst described from the upper De- vonian beds of Lime Creek and Hackberry Grove, Iowa, was identified some years ago in the Chemung beds lying near the base of the formation, in Ontario .County, New York, where it is associated with a number of other western species.' Elsewhere in the Chemung of 'New York the species has not been recorded. Douvillina arcuata is of the same type of generic structure as its asso- ciate D. cayuta and the Hamilton species D. inequistriaia Conrad, char- acterized by its subcircular and elevated ventral muscular platform and the divergent fulcra between the anterior and posterior pairs of adductor scars in the dorsal valve. In contour the shell has a flattened umbonal area and a rather abrupt deflection and long slope to the anterior margin. Indeed in these respects the shell is rather more convex than specimens from the Iowa localities. The surface bears quite regularly fasciculated striae. The shell is always small and its dimensions are quite in con- sonance with those of the species as elsewhere found. Length 15 mm.; width 17 mm. OiCcwrrence. — Jennings Formation, Chemung Member. Garrett County, between Oakland and Deer Park and 3 miles south of Oakland and in Green Glade Run; near Eedhouse; National Eoad, 6% miles west of Frostburg. Collection. — Maryland Geological Survey. Genus STROPHONELLA Hall StROPHONELLA cf. EBVEESA (Hall) Plate XLIX, Fig. 18 Strophodonta reversa Hall, 1858, Geology of Iowa, vol. i, pt. ii, p. 494, pi. ill, fig. 4. Strophonella reversa Hall and Clarke, 1892, Paleontology of New York, vol. viil, pt. i, pi. xli, flgs. 16-20. ' Clarke, Bull. U. S. Geol. Survey, No. 16, 1885. 558 Systematic Paleontology — ^TJppbr Devonian Strophonella reversa Grabau and Shimer, 1909, N. Amer. Index Fos., vol. i, p. 222, flg. 270. Description. — Strophonella is a stropheodontid in which the relative convexity of the valves is normal in early growth but subsequently the ventral valve becomes concave and the dorsal convex. Strophonella reversa is distinguished by its considerable size, coarse radial plications in the umbonal region, almost or fully obliterated deltidium, denticulate hinge, strongly elevated ventral muscle scars, thickened and sinused pallial region. Whether or not the shell here under observation is a true Strophonella can not be fairly determined from the single interior of the dorsal valve in the collection. Nevertheless it is directly comparable with the species above cited as it shows a surface curvature normal to the younger conditions of that species where the primitive concavity of the dorsal surface is gradually changing to convexity about the margins. The in- ternal markings are those of the species and in addition thereto the shell bears the median often irregular depression of the surface which is always noteworthy in S. reversa. Length 17 mm. ; width 35 mm. The single specimen recorded is from the region a few miles south of Oakland. Strophonella reversa is common in the upper Devonian of Eockford, Iowa, of rare occurrence in the Chemung of New York. Occurrence. — Jennings Formation, Chemung Member. South of Oakland. Collection. — Maryland Geological Survey. Stuophonella sp. Description. — ^An individual of this genus, which is too poor for specific identification, has been observed at the locality given. Occwrre;w;e.— Jennings Formation, Chemung Member. National Eoad west of Prostburg. Collection. — Maryland Geological Survey. Maryland Geological Survey 559 Genus SCHUCHERTELLA Girty SOHUCHERTELLA CHEMDNOENSIS (Conrad) Plate XLIX, Figs. 19-32; Plate L, Pigs. 1-3 Streptorhynchus chemungensis Hall, 1867, Paleontology of New York, vol. iv, p. 67, pis. IT, ix, X. Orthothetes chemungensisi Hall and Clarke, 1892, Ibid., vol. vlli, pt. 1, pis. X, xi. Schuchertella cJiemungensis Grabau and Shimer, 1909, N. Amer. Index Fos., vol. i, p. 230, fig. 281. Description. — ^This is a shell attaining considerable size, often with the nmbonal region more or less distorted from irregular growth, due in part at least to early cementation to foreign objects by the beak of the ventral valve. The shell, however, may be entirely free from evidence of such distortion and in the regularity of its form indicate undisturbed growth. The beak of the ventral valve is generally elevated with a cor- respondingly high cardinal area on which the deltidium is prominent. The ventral valve slopes anteriorly with normally convex but sometimes irregularly concave surface. The dorsal valve is gently convex or flat, also frequently showing irregularities of growth. On the interior of this valve is an erect lamellar cardinal process divided medially, and the four adductor scars are situated about or pos.terioT to the middle of the shell. The exterior of the valves bears more or less regular and coarse subequal plications with occasional concentric interruptions to growth. Length 25 mm.; width 35 mm. Abundant at certain outcrops of the New York Chemung beds. Occurrence. — Jennings Formation, Chemung Member. National Koad, 6 miles west of Frostburg; Oakland-Eedhouse Koad; Oakland- Altamont Eoad; Trout Creek section, near Deer Park Station; Green Glade Eun; Cherry Creek; Allegany Grove, 1633, 1750, 2000, 2076, 2340 ; EUerslie, Pa., 1310 abundant, 1470 abundant, 1519 ; National Eoad, on Polish Mountain, 2706 abundant ; Town Creek, 3593, 3942, 3982, 4480, 4769; 2 miles west of Pawpaw, West Virginia, 3540 common, 4570 ?; Pifteenmile Creek, 1 mile above mouth, 3286. Parkhead Member. Allegany Grove, 860 ?. Collection. — Maryland Geological Survey. 560 Systematic Paleontology — Upper Devonian SCHUCHEETELLA ELLIPTICA n. sp. Plate h, Pig. 4 Description. — Shell large, subelliptical. Ventral valve low convex, greatest convexity slightly posterior to middle; cardinal angles rounded. Dorsal valve not observed. Hinge-line straight, area triangular. Surface with numerous rounded stria which are intersected by faint concentric striae. Interior of ventral valve has two deep, divergent, iiabelliform muscular sears and shows faint radiating strise which are especially well preserved toward margins. Length 30 mm. ; width 48 mm. This species differs from S. cherrmngensis in its rounded cardinal angles and unusually large flahelliform muscular scars. It is perhaps a very variant form of that species. Occurrence. — Jennings Poemation, Chemung Member. Town Creek, 4631. CoZZeciioM.— Maryland Geological Sur\'ey. SCHUCHERTELLA ? PONDEEOSA n. Sp. Plate L, Pig. 5 Description. — Shell large, semiovate, transverse, length about seven- eighths of width. Ventral valve convex, point of greatest convexity near umbo, anterior margin rounded, center depressed to form a broad, shal- low, scarcely defined sinus. Umbo elevated, projecting beyond hinge-line. Shell thick. Dorsal valve unknown. Area triangular, inclined towards front, about 7 mm. high. Surface not known. Cast of interior of ventral valve shows large flahelliform scars for attachment of the diduc- tor muscles, separated by small elliptical scars for attachment of adductor muscles. Diduetors limited by a low, broad elevation, seen as a semi- circular depression in cast. Surface of cast with irregular elevations due probably to imperfections in shell. The cast of the interior of a single ventral valve distorted by pressure has been observed. Its features indicate that it is probably a Schuchertella although its generic relations are insecure. Maryland Geological Survey 561 Length 37 mm.; width 55 mm. Occurrence. — Jennings Formation, Ciiemung Memjucr. Millstone, 2444. CoUeciion. — Maryland Geological Survey. Family PRODUCTIDAE Genus CHONETES Fischer, Chonetes lepidifokmis n. sp. Plate L, Figs. 6-10 Desciiption. — Chonetes lepidus Hall, a common species occurring in the Hamilton fauna of 'New York, and extending into tlie fauna of the Ithaca and Chemung beds, is a shell characterized by its small size and 2 strong divergent median plications, between which lie 3 or 4 small plications. On the lateral slopes are 10-13 sharp angular plications which bifurcate freely (see Paleontology of Xew York, vol. iv, p. 133, pi. xxi, Rg. 5, pi. xxii, figs. 12, 13) . This character of surface is presented by a Maryland shell which deviates from C. lepidnn in its larger size, pro- portions and the degree of its plication. At times approaching that species very closely, these shells show a variability in form and surface which requires for them a distinct designation though they show in their own structure their ancestry as is suggested in the specific name. Shells small or of medium size for this genus; generally subsemi- circular or slightly elongate axially, often however quite transverse. Sur- face depressed convex. Two strong strise or plications start at the beak, soon taking on the character of low folds dividing into plications but leaving a marked axial depression between them to the pallial margin. In some cases 3 plications of conspicuous size are continuous from beak to margin and in this respect the resemblance to C. lepidus is pro- nounced. The axial plications are somewhat smaller than tiie rest and each of the lateral slopes may bear 12-15 plications which bifurcate toward the margin. The cardinal margin of the ventral valve bears spines of considerable length the outermost being directed outward with a slight curve. The shells of this species attain a length of 10-12 mm. and usually have about the same width on the hinge. 36 562 SxsTEiiATic Paleoxtologt — Uppeu Devoxia>j- The species is not common and has been found freely only at one locality, on the National Eoad, just east of Millstone, where it occurs in a yellow argillaceous sandy shale. It is also reported from the soft olive shales of the lower beds of the series at the foot and on the slope of Polish Mountain, on the iSTational Eoad. Occurrence. — Jennings Formation, Parkhead ilEMBEE. l^ational Eoad, east of Millstone ; Polish Mountain, east of Gilpin. Collection. — Maryland Geological Survey. Chonetes oaklaxdensis n. sp. Plate L, Figs. 14-18 Description. — Shell transverse, semielliptical, hinge-line longer than width of shell, cardinal angles acute. Ventral valve convex, regularly rounded from umbo to anterior margin, greatest convexity near middle of valve ; concave toward cardinal angles. Umbo narrow, elevated. Area narrow, not distinctly shown in individuals observed. Dorsal valve con- cave, the concavity less than convexity of pedicle valve. Surface bearing 50 to 60 fine, rounded, straight striae which increase by intercalation and occasional bifurcation. Striai obsolete near cardinal angles. About 4 strijE occupy the space of 1 mm. near the anterior margin of shell. The stria are crossed by very fine concentric strise which are visible only in very perfectly preserved specimens. A few coarser concentric growth lines occur near anterior margin. The cardinal margin bears 3-4 short spines on each side of umbo which are directly obliquely outwards. Interior muscular markings not observed. Length 6 mm. ; width 9 mm. This species resembles C. scitulus in its outline. The striae, however, are quite different. In C. scitulus many of the intercalated strife are very short, being present only near the margin. In this species the striae are much finer while the intercalated striae are much longer. It closely approaches C. lineata of the Hamilton of New York, but differs in being less convex, valves not distinctly flattened in the middle, spines more numerous. It belongs, however, to the group of C. lineata and C. yandel- lana. Maryland Geological Survey 563 Occurrence. — Jenxixgs FociiATioN, Chemung Member. National Eoad, 6 miles west of Frostburg; Oakland- Altamont Eoad; Eedhouse Eoad, west of Green Glade Eun on road from Deer Park; Allegany Grove, 1750, 20TG abundant; Cherry Creek; Bear Pen Eim, near junction with Savage Eiver. Collection. — Maryland Geological Survey. Ci-ionetes scitulus Hall^ Plate L, Pigs. 11-13 Description. — This species is common in the Chemung, less frequent in the Parkhead. The Maryland individuals agree well with the typical forms from New York. Occurrence. — Jennings Formation, Ciiemuxg ilEMBER. Allegany Grove, 2076; Town Creek, 2023, 2228; Fifteenmile Creek, 1 mile above Little Orleans, 2215; Hancock, 2219, 2223; ilillstone, 2225, 2322 abun- dant. Parkhead Member. Eoeky Eun : Eoad 1 mile north of Eocky Eun, abundant; Williams Eoad, east of Cumberland, 1466 common; Williams Eoad on Polish Mountain 1289, 1371, 1422. Collection. — ^Maryland Geological Survey. Choxetes roavei n. sp. Plate L, Fig. 19 Description. — In association with C. lepidiformis at Millstone, occurs a specimen here figured, a very transverse ventral valve bearing about 40 subequal, rounded and very irregularly bifurcating plications, the surfaces of which are minutely but distinctly spinous. This last is a most notable feature for a shell of the genus Chonetes and has not been recorded before. This single specimen is defective along the beak and it cannot be clearly determined whether cardinal spines are or were present, but the expres- sion of the shell favors the view that these chonetid characters existed. We are not Justified in regarding these spinules related to or structur- ally connected with the papillose internal surface and exposed by exfolia- ' For synonymy and description see p. 150. 564 Systematic Paleontology— Upper Devonian lion. Tlie development of these characters is insufficient to bring the fchell into close association with the productoid genera, Productella and Productus. It is much to be regretted that other representatives of this interesting shell have not been observed. Length 6 mm.; width 10 mm. Occurrence. — Jexnixgs Formation, Parkhead Membkr. Millslojie. Collection. — Maryland Geological Survey. Genus PRODUCTELLA Hall Productella lachrymosa (Conrad) Plate L, Pigs. 20-22; Plate LI, Figs. 1-3 Strophomena lachrymosa Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 256, pL xi, fig. 9. Productella lachrymosa Hall, 1867, Paleontology of New York, vol. iv, p. 172, pi. XXV, figs. 23-28. Description. — Shells subhemispheric, subelliptical in marginal outline ; hinge-line equalling or shorter than the width of the valves. Ventral valve convex or ventrieose, often medially depressed. Surface closely spinous, the spine bases being elongate and arranged with some regularity in concentric rows, depressed lateral slopes with more erect spines. Dorsal valve concave. Sharp internal casts show admirably the narrow cardinal area in both central and dorsal valves, and the matrix of the specimens contains spines a half-inch in length. The interior of dorsal valve shows but faint trace of median septnm and the cardinal process is erect, thin and bifurcate at its crest. The expression of some of the shells which are medially depressed and somewhat extended transversely is that of the New York variety Jima Hall, but it is impracticable here to differentiate these from the associated shells. Length 22 mm.; width 27 mm. This species is subject to wide variation. It differs from P. speciosa in its large inflated nmbo and in possessing fewer spines, which are at- tached by elongated bases. This form is abundant in the Parkhead, and somewhat less abundant in the Chemung of Maryland. Occurrence. — Jennings Formation, CHBMUiVG Member. Oakland- Eedhouse Eoad; Trout Bun; National Eoad, on Polish Moimtain near Maryland Geological Survey 565 top of mountain, abundant; Williams Eoad, on Polish Mountain, 2043. Parkhead Member. Allegany Grove, 850 ? Williams Koad, on Polish Mountain, 1660 abundant; Town Creek, 1863; 2 miles west of Pawpaw, iro-i. Collection. — ^Maryland Geological Survey. Proddctella lachrymosa var. marylandica n. var. Plate LI, Pigs. 4-9 Description. — Quite as abundant locally as the preceding species is a mueli and persistently smaller shell, with more sparsely echinate surface. There is no material difference between these and P. lachrymosa in the proportions or internal structure of the valves, but the exterior distinction is marked, the surface being sometimes almost devoid of spines and apparently irregularly tubercled, but generally the elongate spine-bases are well apart over the pallial region ; on the cardinal slopes they become erect and are somewhat more abundant. This shell is readily dis- tinguished by these features and it is clearly allied to P. lachrymosa. Individuals occurring in the section on Williams Koad on Polish Mountain are larger than those figured and the umbo is more inflated, in which respect they approach the normal form more closely. Length 13 mm.; width 16 mm. Occurrence. — Jemxixgs Formation, Chemung Member. Williams Eoad, Polish Mountain, 1967, 2024 abundant; National Eoad, Polish Mountain, abundant in b^ocky arenaceous shales; along Sideling Hill Creek on Pennsylvania-Maryland state line, on top of hill. Collection. — Maryland Geological Survey. Productella lachrymosa var. Plate LI, Figs. 10-12 Description. — This variety differs from the typical form of P. lachry- mosa in its closer and more slender spines in which respect it approaches P. spcciosa. The umbo is larger, however, than in that species. It sug- gests P. Idrsula but does not show the concentric strise of that species. 566 Systeiiatic PALEOXTOLoey— rppER Devonian The specimens figured resemble the latter species in their irregular shape, though this is not a constant feature of this variety. Length 32 mm.; width 35 mm. Occwrence. — Jennings Formation, Chemung Member. Xational Eoad 7 miles west of Frostburg; Oakland- Altamont Eoad; Oakland- Eedhouse Eoad; Trout Eun; near Deer Park; Xational Eoad near top of Polish Mountain ; Ellerslie, Pennsylvania, ISli'i, 1474. CoUection. — Maryland Geological Survey. Productella speciosa Hall Plate LI, Figs. 13-15 Productus speciosus Hall, 1857, lOth Rept. N. Y. State Cab. Nat. Hist, p. 176 ProdiicteUa speciosa Hall, 1867. Pal. of N. Y., vol. iv, p. 175, pi. xxv, figs. 1-11. Productella speciosa Grabau and Shimer, 1909, N. Amer. Index Foss., vol. I, p. 242, fig. 294. Description. — Shell broadly ovate, subhemispheric ; hinge-line shorter than the greatest width of the shell. Ventral valve ventricose; dorsal valve concave. Surface of ventral valve with fine concentric strise and a few short wrinkles on the umbonal slopes. Both valves abundantly spinous, much more so than in P. laclirymosa. Length 30 mm.; width 37 mm. This species differs from P lachrymosa in its more closely set spinules and smaller umbo. In some of the Slaryland individuals the umbo is larger than in the specimens figured by Hall. It is, however, smaller and less inflated than in P. lachrymosa. This is one of the most abundant and characteristic species of the Ithaca fauna both of ]\Iaryland and of Xew York . Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1340, 1388 abun- dant; Little Orleans, 1446 abundant; Fifteenmile Creek, 1 mile above Little Orleans, 1446; Woodmont, 710, 776, 1030, 1033, 1067; Xational Eoad, west of Tonoloway Eidge, 980, 1039 abundant, 1038 abundant; Berkeley Springs, W. Va., 775, 1058, 1064, 1074, 1080, 1163, 1371; Xational Eoad, east of Hancock, 690, 994, 1149 1231; Hancock-Harrison- Maeyland Geological Survey 567 ville Eoacl 882, 94-±; Thompson To^vnship, Fulton County, Pennsylvania, 1300; Yellow Springs Eun, 1124, 1139, 1232 ; Millstone, 795, 1122, 1119. Collection. — Maryland Geological Survey. Peoductella hystbicula Hall Plate LI, Figs. 16-19 Productella hystricula Hall, 1867, Paleontology of New York, vol. iv, p. 178, pi. xxvl, figs. 1-8. Description. — Shell small, convexo-concave; hinge-line shorter than the width of the valves, surface puckered along the hinge toward the cardinal angles, wrinkles continued over the shell as fine concentric lines bearing numerous slender spines. Dorsal valve with pustulose concentric wrinkles. Length 9 mm.; width 12 mm. This is a very small species as preserved in the Maryland rocks and has not been found well enough retained to permit its illustration. It may, however, be recognized by its diminutive size and the abundance of hair- like spines on its surface. Occurrence. — Jennings Formation, CniaiuNG Member. On the road over Trout Eun, 2 miles south of Oakland. Collection. — ^Maryland Geological Survey. Peoductella navicellifoemis n. sp. Plate LI, Fig. 20 Description. — Shell small, subeircular, length and width subequal. Hinge-line straight, a little shorter than greatest width of shell. Ventral valve very gibbous, arcuate; umbo much incurved, projecting a little beyond hinge-line. Point of greatest convexity posterior to middle of shell, surface curving abruptly towards cardinal angles which are con- cave. Dorsal valve not observed. Surface ornamented by closely set spinules, the bases of which are linear and form slender interrupted eostse. This species closely resembles P. navicella of the Onondaga and Hamilton but differs in being less elono-ate and having a less prominent umbo. It resembles P. hystricula 568 Systematic Paleontology — Upper Devonian from which it differs in being less transverse, more gibbous with less conspicuous spinules, the bases of which form more distinctly elevated interrupted costse. It differs from the other species of the fauna in its smaller size. Length 10 mm. ; width 11 mm. Occurrence. — Jennings Foemation, Parkhead MEiiBER. Williams Eoad, east of Cumberland, 1466 common; roadside, 1 mile north of Eoeky Eun ? Collection. — Maryland Geological Survey. Genus PRODUCTUS Soweiby Subgenus MARGINIFERA Waagen Pkoductus (Maeginifera) hallanus Walcott Plate LI, Figs. 31-23 Productus dissimilis Hall, 1858, Geology of Iowa, vol. 1, pt. ii, p. 497, pi. iii, flg. 7. Productus (Productella) hallanus Walcott, 1885, Paleont. of the Eureka Dist, p. 130, pi. xili, fig. 17. Productus {Marginifera?) dissimilis Hall and Clarke, 1892, Paleont. of New York, vol. viii, pt. i, pi. xviia, figs. 11, 12. Description.. — Shell subcircular, strongly convex; surface of ventral valve bearing distinct radial striae interrupted by occasional growth lines, spines few, erect and irregularly scattered. Dorsal valve with no radial surface lines or spines but with sharply defined and regular concentric ridges. On the interior the umbo-lateral areas are ilat and denticulated along ridges diverging obliquely from the beaks. Length 13 mm.; width 14 mm. This shell, first described from the upper Devonian of Eockford, Iowa, has been more recently identified in Nevada (Walcott, loc. cit.) and in the lower beds of the Chemung in western New York.'' In the material described from Maryland the shell has seldom been observed, but its occurrence is undoubted as the characteristics of the species are sharply defined. The exterior of a dorsal valve figured bears the sharp con- ' Clarke, Bull., U. S. Geol. Survey, No. 16. Maryland Geological Survey 569 centric shell lamina and shows the flattened cardinal slopes, two features which serve to distinguish the species. The ventral valve bears the rounded radial striae, sparsely spinous. The reference of this species to the subgenus Marginifera was based upon the development of granulose divergent ridges on the interior of both valves making a sharp division between the cardinal shoulders and the general interior cavity of the shell; an inceptive condition in relation to the fully developed differentials of the Carboniferous and Permian Marginifera. Occurrence. — Jetstnings Formation, Chemung Member. Oakland- Altamont Eoad; Gordon's farm, 1 mile northeast ifountain Lake Park; road over Trout Eun, 2 miles south of Oakland. Collection. — ^Maryland Geological Survey. Family ORTHIDAE Genus DALMANELLA Hall and Clarke DaLMANELLA TIOGA (Hall) Plate LII, Figs. 1-4 Orthis interUneata Hall (non Sowerty), 1843, Geol. N. Y., Rept. 4th Dist., p. 267, figs. 3, 4. Orthis tioga Hall, 1867, Pal. of N. Y., vol. Iv, p. 59, pi. viii, figs. 20-29. Schizopfioria tioga Hall and Clarke, 1892, Pal. of N. Y., vol. viil, pt. 1, pp. 212, 226, pi. vi, figs. 17, 18. Dalmanella tioga Williams, 1908, Proc. U. S. Nat. Mus., vol. xxxiv, p. 55, pi. ill, figs. 1-7, 9, 10, 12. ScMeophoria tioga Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 268, fig. 321. Description. — " Shell transverse, broadly elliptical, about two-thirds as long as wide; length of hinge-line a little greater than half the width of the shell; the extremities rounded into a general curved outline. Dorsal valve convex, the greatest elevation near or above the middle on each side of a well-marked mesial sinus ; sometimes a little flattened at the sides, and regularly curving to the front. Ventral valve very gently convex, with sometimes a slight mesial elevation ; area of medium width, with the beak slightly incurved; foramen wide. 570 Systematic Paleontology — Uppee Devonian "Surface striated; strias angular, often fasciculate, curving upwards on the hinge-line. " . . . , the strise are angular, and every second one in the upper part of the shell, and everjr third or foiirth one in the lower part of the shell, are stronger and more jDrominent; concentric striae fine and closely arranged. In the casts, the character of the strias is tolerably well pre- served in the fasciculate arrangement, and in the curving upward at the sides and on the hinge-line; while on the margin, they are much more strongly impressed than on the middle of the cast. When the cast is preserved in fine shale or shaly sandstone, the surface is minutely punc- tate; and the shell when preserved has the same character. " The muscular impression in the dorsal valve is usually but faintly defined in the casts, which preserve the impression of a strong cardinal process bifid at the extremity. The socket plates are strong and widely diverging, and the area is extremely narrow. In the cast of the ventral valve the muscular impression is subpentagonal, deeply bilobed below ; the bases of the divisions rounded, and the sides slightly indented. The area is narrow, incurved in the middle, and extends about two-thirds the width of the shell." Hall, 1867. A number of individuals observed have greatest width posterior to middle of valve showing a modification towards the form D. carinata. Length 30 mm.; width 27 mm. Occurrence. — Jennings Formation, Chemung Member. Ellerslie, Pennsylvania, 1316 abundant, 1474 abundant, 1508; west of McCool about 1300 abundant. Collection. — Maryland Geological Survey. Dalmanella carinata (Hall) Plate LII, Pig. 5 Ortliis carinata Hall, 1843, Geol. N. Y. Kept. 4th Dist., p. 267, fig. 1. Orthis carinata Hall, 1867, Pal. of N. Y., vol. iv, p. 58, pi. viil, figs. 30-32. SChizophoria carinata Hall and Clarke, 1892, Pal. of N. Y., vol. vlii, pt. i, pp. 213, 226, pi. vi, fig. 22. Dalmanella carinata Williams, 1908, Proc. U. S. Nat. Mus., vol. xxxiv, p. 57, pi. iv, figs. 1, 2, 4, 6. Maryland Geological Survey 571 Description. — " Shell transverse, often much wider than long, sub- plano-convex ; hinge-line nearly or quite equal to three-fourths the great- est ^\•idth of the shell, and about equal to its length ; cardinal extremities rounded. The dorsal valve is very convex or gibbous, with a deep rounded sinus in the median line, abruptly curving towards the cardinal line and somewhat more gently to the front, depressed and scarcely flattened at the cardinal extremities. Ventral valve nearly flat, or rising from the base to the umbo with little convexity; median line carinate, with a strong and defined angular ridge, front abruptly sinuate; area compara- tively narrow, a little curved near the beak; foramen wide. " Surface marked by fine radiating strias, which increase by bifurca- tion and interstitial additions, and are strongly curved upwards to the hinge-line; testure punctate. The specimens are mainly casts, and the lines of growth are obscure. " The cast of the dorsal valve shows a wide subquadrate muscular im- pression, divided by a rounded median ridge, and transversely by a low ridge on either side, after the manner of 0. elegantula and others of that type. The socket plates are strong and very divergent, and the cardinal process is apparently triplicate; the area is narrow and flat. " The cast of the ventral valve is nearly flat on the sides, with a defined angular carina along the median line. The muscular impression is sub- quadrate, deeply bilobed below, and slightly lobed at the sides. The dental lamellae are strong and triangular. "■ In specimens which have suffered compression, the length is about three-fourths the width; but in some individuals the width is nearly double the length." Hall, 1867. This species is characterized by a deep sulcus on dorsal valve, very elevated angular fold on ventral valve, and greatest width posterior to middle of valve. A single valve has been observed. Length 18 mm.; width 38 mm. Occurrence. — Jennings FoRMA'noN, Chemung ]Member. JS^ear El- lerslie, Pennsylvania. Collection. — Maryland Geological Survey. 573 Systematic Paleontology — Uppee Devonian Dalscanella sp. Plate LII, Fig. 6 Description. — A small well-defined ventral valve shows the occasional presence of a species of Dalmanella not unlike D. leonensis Hall of the Xew York Chemung fauna but perhaps more closely comparable to D. infera Calvin from the Independence shales of Iowa. ISTothing is known of tlie species except the exterior of the ventral valve which is subcircular and transverse, gently ridged axially and with shai-ply defined bifur- cating striae. Length 7 mm.; width 9 mm. Occurrence. — Jennings Formation. Polish Mountain section east of Gilpin. Collection. — Maryland Geological Survey. Genus RHIPIDOMELLA CEliIert iiHIPIDOMELLA VANUXBMI (Hall)' Plate LII, Figs. 7-13 Occurrence. — Jennings Forjiation, Chemung Member. Two and three-quarters miles southwest of Eound, West Virginia, in upper Tro- pidoleptus zone. Parkhead Member. Williams Road, east of Cumber- land, 1391 ; 21/4 miles southwest of Cumberland ; Eoclcy Eun ; Williams Eoad on Polish Mountain, 1389, 1371, 1422. Collection. — Maryland Geological Survey. Genus SCHIZOPHORIA King ScHizoPHORiA STRiATULA (ScUotheim) Plate LII, Figs. 14-18 ; Plate LIU, Figs. 1, 10 Anemia Terebratulites striatulus Schlotheim, 1813. Min. Taschenbuch VIII, pi. i, fig. 6. Orthis impressa Hall, 1843, Geol. N. Y. Rept. 4th Dist., p. 267, fig. 2. Orthis impressa Hall, 1867, Pal. of N. Y., vol. iv, p. 60, pi. vlll, figs. 11-19. Schizophoria striatula Grabau and Shimer, 1909, N. Amer. Index Foss., vol. 1, p. 268, fig. 321. Schizophoria striatula Cleland, 1911, Bull, xxi, Geol. Surv. Wis., p. 93, pi. xix, figs. 1-6. " For synonymy and description see page 165. Maryland Geological Survey 573 Description. — Shell with convex dorsal and medially concave ventral valves. The latter has a straight hinge-line and narrow cardinal area, narrow acute beak, and broad plane to slightly convex lateral slopes, while the former or dorsal valve is rotund with umbo full and rounded, and with broad median elevation. In general outline the valves are trans- versely elliptical, much wider than long. Exterior covered with uni- formly fine strise crossed by occasional rings of growth. On the interior the ventral valve has a short obcordate muscular scar, while in the dorsal valve the scar is quadripartite, also short. Frequently vascular sinuses cover the pallial region. Schizophoria striatula is a member of a chain of closely allied shells occurring at various horizons in the Devonian, beginning with S. propin- qua Hall of the Onondaga limestone, followed by S. tulliensis Vanuxem of the Tully limestone; then by S. striatula Schloth. of the Ithaca and Chemung. In the upper Devonian of Iowa the same type is represented by S. iowensis Hall which approaches closely to 8. tulliensis. Schizophoria striatula is a large and robust species attaining uniformly greater size than any of the rest. Its surface markings are also coarser than in its allies; S. tulliensis and its western ally 8. iowensis are of smaller build with very gibbous dorsal valve, narrow median depression on ventral valve and more sharply sinuous anterior margin; 8. propin- qua, is a still smaller less convex and somewhat more graceful shell. The genus Schizophora differs from the genus Dalmanella which has fasciculate strise, carinate ventral valve and different muscular scars. It differs from Rliipidomella which has large flabelliform muscular scars in the ventral valve. It differs from both these genera in having convex dorsal valve and sinus in ventral valve. This is one of the most con- spicuous species of the Ithaca fauna, in which it often attains very large size. It occurs more rarely in the Parkhead and Chemung. The indi- viduals from higher horizons are frequently smaller than those occurring in the Ithaca fauna. Length large individual 30 mm. ; width 40 mm. Occurrence. — Jennings Formation, Chemung Member. Ellerslie, Pennsylvania, 1474 common; Williams Eoad on Polish Mountain, 19G7; 574 Systematic Paleontology — Uppee Dea-qxiax To\ra Creek, 3942 common. Paekhead Member. Eocky Eun ; AVilliams Eoad on Polish Mountain, 1660. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1340 abundant, 1388 abun- dant; Little Orleans, 1446; Woodmont, 1032, 1067 common; Hancock, 690 abundant; Hancock-Harrisonville Eoad, 726 abundant, 880, 944; Millstone, 1057; Berkeley Springs, West Virginia, 786 common, 1058, 1080, 1371 ; Yellow Springs, West Virginia, 734 abundant. Collection. — Maryland G-eological Survey. ScHizoPHOEiA striatula vak. maeylandica n. var. Plate LIII, Pigs. 2-9 Description. — This is a persistently small shell, none of the specimens we have observed attaining the dimensions even of S. propinqua. The largest of these are only about 20 mm. wide while the average specimen in places where they most abound is considerably smaller. Ventral valve convex in the umbonal region with erect but not conspicu- ous beak. A median sintis begins on the umbo, widens rapidly, on the margin covering fully one-half the width of the valve, and becomes deeply and distinctly impressed. Hinge-line shorter than one-half the width of the valve. The dorsal valve is full and gibbous at the umbo which projects beyond the short hinge-line with decided concave slopes to the lateral margins. Corresponding to the median depression of the opposite valve is a broad, low, very obscure convexity, over which the sparse con- centric growth lines when present make a retral curve, and which is flattened or even depressed and grooved on its summit. This median depression of the valve renders it often of an aspect so similar to that of the ventral valve that it is sometimes difficult to distinguish one from the other. The surface striae vary irregularly in size, are rounded and simple, increasing by intercalation. •This variety is very well defined and will be recognized by its uni- formly and contrasting small size, broad ventral sinus, obscure and depressed dorsal fold. It is distinguished from the various Devonian representatives of the genus already mentioned by a greater difference than is recognizable between any two of these, but as it occurs in the same Marylaxd Geological Sdevey 575 fauna with Schizophoria striatula it seems wiser at the present to dis- tinguish it by a varietal term only. Length 13 mm.; width 18 mm. At some localities a few shells have been seen which pass the limits of size of var. marylandica and lack the marked median depression in both its valves. These are probably young shells of S. striatula. Occurrence. — Jennings Formation, Chemung jMember. National Eoad west of Prostburg; Oakland- Altamont Eoad; Deer Park Station and between there and Oakland; south of Oakland at crossing of Cherry Creek; % mile west of junction of Oakland-Deer Park Eoad with Deer Park-Mountain Lake Park Eoad, abundant ; Allegany Grove, 2020, 2076 ; Town Creek, 4769. Collection. — Maryland Geological Survey. Order TELOTREMATA Superfamily RHYNCHONELLACEA Family .RHYNCHONELLIDAE Genus CAMAROTOECHIA Hall and Clarke Camaeotcechia congeegata vae. paekheadensis n. var. Plate LIII, Pigs. 11-16 Description. — Shell ovate, width usually a little greater than length, front rounded or slightly truncate; apex pointed. Ventral valve convex at sides, depressed in middle ; mesial sinus beginning near apex, becoming deep in front where in some cases it may form a lingua-form extension; beak closely incurved over that of dorsal valve in older shells, slightly curved in younger shells. Dorsal valve convex to gibbous, mesial fold beginning near apex and becoming prominent towards front. Surface marked by angular plications of which 3, less frequently 4 and occasion- ally 5, occupy sinus, and 4 to 6 occur on each side of fold. The individuals here described differ from the typical form in fre- quently having a deeper sinus bearing 3-5 plications, and in being less rotund and more transverse. They resemble C. contrata but differ in 576 Systematic Paleontology — Upper Devoniax being less transverse, sinus less sharply depressed, umbo of ventral valve less gibbous, plications less angular, 3-5 plications on sinus, septum and dental lamellffi more prominent. While referable to G. congregata they show clear affinities with C. contrada. These two species are so closely connected by transitional forms that it appears not improbable that C. congregata of the Hamilton may have given rise to C contrada of the upper part of the Chemung rendering the discrimination of the two species insecure at times. This is especially true of individuals occurring in the lower part of the Chemung, some of which might be referred with almost equal propriety to either species. Typical individuals of C. con- trada appear only in the upper part of the Chemung of Maryland so far as observed. This variety is one of the most characteristic and abundant forms of the Parkhead fauna, being found in certain layers in such profusion as to foiTH a veritable coquina, and is one of the most valuable horizon mark- ers of the Parkhead, with which it is coextensive. It occurs chiefly in the massive sandstones and conglomerates of that member. Occurrence. — Jennings Formation, Parkhead Member. Allegany Grove, 800, 850; Williams Eoad, on Polish Mountain, 1289, 1362, 1371, 1524, 1660 abundant; National Eoad, on Polish Mountain, 1196, 1625; section 2 miles north of mouth of Town Creek, 1282 abundant, 1312 abun- dant, 1642 common, 1687 abundant, 1716, 1723 abundant, 1917; Town Creek, 1605 abundant, 1679 abundant, 1863 abundant; 2 miles west of Pawpaw, West Virginia, 1493 abundant, 1584 abundant, 1712 abundant, 1894; Little Orleans, 730 abundant; Fifteenmile Creek, 1 mile above Little Orleans, 1713, 1746 abundant, 1766 abundant, 1773 abundant; Tonoloway, 1285 abundant; Hancock, 1600 abundant; Millstone, 1600 abundant; Berkeley Springs, West Virginia, 1560 abundant; Yellow Springs, West Virginia, 1600 abundant; 21/2 miles north of mouth of Sideling Hill Creek, abundant; Woodmont, 1285; National Road, west of Tonoloway Ridge, abundant. An unusually large form of this variety occurs in the Parkhead in the section on Williams Road, 4 miles east of Cumberland, 1393 ; road 1 mile north of Rocky Run and 13^ miles east of the crest of Knobly Mountains. A variety of this form with sinus Maryland Geological Survey 577 deeper than usual suggestive of C. conimda, occurs associated with the preceding. It differs from C. contrada in the frequent presence of 4 or 5 plications in sinus while length and width are subequal in many indi- viduals. Many specimens are quite convex. Collection. — ^Maryland Geological Survey. Camarotcechia coxtracta (Hall) Plate LIII, Pigs. 18-21 Atrypa contracta Hall, 1843, Geol. of N. Y.; Kept, on the 4th Dist., pi. Ixvi, fig. 3. Rhyncnonella (Stenocisma) contracta Hall, 1867, Pal. of N. Y., vol. iv, p. 351, pi. Iv, figs. 26-39. Camarotwchia contracta Hall and Clarke, 1894, Pal. of N. Y., vol vlil, pt. ii, pi. Ivii, figs. 28-32. CamarotoscMa contracta Grabau and Shinier, 1909, N. Amer. Index Foss., vol. i, p. 288, figs. Z52d-g. Description. — Camarotcechia contracta, is a transversely oval shell with fold and sinus clearly developed from the beak outward and becoming very conspicuous on the margin. The valves are relatively shallow and the plications coarse. Of the latter the fold and sinus bear three or four and each lateral slope 7-8. The boundary plications on fold and sinus have specially broad inner slopes. Concerning the limits of this species see remarks under C. congregata var. parleheadensis. Typical C. contracta is characterized by its transverse form, flat valves, deep sinus and angular plications, 3 of which occupy the sinus. It occurs chiefly in the upper strata of the Chemung. Length 15 mm.; width 18 mm. Occurrence. — Jennings Formation, Chemung Member. AMegany Grove, 29C0, 29S0; Xational Eoad, on Polish Mountain,- 3929; Millstone, 3116 (small var.) ; 5 miles west of Piney Grove in olive shales. Specimens from Millstone at 3116 are much smaller than the other forms termed C. contracta. They also differ from the typical form in that the sinus does not begin so near the umbo and is not so pronounced, the umbo of the ventral valves is unusually convex, the dental lamellse all longer. The 37 578 SYSTEiXATic Paleontology — Upper Devonian reference of the latter individuals to C. contrada is not assured as they approach some varieties of G. congregata var. parlcheadensis. Collection. — Maryland Geological Survey. Camaeotoichia horsfoedi (Hall) Plate LIII, Pigs. 22-25 Rhynclionella horsfordi Hall, 1860. 