UC BERKELEY MASTER NEGATIVE STORAGE NUMBER 03-67.29 (National version of master negative storage number: CU SN03067.29) MICROFILMED 2003 UNIVERSITY OF CALIFORNIA AT BERKELEY LIBRARY PHOTOGRAPHIC SERVICE REPRODUCTION AVAILABLE THROUGH INTERLIBRARY LOAN OFFICE MAIN LIBRARY UNIVERSITY OF CALIFORNIA BERKELEY, CA 94720-6000 COPYRIGHT The copyright law of the United States (Title 17, United States Code) governs the making of photocopies or other reproductions of copyrighted materials including foreign works under certain conditions. In addition, the United States extends protection to foreign works by means of various international conventions, bilateral agreements, and proclamations. Under certain conditions specified in the law, libraries and archives are authorized to furnish a photocopy or other reproduction. 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Preliminary report on the foraminifera from the cretaceous Moreno shales north of Coalinga 1924 BIBLIOGRAPHIC RECORD TARGET University of California at Berkeley Library Master negative storage number: 03-67.29 (national version of the master negative storage number: CU SN03067.29) GLADIS NUMBER: 1847881971 FORMAT : BK AD:991012/FZB LEVEL:b BLT:am DCF:a CSC:d MOD: EL: 7 UD:030604 /MAP CP:cau L:eng INT: GPC: BIO: FIC: CON: ARCV: PC:s PD:1924/ REP: CPI: FSI: ILC: IT:0 040 CUScCU 090 SbDISS.HORTON.GEOL 1924 100 1 Horton, Harold M. 245 10 Preliminary report on the foraminifera from the cretaceous Moreno shales north of Coalinga. 260 $cl1924. 300 [a-d], 24 p. :8$bill., col. maps ;$c29 cm. 504 Includes bibliographical references. 610 20 University of California, Berkeley.S$SbDept. of Geology and Geophysics$xDissertations. 690 0 Dissertations, Academic$xUCBS$SxGeologySy1921-1930 Microfilmed by University of California Library Photographic Service, Berkeley, CA FILMED AND PROCESSED BY LIBRARY PHOTOGRAPHIC SERVICE, UNIVERSITY OF CALIFORNIA, BERKELEY, 94720 DATE: 7/03 REDUCTION: 10 X " PM-1 3%"x4" PHOTOGRAPHIC MICROCOPY TARGET NBS 1010a ANSI/ISO #2 EQUIVALENT 1 28 125 10 BEE I £5 — 53 I E = [j22 R= ee LZ lis fie IEE Ti : gl aly gl | el pn op HL, 8[1 3lt 1 01 [6 I|8 vn BLE EL EI HE OLE lS hl TAA & ul hulk LIVE 261 TOFD NOT JOH SSI nd i: Prel iminary Report on . the . Foraminifera from the Moreno Shales North of Coalinga. Harold M. Horton, Aucust,1924. fe | ve DIs5= Hox To n/ GEo LL 1952.4 ERLT IM REPORT OX THE FORAMINI M THE TACEQ MORENO NORTH OF COALINGA. LIBRARY COPY In fulfillment of the requirements of Geology 112ab, Senior Thesis Course, University of California. HAROLD M. HORTON, Aug. 20 % 1924, BIBLIOGRAPHY Anderson, Fe. Me, " A Stratigraphic Study in the Mt. Diablo Range of California." - Proce Calif. Acad. Sci., 3% Ser., Geol., Vol. 2, No. 2, 1905. "A Further Study in the Mt. Diablo Range +B California." = Proce Calif. Acad. Sci., 4 ser., Vol. 3, 1908. Anderson, Robert "Preliminary Report on Geology and Oil Prospects of the Cantua~- Panoche region, California.” w UeSeGeSe Bull. 431, 1911. Anderson, R., and Pack, Ke We "Geology and Oil Resources of the Western Border of the San Joaquin Valley North of Coalinga." = UeSeGeSe Bull, 603, 1915. Arnold, R., and Anderson, R. "Preliminary Report on the Geology of the Coalinga Region." = UsSeGeSe Bull. 357, 1908. "Geology and 0il Resources of the Coalinga District." = UsSeGeSe Bulle 398, 1910. Dumble, E. Te, "Tertiary Deposits near Coalinga 0il Field, and Their Stratigraphic Relation with the Upper Cretaceous." = Jour. Geol. Vol, 20, No. 1, 1912. Eldridge, Ge He "Petroleum Fields of Californias." — UeSeGeSe Bull. 213, 1903. Watts, We Le "0il and Gas Yielding Formations of California." ~ Calif, State Min. Bur. Bulle 19, 1900. BIBLIOGRAPHY = FORAMINIFERA I E WO ON THE CT. B HoBe "Challenger Expedition = Foraminifera." = Challenger Expedition Report, Vol. IX (Zoology) Foraminifera, (in 2 vol.) Text, and Plates.1884. Carpenter, We Be “Introduction to the Study of the Foraminifera." = Ray. Soc. Pube, Lond. 1862 Chapmen, F. "The Foraminifera™ (a text). - Longmans, Green & Co., Lond. 1902. Cushman, J, As "A Monograph of the Foraminifera of the North Atlantic Ocean." = U.S. Nate. Mus. Bull. 71, Parts I-VI, 1910-1917, Flint, J. Me "Recent Foraminifera.” - Smithsonian Inst., Ann. Report for year ending June 30, 1897, Part 1I. Parker, We XK. and Jones, T. Re "On some Foraminifera from the North Atlantic and Arctic Oceans." = Philos. Trans. Roy. Soc. Lond., Vol. 155, 1865. Williamson, We Ce "On the Recent Foraminifera of Great Britain.” -. Ray. Soce Pub., Lond, 1858, Sherborn, Ce De “Index to Genera and Species of Foraminifera." - Smithsonian Misc. Coll. Vol. 37, 1893=1896« II WORKS ON CRETACEOUS FORAMINIFERA B Re Me. r "Cretaceous Foraminifera of New Jersey." = UsSeGeSe Bull, 88, 1898. Burrows, Sherborn & Bailey " Foraminifera from the Red Chalk of Yorkshire, Norfolk, and Lincolnshire." = Jour. Roy. Micro. Soc., 1890, Part II, p. 549-566 Chapman, Fe "The Foraminifera of the Gault of Folkstone.