fyxmll Urnvmitg ^ilrtJMg THE GIFT OF UrvvU?&nftai*U O^^ t^^ f^zqTT33 \.\:r:j. KS CORNELL UNIVERSITY LIBRARY 3 1924 072 675 410 Cornell University Library The original of tiiis bool< is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924072675410 MINNESOTA ALGAE VOLUME I The Myxophyceae of North America and Adjacent Regions Including Central America, Greenland, Bermuda, The West Indies and Hawaii JOSEPHINE TILDEN Assistant Professor of Botany University of Minnesota Report of the Survey Botanical Series VIII MINNEAPOLIS, MINNESOTA April 1, 1910 A Published by Authority of the Board of Regents of the University FOR The People of Minnesota Edition 2,500 Copies PREFACE Although the recent appearance of the last volume of De Toni's "Syl- loge Algarum," the "Myxophyceae," has removed some of the greatest difficulties which confront the student of this branch of Algology, yet, with the general literature concerning the blue-green algae in its present state, he has a vexatious problem before him if he attempt to work to any purpose in this group of plants. The original specific descriptions with their accompanying notes and figures, are scattered far and wide, many of them in foreign periodicals and rare works. In general these cannot be obtained in more than a very few of the largest botanical libra'^ Ties. In the United States, at least, there is much need for a work in English, suitable for use as a general hand-book, which shall contain de- scriptions and illustrations of these plants. On the other hand, such a work ought not to be written until a considerable amount of information has been obtained from all parts of the country. An accurate treatise of this sort should be prepared only as a result of general investigation car- ried, on by a large number of workers over the entire area to be covered, at all seasons of the year. For instance, many species have so far been reported from a single locality, which without doubt are growing in pro- fusion in other parts of the country. Without question numerous new species await discovery when the study of the group has become more gen- eral. It would seem then that two books need to be written, one as a cause and one as a result of such investigation. If the present treatise proves to be of use as a foundation or ground-work for the second volume, and if it shall be the means of assisting those who are disposed to follow this fascinating branch of microscopic study, the hopes of the author will be realized. The work has been prepared with a view to answering the need of such botanists as do not have access to the special libraries and of others who have not unlimited time to devote to the looking up of litera- ture. Special prominence has been given, in the arrangement of the text, to two features. The student has constantly before him practically all that is known relating to the geographical distribution and the recorded history of each plant in American localities. To quote from Mr. G. S. West, "One cannot emphasize too much the importance of a sound knowl- edge of the geographical distribution of some of the more lowly types of Cryptogams. . . . Such a knowledge, which can only be acquired by the patient labors of the systematist, will throw much light on one of the most interesting of all problems concerned with the later phases of the earth's history, namely, the land-connections of previous periods." It is very much hoped that this volume may encourage interest on the part of general botanists, high school teachers, college students, physicians and bacteriologists in these little plants which are of late coming to be con- sidered of importance even outside of botanical circles. In the present volume the author has brought together the specific descriptions of all the blue-green algae so far known to exist in North America and the adjacent regions (including the Arctic Regions, Alaska, Greenland, Canada, Newfoundland, Labrador, the United States, Lower California, Mexico, Central America, the Bermudas, the Bahamas, the West Indies and the Hawaiian Islands). In addition there are figures illustrating many of the species. The figures have been photographed from the original and redrawn. A number of them are original with the author. An atternpt has been made to have the figures all drawn to the same scale which may be an improvement over the ordinary method. Very simple keys are furnished for the families, genera and species. The second paragraph of each specific description contains the names in chronological order of a number of articles and works referring to the species in question. It is iv Minnesota Algae believed that the plan of writing out in full the author's name and the title of his article will prove a great saving in time for the one who uses the book. In the case of amateurs it will also serve to give in a short time an intimate knowledge of the names of algologists and an idea of the work already done in the group. The descriptions in general follow those of Gomont, Bornet, Thuret and Flahault. Constant reference has of course been made to Forti's re- cent volume. Wherever possible the original descriptions have been con- sulted. Possibly a mistake has been made in not repeating the synonym after each title. Instead each synonym has been inserted but once, follow- ing the first article in which it occurs. The principal aim of the book, however, is to encourage original investigation in the field among the plants themselves. For a full list of synonyms, reference must be made to De Toni's "Myxophyceae." I wish to tender my best thanks to Dr. Frederic E. Clements for advice and much kind assistance during the preparation" and publication of this volume which was undertaken at his request. To Miss Charlotte Waugh I am much indebted for her painstaking work upon the pen and ink draw- ing of the figures. The author hopes that several persons in each state or section of the country may decide to undertake a systematic and careful investigation of the blue-green algae in their neighborhoods, and would be very glad to enter into a correspondence with such workers. JOSEPHINE E. TILDEN. Kimberly Road, Epsom, Auckland, New Zealand, December 21, 1909. MYXOPHYCEAE (Cyanophyceae. Schizophyceae) The Blue-Green