13th Kept. N. Y. State Cab. Nat. Hist., p. 87. Rhynchonella (StenocMsma) horsfordi Hall, 1867, Pal. of N. Y., vol. iv, p. 339, pi. llv, figs. 24-32. Cam.arot(schia horsfordi Hall and Clarke, 1893, Pal. of N. Y., vol. viii, pt. ii, p. 192, pi. Ivil, figs. 7-9. Camarotwchia horsfordi Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 287, figs. 354o, &. Description. — " Shell, in full-grown specimens, transversely subellipti- cal; rostral portion sometimes a little extended; front nearly straight or broadly rounded; length and width about as five to six or seven. Young shells ovoid subtrigonal. " Ventral valve moderately convex, flattened and incurved in front ; a slightly depressed sinus, appearing about the middle of the length, which is flat in the bottom and curving abruptly upwards in front ; beak moder- ately extended, abruptly acute and usually but little incurved. "Dorsal valve very gibbous in old shells, sloping abruptly to the beak; depressed-convex in young shells. Mesial elevation defined below the middle of the length. " Surface marked by about fifteen or sixteen to twenty-four well- defined angular plications, of which four to six or seven mark the medial sinus and fold, which are deeply bifurcated in front. On the sides and towards the cardino-lateral margins of the shell the plications are less angular; concentrically marked by fine undulating striae, which are seen towards the front, but rarely on other parts of the shell." Hall, 1867. Length 15 mm.; width 20 mm. Of rare occurrence in tlie Parkhead. Occurrence. — Jennings Formation, Paekhead ]MEiiBER. Two miles west of Pawpaw, West Virginia; Sideling Hill Creek 2i/^ miles above mouth. Collection. — Maryland Geological Survey. Maeylaxd Geological Survey 579 Cajiarotcechia ohbiculaeis (Hall) Plate LIU, Figs. '?G, 27 Rhynchonella oriicularis Hall, 1860, ISth Rept. N. Y. State Cab. Nat. Hist, p. 88. Rhynchonella (Stenochisma) orbicularis Hall, 1867, Pal. of N. Y., vol. iv, p. 353, pi. Iv, flgs. 40-46. CamarotoEchia orbicularis Hall and Clarke, 1893, Pal. of N. Y., voL viii, pt. ii, p. 192, pi. Ivii, figs. 46-48, 50. Description. — "Shell suborbicular, ventricose on the dorsal valve; width greater than the length. '■' Yentral valve moderately convex, scarcely gibbous on the umbo ; beak incurved; outline gently curving on the lateral and baso-lateral margins, and the center gently depressed in a broad and strongly defined median sinus. " Dorsal valve gibbous in the middle, arcuate from beak to base; sides abruptly curving to the ventral valve; median fold beginning above the middle of the length, and becoming more prominent towards the front. " Surface marked by about twenty-four or more subangular or rounded ribs, those of the central portion being strong and elevated, and those towards the cardinal slope gradually finer and less distinct. There are iouT or five plications in the mesial sinus, and from four to six on the mesial fold, which are moderately elevated and gently curving to the front. The plications on the sides are more or less abruptly curved to the margins of the shell. The shell when preserved, is marked by fine close concentric striae." Hall, 1867. Length rather small specimen 15 mm. ; width 18 mm. Occurrence. — Jennings Fokmation, Chemung Member. Trout Bun section near Mountain Lake Park; 2 miles west of Pawpaw, West Vir- ginia, 3312. Collection. — Maryland Geological Survey. Camaeotcechia eximia (Hall) Plate LIV, Pigs, l-i Atrypa eximia Hall, 1843, Geol. N. Y. 4th Dist, tab. 66, fig. 4. Rhynchonella (Stenochisma) eximia Hall, 1867, Pal. N. Y., vol. iv, p. 348, pi. Iv, flgs. 1-8. 580 Systematic Paleoxtologt— Upper De\-okian Cam.arotoechia eximia Hall and Clarke, 1893, Pal. of N. Y., vol. viil, pt. ii, p. 192, pi. Ivii, figs. 44-45. Desaription.—Shel] triangular-ovate, length and width subequal, valves subequally convex. Angle over umbo acute. "Ventral valve moder- a;tely convex at umbo; a wide undefined sinus arising near middle of valve and becoming slightly better defined near front. Dorsal valve about as convex as ventral valve ; a fold beginning near middle of valve which is sometimes distinct, but is usually illy defined. Surface bearing from 14 to 28 plications of which -i, 5 or at times 6 are in sinus and a corres- ponding number on fold. A mesial septum is present in the ventral valve, extending to near middle of valve. Length usually 7 to 13 mm. ; width about the same. The shells referred to C. eximia differ from the larger individuals figured by Hall in the Paleontology of New York, vol. iv, and resemble the younger specimens illustrated by him. They are characterized by possessing fine plications, finer than in the other species of the fauna, illy defined sinus and fold, and in being usually slightly convex. This species is frequent in the Parkhead and abundant in the upper part of the Chemung. Specimens occurring in the upper iron-rich strata are usually small and apparently depauperate. Occurrence.— J-Ei^smos Formation, Chemung Member. Allegany Grove, 2030, 2960; Town Creek, 3870, 3937, 3942 common, 3963 abund- dant, 3982, 4631, 4716; 2 miles west of Pawpaw, West Virginia, 3846, 4570, 4636, 4694 common. Parkhead Member. Two and one-fourth miles southeast of Cumberland, on road 1 mile north of Eocky Run and 1% miles east of Knobly Mountain; AVilliams Eoad, on Polish Mountain, 1289, 1352, 1371; 2 miles north of mouth of Town Creek, 1313 : Sidelino- Hill Creek 21/2 miles above mouth; Woodmont, 1285; Hancock, 1600; Millstone, 1600. Individuals with unusually deep sinus occur abundantly jji the Chemung at Town Creek 3963 and 3 miles west of Pawpaw, West Virginia, 3846. Collection. — Maryland Geological Survey. Maryland Geological Survey 581 Genus UORHYNCHUS Hall LlOKHYNOHUS MESACOSTALE Hall Plate LIV, Figs. 5-8 Atrypa mesacostalis Hall, 1843, Geol. of N. Y., Rept. on the 4th Dist., p. 64, figs, a, b. Leiorhynchus mesacostalis Hall, 1867, Pal. of N. Y., vol. iv, p. 362, pi. Ivii, figs. 18-25. Description. — Shell of rhynchonelloid aspect with but moderately con- vex valves and quite low median fold and sinus. -Fold and sinus bear three or four rounded plications which do not reach the beak, while on the lateral slopes of the valves plications are obscure or altogether obsolete leaving the surface smooth. With good preservation the exterior shows fine concentric lines crossed on the lateral slopes by radial striae. In the dorsal valve a low median septum reaches to about the middle of the shell and at the beak supports a small triangular spondylium. In the ventral valve the muscular scars are almost linear and situated posteriorly. This species is common in the Ithaca fauna and in the overlying Chemung beds of southern central New York. Length 18 mm.; width 20 mm. Occurrence. — Jennings Formation, Parkhead Member. Allegany Grove, 850 abundant; 314 niiles southeast of Cumberland, south of Poto- mac Eiver; Williajus Eoad, east of Cumberland, 1393 abundant. Collection. — Maryland Geological Survey. LlORHYNCHUS cf. MULTICOSTUM Hall Plate LIV, Fig. 9 Leiorhynchus multicosta Hall, 1860, 13th Ann. Rept. N. Y. State Cab. Nat. Hist., p. 85. Leiorhynchus multicosta Hall, 1867, Pal. of N. Y., vol. iv, p. 358, pi. Ivi, figs. 26-40. Description. — Shell ovate in outline; biconvex; ventral valve gibbous on the umbOj depressed medially to a broad sinus. Dorsal valve the more convex with a broad median fold. Surface marked by rounded or sub- angular plications of which usually 3 to 6 are in the sinus and on the fold and 5-8 on each lateral slope. Fine concentric lines cover these ribs. 582 Systematic Paleoxtologt — Upper Devonian On the interior the ventral valve shows a well-marked pedicle cavity and dental lamellee and in both valves the muscle scars are all obscure. Length 24 mm.; width 25 mm. The single large ventral valve here figured pertains to an individual which in its plicated sides and multiplicate sinus comes within the limits of the characters assigned to this species. This specimen alone is, how- ever, insufficient to finally determine this identity. Liorhynchus muUicostum is a common species in the Hamilton fauna of New York and passes into the Ithaca fauna above. There is no record of its higher range in that State. Occurrence. — Jenxixgs Formation, Parkhead ? Member. The single specimen is from blocky argillaceous layers on the west side of Green Eidge 5 miles west of Piney Grove, Garrett County. Collection. — Maryland Geological Survey. Liorhynchus globuliforme (Vanuxem) Plate LIV, Figs. 10-16 Atrypa gloiuHformis Vanuxem, 1842, Geology of N. Y., Rept. on the 3d Dlst, p. 182, fig. 2. Leiorhynchus glol)uliformis Hall, 1867, Pal. of N. Y., vol. iv, p. 364, pi. Ivii, figs. 26-29. Leiorhynchus globuliformis Hall and Clarke, 1894, Pal. of N. Y., vol. viii, pt. 11, pi. lix, figs. 23-27. JJescriptioii. — Shell suborbicular, rotund. Ventral valve convex over the umbo, depressed anteriorly ; dorsal valve ventricose. Median fold and sinus obscure. Three or four ribs are present on fold and sinus but the lateral slopes are smooth or but obscurely plicate. Usually in casts, of which dorsal valves are characterized by the elongate vaginate muscular scar divided by a narrow median septum. This shell abounds in and is highly characteristic of the Ithaca fauna of central New York. Length 15 to 20 mm.; width 20 mm. This species is distinguished by its convexity and by its muscular markings. It is one of the most abundant and characteristic species of the Ithaca fauna. Maryland Geological Survey 583 Occurrence. — Jennixgs Forjiation, Woodmont Member, Ithaca Fauxa. Two miles west of Pawpaw, West Virginia, 1340, 1388; Eoadside east of Little Orleans, 1446; Fifteenmile Creek, 1 mile above Little Orleans, 1446; Woochnont, 1024 abundant, 1032 common, 1067; National Eoad, west of Tonoloway Eidge, abundant; Hancock, 1274, 1149 to 1274 abundant; Millstone, 1057, 1122 abundant, 1148 abundant; Berkeley Springs, West Virginia, 712 common, 1058, 1080, 1163 com- mon; Yello-vy Springs Eoad, West Virginia, 639 abundant, 665 abundant. Collection. — Maryland Geological Survey. Genus PUGNAX Hall and Clarke PuGNAx PUGKUS VAR. ALIUS (Calvin) Plate LIV, Figs. 17-22 Rhynchonella alta^ Calvin, circa 1875, privately distributed paper with figures. Rhynchonella pugnus var. alta Williams, 1890, Bull. Geol. Soc. Amer., vol. i, pi. xli, figs. 5-7. Pugnax alius Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 203, pi. Ix, figs. 1-5. Description. — Shell triangular to elliptical or subcircular. Slightly transverse or length and breadth subequal. Ventral valve depressed into a sinus which begins near or slightly posterior to middle of shell and becomes deep towards front of shell, umbo erect or slightly incurved, extending much beyond that of dorsal valve. Dorsal valve much more convex than ventral, bearing a fold which becomes prominent towards front. Surface ornamented by coarse plications of which 2 usually occur in sinus, 3 on fold and about 4 on each lateral slope. The plications become obsolete towards umbo which is smooth. In some cases they are confined to marginal portion, on others they extend % length of shell. The variety alius was named by Calvin but does not appear to have been described by him. It differs from the typical form in being much less transverse. Length 18 mm.; width 20 mm. 1 Bull. Geol. Soc. Amer., vol. xxiii, 1912, p. 6. 584 Systematic Paleontology — Upper Devoxlvn This is one of the characteristic species of the Ithaca fauna of New York and Maryland. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1340, 1388 common ; Little Orleans, 1466; Fifteenmile Creek, 1 mile above Little Orleans, 1446; Woodmont, 730, 1024, 1033; National Eoad west of Tonoloway Eidge; Hancock 690, 994 ?; Hancock-Harrisonville Eoad, 735 common, 880, 944; Millstone 795; Berkeley Springs 1058, 1080, 1163 abundant; Yellow Springs, West Virginia. Collection. — Maryland Geological Survey. Superfamily TEREBRATULACEA Family TEREBRATULIDAE Genus CRYPTONELLA Hall CrYPTONELLA cf . EUDORA Hall Plate LIV, Fig. 33 Cryptonella eudora Hall, 1867, Pal. of N. Y., vol. iv, p. 398, pi. Ixi, figs. 34-41. Description. — Shell elongate or broadly oval, terebratulif orm ; bicon- vex; ventral valve produced at the umbo which is truncated by a round foramen beneath which lie, except in advanced growth, two deltidial plates. On the interior the dental plates are well developed. The dor- sal valve is subcireular and regularly convex. Surface of valves smooth or with only fine concentric striae. Length 30 mm. ; width 30 mm. Internal easts which seem to pertain to the species have been found in a few localities. The ventral valve shows the long dental plates, thickened pedicle-sheath and punctate shell characterizing these Devonian tere- bratuloids. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 4716 abundant, 4769; road up Polish Mountain from Tar Creek; Williams Eoad, Polish Mountain. Collection. — Maryland Geological Survey. Maryland Geological Survey 585 Family TEREBRATELLIDAE Subfamily TROPIDOLEPTINAE Genus TROPIDOLEPTUS Hall Tropidoleptus carinatus (Conrad) Plate LV, Figs. 1-5 Strophomena carinata Conrad, 1839, N. Y. Ann. Geol. Rep., p. 64. Tropidoleptus carinatus Hall, 1867, Pal. of N. Y., vol. iv, p. 407, pi. Ixii, figs. 2, 3. Tropidoleptus carinatus Hall and Clarke, 1894, Pal. of N. Y., vol. vili, pt. 11, pi. Ixxxii, figs. 26-36. Description. — Shell concavo-convex, semielliptical in outline, hinge- line straight often equalling the width of the valves. Ventral valve con- vex. Dorsal valve moderately concave, sometimes nearly flat. Cardinal area narrow on both valves. Cardinal process of the dorsal valve pro- jecting into the open delthyrium of the ventral. Surface with simple radial plications; strong and angular in youth, becoming rounded and at times duplicate with age. The median rib on the ventral valve is broader than the rest and produces a carination of the valve. On the interior the ventral valve has strong crenulated teeth which fit into similar sockets on the dorsal valve. In the latter the cardinal process is conspicuous and bilobed. The loop consists of two slender processes uniting in front with a median septum rising from the bottom of the valve. From these two brachial processes project at points near the origin of the brachidium. Shell substance highly punctate. The Maryland forms of this interesting braehiopod do not differ in any material respect from the usual forms occurring with profusion in the shales of the Hamilton group of New York, though none have been seen which attain the maximum dimensions of the latter. The shells bear 12-16 simple plications on either side of a large median plication on the ventral valve and median depression on the dorsal. Interiors show the strong crenulated teeth of the ventral valve and the similarly crenu- lated sockets of the opposite valve. Length 13 mm. ; width 15 mm. In the Ithaca beds of New York the species occurs with other con- tinuing members of the Hamilton fauna but it is with great rarity that 586 Systematic Paleontology — Uppee Devonian it has been recorded there after the introduction of Spirifer disjunctus and the proper Cliemung fauna. This species, which according to Williams is the most prominent member of the Hamilton fauna, occurs in the Jennings at two horizons, the Parkhead and the lower conglomerate zone of the Chemung. It is ver}' profuse locally in the Parkhead, associated with many other recur- rent Hamilton species. It is less profuse, though locally abundant, in the upper horizon, where it is also associated with recurrent Hamilton species. Occurrence. — Jennings Foemation, Chemung Member. Two and three-quarters miles southwest of Eound, West Virginia; Mann, Pennsyl- vania; vicinity of Pawpaw and Magnolia, AVest Virginia; northeast of Pratt; Town Creek, 2691. Paekhead Member. Eoeky Eun; roadside, 1 mile north of Eocky Eun; Williams Eoad, east of Cumberland, 1466 abundant; Williams Eoad, on Polish Mountain, 1389 abundant, 1353, 1371 common, 1422, 1632, 1660 abundant; N"ational Eoad, on Polish Mountain, 1196; 2 miles north of mouth of Town Creek, 1282, 1350, 1642, 1723 abundant, 1843 abundant, 1917 common; Town Creek, 1605, 1679, 1863 abundant; 2 miles west of Pawpaw, West Virginia, 1795 common; Little Orleans; Fifteenmile Creek, 1 mile north of Little Orleans, 1714 abundant, 1746 abundant, 1773; Sideling Hill Creek, 2% miles above mouth, abundant; Woodmont, 1385; Hancock, 1600; Millstone, 1772; Berkeley Springs, West Virginia, 1769 abundant. Collection. — -Maryland Geological Survey. Superfamily SPIRIFERACEA Family ATRYPIDAE Genus ATRYPA Dalman Atrypa reticularis (Linne)' Plate LV, Pigs. 6-11 Description.— Hhh well-known species, the most widely diffused and longest lived of all known organisms, is represented in the Maryland ^ For full illustration and synonymy of the Cliemung form of this species see Hall, Pal. of N. Y., 1867, vol. iv, p. 316, pi. liii, figs. 3-19, and Hall and Clarke, Idem., 1894, vol. viii, pt. ii, pi. Iv, figs. 1-17. Maryland Geological Sue\'ey 587 Chemung fauna by shells which attain considerable dimensions, with depressed or slightly convex ventral valves and highly convex, rotund dorsal valves and with the surface rather coarse ribbed and bearing strong distant concentric varices extended into free lamellas though these lamellEe are seldom shown. The expression of the species is the same as that under which it appears in the Ithaca and Chemung rocks of Xew York. On the interior the ventral valve bears large flabellate diductor scars surrounding an elongate cordiform median scar. This muscular surface is surrounded by a pustulose pallial area. The teeth are elongate, diver- gent and crenulate on their outer surface and on the dorsal valve the dental grooves of the hinge plate are similarly crenulated. The muscle scars in the dorsal valve are quadripartite and usually obscure. Length 25 mm.; width 33 mm. This species is locally abundant in the Ithaca, less frequent in the Parkhead and Chemung. Occurrence. — Jennings Foemation, Chemung Member. Kational Eoad west of Frostburg; Oakland- Altamont Eoad; Trout Eun section; Oakland-Eedhouse Eoad; near Ellerslie, Pennsylvania; Williams Eoad, on Polish Mountain, 2042 ; Town Creek, 3384, 3453. Parkhead Mem- bee. Williams Eoad, on Polish Mountain, 1660; 2 miles west of Paw- paw, 1794; 21/2 miles above mouth of Sideling Hill Creek. Woodmoxt Membee, Ithaca Fauna. Woodmont 500; Hancock 690 common; Hancoek-Harrisonville Eoad, 726, 880 abundant, 944 abundant, 9S8; Berkeley Springs, West Virginia, 712 abundant, 755, 786; Yellow Springs, West Virginia. Collection. — Maryland Geological Survey. Ateypa spinosa Hall Plate LV, Figs. 12, 13 Atrypa spinosa Hall, 1843, Geol. of N. Y. Rept. 4tli Dlst., p. 200, figs. 1, 2. Atrypa spinosa vel. aspira Hall, 1867, Pal. of N. Y., vol. iv, p. 322, pi. liiia, figs. 1-14, 18, 24, 25. Atrypa spinosa Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 311, figs. 391, 392. 588 Systematic Paleoxtology — Upper Devoxiajst Description.— " Shell robust, suborbicular or ovoid; width greater or less than the length; radiatingly eostate and concentrically lamellose or spinose; hinge-line often nearly straight, a little less than the width of the shell. " Ventral valve depressed-convex, becoming more convex in the upper part; nearly flat and often a little concave towards the lateral margins, and cardinal extremities depressed or broadly sinuate in front; beak abruptly rounded; apex truncate and perforate, closely appressed and overlapping the umbo of the opposite valve. "Dorsal valve convex, becoming gibbous in old shells, flattened or slightly concave towards the cardinal angles, regularly curving to the sides and basolateral margins, and a little elevated in front, but without any distinct mesial fold. " Surface marked by strong rounded radiating costse bifuracting at unequal intervals, which are much stronger in the middle of the valve, and become obsolete or appear as gentle undulations toward the cardinal angles. In the middle of the valves there are about seven or eight of these costse in the space of half an inch. The shell is also marked by strong concentric lamellse, which are often about a line apart. In perfect shells these lamellae, at the crossings of the costse, are often produced into tubular spines, which, when worn off, leave the ordinarily lamellose surface. The spaces between these projecting lamellae are marked by fine thread-like striae. " In the separated valves, the hinge-line is often nearly straight, the muscular area of the ventral valve is short and broad, the length from the apex being about equal to the width. There is a slight thickening of the shell at the base of the rostral cavity. The surface around the muscular area is papillose, and limited by a thickened border, except in front, where it is discontinued. Fine vascular markings are sometimes visible near the margin. In the dorsal valve there is a thickened septum in the upper part of the muscular area. "The spires of full-grown individuals show about fifteen turns in each." Hall, 1867. Length 22 mm. ; width 23 mm. Maryland Geological Suevey 589 This species differs from A . reticularis in its coarser, more nodose pli- cations. Occurrence. — Jennings Formation, Chemung Member. Oakland- Eedhouse Eoad; Trout Eun section; Williams Eoad, on Polish Mountain, 2483, 2708; K"ational Eoad, on Polish Mountain, 2706, 2949; Town Creek, 3384; Ellerslie, Pennsylvania, 1316,. 1474 abundant, 1519 abun- dant. ^VooDMONT Member, Ithaca Pauxa. Two miles west of Pawpaw, West Virginia, 1388. Collection. — Maryland Geological Survey. Ateypa hysteix Hall Plate LV, Pigs. 14-19 Atrypa hystrix Hall, 1843, Geol. of N. Y., Rept. 4th Dist., p. 27, fig. 2. Airypa hystrix Hall, 1867, Pal. of N. Y., vol. Iv, p. 326, pi. lilia, figs. 15-17. Atrypa hystrix Grabau and Shlmer, 1909, N. Amer. Index Foss., vol. 1, p. 311, fig. 392. Atrypa hystrix Cleland, 1911, Bull, xxi, Geol. Survey, Wis., p. 73, pi. xiii, figs. 14-16. Description. — Associated with the usual form of Atrypa reticularis already considered occur Atrypas of large size with broad and few plica- tions crossed by projecting concentric lamells. These lamellae present the aspect of a crenulated frill and where they cross the plications project out- ward as a free fold, or these expressions may be so infolded at the sides as to produce hollow spines. The spinous shell is the typical expression of the original A. hystrix of the Chemung and the A. spinosa of the Hamilton stage,' while to the spineless but scraggy shell of the New York Chemung with these few plications Hall originally applied the European (Schlo- theim's) term aspera, subsequently calling the Iowa shell, which is rela- tively plumper and more gibbous, A. aspera var. occidentalis. With a large number of representatives of all these expressions of surface it is diffi- cult to determine how the names are to be restricted, as the passage of the frilled lamellse into hollow spines can often be observed in the individual shell and yet in the main the expressions of the shells indicate their •The allied form from the middle Devonian of Iowa, A. hystrix var. occi- dentalis Hall, is described and figured in Geology of Iowa, 1858, vol. i, pt. ii, p. 515, pi. vi, flg. 3. 590 Systematic Paleontology — Upper Devonian geologic position. Following Schuchert in eschewing the term aspera as not applicable to our Devonian species the writer includes under one term the Chemung species which have been generally known as A. aspera and A. hystrix, the latter presenting the spinous senile or genetic condition of the former in the same maimer as the Hamilton species A. spinosa shows a like hut much more accelerated condition of a more finely ribbed Atrypa. In the broad sense, therefore, the term hystrix is applied to these large rough-shelled Atrypas of the Maryland Chemung. Shells with highly convex dorsal valves, very shallow ventral valves, bearing seldom more than 8-10 plications with sometimes only 3 or 5 obscure ones visible. Among the concentric frills on the surface of these shells occasionally a single fold forms a spine, or a given frill a row of such infolded tubular extensions, though none seem to have attained great length. The rela- tion of these shells to those of Atrypa reticularis is seen upon comparison of the early growth stages of the two. The sparsely ribbed infantile or nepionic condition of A. reticularis is continued throughout the life of A. hystrix, which in this respect is an instance of arrested development, while in company with this life-long, infantile condition is the attainment of great size, and the early manifestation of such senile traits as the ex- cessive exudation of test substance in the form of excrescences. With reference then to A. reticularis, A. hystrix is an overgrown and senile infant, the degenerate offshoot of an expiring race. Length 30 mm. ; width 35 mm. This species is restricted to higher horizons while A. spinosa is more usual at lower horizons. Occurrence.— J-Esm-fiCrS Formation, Chemung Member. Xational Eoad west of Frostburg; Oakland- Altamont Road; Oakland-Eedhouse Eoad; Trout Bun 2 miles south of Oakland; on the road from Oakland to Deer- Park; in the vicinity of Cherry Creek and of Deer Park Station; in the railroad cut at Altamont; Allegany Grove, 2215; Ellerslie, Penn- sylvania, 1316; Town Creek 4769; at many outcrops in the Polish Moun- tain sections along the National and the Williams roads; one-half mile east of Millstone Point; and just west of Tonoloway Hill. Collection. — Maryland Geological Survey. Maryland Geological Sdevey 591 Family SPIRI.FERIDAE Genus CYR.TINA Davidson Cyrtina hamiltonensis Hall Plate LVI, Figs. 1-3 Cyrtina hamiltonensis Hall, 1857, 10th Rept. N. Y. State Cab. Nat. Hist., p. 166. Cyrtina hamiltonensis Hall, 1867, Pal. of N. Y., vol. iv, p. 268, pi. xliv, tigs. 26-33, 38-52. Cyrtina hamiltonensis Hall and Clarke, 1894, Pal. of N. Y., vol. viii, pt. ii, pi. xxviii, figs. 23-33, 43, 45, 46, 53. Cyrtina hamiltonensis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 313, figs. 393. Cyrtina hamiltonensis Cleland, 1911, Bull, xxi, Geol. Survey Wis., p. -75, pi. XV, figs. 7-10. Description. — Shell small, trihedral with erect or incurved ventral beak, high vertical or incurved cardinal area and elongated deltidium. iledian sinus and fold strongly developed; lateral slopes with 6 to 8 rounded ribs crossed by fine concentric striae. On the interior of the ventral valve the dental plates along the bases of the deltidium are highly developed, converge toward each other and unite with the sides of a very strong median septum arising from the bottom of the valve. This species ivhich takes its name from its occurrence in the Hamilton fauna of New York, ranges upward in that State into the Ithaca fauna. Its variations in form in both of these Xew York faunas are found in the size of the shells, the curvature of the ventral valve and cardinal area and the angularity of fold and sinus. Some shells could probably be referred to the small erect shell of New York which Hall distinguished by the varietal term recta and which occurs in both Hamilton and Ithaca faunas. The Maryland shells are casts showing the long median septum of the ventral valve supporting a spondylium or spoon-shaped process formed by the convergence and union of the dental plates. The cardinal area is high and variously curved; the plications are from 4 to 7, those near the hinge being faint; the hinge-line is straight and sometimes slightly extended at the extremities. Length 15 mm.; Avidth 15 mm. 593 Systematic Paleontology— Upper Devonian This is a common species in the Ithaca fauna. It is less frequent in the Parkhead and rare in the Chemung. OccMUTen.ce.— Jennings Formation, Chemung Member. Between Oakland and Deer Park; Town Creek, 2033, 3228; Pennsylvania state line, west of Green Eidge, in upper Tropidoleptus zone. Parkhead Member. Allegany Grove 850; Eocky Eun; Williams Eoad, on Polish Mountain, 1660; 3 miles north of mouth of Town Creek, 1842; Sideling Hill Creek 21/2 miles above mouth. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1340 abundant, 1388 com- mon; east of Little Orleans, 1446; Fifteenmile Creek, 1 mile above Little Orleans, 1446 abundant; Woodmont, 1024, 1032 common, 1067; National Eoad west of Tonoloway Eidge; Hancock, 1149 to 1274 common; Mill- stone, 1122 common; Berkeley Springs, West Virginia, 1163 abundant; Yellow Springs, West Virginia, 639 abundant, 665. Collection.- — Maryland Geological Survey. Genus RETICULARIA McCoy Eeticularia l^vis (Hall) Plate LVI, Pigs. 4-6 Deltnyris Iwvis Hall, 1843, Geol. N. Y., Rept. 4th Dist., p. 245, fig. 1. Spirifer Imvis Hall, 1867, Pal. of N. Y., vol. iv, p. 239, pi. xxxix, flgs. 1-12. Reticularia Imvis Schuchert, 1897, Bull. U. S. Geol. Survey, No. 87, p. 343. Recticularia Iwvis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 339, fig. 432. Descripiion.1 — " Shell ventricose, subcireular or semielliptical, with the cardinal extremities rounded; length and breadth as two to three, or three to four; not plicate. "Ventral valve ventricose; the greatest convexity above the middle, from whence it curves gently to the base and suddenly towards the bealc, which is abruptly attenuate and arching over the area; sinus variable, often shallow, gently concave and scarcely defined; sometimes becoming deep, subangular, and very broad in the lower part. Area extending to the hinge-extremities, of moderate height at the sides and rising abruptly towards the middle ; foramen partially closed by an arching, ver\- convex pseudo-del tidium. Maryland Geological Survey 593 " Dorsal valve depressed or moderately convex, with a wide and usually undefined mesial fold which is much expanded below, leaving the anterior margin sinuate; sides of the shell somewhat regularly curving, and a little flattened at the cardinal extremities. "' Surface usually smooth, or marked only by concentric lines of growth. In older shells there are sometimes a few obscure and undefined radiating folds. " The interior of the ventral valve shows strong short teeth with the dental lamellse much thickened, filling up the rostral cavity and extending along the sides of the upper part of the muscular impression ; the muscu- lar space is of small or of moderate size, deeply marked, and often pre- serving a distinct median crest. " In the dorsal valve the muscular impression is small and narrow, and usually not deeply mai-ked. The cardinal process is strongly striated, and this character is distinctly preserved in the cast." Hall, 1867. Length 20 mm.; width 28 mm. The occurrence of this species in Maryland is of much interest since it is one of the. most important members of the Ithaca fauna of New York where it is restricted to two horizons, one near the base and a second near the top of the beds containing that fauna. Occurrence. — Jennings Foemat.iox, Woodmont Member, Ithaca Fauna. Hancock, &90 abundant, 935 ; Berkeley Springs, "West Virginia, ;13 abundant, 755. Collection. — ^Maryland Geological Survey. Genus SPIRIFER Sowerby Spirifer disjunctus Sowerby ' Plate LVI, Figs. 7-14; Plate LVII, Pig. 1 Spirifer disjunctus Sowerby, 1840, and Sp. verneuili M.urchlson, 1840, and of authors generally. Description. ^Among Devonian Spirifers no species is better known or so widely distributed as this. Throughout the worid wherever later « For extended synonymy and illustrations of American forms see Pal. of N. Y., 1867, vol. iv, p. 243, pis. xli, xlii; also Pal. of N. Y., 1894, vol. viii, pt. ii, pi. XXX, figs. 14-17. 38 594 Systematic Paleontology — Upper Devonian Devonian deposits ocour it has been regarded as indicating an upper Devonian horizon. Its range through this division of the Devonian, however, varies in different countries and sections. Where the life zones are best defined, as for example in New York where this later stage of Devonian (the horizon of Rhynchonella cuboides (Cuboides zone = Tully limestone)) is followed by that of Manticoceras intumescens (Intmnes- cens zone = ]Sraples beds) and this by the Chemung fauna with S. dis- junctus. Here its lower range is more restricted than in certain of the sections in Devon, Germany and Russia, in which the species appears with the initiatory upper Devonian fauna. In New York, on the other hand, the species rises into strata which show a marked change in the fauna and the ingress of later, that is post-Devonian types, and it is assumed that here at least the species continues beyond tlie migration or extinc- tion of its normal faunal associates, and becomes thus what has been termed a " superstitial " or surviving species. Spirifer disjunctus may be at once distinguished from other Devonian Spirifers of this age by the fine ribs on its fold and sinus. However it may vary in its form and proportions from a short, winged, plump shell to a narrow, slender form with greatly extended cardinal angles, this' feature abides as its distinguishing character. Its associate S. mesas- trialis has fine lines on fold and .sinus and 8. mesacostalis a single more or less defined median rib in the sinus. No other Devonian species approach it or are a source of confusion with it. It will be observed from the illustrations cited and here given how much the shell varies in its aspect, and some of the expressions are peculiar to the locality at which they are found, but there is not enough evidence to show that any is confined to a given horizon or dissociated at any spot with other expressions of the species. All attempts, therefore, that have been made to ascribe a zonal value to these various expressions of the species have been attended with little success, and the various designations at one time applied by Hall to such expressions have been for the most part withdrawn from usage at the instance of that author himself. The species is of relatively rare occurrence in the lower beds of the Chemung of New York, and in the New York succession culminates after Maeyland Geological Survey 595 the culmination of Spirifcr mesastrialis and 8. mesacostdis. Douvillina cayuta, also a species which in 'New York is most a,bundant in the earlier Chemung sediments and, as has been observed, attains remarkable pro- fusion and variety in the Maryland strata, is only an occasional associate of the species in New York. Generally speaking, shells of the form represented in fig. 8 are of the most common expression in Marj^land and New York, short wings with margins broadly rounded to the median sinus. The extension of cardinal angles shown in figs. 10 and 11, is also of frequent occurrence; fig. 1, pi. Ivii, represents an extreme condition. A noteworthy expression is shown by the shells found in green shale on Polish Mountain where some are short hinged and some long hinged (fig. 10) but all have the margins of the median sinus not. rounded but quite strongly elevated, a feature persistent irrespective of variation in form. This expression is also seen in some specimens from other localities. The careful study of the variations of this plastic species may eventu- ally disclose the significance of these expressions, whether of geographical or zonal value. The usefulness of such an undertaking will be further shown in determining how far the later expressions of the species pass into those species of recognized carboniferous shells bearing similar features, of which ;S^. newberryi, imbrex and marionensis may be cited among the American forms. TJntil this latter task is done it remains unsafe to carry the Devonian line upward to whatever extent the species may seem to run. Length 20 mm. ; width 40 mm. This species is characteristic of and coextensive with the Chemung of Maryland. It is found at nearly all exposures of that member. Some of the observed horizons are recorded in the following paragraph. Occurrence. — Jennings Formation, Chemung Member. Allegany Grove, 1363, 2335, 2340, 2355, 2380 abundant, 2800, 2960 abundant, 2980 abundant, 3000 abundant; EUerslie, Pennsylvania, 1316 abundant, 1474 abundant; Williams Eoad, Polish Mountain, 1967, 2382, 2708, 2725; National Eoad, on Polish Mountain, 2016, 2185, 2949; 2 miles north of mouth of Town Creek, 1949 ; Town Creek, 2122 abundant, 2228 abundant, 249G abundant, 3982 abundant, 4480 abundant, 4562, 596 Systematic Paleontology — Upper Devonian 4596, 4631, 4716 abundant, 4769 abundant; 2 miles west of Pawpaw, West Virginia, 3124 abundant, 2190, 4564 abundant, 4694; Fifteenmile Creek, 1 mile above Little Orleans, 2216, 2286 ; National Road, on Green Eidge, 1850 ; Woodmont, 1667; Hancock, 2275; Millstone 2390 abundant, 2440, 2919; National Eoad, 5-7 miles west of Prostburg; Oakland- Altamont Eoad; Green Glade Eun; various places near Oakland and Deer Park; vicinity of Trout Eun; near top of Chemung east of Barrel- ville; Wills Creek Station, Pennsylvania. Collection. — ^Maryland Geological S^irvey. Spieifer mesasteialis Hall Plate LVII, Figs. 2-5 Spirifer mesastrialis Hall, 1867, Pal. of N. Y., vol. iv, p. 242, pi. xl. Spirifer mesastrialis Hall and Clarke, 1894, lUA., vol. vili, pt. ii, pi. xxxvii, figs. 4, 5. Spirifer mesastrialis Grabau and Shlmer, 1909, N. Amer. Index Foss., vol. i, p. 332, fig. 423. Description. — This Spirifer is characterized by the fine radial lines which cover fold and sinus and also traverse the numerous flattened lateral plications and furrows of the valves. At times these lineations become interrupted, specially near the margins of the median part of the shell and appear as radial series of elongate pustules. The form of the valves is quite variable, sometimes short on the hinge, plump and round, again with elongated cardinal extremities ; the size of the shell prevailing at a given locality may be large, medium or small, but for all these varia- tions the laws governing their manifestations have not yet been as- certained. Among them all it is usual to find the plications, 10 to 15 in number, moderately broad and flattened, with narrow furrows and fold and sinus low and near the anterior margin very broad. Concentric markings or growth lines are usually absent. Length 25 mm.; width 45 mm. The figures we have given show the characteristic expression of this shell in Maryland. In New York the species is a survivor from the fauna of the Ithaca where it is introduced into that fauna soon after its return to the field it held before the dose of Hamilton time. In the middle Maeyland Geological Survey 597 and upper beds of the Ithaca formation it attains its greatest abundance but continues its existence through the earliest manifestations of the Ohemung fauna. In Maryland this species is very raxe in the Ithaca and Parkheadj but abundant in the Chemung, ranging from the base of the latter member to the upper conglomerate. Occurrence. — Jennings Formation, Chemung Member. National Eoad, west of Frostburg ; section on Trout Kun ; Bear Pen Eun ; Ellers- lie, Pennsylvania, 1508 ; Little Run, % mile west of Wills Creek Station, Pennsylvania; National Eoad, on Polish Mountain, 3706, 2929, 3036; Town Creek, 2122, 2228 common, 2450, 2913, 3404, 3453 common, 3584 ?, 3593, 3963 small; 2 miles west of Pawpaw, West Virginia, 2190 ?, 3540; top of Green Eidge; Pifteenmile Creek, 1 mile above Little Orleans, 2286 abundant; east of Baird on B. & 0. E. E., Bellegrove, 300 feet west of Schoolhouse, abundant; Sideling Hill Creek; National Eoad, west of Tonoloway Eidge; Hancock, 2223, 3406 abundant; Millstone, 2345, 2390, 2444 abundant, 2470, 2749 abundant, 2761, 2796; Berkeley Springs, West Virginia, 2158 abundant. Parkhead Member. Two miles north of mouth of Town Creek, 1723; 2 miles west of Pawpaw, West Virginia; Millstone, 1672, 1694, 1811 abundant, 1916; Berkeley Springs, West Virginia, 1554 to 1566. Woodmont Member, Ithaca Fauna. Hancock, 1149 to 1274; Tellow Springs, West Virginia, 734. Collection. — ^Maryland Geological Survey. Spirieer maecyi vae. supeestes n. var. Plate LVII, Figs. 6-11 Description. — Spirifer marcyi is a species which occurs with some frequency in the soft calcareous shales of the Hamilton group at certain localities in western New York and was described and fully illustrated by Prof. Hall in vol. iv. Paleontology of New York, p. 226, pi. xxxvii, figs. 10-20. The species is characteriized by its broad, many-ribbed lateral slopes, each full-grown shell bearing about 30 flattened plications on each of these slopes ; low, smooth fold and sinus, and having the surface of pli- 598 Systematic PALEONTOLOGr — Uppek Devonian cations, fold and sinus covered with elongated pustules or spine bases and