™ = Jour. Roy. Micro. Soc., 1891-1898 A serial paper distributed as follows: 1891 Part II Miliolidae 1892 ® I Lituolidae; Textularidae 1892 " II Textularidae 1893, * II Lagenidae 1894 Lagenidae 1896 Lagenidae; Globigerinidae; Rotalidae 1898 Rotalidae "Microzoa from the Phosphatic Chalk of Taplow." = Quart. Jour. Geole Soc. Lond., Vol. 48, 1892, pp. 514=518. "The Bargate Beds of Surrey and Their Micro=Content." - Quart. Jour. Geol. Soc. Lond., Vol. 50, 1894, pp. 677=730¢ Egger, Je Ge "Foram, & Ostrakod. aus den Kreidemerglen der Oberbayerischen Alpen." = Abhand. Konig. Bayer. Akad, Wiss. Munchen cl. II, Vol. 21, 1899, abth. 1l. Jones To. Re. nd Parker, We K "On the Foraminifera of the Family Rotalinae (Carpenter) Found in the Cretaceous Foramtions; with notes on their Tertiary and Recent Rep= resentatives." - Quart. Jour. Geol. Soc. Lond., Vol. 28, 1872, pp. 103=131. III PUBLISHED RTS ON IFORNIA FORAMINI Bagg, Re Meo JTe "Miocene Foraminifera from the Monterey Shale of California." « UsSeGeSe Bull, 268, 1905. “Pliocene and Pleistocene Foraminifera from Southern California." w UsSeGeSe Bulle, 513, 1912. Chapman, F. "Foraminifera from the Tertiary of California.™ = Proce Calif, Acad. Sci., Ser. 3, Vol. L, No. 8, 1900, ON THE F FROM T EQUS) | NORTH OF COALINGA. T.I8 S. INTRODUCTION The Foraminifera as described in this report were collected ANE VAL in part by Dr. G. D. Hanna amd in part by myself from the white 7, N 0 NE 47 AE calcareous nodular or lenticular outcrops occurring sporadically with in the Moreno shales north of Coalinga from the vicinity of 0il City and northward along the strike some six or seven miles. The accompanying map, compiled from U.S.G.S. Bull. 603 amd U.S.G.S. Bull. 398, shows the location of the samples and indicates the general geology of the region sufficiently for present purposes. T.19 S. The Moreno shaleshere with the overlying and lithologically very similar Eocene dark shale, form a smoothed belt of depressed topo- graphic relief known along its upper extent as Ragged Valley. Under lying the Moreno formation with apparent and probable conformity, the Panoche sandstone, also of Chico age forms the prominently elevated Joaquin Ridge of rougher aspect on the west and southwest. Overlying the dark Eocene shale the upper Eocene sandstone (Domengine s.s.) and Qual attovivm Tpr, Tulare ne Efcheqo in-Tacal fos Ise Santa Margarita Kreyenhagen formation stand out in relief, strike north and northwest, bo f Xr | ard dip toward the Great Valley, an attitude which is common to all the . fg : z “Nd T.20 S. T tem Te mbler 3 . w ; A : ih. 3 - FE, wim siriforee Misra Sl XK beds of the region from Cretaceous to Pleistocene. T.20 S. TK Kreyen hagen Tess Eocene sandslone Tesh Eocene shale 0oaaooio os wl = io : The Moreno formation was named and defined by Anderson and 1 Kem Merenc (shales) 3 CC Keep TPanoche (3.9) Collecting Localities ’ 17) Moréno shale s ( rMarkec/ anc Pemb- ered rr Green jn. / Pack in 1915, 1 as "overlying the Panoche formation and constituting the YUTHERN BM I | 1 Geol. and 0il Resources North of Coalinga, U.S.G.S. Bull. 603, p.46. r— | R.14 E. 5 gigas gar - J Scale 1zs000 -]l - Contour interval 100 feet. Datum is mean sea level. uppermost part of the Chico group (Upper Cretaceous), a formation composed largely of foraminiferal and diatomaceous chocolate brown and maroon shgle," with the type section at Moreno Gulch on the east flank of the Panoche Hills, some 35 miles north of the area of the present report. Up to the time of the field work of Anderson and Pack, these beds of the Moreno had in general heen considered Tertiary, due to the greater similarity of the lithology to the Tertiary beds of the region than to those of the Cretaceous. \Wattsl termed them Eocene. Eldridge? called them Upper Eocene. F. il. Anderson® correlated them with the Kreyenhagen brown shales exposed south of Coalinga in the Kreyenhagen Hills. In Arnold and Andersons preliminary report? they treated the shale as Eocene, but in their later report®, on the evidence of Pack and Anderson's field work north of Coalinga, they assigned the beds to the Upper Cretaceous or Chico, which is the ac- cepted age at the present time. watts, W. L., Calif. St. iin. Bur., 1900, Bull. 19, De 136. #lariage, G. H., U.S.G.S. Bull 213, 1903, ps 307. Sanderson, Fe Mo, Calif, Acad, Sci. Proc., 3d Ser. Vol. 2, No. 2, 1905, p. 163. 