the plication generally marked by a fine median line. Allied to Spirifer marcyi but distinguished therefrom in its high erect cardinal area, shorter hinge and fewer plications is the species Spirifer asper Hall, originally described from a middle Devonian horizon in Iowa (Eockford and other localities) but also known to occur in the Hamilton fauna of New York. To both of these shells some of the specimens from the Maryland Chemung are closely related. They show the long lateral slopes of S. marcyi and the largest of them indicating full growth bear 30 plications, which are fine, simple and not crossed by concentric growth lines. The surface is distinctly granulose, or sometimes pitted over the fold and sinus and along the plications. The latter are narrower than in S. marcyi and have more nearly the width of the separating furrows. In specimens from the Chemung the cardinal area is high and erect, in which respect the shell is more like Spirifer asper. In individuals from the Parkhead the area is not so high and the expansion of the shell is more normal. The length of the larger shells along the hinge is 50-60 mm. The unusual occurrence of a Spirifer of this type in the upper Devonian of the interior province, a fact not hitherto noted in this region, is worthy of special record as another instance of the survival of Hamil- ton specific types into later faunas which is so emphatically illustrated by the fauna of the Ithaca beds. We have, therefore, designated the shell by the mutational term superstes. This recurrent Hamilton species is abundant in the more westerly exposures of the Parkhead and in the upper Tropidoleptus zone of tlie Chemung. The variety superstes is best characterized in the higher zone. Occiuirence. — Jennings Pokmation, Chemung Member. Upper Tropidolepius zone, 2% miles south of Round, West Virginia; National Road, Polish Mountain above 6th turn; Town Creek, 3691 common; National Road, on Green Ridge, 3690 abundant. Parkhead Member. Williams Road, east of Cumberland, 1466 abundant; Rocky Run abun- dant; road 1 mile north of Rocky Run; Williams Road, on Polish Moun- tain, 1660 abundant; National Road, 1196, 1635; 3 miles north of mouth Maryland Geological Sdkvey 599 of Town Creek, 1723 ; Town Creek, 1863 ; 2 miles west of Pawpaw, West Virginia, 1794 abundant; 21/2 miles north of mouth of Sideling Hill Creek common. Collection. — Maryland Geological Survey. Spirifer mucronatus var. posteeus Hall and Clarke Plate LVIII, Pigs. 1-10 Delthyris mucronata Hall, 1843, (In part), Geol. N. Y., Rept. 4th Dlst., p. 270, flg. 3. Spirifer mucronatus var. posterus Hall and Clarke, 1893, Pal. of N. Y., vol. viii, pt. ii, p. 361, pi. xxxiv, flgs. 27-31. Description. — Shell semicircular to triangular; cardinal angles mu- cronate, extremities often greatly extended ; hinge-line attaining a length of two, three or more times that of shell ; sides straight or curving, usually oblique, or occasionally nearly at right angles to hinge-line. Hinge-line straight. Area narrow triangular. Ventral valve often but little more convex than dorsal, in other speci- mens more gibbous. Umbo small, incurved over area. Mesial sinus broad in front, extending to apex, limited by two plications which may be more prominent than others. Sinus deep, often quite wide in front, in some specimens simple, in others bearing a low plication in center, the position of which is indicated in a few individuals simply by a retral curvature of the laminae. Dorsal valve usually moderately convex; fold prominent, often wide in front, bearing, in most individuals, a median groove. Surface ornamented by about 10 to 15 rather coarse angular plications which are obsolete on the mucronate extensions; plications crossed by numerous imbricating lamella which are often crowded in front. Young specimens, when very well preserved, are seen to be ornamented by fine, interrupted, radiating striae. These striae are but faintly visible in adult specimens and are seen only in unusually well-preserved individuals. Interior of ventral valve bears short teeth, scarcely noticeable in cast, and a striated muscular area in the center of which are small elongate sears for the attachment of the adductor muscles. Median septum absent or represented by a very faint line. 600 Systematic Paleontology — Upper Devonian Length 15-30 mm. ; width 35-60 mm. The presence of fine interrupted radiating strife has not been noted in the published descriptions of this form but H. S. Williams informs the writer that they are observed in well-preserved species of S. mucrona- Uis, S. mucronatus var. posterus, and S. {DeUhijris) mesacostalis in New York. This variety is subject to considerable variation in size and form. The specimens observed in the lower beds containing the Ithaca fauna in Maryland are small and, so far as seen, without a median plication in the sinus, agreeing closely with those found in the Ithaca fauna of central New York. In the lAorhynchus globuUforme zone the specimens attain a much larger size than is usual in individuals in central New York, while some possess a plication in the bottom of the sinus, a feature not seen in the New York forms. The latter feature is, however, not constant. Some specimens have the lateral margins nearly at right angles to the hinge- line being then identical with a form described as S. dactylus by H. S. Williams from the Liorhynchus glohuUforme zone of eastern New York. These modifications are so closely connected by transitional forms in Maryland that it has not seemed possible to discriminate them by varietal names. All are clearly mutations of 8. mucronatus of the Hamilton. This variety may closely approach 8. mucronatus in its general pro- portions. Usually, however, the specimens are somewhat smaller and pos- sess more extended cardinal angles upon which the plications are obsolete. The variety also closely approaches 8. (Delthyris) mesacostalis in its external features, but differs in the absence of a median septum in the interior of the ventral valve. A few individuals have been observed pos- sessing a very rudimentary septum suggesting a transition to the latter species. This is one of the most abundant and characteristic species of the Ithaca fauna of Maryland and adjacent areas. In several localities it may recur in the Tropidpleptus fauna of higher horizons though it is very rare and the stratigraphic relations are obscure or identification is insecure in these rases. When assuredly identified it is confined to the Ithaca fauna. Maryland Geological Suevet 601 Occurrence. — Jennings Formation, Chemung Member. Near Penn- sylvania-Maryland line west of Green Eidge in upper Tropidoleptas hori- zon ?. Paekhk^d Member. Two miles north of mouth of Town Greek, 1842 ?, 1949 ?; 2 miles west of Pawpaw, 1612 ?. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, 1340 abundant; Little Orleans, 1446; Pifteenmile Creek, 1 mile above Little Orleans, 1446; ■\Voodmont, 710, 776, 1024, 1032 abimdant, 1067, 1285; National Eoad west of Tonoloway Eidge; Hancock 690, 935, 994?, 1149 abundant, 1274 abundant, 1149 to 1274 abundant; Hancock-Harrisonville Eoad, 726, 880 abundant, 944; Millstone 1057, 1122, 1141, 1148; Berkeley Springs, West Virginia, 712, 755, 1010, 1058, 1074, 1080 abundant, 1163, 1371 abundant; Yellow Springs, West Virginia, 629, 665, 734 abundant. Collection. — Maryland Geological Survey. Spieifee (Delthteis) mesacostalis Hall Plate LVIII, Figs. 11-23; Plate LIX, Figs. 1, 2 Spirifer mesacostalis Hall, 1867, Paleontology of New York, vol. iv, p. 240, pi. xl, figs. 1-13. Spirifer mesacostalis Grabau and Shimer, 1909, N. Amer. Index Fobs., vol. i, p. 332, fig. 424a. Description.' — This species resembles S. mucronatus externally but dif- fers in possessing a distinct median septum in the ventral valve. While the cardinal angles are ordinarily simply acute in some cases the extremi- ties are greatly extended, increasing the resemblance of the species to 8. mucronatus. The presence of a median septum in the interior, how- ever, affords a distinct criterion for the separation of the two forms. This species is exceedingly abundant in the Parkhead and continues common to the upper conglomerate of the Chemung, above which it is less frequent. Length 15-20 mm.; width 30-40 mm. Occwrence. — Jennings Foematiox, Chemung Mbmbee. National Eoad west of Frostburg; Oakland- Altamont Eoad; Oakland-Eedhouse Eoad; Trout Eun section; Allegany Grove, 1153 ?, 1250 abundant ?, 1310 abundant, 1520, 2020, 2111, 2340; Ellerslie, Pennsylvania, 1316 abundant, 1474; Williams Eoad, on Polish Mountain, 2382 abundant, C02 Systematic Paleontology — Upper Devoniax 1708 abundant, 1725, 3009; National Eoad, on Polish Mountain, 2016, 2159, 2706 common, 2939 abundant, 2949; Town Creek, 3384, 3404, 3453,, 3584, 2 miles west of Pawpaw, A¥est Virginia, 2190 ; National Eoad, on Green Ridge, 3400; Millstone, 2253 ?, 2322. Paekhead Member. Eocky Eun; Turners Eoad, 7 miles southeast of Cumber- land; Williams Eoad, east of Cumberland, 1393 ?; Williams Eoad, on Polish Mountain, 1289, 1524, 1632, 1660 common; National Eoad, on Polish Mountain, 1196, 1625; 2 miles north of mouth of Town Creek, 1723 common, 1917 common, 1949; Town Creek, 1729, 1863 abundant; 2 miles west of Pawpaw, West Virginia, 1612, 1794 com- mon; east of Little Orleans; Pifteenmile Creek, 1 mile north of Little Orleans, 1713, 1746, 1766 common, 1774; Sideling Hill Creek 2% miles above mouth, abundant; National Eoad west of Tonoloway Eidge; Hancock, 1600; Millstone, 1600; Berkeley Springs, West Vir- ginia, 1769; Yellow Springs, West Virginia, 1600. Collection. — ^Maryland Geological Survey. Genus AMBOCOELIA Hall Amboccelia umbonata (Conrad) Plate LIX, Pigs. 3-7 Orthis umbonata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viil, p. 264, pi. xiv, fig. 21. Anvbocaslia umhonata Hall, 1867, Pal. of N. Y., vol. iv, p. 259, pi. xliv, figs. 7-18. Ambocoslia umionata Hall and Clarke, 1894, Pal. of N. Y., vol. viii, pt. ii, pi. xxlx, fig. 17; pi. xxxlx, figs. 4-9. Amiocwlia umbonata Grabau and Shinier, 1909, N. Amer. Index Foss., vol. i, p. 343, fig. 438. Description. — Shell small, convexo-plane, suborbicular in outline. Ven- tral valve gibbous with umbo elevated and incurved. Median sinus distinct. Cardinal area arched. Dorsal valve depressed convex or flat. Surface of both valves smooth or marked only with fine concentric striae. On the interior, the ventral valve has strong teeth, the dorsal valve has strong crural plates and a quadripartite muscular scar situated in front of the middle. Length 6 mm. ; width 6 mm. Maryland Geological Survey 603 This little shell is very widely diffused through the Maryland Chemung strata; frequently heaped together in masses which constitute thin seams through the sandy matrix. So far as can be ascertained the species shows no deviation from its usual expression and there is no evidence to indi- cate the propriety of applying to this shell the varietal name gregaria used by Hall for the Chemung form. The curved, arched ventral valves show a sharply defined median groove and the rotund lateral slopes bear only traces of concentric striae. The dorsal valves are gently convex about the umbo, and flattened or depressed toward the margins. The interior characters are often well preserved on the casts showing the peculiar muscular scars of the dorsal valve and the deep pedicle impres- sion of the ventral valve. It has been diflScult, on account of this mode of preservation, to obtain well-defined impressions of the exterior of the shells. This species is very abundant in the Chemung but rarely occurs below that horizon. The first incoming of the Chemung fauna is usually indi- cated by a profuse development of this form in beds which lie a short distance below the lowest beds containing S'pirifer d&sjunctus, while it continues to be abundant in the higher horizons. The lowest beds con- taining Amboccelia umbonata are here considered to be a part of the Chemung. Occurrence. — Jennings Formation, Chemung Member. Oakland- Altamont Eoad; Deer Park; Mountain Lake Park; Oakland-Eedhouse Eoad; Trout Eun section; Allegany Grove 1153 ?, 1250 abundant, 1310 abundant, 2076 abundant; Ellerslie, Pennsylvania, 1474 abundant; 2% miles south of Eound, upper Tropidoleptus zone, abundant; Williams Eoad, on Polish Mountain, 1837; National Eoad, on Polish Mountain, 1957 2503 ; near Pennsylvania-Maryland state line west of Green Eidge in upper TropiMepius zone ? abundant; Town Creek, 2023 abundant, 2122, 2691 abundant, 2750, 3384, 3453 ; Pifteenmile Creek, 1 mile above Little Orleans, 2215; National Eoad, on Green Eidge, 3400 abundant; Woodmont, 1667; Hancock, 2223 abundant; Millstone, 2225, 2322 com- mon. WooDMONT Member, Naples ? Fauna. Allegany Grove, 475. CoZZecfioM.— Maryland Geological Survey. 604 Systematic Paleontology — Uppek Devonian Family ATHYRIDAE Genus ATHYRIS McCoy AtHYKIS ANGELICA Hall Plate LIX, Figs. 8-10 Athyris angelica Hall, 1861, 14th Rept. N. Y. State Cab. Nat. Hist., p. 99. Athyris angelica Hall, 1867, Pal. of N. Y., vol. iv, p. 292, pi. xlvii, figs. 9-20. Description.— " Shell ovoid, gibbous, transverse or elongate; propor- tions of length and width variable, the prevailing form longer than wide ; deeply sinuate, with the beak very prominent; hinge-line short. "Ventral valve gibbons, most convex above the middle; mesial sinus usually extending nearly to the beak, becoming abruptly and deeply de- pressed below the middle, and much expanded towards the front of the shell ; lateral portions of the valve gibbous, and abruptly curving towards the margins; beak much elevated and curved over the umbo of the dorsal valve. " Dorsal valve much shorter than the opposite, gibbous, transverse or as long as wide; the mesial fold usually not conspicuous above the lower third of the valve ; in the upper part the surface is a little more gibbous, and the strice along this part are more straight or a little curved back- wards, indicating the form during the successive stages of growth. " Surface marked by regular equidistant imbricating lamellae or lamel- liform strise, the edges of which in perfect specimens are projecting and slightly crenulate. These lamellse are marked by short interrupted radiating striae. " The interior of the ventral valve shows a semicircular perforation at the apex, opening on the lower side to a triangular fissure. The teeth are strong, and continued in plates to the base of the rostral cavity, and divaricator imprints occupy an ovate space below and on each side. Sur- face of cast, adjacent to the muscular imprints, strongly papillose. " The muscular imprints of the dorsal valve are not well preserved in any specimens in my collection. There is a slender longitudinal septum Maryland Geological Survey 605 extending from the beak for one-half the length of the valve/' Hall, 1867. Length 17 mm.; vfidth 30 mm. Occurrence. — Jennings Formation, Chemung Member. Allegany Grove, 2941. Collection. — Maryland Geological Survey. Genus MERISTELLA Hall Meeistella humilis n. sp. Description. — Shell broadly ovate, -width somewhat greater than length, umbo prominent, hinge-line short. Ventral valve convex, point of great- est convexity posterior to middle; depressed in front to form a shallow sinus ; slightly concave towards lateral margins, greatest width near mid- dle. Beak nearly straight, projecting beyond that of dorsal valve. A slightly angular ridge extends from beak to extremity of hinge, the sur- face between it and hinge being flattened or concave.. Dorsal valve broadly ovate; bearing a low fold towards front; point of greatest convexity pos- terior to middle; beak small. Cast of interior shows two short dental lamellse in ventral valve and a median septum extending nearly one-third length of shell in dorsal valve, two depressions marking position of teeth. Surface smooth with faint concentric lines of growth. Length of largest individual observed 10 mm. ; width 13 mm. ; thick- ness 4 mm. Only a few individuals have been seen. This species seems quite distinct from any previously described form of the genus. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Millstone, 795 ; Yellow Springs, West Virginia. Collection.— KsiTjlmd Geological Survey. 606 Systematic Paleontology — Uppee Devonian MOLLUSCA Class PELECYPODA Order PRIONODESMACEA Family GRAMMYSIIDAE Genus GRAMMYSIA de Verneuil Geammysia elliptica Hall Plate LIX, Figs. 11, 12 Orammysia elliptica Hall, 1870, Notice Lammellibranclilata, vol. ii, p. 53. Grammysia elliptica Hall, 1885, Pal. of N. Y., vol. v, pts. i, ii, p. 365, pi. Iviii, figs. 1-12. Description.- — ^Shell transversely elliptical, basal margin broadly curv- ing, slightly sinuate about the middle; posterior margin abruptly rounded beloAv^ and curving into the cardinal line above, sometimes more or less truncate. Valves regularly convex becoming more or less gibbous in the umbonal region. B.eaks subanterior, prominent, incurved; cincture ex- tending obliquely to the base of the shell. Surface with fine irregular concentric stris which become aggregated into fascicles at the front and middle of the shell. Length 50 mm. ; height 40 mm. In E"ew York it has a notable vertical range from the beds with the Ithaca fauna upward into the higher Chemung strata. Occurrence. — Jeinnings Pokmation, Chemung Member. One mile east of BarrelvUle near top of Chemung; Allegany Grove, 1633, 2800; Town Creek, 3870, 3963, 3969. Paekhead Member. Town Creek, 1605; 2 miles west of Pawpaw, West Virginia, 1484. Collection. — Maryland Geological Survey. Grammysia subarcuata Hall Plate LIX, Pig. 13 Grammysia subarcuata Hall, 1870, Prel. Notice Lammellebr., vol. ii, p. 61. Grammysia suiarcuata Hall, 1885, pal. of N. Y., vol. v, pt. i, ii, p. 375, pi. Ixi, figs. 10-22, pi. xciii, fig. 26. Maryland Geological Suevey 607 Description. — " Shell of medium size, sub-ovate, widest at the posterior end; length more than one-third greater than the height; basal margin regularly convex, sometimes straight, or constricted toward the anterior end. Posterior extremity rounded, or obtiisely subangular, often sub- truncate above. Cardinal line nearly straight. Anterior end short, ab- ruptly rounded below the lunule. Valves moderately convex in the lower and posterior part, becoming gibbous in the middle and umbonal region. Beaks subanterior, prominent, inclining forward and strongly incurved. Umbonal slope rounded. Postcardinal slope flattened or concave, some- times limited by an elevation, at which line the concentric undulations terminate. Anterior to the middle of the shell, extending from the beak to the basal margin, there is a depression or cincture which often gives a slight undulation to the concentric folds and a constriction to the margin. Surface marked by fine, close concentric stris! and by strong subangular concentric ridges or folds, which are frequently duplicate posterior to the cincture. The surface is also marked by fine, radiating pustulose strise, which are often very conspicuous. Interior unknown. Three specimens measure respectively 36, 38, and 48 mm. in length, and 30, 23, and 33 mm. in height. The largest specimen observed has a length of 70 mm. This species resembles G. arcuaia in its general aspect, but differs in its more elongate form, more pointed posterior end, and the cincture is much more strongly marked." Hall, 1885. Occurrence. — Jennings Formation, Chemung Meqmbbr. National Eoad, on Polish Mountain, 2503. Parkhead Member. Allegany Grove, 950; Williams Eoad, on Polish Mountain, 1289. Collection. — Maryland Geological Survey. Gkammtsia communis Hall Plate LIX, Figs. 14, 15 Grammysia commrunis Hall, 1885, Pal. of N. Y., vol. v, pt. i, ii, p. 378, pi. Ixi, figs. 24-28; pi. xclli, flg. 20. Orammysia communis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 383, flg. 27. Description. — " Shell small, ovate-cuneate ; length less than twice the height; basal margin gently curving with a slight constriction Just ante- 608 Systematic Paleontology—Upper Devonian rior to the middle of the length, abruptly recurving at the postbasal extremity and obliquely truncate above. Cardinal line nearly straight, scarcely declining posteriorly. Anterior end short, obliquely truncate above at the lunule, and abruptly rounded below, having an angle at the junction of the two lines. Valves regularly convex in the lower and posterior portions, becoming gibbous above and especially on the post- umbonal slope. Beaks subanterior, prominent, large, strongly incurved. ITmbonal slope obtusely sub-angular, and extending to the posterior ex- tremity, with a faint indication of a plication on the postcardinal slope. Valves marked by a distinct cincture extending from the beak, more or less obliquely, to the basal margin anterior to the middle of its length. Surface marked by fine concentric striee, which are obscurely visible in the cast; and by strong concentric undulations which mark the anterior and central portion of the valves, becoming obsolete on the umbonal ridge. Interior unknown." Hall, 1885. Length 29-44 mm. ; height 10-15 mm. The individuals observed in Maryland differ slightly from those figured by Hall from New York though they approach them closely. Occurrence. — Jennings Formation, WoodjMONt Member, Ithaca Fauna. Yellow Springs, West Virginia, 665. Collection. — ^Maryland Geological Survey. Grammysia undata Hall Edmondia undata Hall, 1S83, Pal. of N. Y., vol. v, pt. ii. Plates and Ex- planations, pi. Ixlv, fig. 30. Grammysia undata Hall, 1885, Pal. of N. Y., vol. v, pt. 1, ii, p. 379, pi. Ixi, Fig. 23, pi. Ixiv, fig. 30; pi. xciii, fig. 21. Grammysia undata Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 383, fig. 28. Description.- — "Shell below the meidium size; ovate eubelliptieal ; length about one-third greater than the height; basal margin gently curving, nearly straight, and slightly constricted anterior to the middle of its length. Posterior margin curving upward to about the middle of its height, above which it is obliquely subtruncate. Cardinal line straight, more than two-thirds the length of the shell, slightly declining posteriorly. Maryland Geological Survey 609 Anterior end short, regularly rounded. Valves regularly convex in the lower and posterior portion, becoming gibbous in the middle and above. Bealcs at about the anterior third or fourth, rather prominent. Umbonal slope subajigular above, and sometimes continued to the postinferior extremity. Cincture broad, undefined, extending from the bealcs to the base anterior to the middle, and producing a flattening of the valve and a slight constriction of the basal margin. Surface marked by fine con- centric striae, with a few, more or less distinct, concentric undulations, ■which become obsolete at about the umbonal angle. Interior unknown. This species resembles G. communis, but the concentric undulations are not so numerous, the i^mbonal slope less defined, the posterior end broader and not so obliquely truncate above the middle, and the cincture more nearly vertical." Hall, 1885. A few poorly preserved specimens have been observed which seem probably referable to the species. Length 21-30 mm. ; height 14-21 mm. Occurrence — Jennings Formation, Chemung Member. Town Creek, 3870. Collection. — Maryland Geological Survey. Genus PAL/BANATINA Hall PAL.EANATINA ANGUSTA Hall Plate LIX, Figs. 16, 17 Palwantina angusta Hall, 1885, Pal. of N. Y., vol. v, pt. i, ii, p. 490, pi. Ixxix, figs. 29-34. Description. — " Shell small, elongate, narrowly elliptical or subcylin- drical; length from two and a half to three times the height; basal margin straight or slightly sinuate. Posterior extremity obliquely truncate or regularly rounded. Cardinal line straight or slightly declining poster- iorly. Anterior end narrow, rounded. Left valve gibbous in the umbonal region. Eight valve less gibbous and more depressed below the umbonal ridge. Beaks between the anterior third and fourth, small, scarcely rising above the hinge. Umbonal slope obtusely subangular, extend- ing to the postinferior extremity. Postcardinal slope flat or con- 39 610 Systematic Paleontology — ^Upper Devonian cave, with a fold in the left valve, a feature not observed in the right valve. There is a shallow undefined depression extending from the umbo to the base, scarcely affecting the margin. Surface marked by fine con- centric striae, which becomes fasciculate on the posterior end of the shell." Hall, 1885. The specimens, while poorly preserved, have the characteristics of the New York species with sufficient distinctness to render their identifica- tion very probably correct. The species has been observed only in the upper ferruginous beds of the Chemung. Length 21-32 mm.; height 9-10 mm. Occurrence — Jennings Poemation, Chemung Member. Town Creek, 4596 abundant; 2 miles west of Pawpaw, West Virginia, 4694. Collection. — Maryland Geological Survey. Genus SPHENOTUS Hall Sphenotus contractus Hall Plate LIX, Figs. 18, 19 Cypricardia contracta Hall, 1843, Geol. of N. Y., Kept, on the 4tli Dist., p. 292, pi. cxxxix, fig. 4. Sphenotus contractus Hall, 1885, Pal. of N. Y., vol. v, pt. i, p. 399, pi. Ixvi, figs. 1, 3-9, 11-13, 15; pi. xciv, fig. 2. Description. — Shell elongate-trapezoidal, wider behind; length more than twice the height; basal margin nearly straight, faintly constricted in the middle. Posterior extremity oblique, rendered somewhat doubly truncate by the ridge on the posterior slope. Cardinal line straight, long, nearly parallel to the basal margin. Anterior end short, abruptly de- clining from the beak and narrowly rounded below. Valves equally con- vex. Umbonal slope angular and extending to the postlateral extremity. Surface with fine concentric striee. Length 35 mm. ; height 13 mm. Occurrence. — Jennings Formation, Chemung Member. On National Eoad, 1 mile west of Sideling Creek; near top of Green Eidge; 1% miles west of Corriganville and near contact with Hampshire formation 1 mile east of Barrelville. Northeast edge of Deer Park. Collection. — Maryland Geological Survey. Maeyland Geological Survey 611 Family PRAECARDIIDAE Genus BUCHIOLA Barrande This name was introduced for shells which had been passing current in European literature as Venericardium retrostricdum von Buch and Cardium palmatum Goldfuss. Professor James Hall had at an early date described a species of the same general type as these under the name Avicula spedosa and afterwards (in 1885) introduced the generic name Glyptocardia for this particular species, a term which was too late for recognition, as Barrande's name already occupied the field. These small shells all agree in the general expression of their exterior which is, in a characteristic example of the genus, quite strongly ribbed, the ribs bear- ing sharp recurved and often chevron-shaped concentric ridges. Uniform- ity in the character of the exterior has led to the assembling, up to within recent years, of all forms known under one or another of the specific terms above mentioned, but a more careful analysis of the species under- taken by Beushausen has shown the existence, in the stages of the German Devonian, of a very considerable number of well-defijied specific types. Similarly a careful restudy of the shells which have been known in New York as Avicula or Cardiola, or finally Glyptocardia spedosa Hall, which had been assigned a range from the Marcellus shales to and into the Portage stage, shows that here again a number of distinct, specific types have been brought under one term. The senior author has had occasion to work out in some detail the nature, persistence and local value of the various types of Buchiola in the Naples fauna of western New York and the facts there acquired are supplemented in a very interesting manner by the manifestations of this genus in the same fauna in its Maryland repre- sentation. The shells of Buchiola were small, diaphanous, fragile bodies apper- taining to the group which Neumayr termed the PalEeoconchee and which Beushausen proposed to change on account of their not being essentially early types, to the form Cardioconchse. In these shells the hinge is long and straight, and bears a narrow linear ligamental area. Preparations of delicate replacements of the shell in barium sulfate, acquired from the 612 Systematic Paleontology— Upper Devoniax limestone nodules of the Naples beds in Ontario County, New York, show that the hinge may bear on its edge a row of minute denticulations which is in accordance with the determination made by Neumayr, but it seems quite unlikely that these denticulations are homologous with true hinge teeth, save in so far as they assist the axticulation of the valves and it is certain that they are not always present. In the stronger ex- pressions of this type of structure there is no difficulty in associating germane members of this genus, but it is to be observed that the genus passes by very easy gradation into that group which has been characterized by the term Paracardium Barrande. We find the latter shells recogniz- able by greater numerical development of the ribs, the lack of the charac- teristic concentric ornament upon these ribs, and the general extinction of the characteristics of Buehiola; not that there is any fundamental dif- ference in the structure of the two groups, but both are of the same diaphanous, fragile character peculiar to the palseoconchs, and in respect to hinge structure both seem to be alike. There are species however upon which each genus seems to have a distinctive claim. With the multi- plication of the number of ribs the ornamentation of the surface becomes progressively obscured, and while the latter may become quite extinct there are forms in which the two features are combined and which, hence, appertain as fairly to one of these divisions as the other. Para- cardkcm doris Hall, which we find abundant in the New York and Mary- land development of the Naples fauna is an excellent representation of the fully developed Paracardium type. In New York the genus BiuMola reaches, as before observed, from the early middle Devonican into the lower upper Devonian. It is in the latter, the Naples fauna or the zone of Manticoceras intumescens, where the genus attains its culminant development, and it is at this horizon also that throughout the paleozoic faunas of the world the genus attains its maximum. In Maryland the genus has not yet been recorded from hori- zons other than those of the Naples fauna, while in the now thoroughly well-known range of the genus in Germany it has very much the same extent as in America, with its maximum in the lower upper Devonian, species passing even higher into the stages of the upper Devonian. Maryland Geological Survey 613 BUCHIOLA EETROSTRIATA (v. Buch)' Plate LX, Figs. 1-3 Description. — The specific name of this shell entered into literature as long ago as 1832 when von Bnch used the name Venerica/rdium reiro- striatum for shells from the upper Devonian of Biidesheim. With what- ever generic name this specific term or the term pcdmatum employed by Groldfuss has since then been combined, whether Avicula, Cardiola, Glyp- tocardia or BucJiiola, the expression was in effect a generic one until the date of Beushausen's careful analysis of the German species of BucMola and the differentiation of the typical B. retrostriata. The American species of the genus, derived from the Devonian and in the main from the characteristic horizon at the base of the upper Devonian {Intumescens zone) have had a similar history. The name Avicula spedosa was first applied to them by Hall in 1843 and he subsequently introduced the generic term Glyptocwrdia for the species though too late for recognition, as Barrande's Buchiola was already in the field. The identity of the New York and European shells was recorded in 1891 by the writer who has since that date been enabled to determine in part, at least, the substantial local variations of the American shells which have heretofore been con- cealed under v. Bueh's name. Buchiola retrostriata, the original and typical species, is distinguished from other species of the genus by the following combination of charac- ters. It bears 12-15 ribs which have elevated margins, more or less de- pressed, and flat summits which are crossed by pretty strong retrally curved or often chevron-shaped ridges, not traversing the line-like mar- gins, and often varying in strength in different parts of the shell. The condition exhibited in one of our figures which is that of an old shell is quite characteristic of the species, showing the variation in the strength of these concentric markings, subdued in early age, strongest at maturity and again declining in strength about the margins of the old shell. The furrows between the ribs are narrow, flat and always smooth. These ^ For synonymy see Clarke, Naples Fauna in Western New York; N. Y. State Mus„ Mem. vi, p. 292, 1904; for figures, idem, pi. x, flgs. 1-14. 614 Systematic Paleontology — Upper Devonian features seem to persist and to exclude danger of confounding the species with its many associates in the Naples fauna of both ;\[aryland and Xew York. Buchiola retrostriata is not known to occur in American strata older than the Portage or Naples fauna. The genua does indeed occur in the shales of the Marcellus and Hamilton stages in New York and has been reported as Glytocardia speciosa, but these shells are altogether distinct from B. retrostriata,. In New York the species occurs first in the Styliola limestone (Gen- esee stage), which embodies the initial appearance of the Naples fauna and is extremely abundant throughout the manifestations of this fauna in the Naples (Portage) beds of region between the Cayuga Lake and Genesee valleys in the Naples subprovince. In the more eastward exten- sion of Portage rocks it is only occasionally seen where accompanying a tongue of Naples sediment penetrating into the central province, and in the westerly counties having outcrops of Portage rocks, Erie and Chau- tauqua (Chautauqua subprovince), it is quite rare. In the broad and older use of the term the shell is very widely dis- tributed on the horizon of the lowest upper Devonian in Britain, Ger- many, France, Belgium, Eussia and Siberia, but in its more restricted application some of these records must be regarded as subject to modifica- tion. Yet, notwithstanding this consideration, it is the most generally diffused representative of the genus. In Westphalia and in the Hartz it occurs in both lower and upper stages of the upper Devonian. Length 8 mm.; height 6 mm. Occurrence. — Jennings Poematton, Genesee Member. About 100 feet above junction of Plintstone and Town creeks; Gilpintown ; Cumber- land, Williams Eoad and McKay's Hill, southeast of city; Barrelville Eoad one-half mile west of Corriganville ; National Eoad just west of Wolfe Mill; five and one-half miles southwest of Burlington, West Vir- ginia, on the Eomney Eoad. Woodmont Member, Naples Pauna, Gilpintown east of bridge over Town Creek. Mar-xland Geological Survey 615 BucHiOLA CONVERSA Clarke Plate LX, Figs. 4-6 Buchiola conversa Clarke, N. Y. State Mus., Mem. vl, p. 300, pi. x, fig. 22, 1904. Description. — This species is smaller than the average of B. retro- striata and has a more circular outline. While it has about the same number of ribs as that species, 12-15, these are extremely fine and though flat at the staa-t become highly concave over the body of the shell by the elevation of the lateral margins into linear ridges. As the fur- rows between the ribs have about the same width the shell may present the appearance of bearing double the number of ribs ascribed to it, each rib assuming a duplicate appearance due to the depth of its surface de- pression. Only the faintest trace of concentric markings is to be dis- covered. The peculiar surface characters render it quite easy of separation from its associates in the same genus, but we find that this style of ornament is approached by some of the forms assigned to the genus Paracardium (e. g., p. dupUcatii^m Clarke, Naples fauna of New York) and serves to indicate the quite conventional value of the latter genus. Length 6 mm.; height 5 mm. The typical specimens of this species are from the lower beds of the Naples shales in New York north of Portage ville in the Genesee Valley and a figure of the type specimen is here given. Occurrence. — Jennings Formation, Woodmont Member, Naples Fauna. Polish Mountain section on the National Eoad east of Gilpin- town. Collection. — Maryland Gedogical Survey. Buchiola mari^ n. sp.' Plate LX, Figs. 7, 8 Description. — This species will be found to difEer from other repre- sentatives of the genus in the following particulars : It has the size and form of B. retrostriata but carries fully 20 ribs, all sharply elevated ' See Clarke, N. Y. State Mus., Mem. vi, p. 212, 1904. 616 Systematic Paleontology — Uppee Devonian and flat, their upper surfaces bearing concentric, retrally curved but not angulated strige, all of which are fine, small and of uniform size. The interspaces between the ribs also show such concentric strife on the lateral slopes of the valves but these are very much finer than on the ribs, and over the median parts of the shell cannot be discerned. The distinction from B. livonicB, described below is found in the prominence of the ribs and the distinct concentric ornamentation as well as somewhat also in the form of the shell. Length 5 mm. ; height 3 mm. Occwrence. — Jennings Poemation, Genesee 'Member. This form of Buchiola is not common having been found only in the shales on the Williams Eoad I/2 mile east of the Queen City Hotel, Cumberland, and no precisely similar expression has yet been observed in the Intumescens fauna of New York or Europe. Collection. — Maryland Geological Survey. Buchiola ( ?) livoniae Clarke Plate LX, Pigs. 9-12 Buchiola livonice Clarke, 1904, N. Y. State Mus., Mem. vi, p. 299, pi. xi, figs. 1, 2. Description. — Shell of rather, large size and transversely ovate with the greatest vertical diameter posteriorly. It is specially distinguished by the character of its surface which is marked by about 20 very low fiat ribs having nearly twice the width of the spaces between them. The sides of the ribs are erect though very low and so obscurely are they developed that sometimes it is difficult to trace them on the anterior slope of the valves. In every case, however, the first or three short ribs be- neath the beak on the anterior moiety of the hinge are strong elevated and rounder than the rest. Extremely fine concentric lines cover both ribs and furrows but this ornamentation can only be seen by favorable illumination. Length 7 mm.; height 5 mm. Buchiola livonice was first found in the Styliola limestone (Genesee ■shale) of the great salt shaft put down at Livonia, New York, and it Maryland Geological Suevey 617 appears to have been a rather rare form in the Naples fauna of that region. In Marj-land, however, it is much more generally diffused. , The typical form of the species from the Styliola limestone of New York is here figured for comparison with the Maryland specimens. Occurrence.' — Jexxings Formation, Genesee Member. Eomney Eoad 31^ miles southwest of Burlington, West Virginia; Wolfe Mill on National Eoad, 3 miles northeast of Cumberland; hill on Williams Eoad near Cumberland. Woodmont xVIembee, Naples Fauna. Gilpintown on National Eoad about 80 feet east of Town Creek. Collection. — ilaryland Geological Survey. Genus TARACARnUM Barrande Under this term have been placed certain paleoconchs which, as has been observed above, are similar to Buchiola in all particulars except the general expression of the surface. The latter is many-ribbed and in its typical expression as shown in P. doris, these ribs lack the chevroned character of Buchiola. Yet in some species there is an evident though fine concentric ornament on ribs and furrows alike. The hinge structure is identical with that of Buchiola showing a linear ligament groove and sometimes a single row of fine denticulations on the hinge margin. While the validity of the genus Paracwrdium may be regarded as open to ques- ■fion, it forms at the present a convenience in the nomenclature of these shells. Paracaedidm DORIS Hall Plate LX, Figs. 13-16 Cardiola doris Hall, 1783, Pal. of N. Y., vol. v, pt. i, plates and explanations 70, figs. 10, 11. Paracardium doris Hall, 1885, Ibid., p. 428. Paracardium doris Clarke, 1904, N. Y. State Mus., Mem. vi, p. 304, pi. xi, figs. 5-10. Description. — These shells are small, averaging about the same size as specimens of BucMola but are quite regularly ovate with the greatest vertical diameter posteriorly. There are from 20-25 simple rounded ribs running from beak to margin, separated by furrows of the same 618 Systematic Paleontology — Upper Devonian width as the ribs themselves. The shell normall}' assumes the circular form and curved ribs represented by Hall's figures, but this outline is seldom retained in the shales, though always shown in the barite replace- ments occurring in the lime nodules of the New York strata. In jS'ew York the species is very abundant in the Styliola limestone (Genesee) and in the olive Naples shales throughout the region between the Genesee Eiver and Cayuga Lake and is occasionally seen in the lower eastward horizons. West of the Genesee Eiver, in the Chautauqua sub- province, it is seldom seen. Paracardium doris is quite generally diffused throughout the Genesee member and the beds containing the Naples fauna in the AVoodmont member. Length 7 mm.; height 5 mm. Occurrence. — Jennings Formation, Genesee Member. On the hill directly southeast of Cumberland; west of Corriganville on the Barrel- ville Eoad ; just west of Wolfe Mill ; and on the Parker farm near Bur- lington, West Virginia. Woodmont Member, Naples Fauna. National Eoad east of Gilpintown. Collections. — Maryland Geological Survey, New York State Museum. Paracardium delicatulum Clarke Plate LX, Figs. 17, 18 Paracardium delicatulum Clarke, 1904, N. Y. State Mus., Mem. vi, p. 304, pi. xi, fig. 4. Description. — To this species, which has already heen observed in the Styliola limestone on Canandaigua Lake, New York, is referred a small shell with hair-lined surface and subcircular outline. A drawing of the New York form is introduced here for purposes of comparison. The surface of the shell bears from 50-70 very fine simple riblets, this char- acter in itself serving as the distinguishing feature of the species. Length 5 mm. ; height 3 mm. Occurrence. — Jennings Formation, Genesee Member. On the Na- tional Eoad just west of Wolfe Mill, near Cumberland. Collection. — Maryland Geological Survey. Maryland Geological Survey 619 Superfamily NUCULACEA Family NUCULIDAE Genus NUCULA Lamarck NUCULA CORBDLIFORMIS Hall Plate LX, Figs. 19-23 Nucula corluliformis Hall, 1870, Preliminary Notice LamelUbranchiata, 11, p. 2. Nucula corbuliformis Hall, 1885, Pal. of N. Y., vol. v, pt. i, p. 319, pi. xlvi, flgs. 24-34. Nucula corbuUformis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 396, flg. 503. Description. — Shell small, triangular; beak prominent acute and an- terior, umbonal slopes direct. Length and height sometimes nearly equal, anterior margin broadly rounded. Hinge-line sloping and bearing denticulations on both sides of the beak. Surface convex, depressed in the umbonal region ; covered by fine but not conspicuous concentric striae. Length 9 mm.; height 6 mm. Niicida corbuliformis is common in the Hamilton shales and occasion- ally occurs in the Ithaca fauna of New York. It is of rare occurrence in the Chemung, occasional in the Parkhead, and locally abundant in the Ithaca fauna of Maryland. A single specimen was found in the Ithaca fauna at Hancock which is unusually gibbous and has very deep muscular sears. It is probably a gerontic individual of this species. Occurrence. — Jennings Formation, Chemung Member. Oakland- Altamont Eoad; Town Creek, 2238. Parkhead Member. Williams Eoad, on Polish Mountain, 1352; 2 miles north of mouth of Town Creek, 1716 abundant, 1803. Woodmont Member, Ithaca Fauna. National Eoad west of Tonoloway Eidge in soft yellow argillaceous sandstone; Hancock, 1149 to 1274; Yellow Springs, West Virginia. Collection. — Maryland Geological Survey. 620 Systematic Paleontology — Upper Devonian Genus NUCULITES Conrad JSTdculites sp. ? Description. — The presence of this genus in the Jennings of Maryland is indicated hy a single specimen too incomplete for identification yet showing the hinge teeth and the anterior vertical interior ridge or clavicle behind the forward muscular scar. Occurrence. — Jennings Formation, Chemung Member. West slope of Polish Mountain ; Allegany County. Collection. — Maryland Geological Survey. Family LEDIDAE Genus PALy^ONEILO Hall Pal^oneilo constricta (Conrad) Plate LXI, Pigs. 7-10 Nuculites constricta Conrad, 1842, Jour. Acad. Nat. Sciences, Phila., vol. viil, p. 249, pi. XV, fig. 8. Palwoneilo constricta Hall, 1885, Pal. of N. Y., vol. v, pt. i, p. 333, pi. xlviii, figs. 1-16, pi. 11, fig. 17. Palwoneilo constricta Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 400, figs. 510a, 6. Palwoneilo constricta Cleland, 1911, Bull, xxi. Gaol. Survey Wis., p. 102, pi. XX, figs. 9, 19-22. Description. — Shell of rather small size, ovate-euneate, subnasute be- hind. Basal margin rounded in the middle and anterior portions, straight or slightly constricted toward the posterior end. Posterior end narrow and constricted below. Valves equally convex. Beaks at anterior third. Umbonal ridge rounded with a depression or undefined furrow below it extending from just behind the beak to the postinferior margin. Surface with fine, concentric, thread-like lines. Hinge with numerous denticulations and sockets characteristic of the genus. Length 20 mm. ; height 14 mm. Occurrence.— Jw^mNGS Formation, Chemung Member. Northeast of Deer Park; National Eoad on top of Green Eidge. Woodmont Mem- ber, Ithaca Fauna. Woodmont, 710. Collection. — Maryland Geological Survey. Maryland Geological Survey 631 Paljeoneilo plana Hall Plate LXI, Figs. 1-3 Palwoneilo plana Hall, 1870, Prelim. Notice Lammelllbr., vol. ii, p. 7. Palwoneilo plana Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. II, p. 334, pi. xlvili, figs. 21-28. Palwoneilo plana Grabau and Shimer, 1909, N. Amer. Index Foss., vol. 1, p. 399, fig. 510. Palwoneilo plana Cleland, 1911, Bull, xxi, Geol. Survey Wis., p. 104, pi. xx, flgs. 15-16. Description. — Shell helbw medium size, elongate-ovate, length about twice height, occasionally greater. Cardinal margin curved, slightly con- cave anterior to umbo, slightly convex posterior to umbo ; ventral margin gently curved; anterior extremity rounded; becoming narrower towards posterior extremity which is abruptly rounded. Valves convex, somewhat gibbous towards umbo; cast of interior slightly concave in some speci- mens towards posterior extremity. Beak small, not much elevated above hinge-line, situated about one-third length from anterior extremity. Um- bonal slope rounded, not distinct. Casts of interior show hinge teeth in a curved line, teeth at extremities being stronger; anterior and posterior muscular scars shallow; anterior scar separated from umbo by a slight ridge in some shells. Surface with faint concentric lines. Test thin. Length 18 mm., occasionally more; height 9 mm. The individuals referred to this species differ in some respects from those described by Hall. They are, however, probably the same species although this identification is not without question. A specimen from near Pratt is much more elongate than usual. This species closely re- sembles p. elongata of the Chemung of ISTew York. It differs in being larger with beak nearer anterior extremity. It differs from P. crassa in being smaller, more elongate, test thin, muscular scars shallow. Occurrence. — Jennings Formation, Chemung MEaiBEE. N"ational Eoad west of Frostburg; Town Creek, 3328, 3391, 3969; 3 miles west of Pawpaw, 2134; 31^4 miles northeast of Pratt near home of Mr. Cheney ?; Millstone, 2322 abundant. Parkhead Member. Town Creek, 1679 ?, 1851. WooDMONT Member, Ithaca Fauna. Little Orleans, 1446. Collection,. — Maryland Geological Survey. 623 Systematic Paleontology — Uppek Devonian Pal^oneilo maxima (Conrad)' Plate LX, Fig. 35 A few specimens have been observed which are not well enough pre- served to permit confident identification. They are probably of this species. OccurrencBj — Jennings POrmation, Pakkhead Member. Two miles north of mouth of Town Creek, 1283, 1313. Collection. — Maryland Geological Survey. Pal^oneilo beevis Hall Plate LXI, Pigs. 4-6 Palwoneilo hrevis Hall, 1870, Prelim. Notice Lammellibr., pt. ii, p. 10. Pakeoneilo irevis Hall, 1885, Pal. of N. Y., vol. v, pt. i. sec. ii, p. 342, pi. 1, figs. 24-33. Palwoneilo irevis Grabau and Sliimer, 1909, N. Amer. Index Foss., vol. i, p. 400, fig. 510. Palwoneilo brevis Cleland, 1911, Bull, xxi, Geol. Survey Wis., p. 101, pi. xx, figs. 6-7. Description. — "Shell small, ovate, or ovate-subtriangular; length about one-third greater than the height; basal margin gently curving, with a slight constriction toward the posterior extremity. Cardinal line arcuate. Anterior end usually short and regularly rounded. Valves convex below, gibbous in the middle and on the umbonal ridge. Beaks usually at about the anterior third or a little posterior thereto, prominent, moderately elevated above the hinge-line. Umbonal slope marked by a slight flattening of the shell, which produced a gentle constriction in the postinferior margin. This depression is rarely 'margined on each side by an undefined elevation. Surface marked by fine, even, concentric striae; the casts exhibiting only the stronger elevations which give an ir- regular appearance to the concentric stris. Anterior muscular impression very strongly marked. Posterior scar large and shallow. Hinge marked by numerous minute crenulations. Three specimens of this species meas- ure respectively 31, 20, and 14 mm. in length, and 14, 12, and 10 mm. in height. This species is allied to P constricta, but is more gibbous, ' For synonymy and description see page 238. Maryland Geological Survey 633 less curved along the basal margin, and the constriction of the posterior end is so slight as to be scarcely detected in most individuals." Hall, 1885. Occurrence. — Jennings Formation, Parkhead Member. National Eoad, on Polish Mountain, 1196 ? ; 2 miles west of Pawpaw, West Vir- ginia, 1484, 1763 common. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1388; Little Orleans 1446; Wood- mont 1032, 1067 cf.; Hancock, 1149 to 1274; Berkeley Springs, West \'irginia, 1674 cf.; Yellow Springs, West Virginia. Collection. — ^Maryland Geological Survey. Pal^oneilo filosa (Conrad) Plate LXI, Figs. 11, 12 NucuUtes filosa Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vili, p. 250, pi. XV, flg. 7. Palmoneilo filosa Hall, 1885, Pal. of N. Y., vol. v, pt. i, p. 343, pi. xlix, flgs. 33-38. Description. — Shells small, transversely subelongate, length about twice the height; tapering posteriorly with a decided sinuosity on the posterior margin caused by the oblique groove between which and the hinge is a low ridge. Beaks at the anterior third of the transverse diameter. Surface with regular and sharp and elevated lamellose concentric striae becoming more conspicuous on the posterior slope. Dimensions of the Maryland specimens, which are of smaller habit than the Few York shells ; length 9 mm., height 5 mm. Notwithstanding the small proportions of these shells they agree with the typical form in all essential particulars. The New York shells occur in the Ithaca fauna of the central region of that State. Occurrence. — Jennings Formation, Chemung Member. Near Deer Park; Tiger Valley about 1 mile west of Wills Creek Station, Pennsylvania; 214 niiles northeast of Pratt near home of Mr. Cheney, near base of Chemung. Collection. — ^Maryland Geological Survey. 634 Systematic Paleontology — Upper Devonian Pal^oneilo angusta Hall Plate LXI, Fig. 13 Palwoneilo angusta Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. ii, p. 344, pi. xciii, fig. 11. Description. — Shell below medium size, elongate-elliptical, length more than twice height. Postumbonal part of cardinal margin straight, declin- ing from umbo; anterior extremity rounded; ventral margin curving slightly, nearly straight in middle part; posterior extremity produced, doubly emarginate. Valves low, convex with a slight sulcus in front of umbonal slope. Umbo about one-third length from anterior end, low, closely appressed, rising but little above hinge-line. Umbonal slope slightly angular, postcardinal slope broad, ditided longitudinally into two parts by a low angular fold which extends to posterior extremity. Surface bearing faint concentric strise save on postcardinal slope where the striffi become stronger, thread-like and are about 1 mm. apart. Length 17 mm.; height 7 mm. A single valve has been observed. It differs from the typical form in being more elongate, surface smoother, lamellcse lines on postcardinal slope more distant. It agrees, however, in its general features with" the species to which it is referred. The surface ornamentation distinguishes this species from all other species of Palaeoneilo in the fauna. Occwrrence. — Jennings Pormation, Chemung Mesiber. Oakland- Eedhouse Eoad. Collection. — ^Maryland Geological Survey. Palwoneilo petila Clarke Plate LX, Fig. 34 Palwoneilo petila Clarke, 1904, Mem. N. y. State Mus., No. vl, p. 311, pi xv figs. 1-8. Description.—" This little shell in some features is similar to P. con- stricta, having a sinuous posterior extremity and the arrangement of the ligament pits as in that species. It is, however, always small, transversely ovate, never so broad as in P, constricta; beak behind the anterior third of the length, anterior margin subelliptic, basal margin convex, broadly Maryland Geological Survey 625 curved, often with an interruption to this curvature caused by the pro- jection of the low umbonal ridge; narrowing behind to a subattenuate posterior extremity and emarginate by the posterior sinus. Postcardinal slope long and oblique. Surface convex on the umbones, sloping rather abruptly to the front margin ; behind, the surface is sinused by a broad, low depression which brings into prominence a postmedian umbonal ridge. Specimens from the shales and the barite replacements indicate that the surface was smooth or with obscure concentric growth lines. This con- dition is clearly shown in most of our figures. Only one, an incomplete replacement, shows that over the posterior part of the shell the concentric lines are well defined and elevated, but not to such degree as in other species. On the interior, anterior and posterior part of the shell the con- centric lines are well defined and elevated, but not to such degree as in other species. On the interior, anterior and posterior muscular scars, with thickened inner walls, are at times very sharply defined. The cardinal area is broadly arched, the denticulations are all vertical and decrease in size beneath the beak." Clarke, 1904. Length 17 mm. ; height 11 mm. Occurrence. — Jennings Formation, Woodmont Member, Naples Fauna. "Williams Eoad, 31/2 miles east of Cumberland. Collection. — Maryland Geological Survey. PAL.ffiONEILO CRASSA U. Sp. Plate LXI, Figs. 14, 15 Description-^^heW of medium size, ovate, length about 1.6 height. Cardinal margin arcuate, declining posteriorly; ventral margin gently curved ; anterior extremity regularly rounded ; posterior extremity nar- rowly rounded. Valves convex, becoming decidedly gibbous near umbo in older individuals, surface sloping abruptly towards hinge-line, more gradually towards anterior end and ventral margin; very gradually to- wards posterior extremity near which the cast is occasionally concave. Beaks small, anterior, situated between one-fourth to oncrthird trans- verse diameter from anterior end, elevated slightly above hinge-line. Umbonal slope rounded, not defined. 40 626 Systematic Paleontology — Uppee Devonian The shell becomes thick and massive in older individuals. Surface smooth with faint concentric striae. Cast of interior shows a broad hinge- plate bearing long teeth which are in one line, teeth coarse at extremities of hinge, fine beneath umbo. Anterior and posterior muscular scars deep; umbo bearing a number of umbonal pits ; pallial line distinct. Length of larger individuals 35 mm. ; height 16 mm. or slightly greater in some cases; attaining a thickness of 14 mm. This species is characterized by its thick test and the lack of a defined umbonal ridge and sulcus. In the latter respect it resembles P. elongata of the Chemung of New York but it is less elongate than that species. Occurrence. — Jennings Formation, Chemung Mbimber. National Eoad west of Frostburg; Town Creek, 3453 of., 3538 common, 3584 abundant, 3593 common; west of Tonoloway Ridge near Pennsylvania- Maryland state line opposite school house. Collection. — Maryland Geological Survey. Genus LEDA Schumacher LeDA Cf. DIVEBSA Hall Plate LXI, Figs. 16, 17 Leda diversa Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. ii, p. 329, pi. Ixvii, flgs. 31-37. Leda diversa Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 401, fig. 511. Description. — Shell small, falciform ; length twice or a little more than twice width. Cardinal margin convex, post-umbonal portion concave upwardly, anterior portion slightly convex, declining from beak; ventral margin gently curved ; posterior end smaller than anterior end, attenuate, curved upwards. Valve convex. Umbo situated about one-third length from anterior end. Umbonal ridge extending from beak to posterior extremity; surface of shell sloping abruptly from it to hinge-line, round- ing gently to ventral margin. Surface ornamentation unknown. Length 10-12 mm.; height 3-5 mm. The specimens figured differ considerably in form and may not all be- long to the same species. Their proportions suggest L. diversa of the Ham- Makyland Geological Survey 637 ilton of New York but the concentric striae which ornament the surfa.ce of that species have not been observed, as casts of interior only have been found in Maryland. Occurrence. — Jennings Formation, Chemung Member. Allegany Grove, 1633 ; Town Creek, 3760, 3870. Parkhbad Member. Four miles southeast of Pratt on White Sulphur Branch. Collection. — Maryland Geological Survey. Superfamily ARCACEA Family PARALLELODONTIDAE Genus MACRODON Lycett Macrodon chemdngensis Hall Plate LXI, Fig. 18 Macrodon chemungensis Hall, 1870, Prelim. Notice Lammellibr., pt. ii, p. 14. Macrodon chemungensis Hall, 1885, Pal. of N. Y., vol. vi, pt. i, sec. ii, p. 350, pi. 11, figs. 11-16. Description. — " Shell of medium size or larger, arceeform ; cardinal and basal margins subparallel; length more or less than twice the height; basal margin nearly straight or gently curving with a slight constriction anterior to the middle. Posterior end broad, subtruncate or sometimes rounded. Cardinal margin straight, extremities angular. Anterior end rounded below, truncate above. Valves convex in the posterior portion^ becoming gibbous in the middle and anterior. Beaks subanterior, prom- inent, rising a little above the hinge-line. Umbonal region gibbous, with a prominent, undefined ridge extending toward the postinferior extrem- ity, and a vertical depression extending from the umbo to the base. Sur- face marked by irregular, concentric, lamellose lines of growth. Three specimens measure respectively 31, 27, and 23 mm. in length, and 14, 15, and 10 mm. in height. This species is distinguished by its parallel basal and cardinal margins, the truncated posterior end and its narrow form." Hall, 1885. A single valve has been observed which seems clearly referable to the species. 628 Systematic Paleontology — Upper Devonian Occurrence. — Jennings Formation, Parkhead Member. Four miles southeast of Pratt on White Sulphur Branch. Collection. — Maryland Geological Survey. Superfamily PTERIACEA Family PTERINEIDAE Genus PTERINEA Goldfuss Pterinea nodocosta n. sp. Plate LXI, Pigs. 19-21 Description. — Shell of medium to large size, suberect, scarcely oblique. Body broad, subtransverse in front. Anterior wing small ; posterior wing broad and acute but not greatly extended. Surface with 4-5 very strong radii, nodose at distant intervals. Between these radii lie others of vari- ous or alternating size, 3-5 in each interval over the shell body. On the posterior wing the radii are obscure and subequal; the anterior wing is also plicate. Strong concentric striae cover the marginal parts of the shell. Of an average individual, height and hinge-length 62 mm. ; width across the body 55 mm. Prof. Hall figured in Paleontology of New York (vol. v, pt. i, pi. Ixxxiii, fig. 11) a large shell from the Chemung beds which he referred to Pterinea flabella Hall of the Hamilton fauna but which has characters very similar to those here described. The size, suberect form and the nodate or subnodate character of the princapal radii are features in which this later shell differs from P- flabella. The single example show- ing the exterior given by Hall does not indeed represent the major ribs as distinctly nodate but the specimen has been corroded by exposure and in its original condition was probably similar in structure to that here described. Occurrence. — Jennings Formation, Chemung Me:mber. Oakland- Altamont Eoad; E. Gordon's farm 1 mile northeast of Mountain Lake Park; northeast edge of Deer Park; 2 miles south of Oakland. Collection. — Maryland Geological Survey. Maryland Geological Suevey 629 Ptekinea CHEMUN6ENSIS (Conrad) Plate LXI, Fig. 22 Avicula chemungensis Conrad, 1842, Journ. Phila. Acad., vol. viil, p. 243. Pterinea chemungensis Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 98, pi. xvi, figs. 3, 7, 10, pi. Ixxxiv, fig. 21. Pterinea chemungensis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. I, p. 421, fig. 552. Description. — Shell large, obliquely subovate in outline; length less than height, greatest length below the middle. Left valve moderately- convex, right valve depressed. Hinge-line straight, nearly equalling the length of the shell. Beak anterior; anterior wing short, nearly equilat- eral, well set off from body of shell; posterior wing large subtriangular. Surface of left valve marked by slender subequal or alternating rays con- tinuing over the posterior wing; interspaces flat. These are crossed by concentric strise or interrupted by growth varices. Length 60 mm.; height 50 mm. This is a very characteristic member of the Chemung fauna in New York. Williams cites this as one of the dominant species of the Chemung of Xew York. While abundant in the Chemung of Maryland it is not con- fined to that fauna, but occurs, though rarely, both in the Parkhead and Ithaca. Occurrence. — Jennings Poemation, Chemung Membee. Oakland- Altamont Eoad; National Eoad west of Prostburg; Ellerslie, Pennsyl- vania, 1316, 1474 abundant, 1508 abundant; Williams Eoad, on Polish Mountain, 2042; National Eoad, on Polish Mountain, 2706, 2929; Penn- sylvania state line, west of Green Eidge, upper Tropidoleptus zone; Town Creek, 2228; Pifteenmile Creek, 1 mile above Little Orleans, 2215 ?; 21/4 miles northea.'it of Pratt near home of Mt. Chetney. Paee:head Membee. Allegany Grove, 850. Woodmont Membee, Ithaca Fauna. Little Orleans, 1446 ; Fifteenmile Creek, 1 mile above Little Orleans, 1446. Collection. — Maryland Geological Survey. 630 Systematic Paleontology — Uppek Devonian Family LUNULICARDIIDAE Genus LUNULICARDIUM MiJnster There has been a recent effort to restrict the application of this term veiy narrowly and this has given opportunity for the erection of a con- siderable mimber of additional generic terms for shells commonly passing asi Lunulicardium. The authors after a careful analysis of an extensive series of these shells have failed to find a satisfactory basis for either the restriction of the genus or the renaming of its species. Lunidicardium has subtriangular shells with a long and arched hiatus between the valves on the posterior slope. This opening is bounded by narrow smooth areas (sicse) which may be either erect or projacent and which start at the umbo from the outer margin of the primitive shell. Behind the beaks is a short triangular cardinal area. The surface may be radially plicated, striated or smooth. These shells are very abundant in the Naples fauna of ISTew York especially in the JSTaples subprovince. In Maryland only the following two small species have been observed. Lunulicardium enceinitum Clarke Plate LXII, Pigs. 1-3 LunulicarSium encrinitum Clarke, 1904, N. Y. State Mus., Mem. vi, p. 239, pi. ii, fig. 20. Description. — Shell small subtriangular, umbo acute, lateral margins diverging rapidly and anterior margin forming a broad curve, not greatly truncating the anterior moiety of the commissure, its length equalling about two-thirds of the length of the shell. Sica smooth and nearly erect. Body of the shell generally convex, and covered with very fine simple radial stri^ which number 100-135. Extremely fine concentric stria are observable with favorable preservation. Length 7 mm.; height 7 mm. This species in New York has been recorded only from the village of Naples and it is on the specimens from this locality that the species is founded. Maryland Geological Survey 631 Occwrre /ice. —Jennings Formation, Genesee Member. Near Wolfe Mill, Gilpintown. Collection. — Maryland Geological Survey. LUNULICARDIUM CYMBULA Sp. nov.' Plate LXII, Pig. 4 Description. — ^This species is distinguished by its transverse form and central umbo, the latter feature making the hiatus of about the same length as that of the hinge-line on the other side of the beak. In this respect the shell presents a quite unusual aspect, not indeed otherwise noted among these species. The transverse diameter of the shell is 1% times its length. The surface is very finely lined as in P. encrinitum though the number of riblets is not so great. Length 5 mm. ; height 3 mm. Occurrence. — Jennings Pormation, Genesee Member. Wear Cor- riganville where it is associated with Paracardium doris, Tomoceras uni- angidare, Pterochcenia fragilis, etc. Collection. — Maryland Geological Survey. Genus PTEROCHAENIA Clarke Pterochcenia is distinguished from Lunulicardium by the fact that the hiatus is anterior and the sica are in their normal condition extended outward and upward in the form of long narrow wings. These aliform sicae are broad and convex near the beaks, narrowing rapidly downward ; they are separated from the body of the valve by a deep and narrow double groove extending to the apex and enclosing a low ridge. In Lunulicardium the sicje are normally vertical and much thickened; in Pterochcenia they are always thin and their surface lines are continued directly from those on the body of the shell. Beneath the beak there is no triangular striated area as in the genera referred to and no ligamental stria or articular processes are discernible. The surface of the valves is smooth; when well retained only concentric strije are apparent but slight ' See N. Y. State Mus., Mem. vi, 1904, p. 212. 632 Systematic Paleontology — Uppee Devonian exfoliation frequently shows evidence of fine radial lines on the inner shell layer. The type is Avicida fragilis Hall. Pteeoch^nia eeagilis (Hall) Plate LXII, Figs. 5-7 Avicula fragilis Hall, 1843, Geol. of N. Y., Rept. 4tli Dist., p. 222, fig. 94 (1, 2). Lunulicardium fragile Hall, 1870, Preliminary Notice Lamellibr., pt. il, p. 97. Lunulicardium fragile Hall, 1885, Pal. of N. Y., vol. v, pt. i, p. 434, pi. Ixxi, figs. 1-14. Lunulicardium fragile Clarke, 1885, Bull. XJ. S. Geol. Survey, No. 16, p. 62. Lunulicardium frafifiZe •Williams, 1887, Bull. XJ. S. Geol. Survey, No. 4, p. 38, pi. ill, fig. 7. Pterochmnia fragilis Clarke, 1904, N. Y. State Mus., Mem. vi, p. 249, pi. v, figs. 1-10. Description. — Shell small, somewhat ohovate, often suhcircular. Ob- liquely truncate in front, the margins gaping and bounded by thin expansions. Valves moderately convex with rather abrupt posterior slope. Beaks attenuate, erect or progyre. Surface with fine concentric striae, radial striae only in internal laminae. This peculiar and widely distributed species, the only described repre- sentative of its generic type of structure has already been pretty fully made known in the works above cited. It has an unusual vertical range without wide variation of the specific type, occurring first in the bitum- inous shales of the Maieellus stage, occasionally in the more calcareous beds of the Hamilton and again in the dark shales of the Genesee. In the Styliola limestone of the latter divisions it is profusely abundant while in the argillaceous beds carrying the Naples fauna it is one of the less common species of pelecypods. It is known also to have entered the Chemung fauna of western New York, a survivor of the migration of the Naples fauna from that region. Notwithstanding its extensive vertical range in the Devonian strata of western New York the species is not abundant west of the Naples subprovince of Portage time. In Maryland the species seems to be quite widely diffused. Length 6 mm. ; height 7 mm. Maryland Geological Survey G33 Occurrence. — Jennings Formation, Genesee Member. Near Cum- berland; Wolfe Mill; Corriganville ; Parker farm near Burlington, West Virginia. Woodmont Member, Naples Fauna. National Eoad, Polish Mountain, east of Gilpin; National Eoad west of Tonoloway Eidge. Collection. — Maryland Geological Survey. Genus ECTENODESMA Hall ECTENODESMA BIEOSTUATUM Hall Plate LXII, Figs, 8, 9 Ectenodesma Hrostratmn Hall, 1884, Pal. of N. Y., vol. v, pt. i, sec. i, p. 242, pi. xxiii, figs. 27-30; pi. Ixxxiv, fig. 20. Description. — "Shell large; body ovate, oblique; height greater than the length ; margin regularly curving from the base of the anterior wi'ng to the postbasal margin, where it is somewhat abruptly recurved. Left valve regularly convex below, gibbous in the umbonal region, somewhat arcuate, the point of greatest convexity being about the middle of its length. Eight valve concave below, depressed-convex in the middle, convex on the umbo. Hinge-line straight, much longer than the length of the shell, and, in extreme specimens, more than once and a half greater than the length of the shell. Beaks acute, anterior to the middle of the shell, inclined forward, and arching over the hinge-line. Umbonal region gibbous, limited on the anterior side by a shallow, undefined sulcus, and on the posterior side by the abrupt depression of the body, subtending an acute angle. Anterior wing large, triangular; margin concave; extremity produced to an acuminate extension. Byssal sinus shallow and undefined. Posterior wing large, triangular, joining the body below the middle of its height; margin concave; extremity produced into an acute termination. Test of left valve marked with regular and even radii which are rounded above, fiattened and sometimes bifurcate below; similar but more acute radii continue over the posterior wing. In the right valve the rays are more numerous, finer and sharp, and are con- tinued upon the posterior wing with a little less force than on the body of the shell; and very much subdued upon the anterior wing; entire sur- face marked by fine, even, concentric striae of growth. The specimens 634 Systematic Paleontology — Upper Devonian show an oblique lateral tooth, with obscure, indications of anterior teeth or folds. Ligamental area narrow, marked with fine parallel striae. A left valve has a length of 45 mm. ; height 50 mm. ; hinge-line, when en- tire, about 75 mm. A small right valve has a length of 34 mm., height 37 mm., hinge-line about 45 mm. This species is distinguished by the great and nearly equal extent of the hinge-line on both sides of the beak; by the peculiar form of the body of the shell; and by its surface characters, which are unlike any yet observed." Hall, 1884. This species is characterized by its greatly elongated, acute, cardinal angles. It is an abundant and characteristic species of the Ithaca fauna of Maryland. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1340, 1388; Little Orleans, 1446; Pifteenmile Creek, 1 mile above Little Orleans, 1446; Woodmont 1033; Yellow Springs, West Virginia. Collection. — Maryland Geological Survey. Genus LIOPTERIA Hall LlOPTERIA BIGSBYI Hall Plate LXII, Figs. 10, 11 Liopteria iigsiyi Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 165, pi. xx, figs. 3, 11, 13-15; pi. Ixxxviil, fig. 23. Description. — Shell moderately large, suberect, broadly ovate body. Height greater than length. Anterior margin nearly vertical for about half the height of the shell, thence regularly rounded along the base. Both valves convex on the umbo, the right valve becoming depressed over the body. Hinge-line straight and less than the length of the shell. Beaks anterior, ear short, wing triangular and flat. Surface with lamel- lose concentric strise. Length 30 mm.; height 30 mm. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 2023. Parkhbad Member. Two and one-quarter miles south- east of Cumberiand ?; Williams Eoad, 31/2 miles east of Cumberiand, 1466 ; Williams Eoad, on Polish Mountain, 1289 ?, 1660; National Eoad, Maryland Geological Survey 635 on Polish Mountain, 1196 ?; 2 miles north of mouth of Town Creek 1313 ?, 1642 ?, 1842 ?; 2 miles west of Pawpaw, West Virginia 1493; 214 miles above mouth of Sideling Hill Creek ?; National Eoad west of Tonoloway Eidge. Collection. — Maryland Geological Survey. LlOPTERIA cf. BIGSBYI Plall Plate LXII, Fig. 12. Description. — A large individual, compared with L. ligsbyi, differs from Hall's figure of that species in several respects. The umbo is more attenuate, not appearing to be extended beyond hinge-line and wing is not so sharply defined from umbo by a sulcus. Occurrence. — Jennings Formation, Chemung Member. National Eoad, on Polish Mountain, 2714. Collection. — Maryland Geological Survey. LlOPTERIA MARYLANDICA n. Sp. Plate LXII, Figs. 13, 14 Description. — Shell subrhomboidal, body moderately oblique, broadly ovate; length a little greater than width. Margins regularly rounded ventrally, slightly extended posteriorly, valves moderately convex. Cast slightly concave near anterior and posterior margin. Hinge-line straight, umbo acute, arching over hinge. Ear short, rounded, limited by a sulcus. Wing large, triangular, not sharply defined from body, its margin concave, its extremity not observed. Cast of interior of left valve shows two slightly oblique folds upon hinge, posterior to umbo. Length, 45 mm. ; height 40 mm. The left valve only has been observed. This species closely resembles L. greeni. It differs chiefly in its slightly concave margins and less convex body. It may be a variety of that species. Occurrence, — Jennings Formation, Chemung Member. Town Creek, 2023. Collection. — Maryland Geological Survey. 636 Systematic Paleontology — Upper Devonian LlOPTEEIA AUEICDLATA n. Sp. Plate LXIII, Fig. 1 Description. — Shell small, very convex, body ovate, quite oblique; height two-thirds length. Margin curving regularly from below middle of anterior side to about middle of posterior side. Hinge-line long, straight, ear large for this genus, limited by a broad sulcus near margin. Cardinal margin of ear straight, continuous with hinge-line. Wing triangular, bounded by a broad sulcus, its margin concave, posterior angle acute, produced. Surface marked by fine concentric striae. Length 30 mm.; height 11 mm. A single left valve only has been observed. This specimen is char- acterized by its large ear, the cardinal edge of which is in same line with hinge-line. It resembles L. gabbi in this respect but its body is much more oblique. The reference of this species to the genus Liopteria is not assured, the ear being so large as to place it neax the genus Leptodesmoi. Occurrence. — Jennings Formation, Woodmont MEMBEaa, Ithaca Fauna. Millstone 795. Collection. — Maryland Geological Survey. Genus LEPTODESMA Hall Leptodesma eogeesi Hall Plate LXIII, Fig. 3 Leptodesma rogersi Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 176, pi. xxi, flgs. 1-9. Leptodesma rogersi Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 426, fig. 556. Description. — Shell usually of small size, body ovate, very oblique, length greater than height; anterior and basal margins broadly rounded, posterior margin extended and abruptly recurved. Valves subequally convex above. Eight valve somewhat depressed below, comparatively higher than ihe left. Hinge-line longer than the length of the shell. Surface with fine concentric strife. Length 25 mm.; height 15 mm. Maryland Geological Survey 637 Occurrence. — Jennings Formation, Chemung Member. Two miles south of Oakland, Garrett County. Collection. — 'Maryland Geological Survey. Leptodesma longispinum Hall Plate LXIII, Figs. 4-8 Avicula longispina Hall, 1843, Geol. Surv. N. Y., 4tli Dist, p. 262, fig. 3. Leptodesma longispinum Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 179, pi. xxi, figs. 14, 17-19, pi. Ixxxix, figs. 2-4. Description. — Shell rather small, elongate subrhomboidal, body elon- gate, obliquely ovate, length gi'eater than height; margin from byssal sinus to beyond the base broadly rounded, posterior margin regularly recurved. Posterior wing prominent, depressed on right valve and on both produced into a long narrow spine. Surface convex on both valves broadly depressed by the anterior oblique sinus, this depression dis- tinguishing the species from forms like L. lichas having similar pro- portions but with a broader anterior ventral slope. Fine regular con- centric lines over all the surface. Dimensions of an average specimen; length from anterior to posterior extremity 35 mm. ; height complete 14 mm. This species is quite common in the sandy flags at various localities seldom however attaining the size which it frequently reaches in the Chemung fauna of New York. Occurrence. — Jennings Formation, Chemung Member. ISTear Deer Park; National Eoad 6 miles west of Frostburg; Ellerslie, Pennsylvania, 1508. Collection. — Maryland Geological Survey. Leptodesma agassizi Hall Plate LXIII, Figs. 9, 10 Leptodesmu agassizi Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 182, pi. Ixxxix, figs. 17-19. Description.— Shell of medium size, subrhomboidal; body broadly ovate and more erect than in associated species of the genus. Anterior 638 Systematic Paleontology — Upper Devonian margin broadly rounded belo-vv the byssal sinus ; ventral margin regularly curved. Anterior wing short, hardly depressed, obtuse. Posterior wing not extended beyond the body of the shell. Surface .with concentric growth lines. Length 25 mm. ; height 23 mm. Occurrence. — Jennings Foemation, Chemung Member. Road north of Deer Park Station; Allegany Grove, 2355 ?. Collection. — 'Maryland Geological Survey. Leptodesma medon Hall Plate LXIII, Pigs. 11-15 Leptodesma medon Hall, 1884, Pal. of N. Y., vol. v, pt. 1, sec. i, p. 197, pi. xc, figs, 1-4. Description. — " Shell of medium size, subrhoraboidal ; body broad- ovate, oblique at an angle of about 60° with the hinge-line; length nearly one-third greater than the height; antebyssal margin curving slightly outward, concave at the sinus; basal and posterior margins broadly rounded, passing directly into the wing. Left valve gibbous above, de- pressed-convex below. Eight valve somewhat less convex than the left. The right valve appears to have been somewhat smaller and the base more extended than in the left valve. Hinge-line straight; length a little greater than the height of the shell. Beaks at about the anterior third of the hinge, acute, prominent, arching over the hinge-line. Umbonal region gibbous, descending almost vertically on the posterior, and sloping abruptly on the anterior side. Umbonal angle acute. Anterior end short, separated from the body by a marked sinus; extremity angular, gently rounded below. Wing not defined, broad-triangular, reaching nearly to the posterior end of the body; mai-gin slightly concave; ex- tremity acute. Test thin, marked by concentric striae, which, on the body of the shell, are crowded into fascicles and assume a distinct regu- larity in passing over the wing. The hinge shows one or two slender parallel grooves. Three similar specimens of the left have respectively the following dimensions : Length 32, 32 and 33 mm. ; height 22, 25 and 23 mm. ; and hinge-line 25, 27, and 25 mm. In this species the body of the shell resembles L. robustum and L. patens, but is less oblique to the Maryland Geological Survey 639 hinge-line, the wing less defined, and its posterior extremity not pro- duced into a spine." Hall, 1884. The individuals referred to this species present considerable variation in shape as shown by the figures. Occurrence. — Jennings Formation, Chemung Member. National Eoad 7 miles west of Frostburg; Oakland-Eedhouse Eoad; Allegany Grove, 2020 common, 2215, 2307, 2325 common. Collection. — Maryland Geological Survey. Leptodesma naviforme Hall Plate LXIII, Figs. 16, 17 Leptodesma naviforme HaJl, 1884, Pal. of N. Y., vol. v, pt. i, sec. i, p. 200, pi. xxii, fig. 15; pi. xxlii, flg. 1. Description. — " Shell below the medium size, rhomboidal ; body very oblique, short-ovate; length more than one- third greater than the height; anterior extremity subtruncate; margin curving forward, nearly vertical. Left valve convex below, very gibbous above the middle. Right valve depressed-convex below, gibbous above. Hinge-line straight, more than one-third greater than the height of the shell. Beaks obstuse, situated at the anterior fourth of the hinge-line, prominent, directed slightly forward. TJmbonal region gibbous, sloping abruptly into the wing. Anterior end short, acute. Wing large, not distinctly limited, extending almost to the posterior extremity; margins scarcely concave below; ex- tremity produced, acute. Test marked by fine concentric strise, which are crowded into fascicles at nearly equal intervals, rounded upon the upper part of the body, and subangular on the lower part. The strise are crowded and lamellose on the anterior; on the posterior slope they make a short abrupt curve, passing over the wing with a gently forward direction and curving backward Just below the hinge-line. In the weathered surface of the right valve the concentric undulations are stronger, the postcardinal slope is marked by strong interrupted radii which appear to belong to the intimate structure of the shell. The hinge is marked by a single narrow groove." Hall, 1884. Length 20 mm. ; height 13 mm. 640 Systematic Paleontology — Upper Devonian This species is distinguished from all others in the fauna by its faint, radiating strise^ a feature observed also on the specimens from New York. It is confined so far as observed to a single horizon near the base of the Parkhead fauna. Occv/rrence. — Jennings Foemation, Paekhead Membee. Eoad 1 mile north of Eocky Eun; Williams Eoad, east of Cumberland, 1393; Williams Eoad, on Polish Mountain, 1163; ISTational Eoad, on Polish Mountain, 1196; 2% miles above mouth of Sideling Hill Creek; National Eoad west of Tonoloway Eidge. Collection: — ^Maryland Geological Survey. Leptodesma lichas Hall Plate LXIII, Pigs. 18, 19 Leptodesma lichas Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 232, pi. xxi, figs. 35-39; pi. xci, figs. 19, 20. Description.