4)rnold; Anderson, U.S.G.S. Bull. 357, 1908, p. 23. ®Arnold; inderson, U.S.G.S. Bull. 396, 1910, p. 57, Altho it is not possible to trace these beds continuously from the type section down as far as the region of this report, there seems to be no doubt as to their correlation with the type loremos Cretaceous fossils such as Baculites and Hamites from similar cal- careous nodules of this particular region (from the west side of SW/4 of Sec. 17, T. 19 S., Re 15 E.,) are reported by Arnold and Anderson in Bull. 398, page 58; and other Upper Cretaceous fossils are known from the 0il City region. Molluscan fossils are fairly common in the material examined in this report, from which the foraminifera were taken, but they consist almost entirely of pelecypods, a snall Acila (undetermined) being the most common form. One cephalopod was found, but its preservation precludes its definite detemination as an ammonite, and it may be an Aturia. Dr. Hanna, however, reports a Cretaceous Ammonoid from one of his samples, the fossil occurring in the same matrix with the foraminifera, thereby unquestionably establishing their Cretaceous age. Anderson and Pack, however, stress the fact of the finding of abundant diatom tests in their material from the Moreno. In fact they apply to the shales the word diatomaceous as descriptive, and report parts of it to be so abundantly diatomaceous as to be identical in lithological character with the pure diatomaceous material occurring in the Kreyenhagen shale, and well-known in the Miocene shale of the Monterey group in the Coast Ranges. Several samples of the purple shale of this area, in which occur the foraminiferal calcareous nodules, were taken - samples of material selected in the field as most suggesting a diatomaceous character, but upon examination under the binocular microscope I was unable to find any diatoms, Certainly none of my samples can be characterized as diatomaceous. The typical purple shale of | this region seems to be argillaceous to partly silicious in character, with foraminifera as the only micro-organisms observed in the few samples I have examined. This question has a bearing, naturally, on the importance of the Moreno shales as a petroleum source rock. The light gravity oil obtained by the wells in the Oil City region is found in this formation, which evidently is at once the source rock and reservoir, as there are no beds lower in the region which could possibly be termed organic in character. It is noticed that the character of the Moreno petroleum is widely different from that obtained from the Tertiary horizons of the same region, in that it is a light colored, high gravity oil of paraffin base, while all other oil from the Coalinga basin is heavier and, like the greater part of California petroleum,of asphalt base. It may be noted, too, that in the other localities in Califomia where paraffin base oil is obtained, it is usually derived from the Cretaceous as a source rock, or from beds which are predominately foraminiferal instead of diatomaceous; and that in gensral it is found in small quantities. From my examination of this limited region, therefore, I am led to believe that the paraffin base oil of Oil City can have of which fossil Traces remain) 7m evidence no other original souree) than the foraminiferal organisms within the shale. - 4d - The value of a study of the foraminiferal fauna of any formation or horizon, * believe, lies in two main directions. First, as a means of furnishing data which lends itself to the correlation of strata within a basin of deposition or a limited region; and second, as an indication of depositional conditions such as temperature, depth, and so forth. Along the first line, two factors must be noted: the lateral extent of a fauna or form, and the vertical limit. In the present state of kmowledge I do not believe it practical to attempt to establish long range correlations or to determine the general age of a bed or series of beds by means of the foraminifera such as are found in the shales of the Tertiary. The more specialized rock building types, such, for instance, as the Orbitoid and other Nummulitic genera and sub-genera, furnish forms which are without question valuable for long range correlation of beds and for establishing the position in the geologic column. But an tnepeetion of any foraminiferal fauna from the Tertiary shales of the west will reveal the fact that certain forms, in fact, most forms, are likely to appear in any horizon from Eocene and earlier to the Recent. The