—'ShQW having proportions similar to those of L. longi- spinum but the umbonal ridge is more conspicuously developed and nearer the hinge, making a shorter cardinal slope and a broader antero-ventral slope, the latter barely depressed by the byssal sinus. The umbo is prominent and overarches on the hinge-line. No extended spine on the posterior extremity. These shells occur occasionally in association with L. longispinum and though smaller than the usual New York examples retain throughout the expression of the species. Length 30 mm. ; height 20 mm. Occurrence.—JsNmNGS Foemation, Chemung Membee. Deer Park; National Eoad west of Prostburg; Oakland-Eedhouse Eoad; Town Creek' 3584 common, 3760, 3963, 4631. Conectwnj—M.aTyla,nd Geological Survey. Leptodesma elongatum n. sp. Plate LXIII, Fig. 20 DescnpUon.-Shell large, elongate subrhomboidal; body spatulate very oblique, length of hinge-line less than one-half length of body. Ad- Maryland Geological Survey 641 terior margin oblique, curving but slightly below the sulcus limiting anterior extremity; ventral margin rounded; posterior margin nearly straight, making a slight angle with anterior margin to which it is nearly parallel. Left valve convex, point of greatest convexity slightly anterior to middle. Umbo obtuse, projecting a little beyond hinge-line. Anterior extremity large, subangular, its surface concave near point, convex to- wards body from which it is separated by a depression which increases in depth towards anterior margin. Wing not much longer than anterior extremity, its posterior margins slightly concave. Separated from body by a depression which becomes deeper near hinge-line. Length of hinge 23 mm.; length of body 48 mm. Eight valve only observed. This species differs from previously de- scribed species in its very long narrow body. Occurrence. — Jennings Formation, Chemung Member. Keyser- Piedmont Eoad, 21/2 miles west of Keyser near top of Chemung; Cum- berland-Barrelville Eoad near top of Chemung, 570 feet west of upper conglomerate. Collection.' — ^Maryland Geological Survey. Family AMBONYCHllDAE Genus GOSSELLETIA Bariois GOSSELLETIA Sp. Plate LXIII, Fig. 21 Description.— Shell triangular, body oblique, length less than height. Anterior margin straight, forming nearly a right angle with cardinal margin at uinbo; ventral margin curving to meet posterior margin. Left valve only observed. Its umbo elevated, side flattened, anterior and dorsal margins abruptly incurved. Hinge-line straight, nearly equalling length of shell. Ligamental area wide, striated. Surface not observed. Length 58 mm. ; height 48 mm. The cast of the interior of a single valve only has been observed, which is not sufficiently well preserved to permit coniident specific determination. 41 642 Systematic Paleontology — Upper Devonian Occurrence. — Jennings Foemation, Chemung Membek. Williams Eoad, on Polish Mountain, 1967. Collection. — Maryland Geological Survey. Family PTERIIDAE Genus ACTINOPTERIA Hall AcTINOPTEEIA Cf. EPSILON Hall Plate LXIY, Pig. 1 Actinopteria epsilon Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 122, pi. xxlii, ■ figs. 4-6, 8. Desa-iption.—Bhell rhomboidal with broad, suberect body. Base broadly curved, posterior side abruptly rounded. Hinge-line straight, ear small, wing well developed. Left valve normally convex ; right valve depressed. The surface of the former bears distinct, fine radial lines with intercalary additions, all crossed by fine concentric strise. On the right valve the radial lines are subdued and tlie concentric strias more con- spicuous. This is one of many species of Actinopteria which appeared in the Ithaca beds of New York and have definite phylogenetic relations with the abundant A. hoydi of the Hamilton fauna. The occurrence of this type of shell in the Maryland strata is of interest. Occurrence. — Jennings Poemation, Chemung Membee. Six miles west of Prostburg, Allegany County. Collection. — Maryland Geological Survey. AcTiNOPTEEiA BOYDi (Conrad) Plate LXIV, Fig. 2 Avicula ioydU Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 237, pi. xli, fig. 4. Avicula guadrula Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 243, pi. xiii, fig. 5. Actinoptera ioydi Hall, 1884, Pal. of N. Y., vol. vi, pt. i, sec. i, p. 113, pi. xix, figs. 2-24. Actinopteria ioydi Grabau and Shimer, 1909, N. Amer. Index Foes., vol. i, p. 449, fig. 592. Maryland Geological Survey 643 Actinopteria hoydi Cleland, 1911, Bull, xxi, Geol Survey Wis., p. 109, pi. xxil, flgs. 7-8. Description. — " Shell of medium size, rhomboidal ; body ovate, varying in proportions, the longitudinal axis forming an angle with the hinge-line of from 45° to 60°; length varying from nearly equal to one-fourth greater than the height; margins regularly rounded below, straight and nearly vertical for a short distance in front; postbasal side extended. Talves convex, the right valve a little less convex than the left. Hinge- line straight from the anterior side of the beak to the posterior extremity. Beak anterior, acute, prominent, inclined forward, rising above the hinge in the left valve. Umbonal region prominent, subtending an acute angle. Ear short, oblique, limited by a deep but not sharply defined sulcus. Wing large, triangular, not distinctly separated from the body of the shell; margin concave; extremity acute. In the right valve the ear is somewhat more extended, the sulcus not strong, but the byssal sinus is marked ; the wing is proportionally larger and usually more acute at the ex- tremity. Test thick ; the left valve, in well-preserved specimens, is marked,,, by numerous strong, simple, sharp rays, which are continuous from the umbo to the margin, with rarely intercalated finer rays ; crossed by regul- lar, sharp, elevated, concentric lanielljE which (in good specimens) are produced into subtubular, spiniform extensions upon the rays. Lines of growth are seen between the lamellse. On the wing the rays are more subdued while the concentric lamellae are strong. The ear is marked only by the crowded concentric striae. On the right valve the radii are obsolete on the body and well marked on the wing, and the lamellose ex- pansions are conspicuous. In some casts they appear as undulating, elevated lamellse. Pallial line extending parallel to the margin of the shell and terminating in a muscular impression on the posterior slope. A small muscular impression is also seen Just in front of the beak, and obscure indications of one or two cardinal teeth. Ligamental area nar- row, striated, marked by two or three slender grooves, which are slightly divergent from the hinge-line." Hall, 1884. Length 20 mm.; height 15 mm. A single valve has been observed, which is probably of this species. 644 Systematic Paleontology — Upper Devonian Occurrence. — Jennings Formation, Woodmont Membee, Ithaca Fauna. Woodmont, 1067. Collection. — Maryland Geological Survey. Genus PTYCHOPTERIA Hall Pttchopteeia sp. Description. — A single specimen has been observed, which is too poor to permit specific identification. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Woodmont about 1000 feet altitude. Collection. — Maryland Geological Survey. Family MYALINIDAE Genus PTYCHODESMA Hall and Whitfield Ptychodesma sp. Description. — A single specimen has been observed which is probably of this genus. Occurrence. — Jennings Formation, Parkhead Member. Williams Eoad, east of Cumberland, 1393. Collection.— M.axyla.ni Geological Survey. Superfamily TRIGONIACEA Family TRIGONIIDAE Genus SCHIZODUS King ScHizoDus CHEMUNGENsis (Conrad) ? Plate LXIV, Figs. 3-5 NucuUtes cJiemungensis Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. vlil, p. 247, pi. xlii, fig. 13. ScUzoaus chemungensis Hall, 1885, pal. of N. Y., vol. v, pt. i, sec. il, p. 453, pi. Ixxv, figs. 37-40, 45, 41?. Schisodm chemungensis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. 1, p. 482, fig. 642. Description.— " Shell large, rhomboidal-ovate ; length one-fourth greater than the height. Anterior margin broadly rounded, curving into Maryland Geological Survey 645 the basal margin, which is sometimes nearly straight posteriorly. Post- inferior extremity angular. Posterior margin obliquely truncate. Car- dinal line straight, less than half the length of the shell. Valves de- pressed-convex below, becoming gibbous in ihe middle and above. In its usual condition of preservation the shell is VC17 much depressed. Beaks at about the anterior third, prominent. Umbonal slope subangular, defined above, less prominent below. Surface marked by fine concentric strise of growth, which are partially preserved in the cast. Three specimens measure respectively 33, 35, and 43 mm. in length, and 25, 29, and 30 mm. in height. This species resembles 8. appressus in form and pro- portions and is probably only a variety of that species which lived under different conditions." Hall, 1885. The shells referred to this species have a more gibbous umbo and are more convex than the specimens figured by Hall appear to be. They are also somewhat smaller in size. They differ from S. oherni in being larger, more transverse, more obliquely truncated behind, umbonal slope more angular. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 3496 cf., 3453 abundant, 4631 ? Collection. — Maryland Geological Survey. SCHIZODUS CHEMUNGENSIS VAE. QUADRANGULAEIS Hall Plate LXIV, Pig. 6 Cythero&on (SeMzodus) quadrangularis Hall, 1870, Preliminaty Notice Lamellibr. Shells, pt. li, p. 96. ScMzodus chemungensis var. guadranglaris Hall, 1884, Pal. of N. Y., vol. v, pt. 1, p. 454, pi. Ixxv, figs. 31-34, 36. ScMzodus guadrangularis Grabau and Shimer, 1909, N. Amer. Index Foss., vol. 1, p. 482, fig. 642. Description. — Shell subrhomboidal, with angles rounded; beaks sub- central ; anterior margin semicircular, posterior sloping and subtruncate ; postlateral angle due to prominence of umbonal ridge, conspicuous but not acute; posterior slope from the umbonal ridge concave; umbones concave and sloping regularly forward and downward. Surface smooth. 646 Systematic Paleontology — Upper Devonian This species is distinguished from allied Devonian forms of the genus by its low umbonal ridge and direction of its posterior margin. It is a well-known Chemung and Ithaca fossil in New York. Length 25 mm.; height 20 mm. Occurrence. — Jennings Formation, Chemung Member. Near Deer Park Station. Collection. — Maryland Geological Survey. SCHIZODUS OHEENI n. sp. Plate LXIV, Pigs. 7-14 Description. — Shell small, varying from rhomboidal to suborbicular, the latter shape more frequent in young shells; length nearly equal or slightly greater than width; hinge-line short, convex. Posterior margin gently curved, descending obliquely to postinferior extremity, or rounded; anterior margin curving to ventral margin; postinferior extremity ex- tended in some individuals, or in other cases but slightly so. Valves convex to gibbous; beaks anterior or nearly subcentral in position, gibbous, elevated above hinge-line, incurved; umbonal slope rounded to angular; surface descending abruptly to postcardinal margin, this portion being convex to concave; convex towards anterior and ventral margins. Surface smooth, bearing faint concentric striae. Test thick, especially so near umbo. Interior shows deep anterior and posterior muscular scars, the anterior scar a little higher ; right valve bearing two diverging teeth with smooth edges, a slight depression between them ; left valve with two corresponding depressions separated by a slightly bifid elevation which appears as a bifid pit beneath beak in casts of interior. Length 15-17 mm.; height 14-16 mm. in large individuals. This species is characterized by its strong muscular scars, small size, small umbo neatly incurved over hinge, and oblique shape. The test is quite thick over umbo so that the exterior appears much more gibbous than casts of interior. The shape is quite variable. It has the character- istic hinge of the genus Schizodus and is not clearly referable to any pre- viously described species. Specimens occurring at higher horizons are usually somewhat larger than those from the lower horizons. This species occurs chiefly in conglomeratic sandstones. Maryland Geological Survey 647 Occurrence. — Jennings Formation, Chemung Member. Allegany Grove, 26C2; Williams Eoad, on Polish Mountain, 2382; Town Creek, 2228 common, 2391, 2496 ?, 3593, 4631; near Pennsylvania-Maryland state line, west of Tonoloway Ridge near school house in lower conglom- erate zone. Millstone, 2332, 3116 abundant. A smaller form, probably of this species, occurs at Town Creek, 3760, 3870. Parkhead Member. Two miles west of Pawpaw, West Virginia, 1763; Millstone, 1773 abundant. Collection. — Maryland Geological Survey. Sghizodus frostbergensis n. sp. Plate LXIV, Pig. 15 Description. — Shell small, elliptical-ovate, length about 1.4 times height; hinge-line short. Anterior margin rounded; posterior margin oblique, nearly straight above, abruptly rounded at junction with ventral margin; ventral margin curved. Beaks situated about one-third length of shell from anterior extremity, small, slightly elevated above hinge-line, incurved. Valves convex, somewhat gibbous beneath umbo ; surface slop- ing regularly towards margins; umbonal slope not angular, indistinct. Anterior and posterior muscular scars distinct. Surface not distinctly observed, probably smooth. Length 14 mm.; height 10 mm. This species is quite distinct from previously described species of this genus in its general expression. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 3760, 3870. Collection. — ^Maryland Geological Survey. SCHIZODUS TRIGONALIS n. Sp. Plate LXIV, Figs. 16-18 Description.— Shell large, triangular to rhomboidal; equivalve; slightly longer than high; hinge-line short. Anterior and posterior margins slightly curved, oblique; ventral margin curving strongly at its junction 648 Systematic Paleontology — Upper Devonian with anterior margin, more abruptly at junction with posterior margin. Beaks subeentral, slightly anterior to middle of valve; somewhat elevated, incurved over hings-line. Valves convex, slightly gibbous near umbo; surface sloping rapidly towards anterior margin, slowly towards posterior and ventral margins. Umbonal angle not distinct. Casts of interior show a bifid tooth in right valve; posterior and anterior muscular scars well marked. Length of larger individual 50 mm. ; height 45 mm. This species differs from previously described species of ScMzodus in its nearly central umbo and almost equilateral triangular outline. It somewhat resembles a shell referred with doubt to S. chemungensis by Hall in the Paleontology of New York, vol. v, part i, section ii, pi. Ixxv, fig. 41 but its umbonal slope is less distinctly angular. An individual illustrated in pi. Ixiv, fig. 18, is questionably referred to this species. Its outline suggests the genus Edmondia. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 2023, 2228. Paekhead Member. Williams Eoad, on Polish Mountain, 1352; Millstone 1772 ?. Collection. — Maryland Geological Survey. Superfamily PECTINACEA Family PECTINIDAE Genus AVICULOPECTEN McCoy AviCULOPECTEN cf. OANCELLATUS Hall Pecten cancellatus Hall, 1843, Geol. of N. Y., Rept. ith Dist., p. 265. Aviculopecten cancellatus Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 18, pi. vii, figs. 12, 14-19. Description. — Shell rather small, oblique-ovate ; beak subeentral. Sur- face covered with fine radial striae alternating in size and crossed by delicate cancellating lines. A single valve has been observed which is questionably identified with this species. Maryland Geological Survey 649 Occurrence.— JENmxGs Formation, Parkhead Member. Williams Road, on Polish Mountain, 1289. Collection. — Maryland Geological Survey. AVICULOPECTEN ? sp. Descrlption.~An imperfect valve which has been observed in the Chemung at Allegany Grove is probably referable to this genus. It has not been figured. Occurrence.— jEi^mnGS Formation, Chemung Member. Allegany Grove, 1633. Collection. — Maryland Geological Survey. Genus LYRIOPECTEN Hall Lyriopecten tricostatus (Vanuxem) Plate LXV, Fig. 1 Avicula tricostata Vanuxem, 1842, Gaol, of N. Y., Rept. 3d Dlst., p. 179, fig. 1. Lyriopecten tricostatus Hall, 1884, Pal. of N. Y., vol. v, pt. i, p. 48, pi. iv, fig. 11; pi. vii, fig. 26; pi. x, figs. 6-12. Description. — Shell large, subcircular or obliquely broad-ovate; beak subeentral. Wings relatively small and smooth. Surface marked by strong simple and distant radial costse most of which reach the umbo, those of the major series being 14-16 in number. These are abruptly elevated from the general surface and in the broad flat interspaces are finer striae usually of two orders, the larger in the middle and the lesser at the sides. This is a very well-characterized species of the New York Chemung fauna. Few examples have been observed in the Maryland rocks. Length 45 mm.; height 45 mm. Occurrence. — Jennings Formation, Chemung Member. Oakland- Altamont Eoad ; Oakland-Eedhouse Eoad ; National Eoad 6 miles west of Frostburg-; 2 miles west of Pawpaw, West Virginia ; on county road near top of Jennings, top of Green Eidge. Collection. — Maryland Geological Survey. 650 Systematic Paleontology — Uppeii Devonian Superfamily MYTILACEA Family MODIOLOPSIDAE Genus MODIOMORPHA Hall MODIOMORPHA SUBANGULATA Hall Plate LXV, Fig. 2 MoMomorpha subangulata Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. li, p. 287, pi. XXXV, figs. 10, 11. Description. — ■" Shell of medium size, elongate subovate, wider behind ; length more than twice the height, basal margin slightly arcuate, abruptly rounding at the extremities ; posterior margin acutely rounded below and obliquely subtruneate to the cardinal line; cardinal maxgin nearly straight. Anterior end rapidly declining from the beak and abruptly rounded below. Valves moderately convex in the posterior part, and gib- bous and subangular in the umbonal region. There is a broad depression or sinus which extends from Just posterior to the beak to the basal margin near the middle of the length of the shell. Hinge-line slightly oblique, extending about half the length of the shell. Beaks almost anterior, prominent, small, angular, incurved and elevated above the hinge-line. Umbonal region gibbous, with a prominent ridge extending from the beaks to the postbasal extremity, angular in its upper portion, becoming more subdued toward the posterior end. Test thick, marked by fine con- centric strise, which are sometimes fasciculate, making stronger ridges on the surface. Anterior end marked by a strong, muscular impression just below the bealc, close to the anterior margin. A large individual of this species has a length of 55 mm.; and a height of 26 mm. A smaller specimen has a length of 39 mm., ,and a height of 19 mm. This species bears some resemblance to M. svialata, but differs in its much stronger and more aJigular umbonal ridge, which reaches to the postbasal ex- tremity, the basal margin is more arcuate, the cardinal and basal margins are more nearly parallel, and the anterior end is shorter." Hall, 1885. Occwrmce.— Jennings Foemation, Chemung Membee. Williams Road, on Polish Mountain, 2383. Collection. — ^Maryland Geological Survey. Maryland Geological Survey 651 Genus GONIOPHORA Phillips GONIOPHOEA HAMILTONENSIS Hall ' Plate LXV, Fig. 3 Occurrence.— Jennings Formation, Paukhead Member. Williams Eoad, 1353, 2 miles west of mouth of Town Creek, 1842; Town Creek, 1679, 1863; 2 miles west of Pawpaw, West Virginia, 1484 common; 2Vi; miles above mouth of Sideling Hill Creek. Woodmont Member, Ithaca Fauna. Two miles west of Pawpaw, West Virginia, 1388. Collection. — ^Maryland Geological Survey. GONIOPHORA TRUNCATA Hall Plate LXV, Figs. 4-6 aoniophora truncata Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. ii, p. 298, pi. xlii, figs. 9, 10; pi. xliv, figs. 1-5. Goniophora truncata Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 519, fig. 699. Description.- — "Shell of medium size, trapezoidal; length more than twice the height; basal margin rounded in the anterior part, slightly sinuate a little anterior to the middle and nearly straight or slightly curv- ing to the postbasal extremity; posterior margin obliquely subtruncate, slightly curving. Cardinal line short, straight. Anterior end short, rounded, limited by an oblique sinus extending from the beak. Valves convex below the umbonal ridge, gibbous in the umbonal region ; the area above the umbonal ridge is flat or concave, or sometimes a little convex. Beaks anterior, acute and incurved ; umbo prominent, angular. Umbonal ridge strongly defined, acutely angular, extending to the postbasal ex- tremity. Test of moderate thickness ; entire shell marked by fine, lamel- lose, concentric striae, and that portion of the surface between the umbonal ridge and the sinus is marked by strong, elevated, radiating strise, which dominate the concentric strise. The test is raised into a crest along the umbonal ridge, especially in the posterior half of its length. Anterior muscular impression large and deep, situated close to the anterior margin, ^ For description and synonymy see page 271. 652 Systematic Paleontologt — Upper Devonian truncated posteriorly by a strong ridge or clavicle. Pallial line parallel to and near the basal margin, appearing as a shallow groove, recurving near the postbasal extremity and terminating in a broad, muscular impression, the anterior margin of which is near the center of the length of the shell. A specimen of medium size is 54 mm. in length and 20 mm. in height. This species is very closely allied to G. perangulata of the Schoharie grit, and it is possible that they are identical. In the specimen fig. 3 of plate xl, the hinge-line is shorter than in specimens of G. per- angulata, but the comparative length of the hinge-line appears to be variable in the two species." Hall, 1885. This species is distinguished from others in the fauna by its small size, its oblique truncation posteriorly, and very angular posterior umbonal slope. The individuals observed in Maryland seem uniformly smaller than those figured by Hall from New York, and" do not show a distinct sulcus in front of umbonal slope. Occurrence. — Jennings Poemjation, Parkhead Member. Williams Eoad, on Polish Mountain, 1660 common; 3i/^ miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. GONIOPHORA GLAUCA Hall Plate LXV, Fig. 7 SanguinoUtes glaucus Hall, 1840, Prelim. Notice Lammellibr., Pt. ii, p. 38. Goniophora glaucus Hall, 1885, Pal. of N. Y., vol. v, pt. i, sec. ii, p. 299, pi. xliii, fig. 16 ; pi. xllv, figs. 10-17. Description. — •" Shell large, trapezoidal ; length once and a half greater than the height; basal margin gently curved, sometimes scarcely sinuate anterior to the middle; posterior margin obliquely truncate; cardinal line nearly straight or slightly oblique; anterior end declining from the beaks and abruptly rounded below. Valves moderately convex below, some- times becoming gibbous on the umbonal region. Beaks subanterior, small and closely appressed; umbo prominent; umbonal ridge more or less strongly defined and distinctly angular, extending to the postbasal extrem- ity. Test of moderate thickness, marked by regular, concentric, thread- Maryland Geological Survey 653 like striae, which are abruptly recurved on the umbonal ridge; anterior muscular impression deep and strong. The pallial line extends parallel to the basal margin, and abruptly recurves over the umbonal ridge, terminat- ing in a large shallow posterior scar upon the cardinal slope. The hinge is furnished with a strong triangular fold beneath the beak of the left valve, and a corresponding depression in the right valve. Three specimens measure respectively 90, 91, and 49 mm. in length, and 49, 39, and 38 mm. in height. This species closely resembles G. hamiltonensis, but differs principally in its proportionally shorter form, more convex basal margin and more direct umbonal ridge." Hall, 1885. The individual observed agrees with Hall's figures of New York speci- mens save that the posterior extremity is a little more obliquely truncated. Occurrence. — Jennings Formation, Parkhead Member. Four miles southeast of Pratt, on White Sulphur Branch, rare. Collection. — Maryland Geological Survey. Order TELEODESMACEA Superfamily GYPRICARDIACEA Family PLEUROPHORIDAE Genus CYPRICARDELLA Hall Cyprioardella bellisteiata (Conrad) ^ Plate LXV, Figs. 8-10 This species differs from C gregaria in possessing much stronger con- centric striae which are distinct even in casts of the interior. It differs from G. marylandica in being larger, less convex in its proportions as well as in occurring at a lower horizon. Bather common in the Parkhead fauna. Occurrence. — ^Jennings Formation, Parkhead Member. One and one half miles south of Round, West Virginia; 2 miles north of mouth of Town Creek, 1642, 1716. Collection. — ^Maryland Geological Survey. ' For synonymy and description see page 273. 654 Systematic Paleontology — Upper Devonian Cypeioaedella maeylandica n. sp. Plate LXV, Figs. 11-15 Description. — Shell considerably larger than C. nitidula, subcircular or somewhat obliquely ovate. Beaks anterior; hinge-line gently convex; posterior margin slightly extended and narrowed, rounding somewhat abruptly to the broadly and regularly curved base. The anterior margin is short and inflected beneath the beak, curving outward to the anterior extremity of the shell which lies near the middle transverse axis. Beak depressed ; umbo full, regularly convex, surface falling away equally to all margins except toward the hinge where the convexity is carried farther. Faint trace of a depression on the cardinal slope. Surface marked by regular concentric elevated lines which are at times bunched together in groups or festoons with depressed intervals. This shell has much the aspect of some well-known forms of Nucida but though no single specimen displays the hinge in condition for illus- tration, it is evident from certain impressions that the cardinal struc- ture is that of Cypricardella. It differs distinctly in form and contour from any New York species of the genus and approaches most closely its associate C. nitidula from which it may be distinguished by its obliquely ovate form and prevailing larger size. Length 16 mm. ; height 15 mm. The individuals occurring in the upper ferruginous beds of the Che- mung are small and depauperate though they seem referable to this species in other respects. Occurrence. — Jennings Formation, Chemung Member. Near Deer Park; National Eoad west of Frostburg; Oakland-Altamont Eoad; Town Creek 2496, 3969, 4631. Collection. — Marj'land Geological Survey. Cyprigardella gregaria (Hall) Plate LXV, Figs. 16-18 Microdon gregarius Hall, 1870, Prelim. Notice Lamellibr., pt. ii, p. 32. Microdon (Gypricardella) gregarius Hall, 1884, Pal. of N. Y., vol. v, pt. 1, p. 309, pi. Ixxiii, figs. 1-6; pi. Ixxxiv, figs. 1-4. Maeylanu Geological Survey 655 Cypricardella gregaria Grabau and Shimer, 1909, N. Amer. Index Foss., vol. i, p. 535. Description. — Shell rhomboid-ovate, broadest posteriorly; hinge-line straight and more than half the length of the shell; posterior margin sloping, lower margin subtransverse ; beaks anterior; valves depressed convex; surface smooth or with fine concentric lines. This species lends itself to ready recognition by its slight convexity and smooth valves, in which respects it may be distinguished from the common member of the genus, C. bellistriata. C. gregaria occurs occa- sionally in the Ithaca fauna of New York and is locally abundant in the Chemung fauna. Length 30 mm.; height 14 mm. Occurrence. — Jennings Formation, Pakkhead ? Member. In blocky argillaceous sandstone, 5 miles west of Piney Grove on west side of Green Eidge, Allegany County. Collection. — Maryland Geological Survey. Cypricardella gregaria (Hall) var. Description. — The specimens referred to this variety do not differ in proportions from the typical C. tenmstriata of Maryland, but they are usually smaller, while the surface is without distinct elevated striae. They differ from C. gregaria in being proportionally longer, umbonal slope not angular, posterior extremity less oblique, convexity slight. Length 30 mm. ; height 18 mm. Occurrence. — Jennings Formation, Chemung Member. Allegany Grove, 1750, 2662. Pakkhead Member. Williams Eoad, on Polish Mountain, 1352; 2 miles north of mouth of Town Creek, 1282, 1642; 4 miles southeast of Pratt on White Surphur Branch; Town Creek, 1679, 1851 ; 3 miles west of Pawpaw, West Virginia, 1763 ; Berkeley Springs, West Virginia, 1554 to 1566. A variety occurs in the Parkhead at Mill- stone at 1772, which is more elongate, its inferior-anterior angle more produced. Collection. — Maryland Geological Survey. 656 Systematic Paleontology — Uppek Devonian Cypeioaedella tenuisteiata (Hall) ' Plate LXVI, Pigs. 1-5 The individuals observed in Maryland are somewhat longer proportion- ally than is nsual in the species in New York as shown by Hall's figures. This species is characterized by having strong concentric strias on umbo. It differs from C. hellistriata in having a more acute posterior-inferior angle, weaker strife save on umbo, and in hinge-tooth. It differs from C. gregaria, which it closely resembles, in having much stronger stria on umbo and also in its proportions. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 3132. Parehead Member. Williams Eoad, on Polish Mountain, 1660 ; 3 miles north of mouth of Town Creek, 1716 ; Town Creek, 1605 ; 3% miles above mouth of Sideling Hill Creek; Woodmont, 1385. Collection. — Maryland Geological Survey. Cypeioaedella nitidula n. sp. Plate LXVI, Figs. 6-13 Description. — Shell rather small, subcircular in outline, slightly trun- cate on posterior margin, expanding somewhat posteriorly; beak anterior; hinge-line curved. Surface regularly convex, with broad and low but dis- tinct umbonal ridge sloping posteriorly to margin; depressed between umbonal ridge and hinge ; covered with regular and, for this genus, strong, rounded and continuous concentric ridges. On internal casts the cardinal area appears broad and subtriangular centrally, extending backward to the posterior extremity of the shell. A deep central socket in the right valve is bounded by low ridges and in the left valve is a strong central tooth with lateral depressions for the reception of the teeth of the other valve. Anterior and posterior muscular scars well defined. Central area more of less decidedly marked by an oblique ridge. An average specimen has a length of 11 mm. and extreme height of 10 mm. 'For synonymy and description see page 275. Maryland Geological Survey 657 This very pretty and '^^•ell-defined species has the external aspect of a nuculoid but carries the hinge cliaracters of Cypricardella in quite re- markable development compared with the usual condition in which these have been heretofore observed. On this account the species is of more than ordinary interest as exemplifying the hinge characters of a genus in which they have not been well understood. Occurrence. — Jennings Formation, Chemung Member. Eoad north of Deer Park Station in buff sandstone, Garrett County; a few miles west of Frostburg. Collection. — Marj'land Geological Survey. CYPRICARDELIiA CUMBEELANDI.E n. Sp. Plate LXVI, Pig. 13 Description. — Shell subrhomboidal to subcircular, length about one- fifth greater than height. Anterior and posterior extremities rounded, ventral and cardinal margins curved, umbo anterior, not promment. Surface ornamented by strong concentric stria. Interior unknown. Length 26 mm.; height 23 mm. This species differs from Cypricardella hellistriata in being more cir- cular, less constricted anteriorly and not so distinctly truncated poster- iori}', umbonal slope less angular. It resembles C. marylandica but is much larger in size, more circular in outline, its anterior margin less oblique, its concentric striaj coarser. Only two poorly preserved valves have been observed, which do not seem clearly referable to any previously described species. Occurrence.— 3 mm^Gs Formation, Chemung Member. Allegany Grove, 2340. CoZZerfw»i.— Maryland Geological Survey. Cypricardella ceassa n. sp. Plate LXVI, Figs. 14-20 Desaription.-miAl small, subrhomboidal, height about eight-tenths or eight-ninths length, umbo anterior, cardinal margin forming a slight 42 C58 Systematic Paleontology — Uppek Devoxiax angle over umbo. Anterior extremity nearly on a line with middle of length of valve; posterior margin roimding somewhat abruptly to ventral margin. Shell quite convex, umbo full, rounded; surface sloping regul- larly from umbo to margins, umbonal ridge rounded, not distinct. Shell massive. Interior shows an oblique tooth in left valve corresponding to a depression in right valve; pallial line distant from margin. Surface ornamented by faint concentric lines. Length 20-25 mm. ; height 16-19 mm. This species approaches C. gregaria but differs in its more massive shell, marked pallial line, more elliptical and less rhomboidal shape, umbonal slope scarcely angular. Occurrence. — Jei^nings Poemation, Chemung Membee. Williams Eoadi on Polish Mountain, 2142 ?; Town Creek, 2132 ?, 2228 ? abun- dant; Millstone, 2761 abundant. Collection. — Maryland Geological Survey. Cypeicaedella ? sp. Description. — Several impressions and exteriors and interiors indicate the presence of another species of this genus of transversely elongate form, with fine concentric surface striations and low postumbonal ridge situated close upon the postlateral slope. The outline of the shells ap- proaches that of C. tenuistriata Hall, a Hamilton and Ithaca species in New York, but in the position of the posterior ridge they are distinct. The material obtained is insufficient for final determination. Length 38 mm. ; height 32 mm. Occurrence. — Jennings Formation, Chemung Member. iSTational Eoad a few miles west of Prostburg. CoZZec/iow.— Maryland Geological Survey. Maryland Geological Survey 659 Genus CYPRICARDINIA Hall Cypeicaedinia elegans n. sp. Plate LXVI, Fig. 31 Description. — Shell of medium size, subrhomboidal elongate; ventral margin nearly straight, slightly sinuate posterior to middle. Posterior extremity obliquely truncate, abruptly rounded below; cardinal margin nearly straight; anterior end projecting slightly, rounded below. Valves quite convex near umbo; umbonal slope prominent, rounded, with a conspicuous sinus anterior to it. Surface marked by concentric, sub- equally distant lamellose undulations, between which are fine concentric strise. Length 37 mm.; height 15 mm.; thickness 11 mm. The generic .relations of this species are not fully determined, the exterior of one valve only having been observed. The ornamentation is that of the genus Cypricardinia. The interior of a variety of this species is, however, known. This species closely resembles C. indentata of the Onondaga and Hamilton of New York. It differs from that species in shape, not being ovate, the posterior end being little wider than the anter- ior end at umbo, while the hinge-line is shorter. It also differs in orna- mentation. It resembles species of Goniophora hut the umbonal slope is not so angular as in that genus, while the ornamentation is that of the genus to which it is referred. Occurrence. — Jennings Formation, Chemung Member. Bellegrove, 300 feet west of schoolhouse. Collection. — Maryland Geological Survey. Ctpricaedinia elegans var. angusta n. var. Plate LXVI, Figs. 22-24 Description. — This variety differs from the typical form in having a much more angular umbonal slope and in being proportionally somewhat higher. The cast of the interior shows distinct scars for attachment of the anterior adductor muscles and small scars above and posterior to them. 660 Systematic Paleontology— Upper Devonian which probably served for the attachment of the pedal muscles; pallial line distinct; cardinal area deeply striated anteriorly to umbo, stria curved. A posterior lateral tooth or slender fold is parallel to cardinal margin. The valves are unequal in convexity, a feature not well shown in figure. Length 50 mm.; height 20 mm. A larger amount of material may show this to be a distinct species. Occurrence.— JwmsGS Fobmation, Chemung Member. Town Creek, 3578, 3584 common. CoZZerfton.— Maryland Geological _ Survey. Superfamily LUCINACEA Family LUCINIDAE Genus PARACYCLAS Hall Pahacyclas marylandica n. sp. Plate LXVI, Fig. 35 Description. — Shell of medium size, su.bcircular ; height equal to or slightly greater than length; pallial margin regularly curving from ex- tremities of hinge; cardinal line short. Valves regularly convex, lenticu- lar in shape. Beak slightly anterior to middle, small, appressed, closely incurved, rising but little above hinge-line; umbonal slope limited by a shallow furrow extending to about middle of posterior extremity. Test thin, bearing concentric striae which are in fascicles at irregular intervals. Length 25 mm. ; height 23-25 mm. This species closely approaches F. ellipiica of the Onondaga, differing chiefly in its smaller size, less convexity of valves, umbo slightly less pronounced. It resembles that species so closely, however, that it may be regarded simply as a mutation of that form. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 3770. Collection. — Maryland Geological Survey. Maryland Geological Survey 661 Class GASTROPODA Subclass STREPTONEURA Order ASPIDOBRANCHIA Suborder RHIPIDOGLOSSA Family PLEUROTOMARllDAE Genus PLEUROTOMARIA Defrance Pleueotomaeia (Gyroma) captllaeia Conrad Plate LXVII, Pigs. 1-3 Pleurotomaria capillaria Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 271, pi. xvi, fig. li. Pleurotomaria capillaria Hall, 1861, Description of New Species of Fossils, p. 17. Pleurotomaria capillaria Hall, 1862, 15th Rept. N. Y. State Cab. Nat. Hist., p. 45, pi. V, fig. 2. Pleurotomaria capillaria Hall, 1876, Illus. Devonian Foss. Gastropoda, p. 20. Pleurotomaria capillaria Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 77, pi. xx, figs. 18-21. Gyroma capillaria Pernor, 1907, Syst. Sil. Boheme, vol. iv, th. li, p. 25. Gyroma capillaria Grabau and Shlmer, 1909, Index Foss. N. Amer., vol. i, p. 647, fig. 882. Description. — "Shell turreted, one-fourth to one-third higher than wide. Volutions four or more, somewhat rapidly increasing in size, the last one ventricose, subangulated above by two or three prominent revolving carinse, and rounded on the lower side. Aperture subrhomboidal. Sur- face on the upper side of the volutions marked by two or three revolving carinse, with finer intermediate ones on strong striae, and all are erenu- lated by finer distant transverse strite ; lower side of volutions marked by regular, strong, revolving cariniform strige, which are more approximate as they approach the umbilical depression, and all crenulated by con- centric striffi. Peripheral band narrow and prominent, margins carinate, and the intermediate space marked only by curving strise. Above and below the band there is usually a broader smooth space than between the cariniform striae. In some specimens the transverse striae are con- spicuous only in crossing the revolving stris, while in others they are 662 Systematic Paleoxtologt— Upper Devonian conspicuous and dominate the revolving stria. In nearly all the speci- mens there is a distinct alternation in the strength of the revolving lines, and the finer ones become obsolete." Hall, 1879. Length 23 mm.; diaiu. 20 mm. Excellently preserved and characteristic specimens of this recurrent Hamilton species are present in the Parkhead. It may be readily recog- nized by its sculpture and by the revolving peripheral band characteristic of this genus. Occurrence. — Jennings Formation, Pakkhead Member. Kocky Eun ?; Town Creek, 1863; 2 miles west of Pawpaw, 1493 common; 21/^ miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Pledeotomabia ? sp. Description. — A greatly, compressed individual found at Ellerslie, Pennsylvania, is doubtfully referred to this genus. It is not sufficiently well preserved to permit illustration. Occurrence. — Jennings Formation, Chemung Member. Ellerslie, Pennsylvania, 1316. Collection. — Maryland Geological Survey. Genus MURCHISONIA d'Archiac and de Vemeui! The genus Murchisonia was formerly made to contain species of many distinct generic types. Further study of these forms has shown that it is desirable to separate them into a number of distinct genera upon the basis of their exterior ornamentation and internal structure. Two of these genera are present in the Jennings fauna, Ilormotoma and Ectomaria. Murchisonia ? sp. Description.— A large species of this genus is found with some fre- quency in the form of external casts but in no instance are the specimens so preserved as to justify an attempt at their identification. These shells attain a length of 50-60 mm. with a basal width of 12-14 mm. and have r-8 whorls. Makyland Geological Survey 663 They are distinguished from the species of Loxonema with which they are associated by their extremely elongate, much narrower form. Occurrence. — Jennings Formation, Chemung Member. Along Trout Eun, south of Oakland, and near Mountain Lake Park; along Green Glade Eun, in Garrett County, and 7 miles west of Frostburg on the National Eoad. Collection. — Maryland Geological Survey. Genus HORMOTOMA Salter emend J. Donald HORMOTOMA BISTRIATA n. sp. Plate LXVII, Fig. 4 Description. — Shell elongate, turretiform, volutions 6 or more, en- larging gradually, last volution scarcely more inflated. Sulcus deep, volutions flattened on periphery. Surface ornamented by two revolving striae bounding a concave band. Length 13 mm. ; diameter at aperture 5 mm. The exterior of a single specimen has been observed which does not seem referable to any previously described species. Occurrence. — Jennings Formation, Paekhead Member. Two and one-half miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Genus ECTOMARIA Koken ECTOMARIA MARTLANDICA H. Sp. Plate LXVII, Figs. 5-8 Description. — Shell elongate, turretiform ; apical angle, small, number of volutions unknown, aperture subelliptical. Surface ornamented by distinct, elevated, thread-like revolving carina;, 3 to 5 in number, 3 of which bounding the peripheral band are slightly more elevated than the others. Peripheral band about midway between the sutures or a little nearer lower suture. One carina, or occasionally two, situated above band and two, usually, below it. There are obscure indications of fine transverse striae on upper side of volution. 664 Systematic Paleontology — Upper Devonian Length of largest specimen observed 30-25 mm.; diameter at aperture 6-7 mm. The genus Ectomaria is regarded by Perner as synonymous with the genus Solenospira of Ulrieh.'' It closely approaches Hormotoma but dif- fers in having the two revolving peripheral carinse more widely separated, while there is no true peripheral band between them as in Hormotoma. Again Hormotoma possesses only two revolving carinas while Ectomaria may have a larger number. This species differs from E. ecclesice in its much larger size, more rounded volutions and in having 3 or more revolv- ing carina. The specimens iigured apparently differ in their apical angles. The medium angle is correct. The drawings were made from squeezes and the apparent differences are imperfections due to this cause. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 2228. Parkhead Member. Williams Eoad, on Polish Mountain, 1660; 2 miles west of Pawpaw, 1493; 2^ miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Ectomaria ecclesice n. sp. Plate LXVII, Pigs. 9-12 Description. — Shell small, extremely terete. Whorls, at full growth not less than 12, each bearing a prominent slit band with elevated mar- gins, from which the surface of the whorl slopes abruptly above and below, the upper slope being twice the width of the lower. Sutures deep, the whorls thus outstanding prominently and angularly. Surface marked by fine raised concentric lines converging abruptly backward on the upper and lower parts of the whorl to meet the slit band. This ornament is not retained on the casts from the sandstones. Length of average speci- men 13 mm., width of body whorl 3 mm. This species approaches closely M. micula Hall from the Hamilton fauna of New York (see Pal. N. Y., vol. v, pt. ii, p. 93, pi. xxi, fig. 11) ^ Syst. Sil. Boheme, vol. iv, th. ii, p. 133. Maryland Geological Survey 665 but is a more slender shell with more prominently outstanding whorls. Where found in the sandstones it is very abundant. Occurrence. — Jennings Formation, Chemung Member. In loose blocks of yellow sandstone with Palceoirochus pm'cwrsor, near Deer Park Station, and in place near Trout Eun, 3 miles south of Oakland. Parkhead Member. Also in olive shales near the base of the section on the west slope of Polish Mountain. Collection. — Maryland Geological Survey. Family BELLEROPHONTIDAE Genus BELLEROPHON Montfort Bellerophon nactoides n. sp. Plate LXVII, Figs. 13-16 Description. — Shell of medium dimensions for this genus, much en- rolled with aperture but slightly expanding. Whorls full and rounded but narrow. Peripheral seam distinguishable over the entire exposed whorl and becoming very prominent over the last half or two-thirds volution where it is abruptly and sharply elevated. The surface at either side of the keel-like seam is noticeably depressed into revolving grooves. Aperture deeply and sharply emarginate at the seam, the sides bending outward in a broad curve. Surface of the shell marked by concentric striae which become rugose near the aperture and are there interspersed with sparsely scattered pustules. Diameter of shell 15 mm. ; width of aperture 13 mm. This shell is characterized by its cariniform seam and revolving de- pressions as well as by the tubercular ornamentation of its apertural region. It is a true Bellerophon and has so much the general aspect of the New York Chemung species B. nactus (see Pal. N. Y., vol. v, pt. ii, p. 131, pi. xxvi, figs. 17, 18) that it is given the above designation. The sparse pustules of the surface suggest the ornament of the Chemung species B. mcera Hall {idem. pi. xxv, figs. 9-14; pi. xxvi, figs. 19-33). Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. On the road west of Tonoloway Hill, Allegany County. Collection. — ^Maryland Geological Survey. G66 Systematic Paleontology — Upper Devonian Bellekopi-ion claeki n. sp. Plate LXVII, Pigs. 17-20 Description. — Shell subglobose ; diameter of shell about equal to great- est diameter of volution at aperture. Inner volutions small, gradually enlarging to middle of outer volution, from which point it expands rapidly to aperture. Aperture expanded; peristome sinuate in front, slightly auriculate on side. Umbilicus small, apparently open. Surface bearing a distinct dorsal carina and ornamented by regular equidistant tine transverse striae, which bend backwards in approaching carina over which they pass with a marked retral curvature. Diameter of shell usually 8-12 mm., diameter of aperture same. This species approaches B. mwrw in form but is much smaller and dif- fers in ornamentation. It resembles B. acwtilircuta in ornamentation but is more globose and has a distinct carina. It also resembles B. pelops of the Onondaga in some respects. This is a common and characteristic species of the Parkhead, rarely occurring in the Chemung. It is named in honor of Wm. Bullock Clark, State Geologist of Maryland. Occurrence. — Jennings Formation, Chemung Member. Two miles north of mouth of Town Creek, 1949; Town Creek, 2228. Parkhead Member. Williams Eoad, on Polish Mountain, 1660; Town Creek, 1679 abundant, 1851 abundant; 4 miles south of Pratt abundant; 2 miles west of Pawpaw, 1493; Little Orleans; 2% miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. BeLLERPHON cf. CLARKI Description. — A species of Bellerphon resembling B. clarhi is found in the Ithaca fauna at Yellow Springs. It differs from B. clarhi in possess- ing faint revolving strise and a somewhat more prominent carina. It is not sufficiently perfect for illustration. Occurrence. — Jennings Formation, Woodmont Member, Ithaca Fauna. Yellow Springs, West Virginia. Collection. — Maryland Geological Survey. Maryland Geological Survey 667 Belleeophon sp. Description. — Fragments show the presence of one or two species of Bellerophon distinct from the foregoing but insufficient for identification. One of these is broad and stout with a well-marked stomal callous, an- other much narrower and both with an apparently smooth exterior. These are from conglomerate near the top of the formation. Occurrence. — Jenkings Formation, Chejiuxg Member. Sideling Hill Creek. Collection. — Maryland Geological Survey. Genus BUCANOPSIS Ulrich Bucanopsis MiERA (Conrad) Plate LXVII, Figs. 21, 22 Bellerphon mwra Hall, 1876, Illus. Devonian Foss. Gastropoda, pi. xxii. Bellerphon neleus Hall and Whitfield, 1876, Illus. Devonian Foss. Gastro- poda, pi. xxii. Bellerphon mcera Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 119, pi. xxv, flgs. 9-14; pi. xxvi, figs. 19-24. Description. — •" Shell subglobose, or broadly subovoid ; length about equal to the greatest width at the aperture; in imperfect specimens the width is usually greater than the length. Inner volutions small and gradually enlarging to the third, which is more rapidly expanded, the exposed portion of the outer one being extremely ventricose. Aperture greatly expanded, the peristome broadly sinuate in front and auriculate at the sides; somewhat thickened and repand as it approaches the um- bilicus, over which it extends, continuing in a thickened callosity across the columellar side. The dorsum is marked by a distinct carina and the entire surface by strong pustulose striae, or rows of pustules, which are arranged along lines parallel to the striae of growth. The dorsal carina is also pustulose. These markings are somewhat less conspicuous on the anterior and lateral margins of the shell. This fossil, when entire, pre- sents a strong rotund form until near the aperture, where it becomes abruptly expanded. The shell is thick, and the surface completely stud- ded with rows of pustules which, in one direction, are arranged in series 668 Systehatic Paleontology — Upper Devonian parallel to the lines of growth in the shell, and, in the other direction, in diagonal lines crossing these, giving the aspect of a quincunx arrange- ment. On the removal of the shell the carina on the cast usually extends but a short distance from the margin of the aperture, and the dorsum beyond this is obtusely or obscurely angular." Hall, 1879. Diameter 20 mm.; diameter aperture 22 mm. The specimens of this species, which occur in Maryland, are usually smaller than those illustrated by Hall from New York although some are equally large. Casts of the interior appear a little less rotund. The surface ornamentation agrees well with that of the typical forms. Cer- tain poorly preserved specimens occurring in the Ithaca fauna at Mill- stone appear to be referable to this species, but do not show the pustules on the surface of the shell clearly. Occurrence.'' — Jennings Formation, Chemung Member. Town Creek, 2391, 2496. Parkhead Member. Williams Eoad, on Polish Mountain, 1660; Town Creek, 1851; 2 miles west of Pawpaw, 1763; Little Orleans; 2^ niiles above mouth of Sideling Hill Creek. Wood- mont Member, Ithaca ? Eauna. Millstone, 1141. Collection. — Maryland Geological Survey. Family EUOMPHALIDAE Genus STRAPAROLLUS Montfort Strapaeollus marylandicus n. sp. Plate LXYII, Pigs. 23-25 Description. — Shell depressed, conical, volutions in contact, four or more in number. Volutions slender, cross-section circular; sutures prO' nounced. Umbilicus very large and deep, exposing all volutions, its diameter much greater than that of volutions. Surface with faint trans- verse strife crossing volutions obliquely and somewhat fascicled. Diameter 20-25 mm.; height 10-13 mm. This species resembles 8. cyclostomus Hall of the Devonian of Iowa but differs from that species in its higher spire. Its very large umbilicus distinguishes it from all other species of the fauna. Maryland Geological Suevey 669 Occurrence. — Jenxixgs Forjiatiox, Paukhead Member. Williams Eoad, on Polish Mountain, 1660; 21/2 miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Genus PHANEROTINUS Sowerby Phaneeotinus laxus (Hall) Plate LXVII, Kg. 26 Euomphalus laxus Hall, 1861, Descriptions of New Fossils, p. 26. Euomphalus laxus Hall, 1862, ISth Rept. N. Y. State Cab. Nat. Hist., p. 54, pi. vi, fig. 2. Euomphalus (.Ecculiomphalus ?) laxus Hall, 1876, Illustrations Devonian Foss. Gastropoda, pi. xvi. Ecculiomphalus comes Hall, 1879, IMd, pi. xvi. Euomphalus laxu^ Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 60, pi. xvi, figs. 8, 9, 16-18. Phanerotinus laxus Grabau and Shimer, 1909, Index Foss. N. Amer, vol. i, p. 656, fig. 901. Description. — "Shell discoid; lower side broadly umbilicate. Volu- tions about four, nearly in the same plane, the inner ones rising moder- ately above the plane of the outer one, disjoined throughout their entire extent, very gradually and regularly expanding from the apex; section circular. Aperture (so far as known.) subcircular, scarcely expanded. Surface marked by crowded concentric strise, which are sometimes regu- lar and equal, and on some parts of the shell more closely arranged, and all directed a little forward, from the inner side of the volution." Hall, 1879. Diameter 35 mm. ; diameter of volution at aperture 7 mm. A single specimen of this species has been observed in the Parkhead of Maryland. Occurrence. — Jennings Fokmaiion, Parkhead Member. Two and a half miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. 'wO Systematic Paleoxtology — Upper Devonian Genus EUOMPHALUS Soweiby EUOMPHALUS TIOGA Hall Euomphalus tioga Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 56, pi. xxvii, fig. 8. Description. — " Shell discoid ; upper side moderately concave from the doTso-lateral angle ; lower side broadly umbilieate, the dorso-basal margin acutely angular. Periphery flattened, oblique to the plane of the shell, and sloping outwards from the upper margin. Volutions probably three or more, gradually enlarging from the apex ; the remains of two only are shown in the specimen figured, in which the extremity of the outer volution is much wider than high. Aperture unknown; transverse section trian- gular, with the inner angle truncated. Surface of the upper side and periphery preserving the remains of striae, which bend abruptly backwards at the lower carina. The specimen is essentially a cast of the interior, and somewhat worn. The species is extremely similar to the E. decewi, with more slender volutions, and the dorso-basal margin more acutely angular." Hall, 1879. Diameter 140 mm. Occurrence. — Jennings Fokmation, Chemung Member. Near Little Orleans. Collection. — Maryland Geological Survey. Family TURBINIDAE Genus CYCLONEMA Hall Cyclonema concinnum Hall Plate LXVII, Figs. 27-39 Cyclonema concinna Hall, 1876, Illustrations of Devonian Foss. Gastropoda, pi. xii. Cyclonema concinna Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 38, pi. xii, figs. 38-40. Description. — Shell subglobose, conical; apical angle large; volutions four or more in entire shells; last volution greatly enlarged, ventricose. Surface of upper volutions bearing 3 to 4 delicate, revolving carinse, two of which are near upper suture; body volution bearing one or two deli- Maryland Geological Survey 671 cate carinse near upper suture and about five revolving carinate bands on lower side of volution. Faint concentric strise cross upper volutions obliquely, becoming obsolete on most of body volutions. Length 25 mm.; diameter 20 mm. This shell differs slightly from the typical form, occurring in the Chemung of New York, in the less ventricose character of the body volu- tion and in the position of the upper carinse which are nearer the upper suture instead of being in the center of the volution as- in that form. Occurrence.-— Jennings Formation, Chemung Member. Town Creek, 2228. Parkhead Member. Williams Eoad, on Polish Mountain, 1660; 3 miles west of Pawpaw, 1493; 2% miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Genus CYCLONEMINA Perner Cyclonemina crenulistriata n. sp. Plate LXVIII, Figs. 1-4 Description. — Shell conical, volutions increasing gradually in diameter to body volution, which is ventricose; height of shell greater than the diameter of last volution. Volutions four or more, high, flattened on periphery. Umbilicus small, covered by the thickened and reflected lip. Surface bearing strong, distant carinse, of which 3 to 4 are on upper volutions, 14 to 18 on body volution. Carinse vary in width, narrower one often arising in interspace between the broader. The wider carinse are nearly flat. Transverse striae cross carinae but do not appear in inter- space. Substance of shell very thick. Length of larger individuals 35 mm.; diameter 30 mm. Other speci- mens are somewhat narrower proportionately. The genus Polytropus is defined by Perner ' as having simply curved not sigmoidal, transverse striae, and usually possessing a well-developed umbilicus, while the genus Cyclonemina has sigmoidal transverse striae ^ Syst. Sil. Boheme, vol. iv, th. ii, p. 205. 672 Systematic Paleontology — Uppek Devonian- and but a small or no umbilicus. That author, however, includes species without umbilicus in the former genus. It seems to the writer that Polytropus as defined by Perner may in- clude more than one genus and that the possession of a well-marked umbilicus may probably be regarded as diagnostic of it. The species in question does not have sigmoidal transverse strife, while it seems to have the small or closed umbilicus of Cyclonemma to which it is here referred. This shell is quite distinct from other species of the genus. It resem- bles C. mvltistriata but differs in much smaller apical angle, in bearing more distant, stronger, broader carinse and in being usually larger. It abounds in a stratum near the base of the Chemung at Town Creek. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 2132, 2228 abundant. Collection. — Maryland Geological Survey. Cyclonemina ceenulisteiata var. obsolescens n. var. Plate LXVIII, Pig. 5 Description. — This variety differs from the typical form in lacking revolving carinse on the upper part of the body volution. Occurrence. — Jennings Poematton, Chemung Member. Town Creek, 2228. Collection. — Maryland Geological Survey. Cyclonemina multistriata n. sp. Plate LXVIII, Pigs. 6-10 Description.— ^heW conical, volutions gradually increasing in diameter to body volution which is ventricose; number of volutions four in ordin- arily preserved specimens. Volutions rounded; suture distinct. Aper- ture oblique. Umbilicus small. Surface ornamented by 20 or more strong revolving carinse, crossed by fine but distinct transverse stria;, which become stronger on crossing carinse, making the latter appear as if somewhat nodose. Length 25 mm. ; diameter 22 mm. Maryland Geological Survey 673 This species approaches C. hamilioniw of the Hamilton of New York in form and size, but differs in having more numerous and closer carinje and in the absence of the conspicuous broad concave band on upper part of the volution which is present in that species, as well as in its more conspicuous transverse strije. It differs from C. crenulistriata in its larger apical angle, smaller size, closer revolving carinas, and more rounded volutions. At times it is difficult to separate imperfectly pre- served specimens of this species from Pleurotomaria {Gyroma) capillaria especially when the peripheral band of the latter is not preserved. The transverse striae of the latter species, however, are much stronger and are distinctly visible in the interspaces between the revolving striae. This is the most common species of Cyclonemina in the Jennings and is very abundant in the Parkhead fauna. Occurrence. — Jennings FoRiiATaoN, Chemung Member. Two miles north of mouth of Town Creek, 1949 ; Town Creek, 2338; 3 miles west of Pawpaw, 3134. Parkhead Member. Eocky Eun, Williams Eoad, on Polish Mountain, 1660 abundant; National Eoad, on Polish Mountain, 1635 ; 3 miles north of mouth of Town Creek, 1723 ; Town Creek, 1863 common; 2 miles west of Pawpaw, 1493 ?, Little Orleans; Pifteenmile Creek, 1 mile above Little Orleans; 1713, 1746, 1773; 31/2 miles above mouth of Sideling Hill Creek abundant; Berkeley Springs, West Vir- ginia, 1544 to 1566. Collection. — ^Maryland Geological Survey. Genus TURBO Klein Turbo coronola n. sp. Plate LXVIII, Figs. 11, 13 Description. — Shell of commanding proportions, low spiral, broad body whorl, oblique enrollment. Early whorls depressed with subconvex sur- faces and clearly impressed suture. On the latter part of the second whorl the surface shows irregular oblique swellings on the upper one- third and these disarrange and disorder to some degree the otherwise regularly concentric growth lines. The body whorl loses the regularity of its convexity, becomes protuberant above and bears a series of very 43 671 Systematic Paleontology — Uppek Devonian strong round nodes with a slightly oblique direction or separated by faintly oblique grooves. These ornamental features give the upper part of the whorl a flattened surface about the suture. They seem to have 8-10 of these strong nodes on the final whorl. Aperture large subovate oblique, broadly rounded on the outer curve with the inferior margin nearly direct to the base of the final whorl. Of the two specimens of this striking gastropod one represents the upper whorls only, the other pre- sents the profile with the characters of the body whorl and aperture. Of the latter the entire height is 70 mm., width of body whorl 40 mm., oblique diameter of aperture 35 mm. This is a very well-characterized species unlike anything known else- where in the higher Devonian of the interior basin. In its size and the nodes of the upper surface of the whorls it may be brought into com- parison with the well-known shell Turbo shumardi Hall which is not infrequently found in the Onondaga limestone of Indiana (see Hall, Pal. N". Y., vol. V, pt. i, p. 165, pi. xxix, figs. 1-4) but this type of shell has not been reported from other horizons. Though both of these may provision- ally be left with the genus Turbo it is quite certain that on a revision of the fossils referred to this genus these will be found to belong to another group. Occurrence. — Jennings Formation, Chemung Member. On the IvT ational Road, 6 miles west of Frostburg. Collection. — Maryland Geological Survey. Family TROCHONEMAIDAE Genus TROCHONEMA Salter Teoohonema (Gyeonema) liratum (Hall) Plate LXYIII, Pig. 13 Cyclonema lirata Hall, 1861, Descriptions of New Species of Fossils, p. 19. Cyclonema lirata Hall, 1862, 15tli Rept. N. Y. State Cab. Nat. Hist., p. 47, pi. V, fig. 15. Cyclonema lirata Hall, 1876, Illustrations Devonian Foss. Gastropoda, pi. xii. Cyclonema lirata Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 35, pi. xii, figs. 27-29. (non Qyronema liratum Ulrich, 1897, Pal. Minn., p. 1056.) Maryland Geological Survey 675 Description. — '' Shell robust, subdepressed-eonical. Volutions about foiir, subangular, the last one becoming very ventricose, flattened from the suture to the first carinate elevation on the upper side, and marked by moderately elevated carinate ridges, of which two or three are visible on the upper volutions, and about five on the body whorl; those ofl the upper side of the volution more distant than those on the lower side. Surface marked by fine, closely arranged strife of growth, which are sometimes crowded in fasciculi, giving gentle inequalities; these strife and directed a little backward from the suture." Hall, 1879. Length 25 mm. ; diameter 17 mm. This species is referred to the subgenus Gyronema Ulrich on account of its ornamentation, which differs from that of Trochonenia sdian stricto. A rare species in the Chemung. Occurrence. — Jennings FoEMAxrox, CiiEiiuxG Member. Hancock, 22"23. Collection. — JIaryland Geological Survey. Order CTENOBRANCHIATA Suborder PLATYPODA Superfamily GYMNOGLOSSA Family PYRAMIDELLIDAE Genus MACROCHILINA Bayle Macrochilina pdlchella n. sp. Plate LXVIII, Figs. 14, 15 Description. — Shell diminutive, tapering quite abruptly, apical angle 45°, whorls 4-5, smooth, regularly convex; body whorl very oblique and having about two-thirds the length of the entire shell. Last suture ob- lique, earlier sutures more transverse. Height of average specimen 7 mm., width of body whorl 3.5 mm. This little species is distinguished by the characters mentioned from other known members of the genus. Occurrence. — Jennings Formation, Chemung Member. In rotten sandstone on the Williams Eoad, Polish Mountain. Collection. — Maryland Geological Survey. 676 Systematic Paleontology — Upper Devonian Genus LOXONEMA Phillips LOXONEMA HAMILTONI^ Hall' Plate LXIX, Figs. 1, 2 This Hamilton species occurs occasionally in the Parkhead member of the Jennings. Occurrence. — Jennings Formation, Parkhead Member. Williams Eoad, on Polish Mountain, 1660. Collection. — Maryland Geological Survey. Loxonema terebrum Hall Plate LXIX, Pigs. 3-7 Loxonema terebra Hall, 1879, Pal. of N. Y., vol. v, pt. il, p. 48, pi. xiv, figs. 6, 7. Loxonema terebra Grabau and Shimer, 1909, Index Foss. N. Amer., vol. i, p. 694, fig. 992. Description. — Shell elongate; spire rapidly ascending; volutions slightly rounded, bearing strong elevated, obtusely angular and sigmoid- curved surface plications which bend backward a little below the suture and make a more gentle curve forward to the base of the volution. Height 60 mm.; diameter 16 mm. Few specimens of this species have been seen whose preservation has permitted the retention of the surface characters though the shell appears to be common at the localities cited. It is also locally abundant in the upper Chemung beds of New York. Occurrence. — Jennings Formation, Chemung Member. Near Green Glade Eun; National Road 6% miles west of Frostburg; Town Creek, 2123, 3238. Collection. — Maryland Geological Survey. Loxonema styliolum Hall Plate LXIX, Figs. 8-10 Loxonema styliola Hall, 1876, Illustrations Devonian Foss. Gastropoda, p. 14. Loxonema styliola Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 48, pi. xiv, figs. 8, 9. ' For synonymy and description see page 294. Maryland Geological Suevey 677. Description. — " Shell elongate, terebrif orm ; spire rapidly ascending. Volutions flattened, regnlarly increasing from the apex, the last one scarcely ventrieose, or but slightly ventricose; about nine in the length of two inches and a half from the base. Aperture snbelliptical ; the colu- mellar lip extended below. " Surface showing remains of fine striae of growth, without evidence of other surface markings; suture banded." Hall, 1879. The surface of this species is ornamented with coarse sigmoidal striae, which are rarely preserved. The Maryland shells agree well with those figured by Hall in general features but differ in greater proportional length of the volutions. Length 60 mm.; diameter 12 mm. Occurrence. — Jennings FoiniATioK, Chemung Member. Town Creek, 3228 abundant. Collection. — Maryland Geological Survey. LOXONEMA ? GLABRCM n. Sp. ' Plate LXIX, Figs. 11-14 Description. — Shell elongate, turretif orm ; apical angle small ; volutions four or more in number, last volution scarcely more inflated. Volutions rounded, slightly flattened on periphery in some specimens, suture deep. Surface smooth, columella absent. Length 30 mm.; diameter 10 mm. Average size of larger volutions: height 5-6 mm.; width 8-10 mm. The generic relations of the individuals referred to this species are not assured. Although preserved in a matrix which shows the fine details of other shells no trace of exterior ornamentation has been observed. Longitudinal sections resemble those of the genus Lonoxnema as figured by Pemer^ in Syst. Sil. Boheme which genus these specimens also re- semble in external form. They differ, however, in the apparent absence of ornamentation, a feature which may possibly be due to conditions of preservation although this does not seem very probable. 1 Vol. iv, th. ii, p. 326, flg. 231. G78 Systematic Paleontologt — Upper Devonian It does not seem desirable to erect a new genus for the reception of the shells described based upon the materials observed. They are hence referred tentatively to the genus Loxonema. Occurrence. — Jennings Formation, Chemung Member. Oakland- Altamont Eoad ; 2 miles north of mouth of Town Creek, 1949. Park- head Member. Williams Eoad, on Polish Mountain, 1353, 1660 abun- dant; 2 miles north of mouth of Town Creek, 1723, 1842 common; 2 miles west of Pawpaw, 1493; Little Orleans, abundant; Fifteenmile Creek, 1 mile above Little Orleans, 1773; 3% miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. Superfamily TAENIOGLOSSA Family PURPURINIDAE Genus TRACHYDOMIA Meek and Worthen TilACHYDOMiA PR.^iCURSOR (Clarke) Plate LXIX, Pigs. 15, 16 Palwotrochus prwcursor Clarke, 1885, Bull. U. S. Geol. Surv., No. 16, p. 55, pi. iii, figs. 6-9. Descri-ption. — Shell rotund, with short spiral, and broad body whorl. Volutions 5-6. Sutures deeply impressed. Apical angle 50°. Body whorl narrowly flattened at the suture, thence the slope being broad de- pressed curve to the greatest diameter which is % the distance across the whorl. Aperture entire, oval, embracing % of the penultimate volution. Outer lip thin, uninterrupted. Inner lip somewhat thickened; excavate. Shell non-umbilicate. Surface with revolving rows of subequal tubercles, those adjoining the suture, and at the periphery, being the more prominent. Nine or ten of these rows occur on the body whorl. Verj' fine concentric lines cross this tubercled surface, and these are more noticeable upon the earlier whorls. Height 10 mm. ; diameter 7 mm. Maryland Geological Survey 679 This interesting shell constitutes one of the characteristic members of the Xaples fauna of Xew' York, where, so far as known, it prevails in the Xaples subprovince of the Genesee province; that is, it occurs with frequency in the rocks from Ontario County westward to the Genesee Biver, but is seldom found in localities further west (Chautauqua sub- province). In a single instance the shell has been found in the higher sands of Ontario County after the introduction of the Ithaca fauna. Its occurrence in Marjdand associated with species which are distinctively of the Chemung assemblage is worthy of special note. The few specimens seen are too illy preserved for illustration but their characters are unmis- takable. Occurence. — Jexkixgs Formation, Chemung Member. From loose blocks of light yellow friable sandstone near Deer Park Station. A number of species are found in the material reported from these blocks but it is not certain that all represented the same position in the strata. With T. prcecursor, however, are found Schizodus, TentacuUies spiculus, Ectomaria ecclesice, Leptodesma longispinum and probably Spirifer dis- junctus. Collection. — Maryland Geological Survey. Family LITTORINIDAE Genus HOLOPEA Hall HOLOPEA rowei n. sp. Plate LXIX, Figs. 17, 18 Description. — This species attains larger dimensions than IJ. mary- landica, the slope from the body whorl upward is much more gradual, the spire higher and more elongate. Volutions 5-6. The body whorl is not ventricose but highly convex and broad, measuring in vertical diam- eter considerably more than the length of the spire. Internal casts show a deeply excavated suture which is not evident in external casts. An average specimen has a height of 25 mm. and basal diameter of 20 mm. The specific name of this shell is intended to commemorate the brief but important services to Maryland geology of the late Dr. Eichard Bur- 680 Systematic Paleontology — Upper Devonian ton Eowe, a graduate of the John Hopkins University and an assistant on the Geological Survey of Maryland; by him much valuable material eniployed in the study of the Jennings formation was collected. Occurrence.- — Jennings Fokmation, Chemung Member. Williams Eoad, Polish Mountain. Parkhead Member. Eocky Eun cf., Town Creek, 1863 of., 2% miles above mouth of Sideling Hill Creek, ef. Holopea marylandica n. sp. Plate LXIX, Figs. 19, 20 Description. — Shell short, rotund, spire short consisting of 4-5 volu- tions, body whorl projecting well beyond the rest of the spire, but not so extremely ventricose as in many of these species. Whorls all convex and smooth, the upper whorls having an obliquely sloping surface and the body whorl having a vertical width equal to the remaining height of the spire. Sutures deep but not excavate. Ko concentric surface lines are retained on the external casts. Height of an average specimen 15 mm. ; diameter of body whorl 18 mm. This species is distinguished from its associate H. rowei by its lower spire and proportionally broader body whorl. Occurrence. — Jennings Formation, Chemung Member. Williams Eoad, Polish Mountain. Collection. — Maryland Geological Survey. Holopea humilis n. sp. Plate LXIX, Fig. 21 Description. — Shell very small, depressed subglobose. Spire very small, body volution abruptly enlarging. Volutions three or more; aperture circular ; umbilicus not observed. Surface smooth. One specimen shows faint sign of a median revolving carina, rendering reference to Holopea uncertain. This feature, however, may be due to condition of preser- vation. Height 8 mm.; width 8 mm. Maryland Geological Survey 681 Occurrence. — Jennings Formation, Parkhead Member. Two miles north of mouth of Town Creek, 1716. Collection. — Maryland Geological Survey. Holopea ? sp. Description.— Kti imperfect specimen possibly of the genus Holopea was found at Town Creek. The shell is subglobose, conical, body volu- tion greatly inflated, number of volutions unknown, surface smooth. The body volution of this species is unusually ventricose. The specimen observed is too imperfect to permit illustration. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 4769. Collection. — Maryland Geological Survey. Family CAPULIDAE Genus ORTHONYCHIA Hall Orthonychia prosseri n. sp. Plate LXX, Figs. 4-6 Description. — A single small and apparently somewhat appressed specimen is the only example of the species observed in the Jennings formation. With the known individual variability of these shells it would be hazardous to apply any name to this form were it not for the fact that no species is recorded from the Chemung fauna elsewhere. It may be characterized as follows : Shell laterally compressed, making one and one-half to two volutions; early growth decidedly flattened and subcarinate; expanding abruptly to the aperture and becoming subconvex above but depressed or concave below. Aperture much elongated and narrow, fluted below near the inner lip. Height 15 mm. Occurrence.- — Jennings Formation, Chemung Member. Oakland- Altamont Eoad; National Eoad 6 miles west of Frostburg. Collection. — Maryland Geological Survey. (i83 Systematic Paleontology — Upper Devonian Orthonychia ungdiculata n. sp. Plate LXX, Pigs. 7-9 Description. — Shell conical, curved; apex minute, incurved; volutions about one and one-half. Initial portion of shell often somewhat com- pressed laterally or even carinate; body volution expanding towards aperture, bearing folds of varying degrees of distinctness. The extent to which the folds are developed is variable, in some specimens being scarcely noticeable, in others pronounced. Aperture subcircular or slightly compressed laterally, oblique, fluted by folds in some shells. Length of specimen of ordinary size 10-13 mm.; diameter of aperture 6-8 mm. This species differs from Platyceras marylandicum in its more attenuate apex and smaller size. Occurrence. — Jennings Formation, Parkhead Member. Williams Eoad, on Polish Mountain, 1660 common; 31?^ miles above mouth of Sideling Hill Creek. Collection. — Marj'land Geological Survey. Orthonychia sp. Plate LXX, Pigs. 10, 11 Description. — A single specimen in the Parkhead fauna differs from the other species observed in increasing less rapidly in diameter toward apex. It resembles 0. unguiculaia, but the apex is less attenuate and aperture more plicate than is usual in that species. It resembles Platyceras marylandicum in its plications but increases much less rapidly in diam- eter, a feature not well shown in the drawings. Larger collections may prove it to be a new species. Length 13 mm.; diameter aperture 7 mm. Occurrence. — Jennings Formation, Pahkhead Member. Two and one-half miles above mouth of Sideling Hill Creek. Collection. — ^Maryland Geological Survey. Maryland Geological Survey G83 Genus PLATYCERAS Conrad Platyceras marylandicum n. sp. Plate LXX, Pigs. 1:2-16 Description. — Shell subcorneal, arcuate. Apex minute, slightly curved and twisted. Body volution expanding rapidly near apex, less rapidly toward aperture in larger shells. Young specimens are slightly, older specimens more strongly curved, the anterior convex side becoming nearly twice as long as the posterior concave side. Eight and left sides subequally convex. Aperture oblique. Surface marked by a few irregu- lar longitudinal folds which are obsolete toward apex, but become dis- tinct in some individuals or even pronounced near aperture. Casts of some shells slightly nodose. Length of convex side 50 mm. in large specimens; diameter aper- ture 30 mm. This species resembles P. conicum Hall of the Onondaga and Hamil- ton of Xew York but is more arcuate. It is distinguished from the other species of the fauna by its larger size and large apical angle, while the apex is not attenuate. Occurrence. — Jennings Formation, Chemung Member. Williams Eoad, on Polish Mountain, 2042. Parkhead Member. Williams Eoad, on Polish Mountain, 1660 common; 2 miles west of Pawpaw 1763 ?; Millstone, 1773 ?. Collection. — Maryland Geological Survey. Platyceras compressum n. sp. Plate LXX, Figs. 1-3 Description. — Shell subconical, arcuate. Shell strongly compressed, the transverse diameter being about one-third the dorso-ventral diameter. Apex incurved ; body volution expanding rapidly from a point near apex. Dorsal margin subangular, curved, fonning a semicircle; ventral margin short, concave. Eight side convex, left side concave. Aperture elliptical, its edges curved. Surface ornamented by growth lines which curve 684 Systematic Paleontology — ^Upper Devonian anteriorly in passing over sides and posteriorly in passing over dorsal and ventral margins. Length 28 mm.; greater diameter aperture 23 mm., lesser diameter 9 mm. This species is quite distinct from any other form known to the author. It may be somewhat distorted, although shells of other species associated with it do not appear to be compressed. Occurrence. — Jennings Formation, Chemung Member. Upper Tropidoleptus zone, ? near Pennsylvania-Maryland state line, west of Green Eidge. Collection. — Maryland Geological Survey. Platyceras sp. Description. — Shell curved, very abruptly contracted at apex which is small. Shape of aperture unknown. This shell appears to be of the type of P. attetmatum of the Hamilton of New York. A single specimen only has been seen, which is too im- perfect for illustration. Occurrence. — Jennings Formation, Chemung Member. Upper Tropidoleptus zone ? near Pennsylvania-Maryland state line west of Green Eidge. Collection. — Maryland Geological Survey. Genus DIAPHOROSTOMA Fischer DiAPHOROSTOMA LINEATAUM (Conrad) Plate LXX, Figs. 17-19 PTatyostoma lineata Conrad, 1842, Jour. Acad. Nat. Sci., Phila., vol. viii, p. 276, pi. xvii, flg. 7. Platyostoma lineata Hall, 1876, Illustrations of Devonian Foss., Gastropoda, pi. ix. Platyostoma lineata Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 21, figs. 1-21. Diaphorostoma lineata Grabau and Shlmer, 1909, Index N. Amer. Foss., vol. i, p. 680, fig. 953. Description. — " Shell subovate, approaching tO' subglobose. Spire elevated above the body whorl, though varying in degree; in some ex- treme varieties, on the same plane or below the outer volutions. The Maryland Geological Survey 685 shell with four or five volutions when entire, but seldom preserving more than three — the apex being usually imperfect. The outer volution usually ventricose and regularly convex, a little depressed below the suture-line (but not canaliculate). Aperture suborbicular in perfect specimens, sometimes subrhomboidal ; outer lip thin, with a sharp entire margin ; columnar lip thickened, folded, and reflexed over the umbilicus, which in adult specimens is entirely closed. Surface marked by fine, nearly equidistant, thread-like revolving strise, which are cancellated by fine concentric strise of about the same strength, but unequally distant; the latter sometimes bent abruptly backwards upon the back of the shell, indicating a sinus in the lip at some period of growth, and are frequently crowded in fascicles giving a rugose character to the surface. In well- preserved specimens the surface is beautifully cancellated; and in worn and partially exfoliated specimens some remains of these surface mark- ings are usually visible, the revolving strise being first obliterated." Hall, 1879. Height 8 mm.; diameter 15 mm. The individual figured is somewhat distorted by pressure. The surface is ornamented by numerous fine radiating strise which curve baclsward near the periphery and are crossed by finer revolving strise causing the surface of the shell to appear finely cancellated. Occurrence. — Jennings Formation, Chemung Member. Upper Tropidoleptus zone ? near Pennsylvania-Maryland state line west of Green Eidge. Collection. — Maryland Geological Survey. Suborder PTEROPODA Family CAVOLINIIDAE Genus STYUOLINA Karpinsky Styliolina fissurella (Hall) Plate LXXI, Figs. 1-3 Tentacutites fissurella Hall, 1843, Geol. N. Y., Rept. 4th Dist, p. 180. Styliola fissurella Hall, 1878, Pal. N. Y., vol. v, pt. ii, p. 178, pi. xxxia, figs. 1-33. Styliolina fissurella Clarke, 1885, Bull. U. S. Geol. Survey, No. 16, p. 57. 