varying sets of conditions of sedimentation, however, seem to have impressed themselves on the foraminiferal fauna present, excluding some forms, modifying others, and adding new forms, according to the Vertical changes and fluctuations im the conditions of deposition. This fact is reflected therefore in the “da relation of a foraminiferal fauna to the geologic section of a region, and becomes of value in separating formations or indeed often in separating horizons within a formation especially in sub surface work, for, in well borings, lithological changes which would never be missed on the surface, are often quite impossible to distinguish. It is here that the value of the foraminiferal con- tent comes into play. It will be seen, that, accepting the fact of vertical variation of forms, the real economic value of their use in cor relation depends equally on the lateral persistence of the forms of any one horizon. Along this line the results of my examination of this horizon of the Coalinga district show that one fom, the genus Siphogenerina, found first at Oil City, is also abundant and the most characteristic form as far north as the samples were taken a distance of seven miles. How much farther north it persists will be discovered by extending the collecting farther north. Also from my examination of shales of the Tertiary all over the Coalinga basin I have found no other form with which it could be confused. In fact, as far as my experience goes, the occurrence of the genus in this district is limited to the lloreno. Because of these facts, the greater part of my time in a very slow work, has been devoted to the study of this fom, and to the preparation of figures and descriptions which will enable one to identify it in this district, if encountered on the surface or in well corese The second objective in the pursuit of a study of the foraminifera of any fommation or horizon, is to secure some indication of the general conditions attendant on deposition of the beds. A great deal of work has been dome on recent foraminifera as regards their climatic, geographical and bath- ymetric habitat and distribution. Significant facts may often be secured, when unquestioned specific determination of fossil forms is possible, by noting the conditions under which the equivalent Recent forms live. But with this material, which furnishes scarcely the proper means of generic determinations in some cases, my lack of confidence, as far as I have proceeded with the examination, in making specific deteminations precludes my attempting to draw any sound inferences as to the depth and conditions under which they lived and were deposited. Most of the genera encountered are genera which have very similar representatives in beds and seas representing practically all ranges of conditions. However, the extremely abundant Siphogenerina, accord- ing to Brady, is rarely found in the recent seas at depths ex- ceeding 200 fathoms; altho there are plenty of instances recorded where it occurs (but never abundantly) at several times that depth. Also we can not fail to notice the absence (negative evidence) in these nodules, as far as we have proceeded, of certain whole groups =- of the arenaceous gemeray and of the Miliolidae, Globigerinidae, and Nummlinidae, all of which are quite common in the Tertiary of California. I make no further attempt at present to interpret the - 7 - significance of these facts. Great difficulty is encountered in studying the micro-organisms embedded in a matrix such as that in which these foraminifera occur. It is extremely hard, and the nodules, which are some two or three feet in greatest length, and somewhat rounded where exposed, weather out in flat white shingly slabs which scatter about down the slopes. The parting is parallel to the bedding planes as shown by the attitude of the tests exposed. These parting faces present the tests in relief, so solidly imbedded that by no means could free speciments be secured for detached examination, altho all known means were employed. It was finally found that the best go ecimens obtainable for study were those which by natural weathering and action of surface waters had been cleaned and left in bas-relief on the exposed surfaces. Such specimens, together with a great many sections made by shaving off the imbedded tests with a razor blade, furnish the only means of study and identification of the fauna of the nodules. The tests of the foraminifera, and especially of the Siphogenerina are characteristically filled with secondary silica; so completely filled in some cases that careful treatment with acid leaves a perfect cast of the interior of the test composed of clear colorless silica. ‘his difficulty in preparation makes it extremely difficult in naming a form or even in describing it. It means that since but one view of a specimen is presented the opposite face must be studied from another similar individual which may or may not be the same species; and perhaps apertural and peripheral characteristics mast be determined from still other individuals. In view of such conditions the present report will name the forms in the main as to genus only with notes on whatever additional relations may be ascertained, Foraminifera from Moreno Shales: List. Sub-kingdom - Protozoa Family I Family II Family III Family IV Family VII - Family VIII- 6lass - Rhizopoda Order - Foraminifera Gromidae (not fossil) « « « o « « « « « « Nome Astrothizidae (arenaceous) .. . . . . « « Nome Lituolidae (arenaceous) « « « « « « « + + «» Nome Textularidae Subfam: Textularinse Textularia pygmaea Subfam. Bulimininae Bulimina, sp. Cheilostomellidae 8 8 0 0 0. 0 8 oo 6&9 9 None Lagenidae Subfam. Nodosarinae Nodosaria filiformis pPyrula farcimen 8Pe 8Pe Frondicularia, spe Cristellaria rotulata Subfam. Polymorphininae Polymorphina, spe Subfam. Uvigerininae Siphogenerina, sp. Globigerinida® + « ¢ « ¢ ¢ ¢ oo ¢ « + + « Nome Rotalidae Subfam. Rotalinae Pulvinulina (?) Rotaliaff) Family IX « Nummulinidae « ¢« « « ¢« « ¢ « « ¢ ¢ « ¢ « o None Fly ZX & BIMIOUIRAD « « « « o + ¢ 0 v0 0 ¢ « oo» Hin FQRAMINIFERA Family Textularidae ‘Subfanily Textularinae Genus Textularia de France (1824) Tex ri Reuss Plate III, Fig. 1, a, Db. This is a very minute species with a distinctly Textularian bisepal arrangement; test ovate in sections; chambers rather rounded, equidimensional, closely fitted; sutures well marked, but only slightly constricted; walls unornamented. The apertural characteristics are not plain but are more evidently Textularian than Bolivine. Two good specimens were found in the same sample (H2); one exposing the lateral, the other the peripheral view as figured. Hggorded by Chapman from the Gault of Folkstone; by Egger from the Lreidermergien of the Alps; and by Parker & Jones from North Atlantic (“decent ). Subfamily Bulimininae Genus Bulimina d'Orbigny (1826) 33 SDe Plate III, Fig. 2, a, be Several specimens of Bulimina, probably more than one species, occur in these samples, altho their study is so difficult that I even hesitate to distinguish the genus in most cases from Polymorphina or Uvigerina. A good many sections, however, to study the apertural cone ditions convince me that we have both Bulimina and Polymorphina, but I - 12 = have yet to find a single specimen exhibiting the Uvigerine neck-and-lip aperture terminating the spiral ortriserial arrangement of chambers. The form most common seems to be a small test of the Bulimina ovata, B. affinis, or B. pupoides type, being smooth exteriorly, unornamented, chambers rather evenly inflated and ih contour ranging from oval, to strongly tapering toward the aboral end. In none of the specimens found, however, could definite apertural characters, or other specific data be made out. Plate I, numbers 10, 11, 14 and 17, depict the occurrence of the tests on the surface. Family Lagenidae ———00£8M1ly Nodosarinae Genus Nodosarig La march (1812) Nodosaria filiformis 4°'Orb Plate III, Fig. 3, a, Db. Elongate, slender, slightly curved, composed of numerous elongate-oval smooth segments joined in linear series; sutures but slightly depressed, and in these specimens, slightly oblique. Our specimens conform very closely to those of Egger, from the Kreidemarl of the Alps. Found from the Cretaceous to the Recent. xr d'orb Plate III, Fig. 4. A much attenuated Nodosaria with rounded or ovate inflated chambers, the distal ends of which form rather narrow connecting tubes; unornamented. Brady (Challenger Report, p. 497) mentions a form close to Ne. pyrula called N, guttifera d'Orb (For. Foss. Vien., p. 49, pl. ii, 11-13) which differs in its more inflated segments and shorter stoloniferous con- necting tubes. This corresponds more closely with our single specimen. But one specimen of this form was met with (in sample 11, ) and one individual foraminiferal test, no matter how well preserved, is not enough on which to base the presence of a species. The relation ships of individual specimens of foraminifera can often only be une assailably determined by the company in which they are found. Nodosaria farcimen Soldani Plate I, No. 16; Plate 1II, Fig. 6, 7. A curving, evenly tapering, elongate shell with 10-12 oval segments separated by straight sutures; the segments