68G Systematic Paleontology — Uppee Devonian Description. — This is a minute pteropod wliose shells, like smooth needle points make spots and patches everywhere through the Genesee of Slaryland. Xo other structure except the form of the flattened shells is evident. In the Genesee of New York these shells entirely compose in places a well-marked limestone layer (Styliola limestone) and again in the argillaceous Naples shales above are accumulated in immense numbers wherever calcareous nodules or nodular layers appear. Length 3 mm. Occurrence. — Jexxixgs Foejiatiox, Genesee Membeh. Present at all the Maryland outcrops of these strata. Collection. — Maryland Geological Survey. Suborder CONULARIDA Family TENTACULITIDAE Genus TENTACULITES Schlotheim Tentaculites descissus n. sp. Plate LXX, Figs. 20-33 Description. — Elongate aculeate cones characterized by diiferential markings in successive growth stages. The early shell, covering from one- third to one-half the length of the tube, bears subequal and closely ap- pressed annulations. These rings gradually become more widely sepa- rated and at intervals coarser and broader annuli occur; finally the spaces between the annuli bear only one or two lesser rings and the. entire surface shows very fine concentric lines. ' The species is well defined, clearly distinct from the form commonly occurring in the Chemung fauna of New York, T. spiculus Hall. The length of a full-grown specimen is 25 mm. Occurrence. — Jexnixgs Fokmation, Chemung Member. Most com- mon in the vicinity of Deer Park, Garrett County; also in the Polish Mountain section, and Green Eidge, Allegany County. National Eoad west of Frostburg; Oakland- Altamont Eoad; E. Gordon's farm 1 mile northeast of Mountain Lake Park. Collection. — Maryland Geological Survey. ^Maryland Geological Survey 687 Tentacdlites spiculus Hal] Plate LXX, Fig. 24 Tentaculites spiculus Hall, 1876, Illustrations of Devonian Foss., Pteropoda, pi. xxvi, figs. 21-25. Tentaculites spiculus Hall, 1879, Pal. N. Y., p. 172, pi. xxxi, figs. 21-25. Tentaculites spiculus Grabau and Shimer, 1910, N. Amer. Index Fobs., vol. ii, p. 12. Description. — " Form a slender-elongate, anniilated cone ; very gently expanding from the apex, and sometimes showing a tendency to cylin- dricity towards the apertnre; annulations abruptly elevated, sometimes rounded and oblique to the axis of the cone; about equal to the spaces between them, and gradually increasing in distance towards the aperture ; ten to fourteen annulations in the space of five mm. in specimens of the same size; apical portion very finely annulated or transversely striate, about twenty in the length of one mm., while an equal distance measured near the aperture gives eleven annulations. Interannular spaces on the body of the shell marked by fine transverse strife, to be seen only under favorable conditions of the fossil." Hall, 1879. Length 6 mm. ; diameter 1 mm. This characteristic species of the Ithaca of Xew York occurs also in the Ithaca fauna of Maryland. Occurrence.' — Jennikgs Formation, "WooDiioNT Member, Ithaca Fauna. Millstone, 795. Collection. — Maryland Geological Survey. Family TORELLILLIDAE Genus COLEOLUS Hall Coleolus texuicixtus Hall Plate LXXI, Figs. 4-6 Coleoprion tenuicintum Hall, 1876, Illustrations of Devonian Foss., Ptero- poda, pi. xxvil, figs. 1-4. Coleolus tenuicinctum Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 185, pi. xxxila, figs. 6-10. Coleolus tenuicinctus Grabau and Shimer, 1910, N. Amer. Index P'oss., vol. Ii, p. 9, fig. 1219. 688 Systematic Paleontology — Upper Devonian Description. — " Shell an extremely elongate, gradually and regularly tapering cone, having in the largest individuals a diameter of six mili- meters at the larger extremity, with a length of seventy-five millimeters. Surface marked by fine closely arranged strise, or frequently with more distant oblique annulations, receding from the aperture, or sinuate on the ventral side — ^the degree of obliquity depending upon the position of the fossil, or the relation of the parts exposed to view. Interrupted longi- tudinal strise are visible in well-preserved specimens." Hall, 1879. This is an abundant and characteristic species of the Parkhead fauna. The specimens observed agree well with those figured by Hall from the Hamilton of New York. Some shells attain a somewhat greater size than those described by him. Occurrence. — Jennings Poemation, Chemung Membee. Two miles north of mouth of Town Creek, 1949 ; Town Creek, 2691 ; upper Tropi- doleptus zone ? northeast of Pratt near Pennsylvania-Maryland state line. Paekhead Membee. Williams Eoad, on Polish Mountain, 1660 abundant; 2 miles north of mouth of Town Creek, 1842; 4 miles southeast of Pratt abundant; Town Creek, 1679; 2 miles west of Pawpaw, 1493, 1799; Little Orleans abundant; Pifteenmile Creek, 1 mile above Little Orleans, 1746. Collection. — ^Maryland Geological Survey. Family HYOLITHIDAE Genus HYOLITHES Eichwald Hyolithes aclis Hall Plate LXXI, Figs. 7-9 Hyolithes aclis Hall, 1876, Illustrations Devonian Foss., Pteropoda, pi. xxvii, figs. 5-7, 10, 11. Hyolifhes aclis Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 197, pi. xxxil, figs. 22-30; pi. xxxiia, figs. 23-25. Hyolithes aclis Cleland, 1911, Bull, xxi, Geol. Surv. Wis., p. 132, pi. xxvi, fig. 8. Description. — "Porm an elongate triangular pyramid, gradually and regularly tapering to an acute extremity. Transverse section somewhat Maktland Geological Survey 689 semielliptieal or subtriangular, a little convex on the ventral side, about twice as wide as high; the lateral margins obtusely angular, sometimes attenuate from compression. Ventral face gently convex, and slightly curving in a longitudinal direction; anterior portion extended in a sub- spatulate expansion. Dorsal face highly convex transversely, and ob- tusely angular along the middle; very slightly concave longitudinally. Aperture oblique, the margin extended on the ventral side; on the dorsal side the peristome is not fully determined, but is apparently nearly straight on the sides, with a sinus at the angle. Operculum in general form subelliptieal, the body of which is moderately convex; the ventral margin (or that corresponding to what may be termed the ventral side of the shell) is regularly curving. The umbo is situated about three- fourths of the width from the base, and extending thence on each side, almost rectangularly to the transverse axis, is a distinct fold which gradually expands towards the margins, and below which is a correspond- ing groove or channel. Above this fold is a narrow border or flange, which turns upward at a considerable angle (varying in two specimens from ten to more than thirty degrees), and in the center of which is an abrupt angular depression. Shell thin, and usually very imperfectly preserved. Surface of the shell concentrically or transversely striated, the marks often appearing in the casts. In well-preserved specimens these strias are cancellated by extremely fine longitudinal ones, which are visible only under a strong lens, and are not preserved in all specimens. These stria are much more conspicuous near the base of the shell, and especially on the ventral margin of the aperture. Surface of the oper- culum distinctly striated concentrically, and also obscurely marked by radiating striae; the margin of the flange is striato-plicate." Hall, 1879. Length 14 mm. ; greater diameter 5 mm., lesser diameter 3 mm. Occurrence. — Jennings Foemation, Parkhead Member. Two and a half miles above mouth of Sideling Hill Creek. Collection. — Maryland Geological Survey. 44 690 Systematic Paleontology — Upper Devonian Genus PHARETRELLA Hall Phaeetkella tenebeosa Hall Plate LXXI, Pig. 10 Pharetrella tenelrosa Hall, 1888, Pal. of N. Y., vol. vil, pt il, Supplement, p. 7, pi. cxiv, figs. 30, 31. Description. — Hall gives no description of this species save as it is contained in the description of the genus Pharetrella which is as follows : " Shell large, elongate, Hyolithes-like in outline; apex acute, transverse section probably triangular, substance tenuous; ornamentation consisting of transverse, imbricating undulating striae." Occurrence. — Jennings Foemation, Genesee Membee. Jennings Eun Eoad, west of Corriganville. Collection. — Maryland Geological Survey. Class CEPHALOPODA Subclass TETRABRANCHIATA Order NAUTILOIDEA Suborder ORTHOCHOANITES Family ORTHOCERATIDAE Genus ORTHOCERAS Bieyn Oethoceeas consoetale Hall Plate LXXI, Pigs, 16-18 Orthoceras consortale Hall, 1886, Fifth Ann. Kept. N. Y. State Geol., pi. 11, flgs. 3-5. Orthoceras consortale Hall, 1888, Pal. of N. Y., vol. vil, Supplement, p. 29, pi. cviil, flgs. 3-5. Description. — " Shell straight, rapidly expanding from the apex to near the aperture; transverse section broadly oval. Apical angle ten degrees. Initial extremity unknown. Chamber of habitation not fully shown in the specimens observed, apparently short and constricted near the aper- ture. Air chambers 5 mm. in depth, where the tube measures 38 mm. in greatest diameter. But little variation in the depth of the air Maryland Geological Survey 691 chambers can be noticed in the tube for a length of 125 mm. Septa thin, deeply cbncave. Sntnres somewhat ciirved, not deeply impressed on the internal mould. Siphuncle moniliform, excentric, distant more than one- third the diameter of the tube from the ventral side. Test marked by irregular lamellose lines of growth, which make a distinct retral curve on the ventral side of the tube. Internal mould smooth." Hall, 1888. The fragments observed are indistinguishable from Hall's type. Occurrence. — Jennings Formation, Chemung Member. Williams Eoad, on Polish Mountain, 2043 common. Collection. — ^Maryland Geological Survey. OrTHOCEHAS Cf. DEMUM Hall Plate LXXI, Pigs. 14, 15 Orthoceras demus Hall, 1879, Pal. of N. Y., vol. v, pt. il, p. 311, pi. xc, figs. 1, 4, 5. Description.- — •" Shell straight, regularly enlarging. Transverse sec- tion circular. Apical angle 6°. Initial extremity unknown. Chamber of habitation not observed. Air chambers regular, increasing in frequency toward the apex, having a depth of from two to three mm. ; varying to this degree in the length of forty-five mm. Septa smooth, thin, having a con- cavity greater than the depth of the air chambers. Sutures straight and horizontal. Siphuncle small, excentric, and at the septa is distant from the nearest point on the margin about one-third the diameter of the tube. The other elements have not been observed. Test nqt preserved, surface markings unknown. The internal mould is essentially smooth." Hall, 1879. Occurrence. — Jennings Formation, Chemung Member. Town Creek, 3760; Hancock, 2233. Collection. — Maryland Geological Survey. Orthoceras eilosum Clarke Plate LXXI, Pigs. 12, 13 Orthoceras filosum Clarke, 1885, Bull. 16, U. S. Geol. Survey, p. B2, pi. ii, figs. 12-14. 693 Systematic Paleontology — Uppek Devonian Description. — Simple straight cones, with normally transverse septa; well characterized by its finely cross-lined surface, these lines being incised in such manner as to leave the adjoining surfaces with an im- bricating aspect. The shells are readily recognized and the authors have little hesitancy in referring thereto some fragments showing this peculiar ornament. Length of fragment 43 mm.; diameter at narrow end 13 mm., at wider end 16 mm. Depth of chambers l%-3 mm. Occurrence. — Jennings Foeiiation, Genesee Mbmbek. Parker farm near Burlington, West Virginia. Woodmont Member, Naples Fauna. Polish Mountain section, exposure east of Town Creek. Collection. — ^Maryland Geological Survey. Order AMMONOIDEA Suborder MICROCAMPYLI Family BACTRITIDAE Genus BACTRITES Sandberger Bactrites aciculds (Hall) Plate LXXI, Pig. 11 Orthoceras aciculum Hall, 1843, Geol. of N. Y., Kept. 4tli Dist, p. 243, fig. 4. Coleolus aciculum Hall, 1879, Paleontology of New York, vol. v, pt. ii, p. 187, pi. xxxila, figs. 11-15. Bactrites acicutiim Clarke, 1898, 16tli Rept. N. Y. State Geol., p. 128, pi. ix, flgs. 17-22. Description. — ^These shells occur in the New York Genesee and Naples beds mostly in flattened condition and it was on such specimens that the species was originally founded. Specimens in the same condition of pres- ervation, smooth, flattened, awl-shaped bodies, showing little structure and no evidences of transverse septa occur in the corresponding beds of Maryland and are referred to the above species. Such examples represent only young shells or the apical portion of the full-grown individuals which probably attained a length with regularly expanding shell of 3 or 4 inches. These bodies have been found at various localities. Maryland Geological Survey 693 Occurrence. — Jennings Formation, Genesee Member. Williams Eoad near Cumberland. Collection. — ^Maryland Geological Survey. Suborder MESOCAMPYLI Family PREMORDIALIDAE Genus MANTICOCERAS Hyatt MaNticooeras patersoni (Hall) Plate LXXII, Figs. 1-3 Goniatites patersoni Hall, 1860, IStli Rept. N. Y. State Cab. Nat. Hist., p. 99, figs. 9, 10. Goniatites patersoni Hall, 1875, 27tli Rept. N. Y. State Cab. Nat Hist., p. 136. Goniatites patersoni Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 464, pi. Ixxii, figs. 1-5; pi. Ixxiv, flg. 15. Manticoceras patersoni Clarke, 1907, Rept. N. Y. State Geol. for 1896, p. 45, pi. 1, figs. 1-12; pi. 11, figs. 1-4, 6; pi. iv, figs. 14-18. Description. — " Shell large, discoid ; the thickness of the disc equal to a little more than one-third the lateral diameter of the shell in young and medium-sized specimens. Volutions about four, the outer ones em- bracing the inner to the depth of one-half or more of their dorso-ventral diameter. Umbilicus of moderate width, exposing all the inner volutions. Transverse section somewhat semielliptical, with the lateral faces convex near the base, slightly concave beyond the middle of the width, and ab- ruptly rounded at the apex or periphery. The base is deeply indented by the preceding volution, and subaurieulate at the baso-lateral angles. The enlargement of the volutions is very gradual in the young state, and more rapidly increasing as the shell advances in age. From the third to the fourth volution the increase is from a diameter of fifteen mm. to thirty- one mm. in a single turn. Chamber of habitation very large, in one specimen occupying more than half a volution; its full extent not known; its capacity is at least twice as great as all the chambered portion of the shell. Aperture elongate semielliptical, narrowing toward the anterior margin, which is subacutely rounded. Base deeply indented by the pre- ceding volution, and, inferring from the form, it is subaurieulate at the 694 Systematic Paleontology — Upper Devonian baso-lateral angles. Air chambers numerous, often somewhat irregular in their depth, those near the chamber of habitation sometimes shallower than those preceding. In a portion of the tube, which has a lateral diam- eter of about forty mm. at the smaller extremity, and of forty-six mm. at the base of the chamber of habitation, making about one-quarter of a volution, there are nine air chambers, which vary in depth from six to ten mm., as measured from the summits of the lateral saddles, the shallowest being the last but one. In a smaller individual there are nine chambers in less than half a volution of the septate portion preceding the commence- ment of the chamber of habitation. The septa are strong, especially in the older shells; much thickened on their exterior margins, and strongly imbricating. In their course from their origin on the umbilical margin they curve more or less abruptly backward to a point from one-quarter to one-third the diameter of the volution or sometimes even less, where they make an acute return, and, curving forward over the later face of the volution, make a retral bend, which terminates at a point within one- fifth or one-sixth of the width of the volution from the peripheral margin, whence they make an acute turn forward, and pass over the margin of the periphery in an abrupt curve, and descending slightly describe a narrow, acute lobe upon the center of the ventrum. This course of the septa includes a narrow acute lobe, near the inner margin of the volution, and thence describes a broad, obliquely semielliptieal saddle; a second narrow, elongate acute lobe, near the outer margin, and a narrow obtuse saddle on the periphery, with one side extremely elongate, and the other very short. The septum describing the wide lateral saddle extends forward, in its advancing curve, to a distance equal to the great- est depth of nearly two air chambers beyond its origin at the umbilical margin. In its retral curve to the bottom of the acute outer lateral lobe, the distance is equal to the depth of two and a half to three and a half air chambers, measured in their greatest depth. The ventral lobe is short, penetrating the adjacent air chamber about two and one half mm., where the entire depth is nine mm. The suture lines are strongly im- pressed upon the interior cast, and in a simply exfoliate specimen are comparatively very wide, from the thickening of the septa at their Maryland Geological Sdevey 695 margins. The siphuncle is small, cylindrical, and placed close beneath the shell, on the peripheral margin. The test is known only upon a single individual, and has a thickness of about one mm. at the base of the chamber of habitation. The surface is imperfectly preserved, show- ing somewhat lamellose, transverse strife, with faint indications of other markings. The sinus, inferring from the direction of the strise, has been narrow and shallow. The internal cast is essentially smooth, preserving the septal margins or impressed suture lines, with impressions of the fine surface strise." Hall, 1879. The thickness of the shells observed in Maryland is less than that shoAvn by Hall's figures. Diameter of largest shell observed 80 mm., diameter of volution 18 mm. The occurrence of this representative of the Manticoceras fauna in the Chemung of Maryland is of much interest. Several characteristic speci- mens have been observed. Occurrence. — Jennings Formation, Chemung Member. Williams Bead, on Polish Mountain, 2043. Woodmont Member, ISTaples Fauna. Woodmont. Collection. — ^Maryland Geological Survey. Genus PROBELOCERAS Hyatt Probelooeras lutheei Clarke ( ?) Plate LXXII, Pigs. 4, 5 Probelooeras lutheri Clarke, 1898, 16tli Kept. N. Y. State Geol., p. 90, pi. vii, figs. 1-10. Description. — Flattened specimens in the shales at various points are referred provisionally to this species though none have yet shown the characteristic acutely lobed septation. These specimens are small, widely umbilicated, flat and smooth shells, with distinct bands or " tire " on the ventral periphery and in these respects they agree with P. lutheri. Examples from the soft shales of New York are often of small size like these. One of those here figured shows a portion of the actual aperture of the shell, the projecting ventral elongation. Diameter of shell 25 mm. ; diameter of volution 12 mm. 696 Systematic Paleontology — ^Uppek Devonian Occurrence. — Jennings Poemation, Genesee Member. Such fossils are widely distributed and are recorded from the vicinity of Cumberland and near Wolfe Mill ; % mile west of Corriganville. Woodmont Member, Naples Fauna. Polish Mountain section at Gilpintown, Parker farm, 514 miles west of Burlington, West Virginia. Collection. — ^Maryland Geological Sur\'ey. Suborder EURYCAMPYLI Family MAGNOSELLARIDAE Genus TORNOCERAS Hyatt ToRNOCERAs UNIAN6ULARE (Conrad) Plate LXXII, Fig. 6 Cfcniatites uniangulare Conrad, 1842, Jour. Acad. Nat Sci., Phila., vol. viii, p. 268, pi. xvl, fig. 4. Ooniatites diseoideus Hall, 1879, Pal. of N. Y., vol. v, pt. ii, pi. Ixxl, figs. 1, 7, 10-13. Ooniatites uniangularis. Hall, 1879, IMd., pi. Ixxi, fig. 14; pi. Ixxii, figs. 6, 7; pi. Ixxiv, fig. 2. Ooniatites diseoideus Hall, 1888, lUd., Suppl. (= vol. vli), p. 127, figs. 11, 12. Tornoceras uniangulare Clarke, 1898, 16tli Rept. State Geol., N. Y., p. Ill, pi. viil, figs. 15-18. Description. — Shell depressed, suborbieular, discoid, with rounded center; sides gently convex. Volutions at maturity all embraced within the outer one, though in early stages slight umbilication is evident; sur- face smooth. Body chamber one-half to two-thirds the outer volution; air chambers numerous; septal sutures quite simple, with broad lateral saddles, lateral lobes with an abrupt slope on the umbilicate side and a narrow and acute ventral lobe. The specimens which have been observed in the Maryland shales are badly flattened but serve to show the highly involute, non-umbilicate character of the shell, and one preserves the outline of the septal sutures. For better drawings than it is practicable to give here the reader is re- ferred to the works cited above. The species may be distinguished from Maryland Geoloqioal Survey 697 the associate goniatites in these rocks by the almost complete obscuration of the inner whorls. In the New York succession the species entered the region during the Hamilton stage and surviving the inroad of the Naples fauna attained therewith its most abundant development, at the same time being wholly restricted to the Naples subprovince while in the Chautauqua subprovince the genus is represented in equal abundance by the species T. bicostatum Hall. Diameter 26 mm. ; diameter of volution 17 mm. Occurrence. — Jennings Formation, Genesee Member. Corrigan- ville and in the vicinity of Cumberland. Collection. — Maryland Geological Survey. Suborder GLOSSOCAMPYLI Family PHARCICERATIDAE Genus SANDBERGEROCERAS Hyatt Sandbergerocekas chemdngensis (Vanuxem) Plate LXXII, Fig. 7 Goniatites chemungensis Vanuxem, 1842, Geol. Survey N. Y., Rept. Sd Dist., p. 182, fig. 1. Goniatites chemungensis Hall, 1876, Illustrations Devonian Foss., Cephalo- poda, pi. Ixlx, fig. 9. Goniatites chemungensis Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 467, pi. ixix, fig. 9; pi. ixxiv, fig. 6. Sandbergeroceras chemungensis Clarke, 1903, Bull. N. Y. State Mus. No. 65, p. 649. Description. — " Shell discoid, expanded. Inferring from the condition of the compressed specimen, the transverse section of the tube has not exceeded one-fourth that of its lateral diameter. Volutions gradually expanding, about four (or five?) ; all exposed in the wide, shallow um- bilicus; the inner ones partially embraced in the outer. The transverse section is broadly oval, and a little sinuate, or somewhat expanded in the middle of the sides of the outer one; rounded upon the periphery. 698 Systematic Paleontology — Upper Devonian and concave on the umbilical side. The enlargement of the volutions is very gradual ; the base of the air chamber, at the end of about the fourth volution, measures a little more than thirty mm. The inner volutions are not in a condition to be measured. The chamber of habitation, known only at its commencement, is continued in the same proportions as the preceding chambered portion of the shell. Aperture unknown. Air chambers numerous; the width of the volution is equal to about three chambers in their greatest depth, and nearly twice as many at the umbili- cal margin. Septa thin, somewhat regular in their arrangement; the margins moderately thickened, and slightly imbricating; distant from each other, at their origin on the umbilical side, from three to five mm. in the last fourth of the outer volution, the last two being closer than any of the preceding. Prom the umbilical side the septa proceed in a gener- ally transverse direction, making several abrupt curves, the posterior ones of which are angular, and describing four saddles, of gradually increasing height and dimensions, and three shallow, angular lobes on the inner half of the width of the volution ; on the outer half of the volution there are deeper and more abrupt curves; and leaving the base of an angular lobe at about the center, the septa describe a wider semielliptieal saddle, a deeper elongate subangular lobe, and a still more elongate and more elevated saddle, which has its apex near the periphery. On the outside of this there is a narrow lobe, and an abrupt turn of the septum to the periphery, upon which its course has not been observed. This arrange- ment gives six lobes on the lateral face of the volution, each one of which has an increasing depth from the umbilical margin. There are likewise six saddles, each successive one of which is higher and wider than the preceding, except the last which is much higher, but not quite so wide as the one preceding it. Suture lines narrow, moderately impressed upon the vast, and more strongly marked at and near the extremities of the lobes and saddles. Siphuncle unknown. Test entirely unknown. The surface markings cannot be satisfactorily determined on the cast of the interior or upon the weathered impression of the exterior, which are the only portions preserved. The cast of the interior is marked by nodulose annulations, which are nearly continuous on the inner half of the volution, Maryland Geological Survey 699 and interrupted on the outer half; the median line of the volntion being marked by a tow of depressed nodes, which become obsolete toward and upon the chamber of habitation. The intermediate spaces are essentially smooth, or marked only by a peculiar pitted or indented surface, which has not been identified with any external marking." Hall, 1879. The specimens found in Maryland consist of parts of a volution which appear to be coiled in one plane. They are referred tentatively to Sand- iergeroceras ch&mungensis of the Chemung of New York. More perfect material is needed to permit confident identification. Occurrence. — Jennings Formation, Paeehbad Member. Williams Eoad, on Polish Mountain, 1389 ; 4 miles southeast of Pratt. Collection. — ^Maryland Geological Survey. ARTHROPODA Class CRUSTACEA Subclass TRILOBITA Order PROPARIA Family PHACOPIDAE Genus PHACOPS Emmrich Phaoops rana (Green)' Plate LXXII, Pig. 8 Description.— SeYeral weU-preserved pygidia of this recurrent Ham- ilton species have been found in the Parkhead of Maryland. Occurrence. — Jennings Formation, Parkhead Member. Williams Road, on Polish Mountain, 1660; National Road, on Polish Mountain, 1625; 21/2 miles above mouth of Sideling Hill Creek; road leading north- east from Pratt, % mile west of Fifteenmile Creek. Collection. — Maryland Geological Survey. ' For synonymy and description see page 329. TOO Ststbmatio Paleontology — Upper Devonl4.n VERTEBRATA Class PISCES Subclass DIPNEUSTI Order ARTHRODIRES Family COCCOSTIDAE Genus GLYPTASPIS Newberry The genus Glyptaspis belongs to the order of Arthrodires which in- cludes armored lung fish (Dipneusti) whose head articulates to the body in such manner as to permit free motion. The armor consists of massive plates which protect the skull and the anterior part of the body, tlhe posterior parts being unprotected. The body armor consists of plates arranged dorsally and ventrally. The ventral armor, which is the part best known in this genus, is composed of lateral plates placed on either side of a median ventral plate. The lateral plates are known as the right and left anterior (antero-ventro-lateral) and posterior (postero-ventro- lateral) plates respectively. Ghjtaspis is closely related to the genus Coccosteus and, like it, the surface of its armor is set with stellate tubercles. It differs from that genus in having its tubercles arranged in linear rows and in the more shield-like shape of the antero-ventro-lateral plates. It is a member of the family Coccostidw which also includes the gigantic armored fish, Dinich- thys and Titanichthys. Glyptaspis eastmani n. sp. Plate LXXIII, Pigs. 1-3 Description. — This species is represented by antero-ventro-lateral and postero-ventro-lateral plates. The description of the antero-ventro-lateral plate is as follows : Plate triangular, shield-shaped. One margin nearly straight; opposite margin slightly curved ; third margin not shown. Surface convex, orna- mented by stellate tubercles, save near the curved margin which was Maryland Geological Survey 701 overlapped by adjacent plate. Tubercles arranged in linear rows which make an angle of about 60° with the curved margin becoming trans- verse and somewhat irregular near center of plate. Distance of rows about 1.5 mm. Length of part of plate observed 90 mm., width 85 mm. A postero-ventro-lateral plate has also been observed which is referred somewhat questionably to the same species. This plate tapers to a point posteriorly; its surface is flat: one margin is nearly straight save for a slight bend near apex; opposite margin is parallel to it for nearly half length of incomplete specimen observed, and then bends abruptly at an angle of 135°, continuing in a nearly straight line to the posterior ex- tremity. The exterior surface is ornamented by stellate tubercles which are airanged in linear rows, placed nearly transverse to length of plate in posterior half, but cross it somewhat obliquely anteriorly; rows of tubercles are about 1.5 mm. apart. Length of part observed 60 mm., width 33 mm. A third fragment has also been figured upon which the ornamentation differs slightly. Its reference to the same species is not assured. These plates have been submitted to Dr. Charles E. Eastman in whose honor they are named. Dr. Eastman identified them as plates of a new species of Qlyptaspis and comments upon the close resemblance of the postero-ventro-lateral plate to plates of the genus Goccosteus. He also questions whether they should be referred to the same species. The similarity of the ornamentation suggests their specific identity though larger collections may prove them distinct. They are, however, tentatively united under the same specific name. Occurrence. — Jennings Formation, Parkhead Member. Horse Eidge, southwest of Hancock, West Virginia, 1600, west of Green Eidge, south of Maryland-Pennsylvania state line. The reference of the specimen from the latter locality to the Parkhead member is not assured. It may be from the Chemung. Collections. — ^Maryland Geological Survey, U. S. National Museum. GENERAL INDEX Allegany Grove, fossils at, 556, 550, 563, 565, 575, 576, 577, 580, 581, 590, 592, 595, 601, 603, 605, 606, 607, 627, 629, 638, 639, 647, 649, 655, 657. Sections near, 523. Altamont, Exposures at, 387. Avllton conglomerate, 384, 534. B Banellville, Fossils near, 596, 606, 610, 614, 618, 641. Bassler, R. S., 21, 115. Bear Pen Run, Fossils on, 563, 597. Bear Run, Fossils on, 556. BellegroTe, Fossils near, 597, 659. Berkeley Springs, W. Va., Fossils near, 132, 160, 327, 336, 543, 548. 551, 566, 574, 575, 576, 583, 584, 586. 587, 592, 593, 597, 601, 602, 623, 655, 673. Section near, 59, 454. Berry, Edward W., 9. Blair County, Pa., Fossils at, 266. Braddock Run, Exposures in, 63, 376, 403. BucMola speciosa fauna, 473, 500, 504, 512, 518, 522. Burlington, W. Va., Fossils near, 614, 618, 692, 696. Conglomeratic sandstone beds, 416. Conrad, T. A., 27. Contents, 13. Correlation of Middle Devonian, 88. of Upper Devonian, 410. Corriganville, Fossils near, 136, 137, 147, 14r, 153, 190, 191, 202, 227, 247, 284, 610, 614, 618, 631, 633, 690, 696, 697. Crabtree Creek, Exposures at, 404. Credner, Hermann, 32. Cumberland, Exposures near, 54, 65, 370, 516. Fossils near, 128, 130, 133, 134, 135, 141, 145, 149, 151, 153, 155, 162, 163, 164, 167, 170, 172, 173, 175, 177, 179, 182, 185, 186, 190, 191, 193, 198, 202, 204, 207, 211, 216, 219, 220, 223, 227, 228, 232, 233, 235, 236, 237, 238, 240, 242, 243, 244, 251, 252, 254, 257, 258, 262, 265, 267, 269, 274, 275, 278, 279, 281, 285, 290, 292, 293, 295, 299, 301, 305, 308, 309, 310, 313, 315, 317, 321, 323, 326, 329, 332, 337, 338, 542, 547, 549, 563, 568, 572, 576, 580, 581, 586, 598, 602, 614, 616, 617, 618, 625, 633, 634, 640, 641, 644, 693, 697. Cummings, E. R., 180. Cyclonemina multistriata zone, 415, 416. Camarotoecbia congregata zone, 415. Camarotoechia eximia zone, 421. Campbell, M. R., 42. CatskiU formation discussed, 399, 435. Catskill formation. Distribution of, 401. Catskill-Chemung boundary, 421. Cbautauqua group, 343. Cbemung formation, 435. Fossils in, 105, 106, 107, 108. member, 417, 428. Chemung-Parkhead boundary, 421. Cherry Creek, Exposures on, 397. Fossils at, 559, 563, 575, 590. Cladocbonus-Reticularia Iffivls zone, 425, 461. aark, Wm. Bullock, 9, 39, 129. Clarke, J. M., 21, 26, 31, 34, 37, 38, 39, 53, 89, 96, 101, 111, 119, 127, 128, 145, 169, 188, 213, 244, 246, 537, 625. Cleland, H. F., 102. Commission, 7. Dalmanella tioga zone, 419. Dana, E. S., 38. Darton, N. H., 42, 345. Deer Park, Exposures near, 391. Fossils near, 553, 556, 557, 559, 563, 566, 575, 590, 592, 596, 603, 610, 620, 623, 637, 638, 640, 646, 654, 657, 665, 679, 686. Devonian of New York, 32. Diefenbaugh, George, 75. Dlefenbaugb, Rufus,. 75. Drew, G. H., 114. Ellerslie, Pa., Section at, 519. Fossils at, 543, 550, 556, 559, 566, 570, 571, 573, 587, 589, 590, 595, 597, 601, 603, 629, 637, 662. Emmons, E., 32, 35. Enfleld fossils, 105, 106, 107, 108. 704 General Index Ernstville, Exposure at, 85. Fossils at, 120, 121, 143, 150, 151, 153, 164, 170, 171, 202, 206, 207, 227, 232, 249, 281, 299, 315, 318, 331, 334. European eguivalents of Middle Devonian, 27. Evitts Creek, Fossils near, 120, 121, 122, 123, 124, 125, 126, 127, 128, 130, 132, 135, 137, 139, 140, 147, 149, 153, 155, 157, 162, 166, 168, 178, 185, 186, 189, 191, 193, 197, 198, 202, 204, 209, 211, 212, 218, 223, 226, 227, 228, 230, 231, 232, 233, 237, 238, 239, 241, 242, 243, 249, 251, 255, 256, 259, 262, 267, 269, 270, 274, 277, 278, 279, 283, 286, 295, 298, 299, 301, 306, 310, 311, 321, 334. Fifteen-mile Creek, Fossils on, 551, 559, 563, 566, 576, 584, 586, 592, 595, 597, 601, 602, 603, 629, 634, 673, 678, 688, 699. Section on, 480. Pllntstone Creek, Fossils near, 136, 147, 150, 151, 153, 155, 157, 172, 175, 182, 185, 190, 191, 196, 202, 228, 232, 233, 249, 251, 256, 267, 274, 281, 614. Four-mile Ridge, Exposure near, 408. FrankvlUe, Exposures at, 404. Freeh, F., 29. Frostburg, Fossils near, 553, 556, 557, 558, 559, 563, 566, 575, 587, 590, 596, 597, 601, 621, 626, 629, 637, 639, 640, 642, 649, 654, 657, 658, 663, 674, 676, 681, 686. Frostburg-Sallsbury road. Exposures on, 382, 406. Genesee member, 343, 411, 423. Fossils In, 105, 106, 107, 108. Genesee-Woodmont boundary, 414. Geological distribution of Middle Dev- onian species, 103. Geological range of Middle Devonian species, 105-108. of Upper Devonian species, 439-444. Giekie, Sir Archibald, 32. Gilpin, Exposure at, 72. Fossils near, 136, 147, 150, 153, 155, 157, 172, 175, 182, 190, 191, 196, 202, 228, 232, 233, 249, 251, 256, 267, 274, 278, 281, 289, 562, 572, 615, 617, 618, 631, 633, 696. Glrty, G. H., 144. Goldsborough, Philips Lee, 7. Gordon, R. H., 67. Grabau, G. W., cited, 102, 120, 213. Great Cacapon, Fossils at, 147, 153, 190, 216, 278, 299, 306, 308. Green Ridge, Exposure on, 360, 504. Fossils near, 582, 592, 596, 597, 598, ' 601, 602, 603, 610, 620, 629, 649, 655, 684, 685, 686, 701. Green Glade Run, Exposures on, 386. Fossils near, 556, 557, 559, 563, 663, 676. Green Spring furnace, Fossils at, 87, 147, 150, 155, 186, 204, 302. H Hall, James, cited, 28, 34, 35, 75, 125, 126, 127, 128, 130, 131, 133, 162, 165, 167, 168, 184, 193, 203, 214, 216, 217, 218, 219, 222, 225, 226, 228, 229, 230, 233, 236, 237, 238, 239, 241, 247, 248, 249, 253, 255, 256, 257, 261, 264, 267, 269, 271, 273, 274, 275, 276, 277, 278, 280, 282, 283, 285, 286, 288, 289, 290, 294, 295, 298, 299, 300, 302, 305, 306, 314, 320, 321, 326, 327, 332, 341, 547, 548, 554, 570, 571, 578, 579, 588, 593, 605, 607, 608, 609, 610, 623, 627, 634, 639, 640, 643, 645, 650, 652, 653, 662, 668, 669, 670, 675, 677, 685, 687, 688, 689, 695, 699. Hamilton member, 50, 59, 98. Character and thickness of, 50. Fauna of, 51. Fossils In, 105, 106, 107, 108. Hancock, Exposure at, 58, 81, 82, 458. Fossils near, 136, 137, 140, 147, 149, 150, 151, 153, 155, 172, 182, 186, 190, 191, 192, 193, 196, 202, 217, 221, 227, 245, 249, 251, 258, 265, 267, 272, 273, 275, 278, 281, 283, 290, 297, 329, 543, 547, 548, 551, 554, 563, 566, 574, 575, 576, 580, 583, 584, 586, 587, 592, 593, 596, 597, 601, 602, 603, 619, 623, 675, 691, 701. Hancock-Harrisonville road. Section on, 462. Hanging Rock, W. Va., Fossils at, 155, 170, 183, 186, 301, 332. Harrington, Emerson C, 7. Horse Ridge, Fossils on, 701. I Illustrations, List of, 19. Ithaca fauna, 105, 106, 107, 108, 343, 414, 424. Geneeal Index 705 Jennings formation discussed, 347, 410. Distribution of, 353. Exposures near, 63, 371, 401, 523. Fossiis in, 136, 137, 147, 149, 153, 191, 202, 227, 247, 284. Sections in, 445, 446, 452, 455, 458, 462, 464, 469, 471, 474, 480, 482, 490, 494, 502, 504, 507, 512, 516, 520, 524, 528, 530. K Keyser, W. Va., Section near, 528. Keyser-Piedmont road. Fossils on, 641. Kendall, Edward M., 21, 25, 47, 88, 93, 94, 97, 98, 115, 134, 251. KnoWey, Mt., Fossils near, 576, 586. , 351. 170, 190, 191, zone, 426, 454, zone, 415, 474, near, 359, 482. 566, 574, 575, 592, 595, 597, 623, 629, 634, 678, 688. Lackawazen conglomerate, I/appareut, A. de, 31. Letter of transmittal, 11. Licking Creek, Fossils on 193, 301. Uorhynchus globullforme 457, 462, 471, 494. Liorhynclius mesacostate 518. Little Orleans, Exposures Fossils at, 551, 563, 576, 583, 584, 586, 601, 602, 603, 621, 666, 668, 670, 673, Little Run, Fossils on, 597. Loomls, T. B., 111. Lowrille group, 34. Luther, M. Etena, 343. M McCool, Fossils near, 570. McCoy's Ferry, Exposures at, 86. Fossils near, 136, 147, 151, 153, 155, 157, 182, 190, 191, 193, 194, 197, 216, 218, 220, 227, 232, 233, 234, 237, 242, 243, 245, 247, 263, 265, 278, 284, 299, 302, 303, 304, 331. Magnolia, W. Va., Fossils near, 586. Mann, Pa., Fossils near, 586. Section near, 474. Marcellus member, 49, 59, 97. Character and thickness of, 49. Fauna of, 50. Fossils In, 105, 106, 107, 108. Martin, G. C, 349. Mathews, E. B., 9. Middle Devonian, Correlation of, 88. Middle Devonian, European equivalents of, 27. 45 Middle Devonian, General Distribution of, 26. Middle Devonian, Geological distribution of species, 103. Middle Devonian, Geological range of species, 105. Middle Devonian classification. Develop- ment of, in New York, 32. Middle Devonian Deposits of Maryland, 25. Middle Devonian systematic paleontology, 115. Middle Fork, Section on, 530. Millstone, Exposure at, 83, 354, 445. Fossils near, 561, 562, 56^, 564, 574, 575, 576, 577, 580, 583, 584, 586, 590, 592, 596, 597, 601, 602, 603, 605, 621, 636, 647, 648, 655, 658, 668, 683, 687. Mt. Lake Park, Fossils near, 553, 556, 569, 575, 578, 603, 628, 663, 686. N Naples fauna, 105, 106, 107, 108, 413, 414. National Road, Exposures on, 73, 78, 347, 362, 378, 406, 458, 471, 512. Fossils on, 136, 147, 151, 153, 155, 182, 185, 190, 191, 193, 211, 219, 228, 232, 237, 251, 278, 281, 284, 285, 289, 299, 302, 331, 539, 540, 549, 551, 553, 556, 557, 558, 559, 562, 563, 564, 566, 575, 576, 577, 583, 584, 586, 587, 589, 590, 592, 595, 596, 597, 598, 601, 602, 603, 607, 610, 614, 615, 617, 618, 620, 621, 623, 626, 629, 633, 684, 635, 637, 639, 640, 649, 654, 658, 663, 673, 674, 676, 686. Ness Lick Run, Exposures on, 387. Oakland, Exposures near, 393. Fossils near, 544, 553, 557, 558, 567, 575, 592, 596, 628, 637, 663, 665. Oakland-Altamont road. Fossils on, 551, 553, 556, 559, 563, 566, 569, 575, 587, 590, 596, 601, 603, 619, 628, 629, 649, 654, 678, 681, 680. Oakland-Redhouse road. Fossils on, 559, 564, 566, 587, 589, 601, 603, 624, 639, 640, 649. O'Harra, C. C, 69, 77, 88, 375. Oldtown, Exposures near, 56, 76. Fossils near, 157, 172, 174, 179, 181. 