near the aboral end becoming more of a straight series with less constriction of the sutures; and the ultimate chamber tapering with a pronounced nipple-shaped apertural elongation. This is a very well defined species, and our specimens which are good conform very closely to the original figure. The species is common from the Cretaceous to the Recent. Nodosaria, sp. "4" Plate III, Fig. 11, 12 and 13. The distinctive point about this species is the large and distinctly rounded primordial chamber; the test has only a slight taper, is slightly curving, and has an appearance of solidity due to the slight constriction of the sutures and the blunt rounded aboral end. The segments are short, the distance lengthwise (suture to suture) being less than the chamber diameter. Specimens with aperture intact were not found. Chambers walls unornamented. Nodosaria, sp, "B" Plate III, Fig. 5. This form presents an evenly curving many chambered tapering test; segments also with length less than diameter; but in this form the aboral end is distinctly pointed, the test tapering regularly to a small elongate initial chamber; unornamented exteriorly. There are 12 chambers in this specimen (figured) and the oral end is uncomplete. Several partially complete tests are found which are believed to belong under this form. Genus Frondicularig de France (1824) Frondicul s Plate III, Fig. 10. A single specimen occurring in sample No. 11 is a very minute test slightly over .0l in length, and it is possible to examine only the single flat face presented. It is sub-ovate in contour, ap- parently complanate, consisting of a number of very faintly marked, curved chambers embracing in Frondicularian fashion, and marked very slightly at the lower peripheral edges by the septal endings. The primordial chamber is flattened but relatively conspicuous. The apertural characteristics are obscured. It bears some slight resemblance to the figure of F, ovata Roemer, which Bagg reports from the Cretaceous of N.J. (U.S.G.S. Bull. 88, Pe 49, pl. II -4,5) but Bagg's specimen is very large, 9 m.m. in length. w 15 = Genus Cristellaria Lamarck (1812) stella t Plate I, No. 8. What is determined to be a Cristellaria due to its apparent termino-peripheral aperture, altho both faces oan not he seen, is here referred to the type of the simplest forms of lenticular involute Cristellarians. It has a sharp peripheral edge to the biconvex test, is smooth externally and unornamented., This specimen exposes 8 chambers. Ce rotulata occurs in all ages from Cretaceous to Recent. Subfamily Polymorphininae Genus Polymorphina d'Orb (1826) Polymorphina (?), sp. Plate III, Fig. 8, 9. In the numerous spiral or triserial forms examined in section some were seen to possess the typical polymorphine aperture, and likewise possessed a slightly more rounded contour. Specific determination is impossible other than that the most common form, (if itbe a Polymorphina and not a Uvigerina or Bulimina) is of the type near P. oblonga, unornamented exteriorly, and distinguished from the Bulimina ovata merely by the fact of the former's radiate aperture. Subfamily Uvigerininae Genus Siphogenering Schlumberger (1883) The names Sagrina and Dimorphina, which had been used previously by d'Orbigny to denote dimorphous forms which were Textularian, were revived by Parker and Jones (P. and U., Philos. Trans. Royal, Soc. Lond., Vol. 155, 1863, p. 363), and Schwager (Novara Exped., Geol. Theil., Vol. 2, 1866, p. 2561) respectively and applied to a group of dimorphous Uvigerininae, whose bd-or triserial initial segments become uniserial in later growth, with the aperture central and terminal, usu ally with an everted lip and often with a neck, of Uvigerine character. The interior of the chamber has a tubular connection running "from the base of the apertural neck to the lip of the aperture below." And the walls are more commonly ornamented than entirely smooth exteriorly. Since, however, the names Sagrina andDimorphina had been employed by d'Orbigny for Textularian forms, the name Siphogenerina as used by Schlumberger (Feuille des Jeunes Naturalistes, ann. 13, 1883, pe 117) becomes the proper name for the genus as outlined above. The uniserial development in this genus comprises the major portion of the test and the genus is isomorphous in mode of growth with the Textularian forms Clavulina and Bigenerina; from both of which it can be distinguished by it's distinctive aperture, and internal tubular connection as well as by its usually finer shell texture and tendency to some form of exterior decoration. According to Chapman, ("The Foraminifera,” Longmans Green & Co., Lond, 1902, p. 202) the genus (Sagrina) has the Eocene as its lower limit; and Bagg (U.S.G.S. Bull. 268, 1905, p. 40) states that the - 17 - genus furst makes its appearance in the Middle Tertiary, being known in Miocene, Pliocene and Recent deposits (presumably of California). Brady (Challenger Exped., Foram., p. 581, 1884) states that the genus in its fossil state "appears to be confined to deposits of Miocene and Pliocene age." However the records show that Egger has reported, des- cribed and figured (Egger, Abh. Kon. bayer. Akad. Wiss. Munchen, Cl. II Vol. 21, 1899, p. 134, pl. 15, 16) unquestionable species of the genus, Se bifrons, and S. columnaris from the Cretaceous Marls of the Alps, Likewise Chapman in his paper on the Gault of Folkstone (Cretaceous) (Jour. Roy. Micro. Soc. 1896, p. 581, Pl. XII) describes and figures S. asperula. In Siphogenerina, as in many other foraminifera, two distinct phases have been discovered. One of these, the microspheric form, has a proloculum or primary chamber of mach smaller size than the other, the megalospheric form, and these two phases are to be looked for ih all species. The microspheric fom results from sexual reproduction and is usually larger in adult test than the megalospheric form which is the result of an asexual process or simplp division, and which as might be expected in such simple organisms, is by far the most common. In many cases the microspheric form is very rare or as yet unknown. In species where there are definite stages of development it is usually the microspheric form which repeats these most fully, the stages being reduced or entirely skipped in the megalospheric phase. - 18 = This general discussion in the foregoing paragraph which is compiled from Cushman's treatment in Zittel's Textbook of Paleontology, aptly fits the case of the abundant Siphogenerina in our samples, in that we undoubtedly have the two phases represented. Siphogenerina is the most abundant foraminifer in these calcareous nodules. It may be said that the genus characterizes the horizon. Apparently, altho there is a good deal of variation in the size, shape and contour of the tests, taken as a whole, all specimens can properly be included in one of two groups and it is very likely that these two groups are the micro and megalospheric manifestation of the same species, with the megalospheric form the characteristic foraminifer of the horizon. Siphogenerina, Spe Megalospheric Form. Plate II, Fig. 1, 2, 3, 4, exterior views. (Figure 1 is typical) Pig. 5, 6, 8, 9, longitudinal sections. Fig. 7, Section of oral region, more highly magnified (40x). Test nearly cylindrical, length averaging four times the diameter, stoutly bullt, sometimes slightly tapering in contour, and rounded at both ends. Segments short and but little inflated gqveraging 9-10 in number; Uvigerine segments usually entirely wanting or at least greatly reduced; aperture central, terminal, rounded, small, with practically no neck, out with an everted rim or lip best seen, in these specimens, in section, on the penultimate and preceding uniserial cham- bers; walls not ornamented conspicuously exteriorly but sutures with a ecrenulated appearance, the crenulations in some specimens extending faintly up the chamber walls giving the test a very faint ornamentation of continuous longitudinal parallel rounded ridges. This ornamentation however is never sharply defined and in most cases the chamber walls would be described as almost smooth, the crenulations of the sutures giving the impression of the longitudinal ornamentation. Interiorly, in section, the anterior ends of the squents are hemispherical, with a small central circular lipped aperture. All sections made show a tubular connection running aperture to aperture through the linear series of chambers, but it can not be made certain that this is of the same material as the external walls. That is is a part, however, of the living organism and not merely the result of inter- apertural infiltration of secondary material is beyond question as will be seen by Fig. 7, Plate II, a section of the oval end of a test, and by Fig. 11, Plate II, a section of a test which contained no secondary materiale Length commonly 08 - .10 of an inch. Microspheric Form Plate 1I, Fig. 10, partial exterior Fig. 11, 12, 13, longitudingl sections, The microspheric form differs from the megalospheric in presenting a contour more evenly tapering toward the initial segments which present a triserial or alternate or spiral arrangement. The uniserial portion of the test however comprises, in all the specimens found, the