190, 199, 202, 204, 212, 213, 220, 223, 224, 225, 232, 253, 259, 265, 281, 289, 295, 299, 301, 303, 308, 314, 329, 331, 332. 706 General Index Oiatown road near Cumberland, Fossils at, 128, 147, 153, 182, 186, 190, 202, 211, 223, 227, 228, 232, 251, 278, 308, 310. Onondaga member, 48, 88. Character and thickness of, 48. Exposure of, 53. Fauna, 7, 49. Fossils in, 91, 105, 106, 107, 108. Onondaga-Marcellus boundary, 50. Paleontologic characteristics of Middle Devonian, 47. Of Upper Devonian, 847. Parkhead member, 415, 427. Parkhead member. Fossils in, 105, 106, 107, 108. Patterson Depot, W. Va., Fossils near, 285, 312. Pawpaw, W. Va., Fossils near, 551, 559, 565, 566, 574, 575, 576, 578, 579, 580, 583, 584, 586, 587, 589, 592, 595, 597, 599, 601, 602, 606, 610, 621, 623, 634, 635, 647, 649, 651, 655, 662, 664, 666, 668, 673, 683, 688. Section near, 489. Pea Ridge, Exposures on, 383. Pine Hill, Exposure near, 77. Fossils near, 136, 147, 173, 181, 182, 187, 190, 191, 220, 259, 289, 299, 308, 314, 329, 331. Piney Grove, Fossils near, 582, 655. Polish Mountains, Exposures on, 362, 367, 507, 512. Fossils on, 539, 540, 549, 550, 551, 553, 556, 559, 562, 563, 564, 565, 566, 572, 573, 574, 575, 576, 577, 580, 584, 586, 587, 589, 590, 592, 595, 597, 598, 601, 002, 603, 607, 615, 619, 620, 623, 629, 633, 634, 635, 640, 642, 647, 648, 649, 650, 652, 655, 656, 658, 664, 666, 668, 669, 671, 673, 675, 676, 678, 680, 682, 683, 686, 688, 691, 692, 695, 697, 699. Portage beds, 343. Pratt, Fossils near, 586, 621, 623, 627, 628, 629, 653, 655, 666, 688, 699. Preface, 21. Prosser, Charles S., 21, 25, 47, 70, 88, 93, 98, 103, 112, 115, 339, 341, 347. Q Queens Point, Exposure near, 54. Range of Middle Devonian species, 105- 108. of Upper Devonian species, 439-444. Red House, Exposure at, 398. Fossils at, 556, 563. Relations of the Middle Devonian fauna to sediments, 109. Remsen, Ira, 7. Renevier, E., 29. Ridgeville, W. Va., Fossils at, 266. Rocky Run, Fossils near, 547, 563, 568, 574, 575, 576, 580, 586, 592, 602, 640, 662, 673, 680. Romney formation discussed, 40, 47, 51. Romney, Fossils near, 228, 288, 310, 315, 614, 617. Romney-Hanging Rock road. Fossils on, 147, 151, 155, 172, 175, 183, 187, 190, 192, 202, 211, 230, 237, 251, 267, 281, 295, 303, 309, 334. Romney-Jennings boundary, 51. Romney-Oriskany boundary, 49. Round, W. Va., Fossils near, 572, 586, 598, 603, 653. Section near, 516. Rowe, R. B., 47, 66, 81, 82, 88, 680. Rush, Fossils near, 147, 190, 193, 197, 200, 227, 251, 263, 281, 290, 329. s Salisbury road. Exposure on, 382. Savage River Valley, Exposures in, 377. Scoharie fossils, 105, 106, 107, 108. Schuchert, Charles, 26, 27, 34, 88, 101, 127, 131, 133, 163, 177, 189, 213. Section in Middle Devonian, 54-87. in Upper Devonian, 445-533. Senecan group, 343. Sherburne fossils, 105, 106, 107, 108. Sideling Hill, Exposures near, 356, 359. Sideling Hill Creek, Fossils on, 541, 545, 565, 576, 578, 580, 586, 587, 592, 597, 602, 610, 640, 651, 652, 656, 662. 663, 664, 666, 667, 668, 669, 671, 673, 678, 682, 689'. Section on, 479. Silvester, R. W., 7. Singerwald, J. T., Jr., 9. Stevenson, J. J., 44, 63, 74, 350. Stratigraphic and paleontologic char- acteristics of the Middle Devonian, 47. of the Upper Devonian, 347. Swartz, Charles K., 21, 25, 55, 88, 97, 103, 339, 349, 445, 537. Systematic paleontology of Middle Dev- onian, 115. General Index 707 Thompson Township, Fossils In, 567. Tiger Valley, Fossils in, 623. Tonoloway, Exposui-es near, 58, 77, 80, 356, 471. Fossils near, 122, 144, 149, 151, 153, 155, 160, 1U6, 182, 228, 232, 245, 247, 251, 281, 284, 301, 302, 321, 332, 546, 553, 566, 576, 583, 584, 590, 592, 597, 602, 619, 626, 633, 635, 640, 647, 665. Town Creek, Fossils near, 136, 147, 151, 153, 155, 172, 182, 190, 199, 202, 251, 253, 260, 261, 281, 545, 552, 553, 556, 559, 560, 563, 565, 574, 575, 576, 580, 584, 586, 587, 589, 590, 592, 595, 697, 598, 601, 602, 603, 606, 609, 610, 614, 617, 619, 621, 622, 626, 627, 629, 634, 635, 640, 645, 647, 648, 651, 653, 654, 655, 656, 660, 602, 664, 666, 668, 671, 672, 673, 676, 678, 680, 681, 688, 691, 692. Section near mouth of, 502. Town Creek Valley, Exposures in, 75. Tropidoleptus carinatus zone, 419. Trout Run, Exposures on, 396. Fossils near, 553, 556, 559, 564, 566, 567, 569, 579, 587, 589, 590, 596, 597, 601, 603, 663, 665. Tuliy limestone, 343. Turners Eoad, Fossils on, 602. 21st Bridge, Exposure at, 59. Fossils at, 128, 129, 130, 136, 139, 145, 147, 149, 151, 153, 155, 158, 162, 172, 173, 177, 182, 189, 190, 191, 197, 209, 212, 213, 221, 227. 228, 233, 237, 242, 243, 248, 256, 259, 265, 274, 277, 289, 301, 320, 323, 332. Section at, 463. U Ulrich, E. O., 21, 115, 336, 338. Unadilla formation, 345. U. S. Geological Survey, 88. Upper Devonian deposits of Maryland, 341. Vanuxem, L., 28. 33, 342. Vaughan, T. W.. 114. Verneuil, E. de, 28, 37. Warrior Mt, Fossils on, 147, 190, 193, 197, 200, 227, 251, 263, 281, 290, 329. Weller, S., 93. White, I. C, 350. Williams, Geo. H., 65. Williams, H. S., 25, 29, 37, 101, 102, 341, 427. Williams road, Exposure on, 54, 69, 367, 507. Fossils on, 125, 128, 130, 134, 135, 145, 147, 175, 265, 274, 279, 285, 547, 549, 550, 553, 563, 565, 568, 572, 573, 574, 575, 576, 580, 581, 584, 586, 587, 589, 590, 592, 595, 598, 601, 602, 603, 607, 616, 619, 625, 629, 684, 640, 642, 644, 647, 648, 649, 650, 651, 652, 6.35, 656, 658, 664, 666, 668, 669, 671, 673, 675, 676, 678, 680, 682, 683, 691, 693, 695, 699. Southeast of Cumberland, Fossils at, 125, 128, 133, 134, 135, 141, 145, 147, 149, 151, 153, 155, 159, 162, 163, 164, 166, 167, 170, 172, 173, 177, 178, 179, 182, 189, 193, 198, 202, 207, 209, 211, 215, 220, 222, 223, 227, 228, 232, 233, 235, 236, 254, 258, 262, 267, 269, 275, 292, 293, 295, 299, 301, 305, 309, 321, 323, 326, 329, 332, 337, 338. Willis, Bailey, 39. AVills Creek Station, Pa., Fossils near, 596, 597, 623. Wills Mountain, Section near, 445, 519. Wolfe Mill, Exposure at, 67. Fossils near, 120, 121, 122, 123, 124, 125, 126, 127-, 128, 130, 132, 135, 137, 139, 140, 147, 149, 153, 155, 157, 162, 166, 168, 178, 185, 186, 189, 191, 193, 197, 198, 202, 209, 211, 212, 218, 223, 226, 227, 228, 230, 231, 232, 233, 237, 238, 239, 241, 242, 243, 249, 251, 255, 256, 259, 262, 267, 269, 270, 274, 277, 278, 279, 283, 286, 295, 298, 299, .301, 306, 310, 311, 321, 334, 614, 617, 618, 631, 633, 696. Woodmont, Fossils at, 566, 576, 580, 583, 584, 586, 587, 592, 596, 603, 620, 623, 634, 644, 656. Woodmont member, 348, 412, 423. Woodmont Sections, Section at, 468. Woodmount-Parkhead boundary, 417. W Warren Point, Exposure at, 83. Fossils near, 170, 202, 301, 321. Yellow Springs, Fossils at, 551, 567, 574, 575, 576, 583, 584, 587, 502, 597, 601, 602, 605, 608, 619, 623, 634, 666. Section on, 452. PALEONTOLOGICAL INDEX Figures In Ijold face Indicate principal discussion. Acroculia erecta, 296. Actinopteria, 258, 642. Actinopteria cf. boydi, 424, 442, 470, 64a. boydi var. gil>bosa, 75, 107, 259. decussata, 62, 69, 77, 107, 258. cf. epsilon, 379, 441, 642. sp., 76, 107, 260. Agoniatites expansus, 53, 55, 57, 89, 90, 91, 92, 96, 108, 321. Aml>occelia, 200, 602. Ambocoelia gregaria, 366, 603. nucleus, 203. prseumbona, 85, 106, 204. umbonata, 55, 56, 58, 59, 65, 66, 67, 68, 71, 72, 73, 75, 76, 77, 82, 84, 85, 102, 106, 200, 355, 359, 360, 361, 362, 364, 365, 367, 369, 388, 390, 392, 395, 432, 440, 447, 459, 469, 480, 492, 497, 498, 499, 500, 505, 510, 514, 515, 516, 520, 525, 526, 527, 528, 602. umbonata var. nana, 202. virginiana, 57, 68, 98, 106, 202. Ambonychiidse, 255, 641. Ammonoidea, 319, 692. Amplexus, 120. Amplexus bamiltonise, 68, 105, 120. Anatinacea, 272. Annelida, 122, 544. Anolotheca acutiplecata, 49, 112. Camilla, 55, 91, 106, 112, 209. (Coelespira) acutiplicata, 54, 55, 57, 68, 71, 91, 92, 93, 106, 207. Anomalodesmacea, 272. Anomla reticularis, 183. terebratulites strialulus, 170, 572. Anoplia, 159. Anoplia nucleata, 58, 59, 91, 105, 112, 159. Anopiotheca. 207. Anthozoa, 119, 5.S9. Arcacea, 248, 627. Artborodires, 700. Arthropoda, 326, 699. Aspidobrancbia, 280, 661. Asteroidea, 543. Atbyrid*, 206, 604. Athyris, 211, 604. Athyris angelica, 433, 440, 524, 604. spiriferoides, 51, 62, 68, 76, 102, 106, 211. Atremata, 124, 546. Atrypa, 586. Atrypa acutiplicata, 207. aspera var. occidentalis, 589. cbemungensis, 183. concinna, 206. concentrica, 211. congregata, 171. ■ contracta, 577. globuliformis, 582. bystrix, 349, 356, 358, 367, 378, 379, 381, 390, 394, 395, 397, 398, 440, 520, 589. limitaris, 175. mespacostalis, 581. reticularis, 66, 68, 72, 106, 183, 360, 367, 369, 379, 395, 397, 424, 440, 453, 456, 457, 461, 462, 463, 470, 480, 492, 497, 498, 509, 510, 586, 589. spinosa, 184, 440, 493, 494, 498, 509, 513, 520, 525, 527, 587, 589. AtrypidiE, 183, 586. Aulopora, 542. Aulopora repens, 439, 542. serpens, 542. sp., 50. Auloporidie, 542. Avicula boydii, 642. cbemungensis, 629. decussata, 258. equilatera, 265. flabella, 250. fragilis, 632. longispinum, 637. parilis, 263.' quadrula, 642. speciosa, 611. tricostata, 649. Avlculopecten, 263, 648. Aviculopecten, cf. cancillatus, 246, 442, 511, 648. equilatera, 91, 107, 265. equilaterus, 265. princeps, 62, 66, 76, 82, 87, 107, 263. . sp., 62, 69, 266, 442, 526, 649. B Bactrites, 319, 693. Bactrites aciculatus, 91, 92, 96, 108, 319, 322. aclculum, 320. aciculus, 55, 90, 91, 108. 347, 348, 357, 363, 368, 370, 371, 372, 444, 692. 710 Paleoxtological Index Bactiitlda;, 31!), 602. Bellerophon, 285, CCS. Bellei-phon acutilirata, 666. brevilineatus, 69, 77. (Bueanopsis) leda, 69, 107, 2S5. clarki, 442, 480, 487, 493, 499, SCO, 502, 510, 515, 666. rnara, 665, 666. nactoides, 358, 442, 665. nactus, 665. neleus, 667. (Patelloslium), patulus, 77, 107, 387. pclops, 666. sp., 61, 62, 66, 76, 77, 82, 83, 359, 443, 454, 667. Bellerophontedffi, 665. Bembexia, 380. Bembexia sulcomarginata, 280. Beyrichiidee, 336. Bollia, 336. Bollia lata, 337. obesa, 55, 58, 91, 108, 112, 337. ungula, 54, 55, 58, 91, 108, 336. Brachiopoda, 134, 546. Bryozoa, 123. Bueanopsis, 385, 667. Bueanopsis leda, 286. ma?ra, 432, 443, 449, 480, 487, 492. 499, 500, 510, 66T. Buchiola, 335, 611. Buchiola eonversa, 363, 441, 615. lialli, 68, 106, 325. (?) livonlse, 362, 363, 370, 371, 441, 616. mariffi. 441, 615. retrosti-iata, 55, 98, 106, 326, 347, 348, 362, 363, 368, 370, 371, 372, 413, 423, 441, 613, 61.5. sp., 463. Calceola sandallna, 30, 32. Calymene bufo var. rana, 329. Calymmenidse, 328. Camarotoeebia, 171, 575. Camarotoeebia congregata, 71, 72, 76, 77, 82, 106, 171, 175, 510, 517, 576. congregata var. parliheadensis, 415, 416, 417, 427, 440, 445, 448, 451, 452, 454, 455, 457, 459, 460, 461, 462, 468, 469, 471, 472, 474, 477, 480, 481, 487, 488, 492, 493, 500, 502, 503, 506, 511, 514, 516, 527, 575, 577. eontracta. 362, 365, 367, 432, 440, 513, 524, 575, 577. contraeta small var., 440, 446. eximia, 363, 367, 440, 448, 459, 469, 476, 490, 493. 494, 495, 496, 503, 311, 526, 579. horsfordi, 440, 480, 578. orbicularis, 440, 491, 579. proliflca, 60, 61, 62, 66, 67, 71, 77, 98, 106, 173. sappho, 77, 106, 174. sp., 66, 106, 175, 360, 464, 400, 496, 508, 513, 526, 527. Capulidae, 396, 681. Cardinildre, 362. Cardlola doris, 617. Cardiolidae, 223. Cardium palmatum, 611. Cavoliniidse, 300, 683. Centronella Julia, 179. ovata, 57, 91, 106, 17!J. Cephalopoda, 307, 690. Ceratodietya annulata, 319. centeta, 318., Cbaetopoda, 122, 544. Cbonetes, 146, 561. Cbonetis, buttsi, 112. carinatus, 148. coronata, 148. eoronatus, 51, 62, 6."i. 66, 68. 71, 72, 78, 81, 82, 85, 86, S7, 102, 105, 148. deflecta, 155, 136, 493. gibbosus, 76. laticosta, 146, 147. leplda, 153. lepidiformis, 336, 363, 367, 439, 433. 470, 561, 563. lepidus, 61, 62, 66, 67, 68, 71, 72, 73, 73, 76, 78, S2, 86, 87, 105, 153. lineata, 562. marylandicus, 62, 103, 137. mucronatus, 55, 61, 62, 65, 66, 68, 71, 72, 73, 74, 75, 76, 77, 81, 82. 83, 86, 87, 91, 105, 147, 153, 156. oaklandensis, 439, 525, 526, 562. rowel, 439, 563. rugosus, 55, 91, 103, 112, 158. scitula, 150. scitulus, 61, 62, 66, 67, 71, 72, 76, 78, 82, 85, 86, 103. 105, 130, 153, 154, 346, 378, 379, 386, 387, 390, 392, 395, 397, 439, 447, 439, 480, 499, 500, 511, 517, 519, 525. 562, 563. setiger, 61, 62, 65, 66. 67. 68, 71, 72. 76, 78, 81, 82, 83, 83, 86, 105, 133, 155. setigera, 130. setigerus, 152. sp., 520. vicina, 155. vlcinus, 68, 72, 76. 86, 105, 133, 138. yandellana, 562. Cimitaria(?) sp., 61. Paleontological Index 711 Cladochonus, 543. Cladochonus humilis, 423, 439, 4G0, 4G1, 456, 463, 520, 542. Coccostidjp, 700. Coelenterata, 119, 539. Coleolus, 305, 687. Coleolus (Dentalium(?)) aciculatum, 319. aeiculatus, 320. aciculum, 306, 320, 692. tenuieinctum, 305, 443, 481, 493. 498. tenuicinctus, 69. 81, 108, 305, 320, 427, 487, 492, 500, 502, 510, 087. Coleoprion tenuicinctum, 305, 687. Coelospira, 307. Coelospira acutiplicata, 208. Camilla, 209. concaya, 209. Conchites rhomboldalis, 141. Conocardildae, 357. Conocardlum, 357. Conocardium cumberlandiffi, 357. cuneus, 257. cuneus var. nasulum, 258. marylandlcum, 107. normale, 107, 257. Conularla, 304. Conularia cf. undulata, 91, 108, 304. Conulai-lda, 301, 6S6. Conulariidas, 304. Cornellites flabella, 250. Crania, 550. Crania hamiltonise, 131. sp., 367, 439, 550. Craniacea, 131, 549. Craniella, 131, 549. Cranlella hamiltonise, 59, 68, 91, 105, 131, 439, 549, 510, 520. sp., 85, 439, 550, 520. Craniida>, 131, 549. Craterillina sp., 58. Crustacea, 336, 699. Crj-phseus boothii, 333. Cryptonella, 584. Cryptonella cf. eudora, 367, 440, 494, 584. linckleeni, 179. Ctenobranchiata, 393, 675. Ctenodonta nasuta, 246. (Tancrediopsis) subcontracts, 246. Ctenostomata, 123. Cyatbophyllida, 131, 543. Cyclonema, 389, 670. Cyclonema doris, 292. hamiltonisE, 67, 74, 82, 108, 289, 291. 292. lirata, 674. liratum yar. grabaui, 71, 108, 290. marylandense, 103, 108, 292. concinnum, 443, 480, 493, 499, 510, 670. multistriata, 291. sp., 516. Cyclonemlna, C71. Cyclonemlna crenulistriata, 443, 499, 671, 673. crenulistriata var'. obsolescens, 443, 499, 672. hamiltonise, 673. multistriata, 427, 443, 455, 480, 481, 487, 492, 493, 499, 500, 502, 510, 515, 519, 673. Cypliaspls, 336. Cyphaspis cf. stepbanophora, 59, 91, 108, 326. Cypricardella, 373, 653. Cypricardella bellistriata, 62, 66, 69, 73, 107, 373, 275, 427, 442, 503, 653, 655, 656, 657. crassa, 442, 446, 499, 589, 657. cumberlandiae, 442, 525, 657. elegans, 442, 659. elegans var. augusta, 442, 497, 659. gregaria, 362, 442, 480, 492, 526, 653, 654, 658. gregaria var., 442, 448, 455, 503, 508, 511, 025, 655. indenta, 659. marylandica, 393, 442, 495, 499, 526, 653, 654. marylandica var. (very small), 442. nitidula, 275, 379, 393, 442, 654, 656. sp., 379, 442, 447, 453, 499, 510, 658. tenuistriata, 66, 82, 107, 275, 442, 469, 480, 500, 510, 655, 656, 658. vanuxemi, 428. Cypricardla contracta, 610. Cypricardiacea, 373, 653. Cypricardinia indenta, 62, 69, 107, 276. sp., 59. Cypricardites bisulcata, 218. concentrica, 266. indenta, 276. mytiloides, 269. sectifrons, 214. subalata, 268. Cyrtina, 185, 591. Cyrtina hamiltonensis, 43, 66, 67, 68, 77, 82, 86, 87, 106, 185, 356, 358, 395, 424, 426, 427, 440, 453, 454, 456, 460, 470, 473, 480, 481, 493, 499, 500, 502. 510, 519, 527, 591. Cyrtochoanites, 318. Cyrtolites, 388. Cyrtolites (Cyrtonella) mitella, 62, 73, 77, 107, 388. 712 Paleontological Iicdex Cyrtonella, 28S. Cystiphyllldffl, 121. Cystiphyllum, 121. Cystiphyllum americanum, 68, 105, 121. cylindricum, 121. vesiculosum, 121. Cytherodon (Schizodus) quadrangularls, 645. Dalmanella, 164, 569. Dalmanella carinata, 440, 520, 570. Infera, 572. lenticularis, 53, 57, 58, 59, 91, 105, 112, 164. leonensis, 572. sp., 367, 440, 572. tioga, 440, 520, 523, 569. Dalmania boothii, 333. Dalmanites, 333. Dalmanites booth! yar. calllteles, 334. (cryphsEus) boothi, 69, 108, 333. marylandicus, 86, 108, 334. Delthyris acuminata, 193. audacula, 192. congesta, 190. consobrina, 198. flmbriatus, 197. granulifera, 190. granulosa, 190. liETis, 592. medians, 192. mucronata, 187, 599. ziczac, 196. Dentalium acieulatum, 319, 320. Diaphorostoma, 298, 684. Dlaphorostoma Ilneata, 684. lineatum, 69, 79, 81, 86, 87, 108, 298, 443, 684. Dipleura delsayi, 328. Dipneusti, 700. Discina lodensis, 42, 129, 130. media, 129, 130. minuta, 42. Discinacea, 129, 549. Discinidse, 129, 549. DouvilLina, 655. Douvillina arcuata, 379, 387, 392, 399, 439, 557. cayuta, 349, 367, 378, 387, 392, 393, 394, 398, 439, 494, 496, 497, 513, 520, 525, 526, 555, 556. cayuta var. graciliora, 379, 393, 395, 397, 398, 439, 556. inaequlstriata, 138, 557. Ecculiompbalus comes, 669. Echinodermata, 543. Ectenodesma, 633. Botenodesma birostratum, 427, 441, 453, 470, 481, 493, 633. Ectomaria, 663. Ectomaria ecclesise, 442, 664. marylandica, 442, 480, 493, 499, 510, 663. Bdmondia undata, 608. Elymella cf. nuculoides, 243. Encbostoma, .305. Enchostoma? sp., 55, 108, 305. Encrinasterise, 543. Errantia, 122. Eucrustacea, 335. Bunella, 179. Eunella lincklaeni, 76, 77, 106, 179. Buomphalus, 670. laxus, 669. (Ecculion phalus?) laxus, 669. decewi, 670. sp., 55. tioga, 443, 670. Euomplatidffi, 668. Eurycampyli, 323, 696. Euryzone itys, 284. Buthydesma sp., 55, 106, 221. Eutbyneura, 300. FaTositidse, 541. FaTOSites, 541. Favosites arbusculus, 541. sp., 359, 439, 541. Gastropoda, 280, 661. Glossocampyli, 697. Glyptaspis, 700. Glystaspis eastmani, 444, 700. Glyptocardia speciosa, 225, 614. Gomphoceras, 318. Gompboceras pingue, 77, 108, 318. Goniatites chemungensis, 697. discoideus, 323, 696. expansus, 321. patersoui, 693. sp., 55, 79. uniaugulare, 696. vanuxemi, 321, 326. Goniophora, 271, 651. Goniophora glauca, 442, 652. glaucus, 652. bamiltouensis, 82, 107, 371, 442, 480, 493, 500, 511, 651, 653. sp. undet, 53. truncata, 442, 480, 510, 651. Gosselletia, 641. Gosselletia sp., 442, 510, 541. Paleontologioal Index 713 Grammysla, 218, 606. Grammysia arcuata, 71, 87, 106, 219. bisulcata, 66, 86, 106, 218. clrcularls, 62, 82, 106, 220. communis, 425, 441, 453, 607, 609. elllptica, 374, 440, 493, 495, 496, 500, 524, 526, 606. hamiltonensis, 218. sp., 55, 106, 220. subarcuata, 440, 511, 514, 527, 606. nndata, 441, 494, 496, 608. Grammysiidse, 218, 606. Gymnoglossa, 293, 675. Gyroma capillarla, 282, 661. Gyronema liratum, 459. H HeUophyllum, 540. Heliophyllum scratarium, 359, 439, 540. sp., 85, 105, 131. HexaeorSUa, 541. Holopea, 679. Holopea humilis, 443, 680. marylandica, 369, 443. parva, 499, 502. rowei, 369, 443, 500, 679. sp., 443, 480, 494, 681. Homalonotus, 328. Homalonotus dekayi, 66, 71, 74, 76, 77, 82, 108, 328. Hormotoma, 663. Hormotoma bistriata, 442, 480, 663. Hyolithes aclls, 443, 688. HyoUtbldae, 688. Incertae saedis, 545. Inoceramus oviformis, 255. Kiouoceratidse, 314. Leda, 247, 626. Leda diversa, 87, 107, 247, 248, 441, 496, 526, 626. rostellata, 61, 65, 79, 107, 247. sp., 441. Ledldae, 235, 620. Lelopteria conradi, 252. IsBvis, 253. Lelorhynchus globuliformis, 582. limitarls, 43. multlcosta, 177. sp., 45. Leperdltia, 335. Leperditla slnuata, 336. cf. subrotunda, 59, 91, 108, 335. Leperditiidse, 335. Leptffina, 141. Leptffina depressa, 142. nucleata, 159. i-bomboidalls, 85, 105, 141. tenuisti-iata, 141. vicina, 155. LeptaBDisca, 143. Leptsenisca australis, 58, 59, 91, 105, 143. liCptocoalia acutiplicata, 207. Leptodesma, 254. Leptodesma agassizi, 393, 441, 525, 637. elongatum, 441. licbas, 379, 393, 441, 495, 496, 497, 637, 640. longispinum, 379, 393, 395, 441, 520, 637, 640. medon, 441, 525, 526, 638. nariforme, 358, 415, 441, 474, 511, 515, 517, 639. rogersi, 69, 107, 254, 399, 441, 636. soclale, 255. sp., 441, 490, 494, 495, 496, 497, 524, 525, 526. Leptostrophia, 552. Leptostrophia interstrialis, 426, 439, 450, 462, 553, 554. perplana, 59, 134. perplana var. alternata, 439, 495, 499, 509, 553, 554. perplana var. nervosa, 390, 392, 393, 395, 397, 439, 552. Lingula, 125, 546. Lingula clarki, 61, 105, 128. cf. compta, 68, 105, 128, 129. delia, 68, 105, 546. densa, 127. ligea, 62, 68, 105, 136, 439, 460, 547. melie, 547. nuda, 65, 71, 105. cf. nuda, 91, 127. obemi, 439, 546, 517. ( ?) pallformis, 124. punctata, 127. spatulata, 439, 456, 457, 460, 548. sp., 439, 548. Lingu«IIa, 124. Lingulacea, 134. Lingulldffi, 125, 546. Llngulella(7) paliformis, 68, 71, 105, 124. Llngulellidffi, 124. Liopteria, 252, 634. Liopteria auriculata, 441, 450, 636. bigsbyi, 358, 427, 441, 493, 503, 510, 511, 515, 517, 634. (sp. near blgsbyl), 441, 500, 513, 635. ri4 Paleontological Index c(. conradi, 66, 107, 252. IffiTis, 55, 90, 91, 107, 253. marylandica, 441, 500, 635. sp., 441. Liorhynchus, 175, 581. Liorhynchus globuliforme, 424, 425, 427, 440, 449, 453, 454, 456, 457, 460, 468, 470, 473, 481, 493, 582, 600. laura, 68, 71, 103, 106, 176, 17T. limitare, 50, 54, 55, 60, 61, 62, 70, 71, 75, 80, 93, 98, 106, 175. limitaris, 175, 179. mesacostale, 364, 367, 415, 440, 522, 581. mesacostalis, 517. 581. multieosta, 176, 177, 362, 581. multicostum, 177, 581. ef. multicostum, 440. cf. mysia, 50, 55, 98, 106, 178. sp., 61, 506. Littorinidfe, 679. Loxonema, 294, 676. Loxonema delphicola, 2P5. ( ?) glabrum, 443. 480, 481, 487, 493, 499, 502, 510, 511, 677. hamiltoniffi, 55, 69, 91, 108, 2»4, 443, 493, 510, 676. nexilis, 294. sp., 67. styliola, 676. styliolum, 432, 443, 492, 499, .ilO, 511, 513, 676. terebra, 676. terebrum, 379, 387, 443, 4(19, 676. Lucina (Paracyclas) lirata, 277. Lucinacea, 277, 660. Lucinldse, 277, 660. Lunulicardiidae, 630. Lunulicardium, 630. Lunilicardium crinitum, 362, 370. cymbula, 372, 441, 631. encrinitum, 441, 630. fragile, 632. Lyriopecten, 649. Lyriopecten trieostatus, 361, 362, 379, 442, 649. M Macrochilina, 675. Macrochilina pulchella, 369, 443, 675. Macrocbilus, 293, 675. Macrochilus hamiltoniie, 77, 108, 29.3. Macrodon, 627. Macrodon chemungensis, 441, 627. bamiltonise, 248. Madreporia, 541. Mseueceras terebratum, 30. Magnosellarida?. 323, 696. Manticoceras, 693. Manticoceras intumescens, 612. patersoni, 432, 444, 509, 693. Marglnifera, 568. Mellepoi'ites repens, 542. Meristella, 605. Meristella humilis, 440, 450, 453, 605. (7)'sp., 106, 213. Mesocampyli, 693. Microcampyli, 319, 692. Microdon bellastriata, 273. bellistriata, 274. (Cypricardella) gregarius, 6.34. gi'egarius, 654. tenuistriata, 275. Modiella, 261. Modlella pygmaea, 66, 67, 69, 71, 107, 261, 269. coneentrica, 266. Modiolopsidse, 266, 650. Modiomorpba, 266, 650. coneentrica, 66, 69, 71, 72, 77. 82. 107, 266. mytiloides, 69, 82, 102, 267, 269. planulata, 269. subalata, 55, 57, 69, 91, 107, 2.68, 270, 650. subangulata, 442, 509, 650. MoUusca, 214, 606. MoUuscoidea, 123, 546. Monticulipora, T23. (?) marylandensis, 68, 105, 123. ( ?) winchelli, 124. MouticuliporidaB, 12.3. Monotis princeps, 263. Murchisonea, 662. Murchisonia ecclesia, 367, 393, 397. (?) sp., 378, 387, 397, 442, 662. Myalinidae, 261, 644. Mytilacea, 266, 650. Jlytilarca, 255. Mytilarca (Plethomytilus) oviformis. 62, 60, 72, 107, 255. N Naiadacea, 262. Naticopsis sp. 55, 108, 293. Nautilinidae, 321. Nautiloidea, 307. Neotremata, 549. Nucleospira, 206. Nucleospira concinna, 55, 58, 59, 85. 91, 106, 206. Nucula, 226, 619. Nucula belletula, 235. bellistriata, 61, 62, 66, 67, 68, 72, 78, 102, 106, 227, 229, 231. cf. corbuliformis. 59, 65, 67, 68, 74. 82, 85, 87, 91, 98, 102, 106, 226, 358, 441. 454, 460, 499, 502, 511, 619. Paleoxtological Index 715 cuneiformis, l!34. llrata, 68, 106, aau. oblongatus, 234. raudalli, 229. sp., 77. varicosa, 106, 230. Nuculacea, 226, 619. Nuculidce, 226, 619. Nuculites, 231. Nuculites bellastriata, 227. chemungensis, 644. constricta, 235, 620. emai'ginata, 241. filosa, 623. grabaui, 87, 107, 234. lirata, 229. maxima, 238. modulatus, 55, 91, 107, 234. oblongatus, 66, 67, 68, 72, 76, 78, 85, 87, 102, 107, 231, 235. radiata, 272. rostellata, 247. submarginata, 222. sp., 367, 441, 620. triqueter, 60. 61, 62, 67, 68, 71. 72. 87, 91, 102, 107, 2.32. Nyassa, 262. Nyassa arguta, 74, 87, 107, 262. Opisthobranchia, 300. Opisthoparia, 326. Orbiculoidea, 129, 549. Orbiculoidea, cf. media, 439, 481, 517, 549. lodiensis var. media, 120. lodiensis, 55, 68, 85, 90, 91, 105, 129. media, 54, 68, 129, 367, 549. minuta, 133. sp., 82. Ortiidae, 164, 569. Ortliis carinata, 570. cyclas, 169. elegantula, 571. impressa, 170, 572. interlineata, 560. iowensis, 170, 573. leucosia, 42, 166. lenticularis, 164. limitaris, 175. nucleus, 203. penelope, 167. prseumbona, 204. sp., 71. striatula, 170. tioga, 350, 569. tuUiensis, 573. umbonata, 200, 602. vanuxemi, 165. Ortboceras, 307. Ortboceias acicula, 320. aciculum, 320, 692. cJ. aulas, 77, 108, 313. bebryx, 67, 77, 81, 108, 307. consortale, 443, 509. constrictum, 67, 69, 108, 300, 311. crotalum, 314. ct demum, 443, 459, 496, 500. emaceratum, 67, 104, 108, 311, 312, 313. cf. exile, 69, 108, 310, 312. fllosum, 363, 443. (Geisonoceras) subulatum, 308. geneva, 318. lineatum, 308. nuntum, 316. sp., 480, 517. subulatum, 69, 104, 108, 308, 310, 311. telamon, 104, 108, 311. Ortboceratidffi, 307. Orthochoanites, 307. Ortbonota, 216. Ortbonota (?) parvula, 68, 106. 217. undulata, 82, 83, 103, 106, 216. Ortbonycbia, 681. Orthonychia prosseri, 443, 6.S1. sp., 443, 682. unguiculata, 443, 480, 510. 082. Ortbothetes bellulus, 145, chemungensis, 393, 559, perversus, 145. variabilis, 62, 145. Ostracoda, 335. Pateanatina, 609. Palseanatina angusta, 441, 490, 49,"i, 609. Palaeaster, 543. Pateaster clarki, 395, 439, 543. eucharis, 543, Palseoneilo, 235. Palseoneilo angusta, 441, 624. brevis, 441, 454, 456, 460, 470, 402. 493, 515, 622. clarljei, 67, 103, 107, 244. constricta, 55, 62, 66, 68, 71, 87, 91, 102, 107, 235, 237, 239, 243, 362, 393, 424, 441, 470, 620, 622. crassa, 441, 497, 621, 625. elongata, 621, emarginata, 62, 65, 66, 68, 87, 107, 241, 371, fecunda, 06. 107, 2.39. fllosa, 393, 441, 623. marylandica, 82, 107, 245. maxima, 68, 107, 238, 622. cf, maxima, 441, 503, miita. 78, 240, 716 Palbontological Index perplana, 499. perplana var. grabaui, 68, 107, 240. petila, 441, 624. plana, 67, 68, 107, 237, 441, 447, 492, 495, 499, 500, 621. rowei, 79, 82, 107, 244. sp., 75, 79, 496, 499, 511, 526. tenuistrlata, 62, 68, 86, 87, 107, 240, 242. Palaeosolen, 279. Palaeosolen minutus, 66, 107, 279. siliquoideus, 279. Palaeotroclies pr^cusor, 393, 665, 678. Palellastium, 287. Panenka, 223. Pauenka alternata, 57, 91, 106, 223. d. dichotoma, 57, 91, 106, 224. cf. multiradiata, 57, 91, 106, 225. obsolescens, 57, 91, 106, 224. sp. undet., 53. Paracardium, 617. Paracardium delicatulum, 370, 441, 618. doris, 362, 370, 371, 372, 441, 617. Paracyclas, 277, 660. Paracyclas elliptica, 660. lirata, 67, 69, 73, 77, 81, 82, 87, 103, 107, 277. marylandica, 442, 496, 660. sp., 442. tenuis, 69, 107, 278. Parallelodon, 248. hamiltoniae, 68, 72, 82, 85, 107, 248. Parallelodontidse, 248, 627. Parodiceras, 323. Parodiceras discoidenm, 91, 108, 323. Perten cancellatus, 648. Pectinacea, 263 648. Pectinidfe, 263 648. Pelecypoda, 214, 606. Phacops, 329, 699. Phacops bufo, 329. cristata, 53, 59, 91, 108, 112, 331. cristata var. pipa, 57, 58, 91, 108, 331, 332. rana, 51, 62, 69, 77, 79, 84, 85, 86, 87, 102, 108, 329, 444, 480, 510, 515, 699. PhsBOpidae, 329, 699. Phanerotinus, 669. Phsenerotinus laxus, 443, 480, 669. Pharciceratidae, 697. Pharetrella tenebrosa, 443. Pholadella, 272. Pholadella radlata, 82, 107, 272. Pholadellidae, 272. Pbolidops, 132. Pholidops cf. areolata, 53, 55, 91, 105, 133. hamlltoniffl, 71, 105, 132. Pholidostrophia, 141. Pbolidostrophia ioweusis, 141. pennsylvanica, 55, 59, 91, 105, 141. Phothyris lanceolata, 106. Phragmo ceratldae, 318. Phthonia, 214. Pbthonia sectifrong, 71, 196, 214. Pisces, 700. Platyceras, 296, 683. Platyceras attenuatum, 684. compressum, 443, 683. erectum, 82, 108, 296. marylandicum, 443, 448, 492, 509, 510, 682, 683. prosseri, 379. cf. symmetricum, 69, 108, 297. sp., 69, 443, 684. Platyopoda, 293. Platyostoma, 299. cf. euomphaloides, 91, 108, 299. llneata, 684. Ilneatum, 298. Platypoda, 675. Plcthomytllus orlformls, 256. Pleurophoridae, 273, 653. Pleurotomarla, 280, 661. Pleurotomarla (Bembexla) sulcomargi- nata, 67, 73, 74, 75, 76, 79, 82, 86, 107, 280, 284. (Euryzone) Itys, 66, 77, 107, 284, 294. (Gyroma) capillarla, 69, 82, 83, 107, 282, 427, 428, 442, 480, 493, 500, 519, 661, 673. llneata, 284. sp., 61, 69, 442, 520, 662. (Trepospira) rotalla, 65, 79, 86, 87, 107, 283. Pleurotomariidse, 280, 661. Polychaeta, 544. Posldonla (?) arcuata, 219. Urata, 277. Polygnathus, 122. Polygnathus sp., 105, 122. Praecardildse, 225, 611. Premordlalidffi, 693. Prionodesmacea, 214, 606. Probeloceras, 695. Probeloceras lutheri, 363. 370, 371, 372, 444, 695. Productella, 162, 564. Productella hlrsuta, 565. cf. spinullcosta, 66, 105, 162. hystricula, 397, 440, 567. lachrymosa, 365, 367, 392, 397, 428, 440, 453, 480, 492, 500, 509, 510, 527, 564, 565, 566. lachrymosa var., 359, 367, 440, 514, 565. lachrymosa var. marylandica, 440, 509, 510, 520, 565. lima, 564. Paleontological Index 717 ( ?) schuchertl, 85, 105, 1C3. naviceUlformls, 440, 517, 567. sp., 509, 514. speciosa, 367, 378, 393, 424, 426, 427, 440, 449, 450, 453, 454, 455, 456, 460, 461, 462, 468, 470, 473, 481, 493, 565, 566. truncata, 160. Productidae, 146, 561. Productus, 568. Productus cora, 163. dissimills, 568. (Marginifera?) dissimilis, 568. (Marginifera?) hallanus, 399, 440, 568. (Productella) hallanus, 568. speclosus, 566. spinulicostus, 162. truncatus, 160. Proetidse, 326. Prothyris, 215. Prothyris lanceolata, 67, 81, 86, 215. Protoparia, 328, 699. Protremata, 134, 551. Pteriacea, 250. Pteridiclinites, 545. Pteridichnites beseriatus, 439, 545. Pteriidae, 258, 642. Pterinea, 250, 628. Pterinea blsulcata, 218. chemungensls, 378, 424, 427, 441, 453, 480, 481, 499, 509, 513, 520, 527, 629. concentrica, 266. consimilis, 252. flabella, 250, 628. flabellum, 66, 67, 68, 72, 74, 75, 76, 79, 82, 107, 250. nodocosta, 393, 395, 441, 628. pygmsea, 261. sp., 251. Pterlneldse, 250, 268. Pterocbsenia, 631. Pterochsenia fragllis, 79, 347, 348, 357, 362, 363, 370, 371, 372, 413, 423,-441, 632. sp., 463. Pteropoda, 300, 685. Ptomatis patulus, 287. Ptychodesma, 644. Ptychodesma sp., 442, 517, 644. Ptychopteria, 644. Ptychopteria sp., 442, 644. Pugnax, 583. Pugnax altus, 583. pugnus var. altus, 424, 426, 427, 440, 450, 453, 454, 456, 460, 461, 462, 463, 468, 470, 473, 481, 493, 583. Purpurinldse, 678. Pyramidellidse, 293, 675. Beticularia, 592. Eetlcularia fimbrlata, 55, 197. Iffivls, 425, 440, 456, 457, 460, 461, 592. Rbipodoglossa, 280, 661. Rhipldomella, 165, 572. Ehipidomella cyclas, 71, 84, 85, 91, 105, 169. leucosia, 66, 105, 166. penelope, 68, 105, 167. sp., 87. vauuxemi, 58, 65, 66, 68, 85, 91, 105, 165, 167, 168, 169, 415, 420, 427, 428, 432, 440, 511, 516, 517, 519, 572. Rhopalonarla, 123. Rhopalonaria tenuis, 68, 105, 123. Rhopalonarlldae, 123. Rbyncbonella alta, 583. horsfordi, 578. (?) laura, 177. orbicularis, 579. pugnus var. alta, 583. sappho, 174. (Stenocisma) congregata, 171. (Stenocisma) contracta, 577. (Stenochisma) exlmia, 579. (Stenocisma) proliflca, 173. venustula-cuboldes, 31. Rhynchonellacea, 171, 575. Rhynchonellidse, 171, 575. S Sandbergeroceras, 697. Sandbergeroceras cbemungensis, 432, 444, 511, 526, 697. Sangulnolites glaueus, 652. hamlltonensis, 271. Schizodus, 644. Schizodus appressus, 645. cbemungensis, 442, 405, 497, 499, 644. cbemungensis rar. quadrangularis, 393, 442, 645. froatburgensis, 442, 647. obernl, 442, 446, 447, 448, 492, 495, 497, 499, 509, 525, 645, 646. ohemi var., 442, 496. quadrangularis, 645. sp., 480. trigonalis, 442, 448, 499, 500, 511, 647. 718 Paleontological Index Scliizophoria, 170. Schizoporia carlnata, 570. impressa, 170, 510. iowensis, 170. strlatula, 85, 105, 170, 358, 424, 426, 427, 440, 447, 453, 455, 456, 460, 461, 462, 463, 470, 493, 494, 496, 510, 519, 520, 572. striatula var. marylandica, 393, 394, 395, 397, 440, 494, 525, 526, 574. tioga, 569. Schuchertella, 144, 559. SchuclierteUa cJiemungensis, 367, 379, 387, 395, 397, 439, 480, 490, 491, 494, 495, 496, 497, 513, 520, 525, 526, 527, 559, 560. chemungensis var. perversa, 145. elliptica, 439, 560. cf. perversa, 144. ( ?) ponderosa, 439, 447, 560. sp., 66, 73, 77, 78, 82. variabilis, 65, 71, 86, 91, 103, 144. Solemyacidse, 214. Solenaeea, 279. Solenlda;, 279. Solenopsidse, 215. Sphserodoma liamiltonise, 289. Sphenotus, 610. Sphenotus contractus, 359, 361, 362, 373, 374, 393, 441, 610. sp., 441. Spiriferacea, 183, 586. Spirlfer, 593. Spirifer acuminata, 193. acuminatus, 31, 86, 106, 193. angusta, 196. angustus, 62, 68, 74, 86, 106, 196. asper, 598. audacula, 192. audaculus, 66, 68, 74, 77, 82, 83, 86, 106, 192, 195, 197. cf. consobrinus, 106, 198, 199. cultrijugalus, 31. dactylus, 600. (Delthyris) consobrinus, 198. (Delthyris) mesacostalis, 440, 448, 4.52, 455, 459, 472, 480, 481, 487, 490, 491, 492, 493, 497, 498, 499, 500, 502, 503, 505, 508, 509, 510, 511, 513, 514, 515, 517, 519, 520, 525, 526, 527, 528, 601. disjunctus, 344, 348, 349, 350, 353, 359, 361, 364, 365, 367, 368, 373, 374, 378, 379, 381, 386, 387, 388, 392, 393, 394, 395, 397, 398, 418, 421, 431, 440, 446, 447, 459, 469, 472, 480, 484, 490, 492, 494, 495, 498, 499, 506, 508, 500, 510, 513, 514, 520, 524, 525, 526, 586, 593. granulifera, 190. granulosus, 51, 62, 65, 66, 67, 68, 72, 75, 76, 77, 82, 83, 86, 102, 106, 190, 193. Iffivis, 592. marcyi var. superstes, 358, 361, 362, 367, 415, 417, 420, 427, 428, 432, 440, 480, 492, 498, 500, 502, 506, 507, 510, 515, 516, 517, 518, 519, 528, 597. medlalis, 192. mesastrialis, 355, 356, 359, 362, 367, 368, 378, 424, 427, 440, 446, 447, 448, 453, 454, 455, 458, 459, 480, 491, 492, 496, 497, 498, 499, 502, 513, 520, 596. mesacostalis, 346, 360, 365, 367, 368, 369, 374, 415, 416, 417, 426, 427, 428, 432, 440, 447, 448, 601. mucronata, 187. mucronatus, 26, 43, 45, 51, 56, 61, 62, 64, 65. 66, 67, 68, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 86, 102, 106, 187, 191, 193, 601. mucronatus var. posterns, 357, 358, 371, 424, 426, 440, 449, 450, 453, 454, 455, 456, 457, 460, 461, 462, 463, 468, 470, 473, 481, 493, 494, 502, 599. permatus, 187. permatus var. posterus, 426. (Eeticularia) fimbriatus, 60, 68, 91, 106, 197. sculptilis, 199. sculptilis var. marylandensis, 74, 106, 200. sp., 526. tullia, 195. tullius, 72, 82, 106, 195. Spirifera augusta, 196. conradana, 197. consobrina, 198. granulifera, 43. pennata, 187. spiriferoides, 211. ziczac. 198. Spiriferid», 185, 591. Spiropbyton velum, 83. sp., 62, 451. Spirorbis, 544. Spirorbis angulatus, 545. gyrus, 359, 439, ■'544. sp., 439, 502, 545. Spyroceras, 314. Spyroceras clarkei, 86, 108, Si 7. erotalum, 77, 86, 108, 314, 317. geneva, 317. nuntium, 67, 104, 108, 316. Stenochisma proliflca, 173. Paleontological Index 719 Stereolasma, 119. Stereolasma rectum, 6S, 85, lli.j, 110. StraparoUus, 668. StroparoUus cyclostomus, 66S. marylandicus, 443, 480, 510, 668. Streptelasma rectum, 119. (Stereolasma) rectum, 119. Streptoneura, 280, 661. Streptorhynchus chemungensis, 45, 346, 350, 559. Strlngocephalus burtini, 26, 30, 32. Strombodes ( ?) rectus, 119. Stropbalosia, 160. Strophalosia truncata, 55, 57, ."iS, 68, 91, 98, 105, 160, 204. Stropbeodonta, 134, 551. Stropheodonta (DouTlUina) cayuta, 139, 555. concava, 68, 82, 105, 139. demissa, 42, 65, 68, 82, 105, 136, 140, 426, 439, 457, 461, 462, 481, 493, 551. (Douvillina) inequistriata, 62, 68, 105, 138. interstrialis, 554. (Leptostropbia) perplana, 56, 62, 65, 60, 68, 71, 72, 73, 75. 76, 77, 82, 86, 91, 103, 105, 134, 137. maynardi, 439, 551. mucronata, 554. perplana var. nervosa, 552. puntl, 141. reversa, 557. sp., 61. Stropbomenacea, 134, 531. Strophomena carinata, 148, 181, 58.3. demissa, 136, 453. depressa, 141. Inffiquistriata, 138. interstrialis, 554. lacbrymosa, 564. mucronata, 146. nervosa, 552. perplana, 134. pustulosa, 160. rhomboidalis, 142, rugosa, 142. setigera, 152. (Stropbodonta) concava, 139. (Stropbodonta) fragilis, 134. syrtalis, 148. undulatus, 141. undulosa, 141. Strophomenidse, 134. Strophonella, 557. Stropbonella reversa, 399, 439, 537. sp„ 439, 558. Styliolina, 300, 685. Styliola flssurella, 300, 443, 685. Styliolina flssurella, 50, 55, 57, 58, 59, 69, 75, 76, 80, 84, 86, 80, 91, 98, 108, 347, 359, 362, 363, 370, 371, 372, 423, 685. Tabulata, 541. Taenloglossa, 296, 678. Tancrediopsis, 245. Tancrediopsis clarkei, 77, 107, 245. Teleodesmacea, 273, 633. Tellina (?) ovata, 238. Tellinopsis, 222. Tellinopsis submarginata, 67, 68, 71, 106. Telotremata, 171, 375. Tentaculites, 301, 686. Tentaculites attenuatus, 78, 79, 86, 87, 108, 301, 303. bellulus, 76, 108, 302. bellulus var. protomacensis, 87, 108, 30i3. decissus, 362, 367, 393, 443, 686. flssurella, 300, 685. scalariformis, 303. spiculus, 443, 450, 686, 687. Tentaculitidffi, 301, 686. Terebratellidse, 181, 584. Terebratulacea, 179, 584. Terebratulidae, 179, 585. Terebratuliuce, 179. Terebratula concentrica, 211. lincklaeni, 179. permata, 187. reticularis, 183. spiriferoides, 211. Tetrabrancbiata, 307. Tetracoralla, 119, 539. ToreUellidse, 305, 687. Tornoceras, 696. Tornoceras uuiangulare, 348, 371, 372, 413, 444, 696. Tracbydomia, 678. Tracbydomia prsecursor, 443, 678. Trepospira rotata, 282. « Trepostomata, 123. Trigoniacea, 644. Trigoniidffi, 644. Trilobita, 326, 699. Trocbonema, 674. Trocbonema (gyronema) libratum, 443, 674. (gyronema) sp.. 443, 525. Trocbonemaidae, 674. TropidoleptimiE, 181, 583. Tropidoleptus, 181, 583. 730 Paleontological Index Tropidoleptus carinatus, 45, 51, 56, 60, 61, 62, 64, 65, 66, 67, 68, 71, 72, 73, 75, 76, 77, 78, 81, 82, 83, 86, 93, 102, 106, 181, 362, 364, 367, 370, 415, 416, 417, 420, 427, 428, 432, 440, 448, 455, 459, 469, 472, 476, 480, 481, 487, 489, 492, 498, 500, 502, 503, 510, 511, 515, 516, 517, 519, 526, 528, 585. Tubicola, 544. Turbinidffl, 289, 670. Turbo, 673. Turbo coronula, 379, 443, 673. lineatus, 284. shumardi, 674. Venericardlum retrostriatum, 611, 613. Vermes, 122, 544. Vertebrata, 700. Vltulina, 210. Vitulina pustulosa, 66, 67, 68, 71, 106, 210. Zaphrentidffl, 119, 539. Zapbrentis, 539. Zaphrentis chemvmgensls, 439, 513, 539, 540. marylandlcus, 439, 539, 540, 513. WEST COLUMNAR SECTIONS OF THE JENNINGS FORMATION OF MARYLAND By CHARLES K. SWARTZ MARYLAND GEOLOGICAL SURVEY WILLIAM BULLCXK CLARK. State Geologist STAI F- I HORIZONTAL (IN EAST-WEST DIRECTION) 1 INCH- 2 MILES ov.rtL-iL. j VERTICAL 1 INCH«200 FEET - 3500 I FGEND ;':;''■?;?.■■■/;;:•.■■> Sandstone Conglomorate WM, Red Strata ■■■°:<>' ■;.■■:''=■■■■.■■■■ mmm Black Shale 1 1 1 Shale Gincealed interval The numbers beside the columns refer to the fossils listed in the table of distribution of Upper Devonian Species, pages 439 to 444. Their positions indicate the horizons at which these species occur in the sections. A single underscore denotes common; a double underscore, abundant. N signifies Naples fauna. J' ^ ^ A^ x^< # COLUMNAR SECTIONS OF THE JENNINGS FORMATION OF MARYLAND By CHARLES K. SWARTZ MARYLAND GEOLOGICAL SURVEY WILLIAM BULLOCK CLARK. State Geologist SCALE- I HORIZONTAL (IN EAST-WEST DIRECTION) 1 INCH- 2 MILES 1 VERTICAL 1 INCH-200 FEET Sandstone Conglomorate LEGEND ••■:':':'::'-V:-'--:-i:'':/i^ WM, Red Strata Shale 1 — __ — Black Shale G)ncealed interval The numbers beside the columns refer to the fossils listed in the table of distribution of Upper Devonian Species, pages 439 to 444. Their positions indicate the horizons at which these species occur in the sections. A single underscore denotes common; a double underscore, abundant. N signifies Naples fauna. -|-5p.Q)jia '^^ !-50, 54, 66, 72 - e? lfc.70 V.^.r^ GS FORMATION d interval 2^, Z9. 46. 53, 61. 66. / / / / / / / / / X ^ y /../■/ ; V/M TO. 71 /^YCC/. < .1 j.i/j.j '///./i/. ////'/. t W?^ - ///// Z' -66 ■|-5p.^, IIS ^-50. 54, ee, n r 1 I. i:2z; ^ 54. 66. 70. Iia ZZ^ ///■ 'k^ 29, 54 6g Y//A w:^. V' Z^ X / 70, iia -53, 70 ■/////. /■/ / A 70, 71 ///// ■//// EAST 51. \ze ^ft 350O CD z D X u 'Z500 m ^ te^ ■'..-'-■' ■■y ' ^Z zJ sna 3 I I I i I I Middle Fotl The numbers beside the columns refer to the fossils listed in the table of distribution of Upper Devonian Species, pages 439 to 444. Their positions indicate the horizons at which these species occur in the sections. A single underscore denotes common; a double underscore, abundant. N signifies Naples fauna. ^sa UPPER CHEMUNG CONGLOMERATE i'i>.o.'».'*..ir; LOWER CHEMUNG CONGLOMERATE - t^^iej^il ' «(st ol Ktiser, W. Vi, ;^:»;i uuLui in me sections. /\ single underscore denotes common; a double underscore, abundant. N signifies Naples fauna. '/■//./■ '■/■/■■//A ei? 66 -TO, II 70, 71 70.71 Green Ridge ee. ae, no -6.6, f_7 31 -§6,C7 -■oj - i:>. 70, 7( 90 -53. «/ 71,146 ITHACA FAUNA _J9. ^, 69 "69, I6p 47, 57, 69 a < a: . UJ H Z o ^ Middle Mi LOWER CHEMUNG CONGLOMERATE - ■ t ift'?.''! ■fi.^y'"; J W(st ol Keiser, W. Yi. GENESEE MEMBER AllefiiDi Grow i, Pt Wlams Rmd, B. ol GoniKiliHl THe L&BO OALTlMDCte POKSS.Qai ork "^f * m^ LOWER CHEMUNG CONGLOMERATE 1 Vest ol Keistr, W. Vi. ESEE MEMBER Etierie, Pa. WluBs RMd E. ot Gonlierliii