major portion; in no case was more than the first ome fourth of the length devoted to the biserial development. <+he uniserial - 20 = portion of this phase is the same as that of the megalospheric form, in structure, and ornamentation. Family Rotalidae Subfamily Rotalinae No attempt is made at present to describe or determine the Rotaline forms, even for separation into genera, With the best of material their separation into the proper groups is always difficult. Both faces of any Rotaline specimen must be studied, as well as the peripheral aspect, apertural characteristics and shell texture. Sections of Rotaline forms are not often diagnostic specifically. With this material it is possible to get but a single view of each specimen, Where this has been a good view of any Rotaline specimen it has been figured; but additional work with other samples will be necessary before the Rotaline forms can be named and described. Rotaline foraminifera are pictured in Plate III, figures 14 to 19, inclusive. Figures 14, 15, 16, 17 are dorsal views, showing the evolute face; figures 18 and 19 are ventral views in which only the last whorl is visible. These forms lie within the five generic groups. Discorbina, Anomalina, Truncatulina, Pulvinulina and Rotalia, and the absence of any coarse porosity of the shell favors their inclusion in the last two generic groups named, Pulvinulina and Rotalia. EXPLANATION OF PLATES Magnification in all cases, except where noted, = 20 diam. Plate I Plate I represents a cameralucida drawing of a group of tests exposed on the surface of one of the samples (No. 4). The abundance of tests as shown is not characteristic of the samples the drawing being from part of a small area in which there was an intense acoumilation of the tests. It is intended to show the state of weathering, and the general appearance of the tests on the parting faces of the nodules. No. 1, 5, 7, 9, 12, and 19 are Rotaline forms (See p. 21). No. 2, 3, 4, 15, 20, and 21 are Siphogenerina (See p. 17). No. 6 and 16 are Nodosaria farcimen (see p. 14). No. 10, 11, 13, 14, 17, and 18(?) are various triserial or spiral tests, belonging to Bulimina, Polymorphina, and perhaps to Uvigerina. 8 is Cristellaria rotulata (See p. 16). Plate II Siphogenerina, SP. Fig. 1 : A typical megalospheric Siphogenerina (see p. 19) exterior view. (Sample 102). Fig. 2, 3, 4: Other specimens, showing variations in contour. (Megalospheriec form); Fig. 3 from Sample K. Fig. 5, 6, 8, 9: Sections of megalospheric form showing intermal connecting tube; Pig. 5, 6 from Sample 40; Fig. 8 from Ho; Fige 9 from 440 Fig. 7 : Section of apertural region in detail (45x) (from sample 4z)e Fig. 103 Partial exterior view of microspheric specimen; test incomplete, broken, showing internal connecting tube; and showing biserial - 22 = stage at initial end of test; from sample l. (See p. 20). Fige 11, 12, 13 : Sectional views of microspheric forms showing bi or Fig. Fig. Fig. Fige Fig. Fig. Fig. Fig. triserial initial growth. (See p. 20). Fig. 11, and 12, shows remains of internal connecting tube. (From sample 24). Fig. 13 shows section across apertural regions of uniserial chambers with connecting tube removed. (From sample Hz). Plate III 1 : Textularia pygmaea Reuss (See p. 12). (2) Lateral view of one specimen. (b) Edge view of another specimen from sample Ho. 2 : Bulimina, sp. (See p. 12). (a) Exterior view of one specimen (sample 107). (b) Sectional view of another specimen (sample 104]. (c) Exterior view of doubtful specimen (sample 4g). 3s Nodosarig filiformis 4'0Orb (See p. 13)/ (a) and (b) - partially intact tests (sample 44). 4 3: Nodosaria pyruls 4'0rb (See p. 13). Test not complete orally (Sample 1l,). 5 3 Nodosaria sp. "B" (See p. 15). Not complete (Sample 97). 6, 7: Nodosaria farcimen Soldamni (See p. 14). Fig. 7 is a complete test (sample 44). 8, 9: Polymorphina, sp (?). (See p. 16). (8) from sample 5; (9) from sample 44. 10 : Frondicularia (?) sp. (See pe. 15). from sample 113. Fig. 11, 12, 13.: Fig. 14 - 19 Fig. 15 Nodosaria, sp. "A" (See p. 14). Partially intact tests, Fig. 11 from sample 4.. rig. 12, 13 from sample 44 Rotalinae (unseparated) (See p. 21). Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. 14-17 dorsal views of separate specimens. 18, 19 ventral views of other specimens. 14 from sample 93. 15 from 16 from 17 from 18 from 19 from HAROLD M. HORTON Aug. 20, 1924. a DAE rate \ EL WN RRR AN NRE NIN diphogenerina H.r 7. rHorTor OS 2 [x] = OO k— Z HH. rr. HorTon [MORE] I"IOREINO Mr M~or7To rm Textularia Bulimina Nodosaria Polymorphina Frondicularia Rotalia: Pulvinulina END OF TITLE