Algae Algae typically blue-green, the coloring matter being a mixture of two pigments, chlorophyll and phycocyanin; pigments of other colors sometimes present. Plant body unicellular or multicellular, sometimes endowed with a peculiar motion; plants existing usually in gelatinous masses, sometimes solitary among other algae. Reproduction always asexual, either by simple cell division in one, two or three directions of space, or by means of hormogones (multicellular fragments of the plant body, at first motile, afterwards coming to rest), or by means of non-motile gonidia formed within gonidangia, or by means of resting gonidia (formed from ordinary cells). Habitat: Plants found in fresh, brackish or salt water, in hot springs, in mineral springs, in aerial situations, or as endophytes. Order I. Coccogoneae. Plants unicellular, single or associated in families or colonies which are usually surrounded by a copious gelatinous integument, rarely forming filaments; reproduction occurs commonly by the vegetative division of cells, rarely by the formation of non-motile go- nidia from the division of the contents of a gonidangium (mother cell). Order II. Hormogoneae. Plants multicellular, filamentous, attached to a substratum or free-floating; filaments simple or branched, usually consisting of one or more rows of cells within a sheath; reproduction occurs by means of hormogones or resting gonidia. Order I. COCCOGONEAE Family I. Chroococcaceae. Plants showing no difference between basal and apical regions, solitary or associated in families or colonies; 2 Minnesota Algae reproduction by vegetative division of cells in one, two or three directions of space. Family II. Chamaesiphonaceae. Plants often shoviring a difference be- tween basal and apical regions, solitary or associated in families or col- onies, usually epiphytic or attached to shells;, reproduction by means of non-motile gonidia formed by the division of the contents of a mother cell (gonidangium). Family I. CHROOCOCCACEAE I. Plants solitary or associated in small, indefinite families or colonies, not surrounded by a common (colonial) gelatinous tegument. 1 Cells spherical; reproduction by cell division in three directions Chroococcus 2 Cells spherical; reproduction by cell division in one direction only Synechocystis 3 Cells oblong, ellipsoidal or cylindrical; sheath wanting; reproduction by cell division in one direction only Synechococcus 4 Cells cylindrical or oblong-conical; sheaths thick, hyaline; reproduc- tion by cell division in one direction only Chroothece II. Plants associated in families or colonies, surrounded by a common gelatinous tegument. I Colonies without definite shape (i) Individual sheaths usually thick, remaining through many divi- sions, sheath of original mother-cell surrounding entire colony A Cells spherical a Cells enclosed in a vesicle-like, thick, colorless or colored sheath, spherical (after division oblong), single or in colonies; cell contents blue-green, or of various colors Gloeocapsa b Cells surrounded by an elliptical membrane, forming colonies, arranged in short filaments Entophysalis c Cells surrounded by thick sheath, forming spherical colonial masses; plant mass cushion-like, cartilaginous, incrusted with lime at base, curled at periphery Chondrocystis B Cells elongate a Cells cylindrical-oblong, surrounded by a thick, mucous sheath, solitary or forming small colonies Gloeothece (2) Individual sheaths not distinct; colony surrounded by common tegument formed of dissolved individual sheaths A Cells spherical (or angular from mutual pressure); cell division in all directions Aphanocapsa B Cells oblong; cell division in one direction Aphanothece 2 Colonies having a definite characteristic shape (i) Colonies free-floating Myxophyceae 3 A Cells having an indefinite arrangement, forming several layers a Cells spherical or oblong; colony spherical or oblong, solid Microcystis b Cells spherical; colonies of variable shape, at first solid, becom- ing saccate and clathrate Clathrocystis c Cells pear-shaped or heart-shaped; colony spherical or ellip- soid, solid Gomphosphaeria B Cells having a definite arrangement, forming a single layer oi cube a Colonies spherical, hollov^r (a) Cells spherical, lying just within the periphery of the colony Coelosphaerium (b) Cells spherical or elongate; individual sheaths distinct Coelosphaeriopsis b Colonies flat ^ (a) Cells of some definite or symmetrical shape, quadrangular or triangular, solitary or forming colonies Tetrapedium (b) Cells spherical; colonies rectangular Merismopedium c Colonies cubical, solid; cells spherical or elliptical Eucapsis (2) Colonies adherent to substratum A Cells spherical or elongate, regularly arranged in radial rows; colonies cushion-like, hard, leathery, verrucose Oncobyrsa B Cells spherical or oval, irregularly arranged in radial rows; col- onies irregularly lobed, epiphytic Chlorogloea Gerius CHROOCOCCUS Naegeli. Gatt. Einz. Alg. 45. 1849. Plants either free-floating or forming a gelatinous or crust-like plant mass in damp places, in fresh or salt water, or within the tissues of other plants, occurring as spherical or angular cells, each surrounded by a more or less definite sheath, solitary or united in twos, fours, eights, etc., but not held together in definite colonies by a common gelatinous tegument; sheaths thin or wide, homogeneous or lamellose, colorless or colored; cell contents homogeneous or granular, usually of a blue-green color, sometimes violet, olive-green, orange or yellowish; reproduction by successive division of the cells alternately in three directions of space. I Sheaths hyaline, often lamellose; cell contents orange or yellowish. 1 Cells less than 3 mic. in diameter C. rubrapunctus 2 Cells more than 15 mic. in diameter (i) Plant mass yellowish green; cells 25-50 mic. in diameter •« C. macrococcus 1 ; (2) Plant mass orange-colored; cells 19-34 ™'e. in diameter .. ,» C. turicensis ' 4 Minnesota Algae II Sheaths hyaline, yellowish or brownish, often lamellose; cell contents blue-green, rarely olive-brown, reddish-green, brownish-violet or copper-red. 1 Cells not embedded in a gelatinous mass, mostly solitary among other algae (i) Sheaths thick, distinctly lamellose; cell contents blue-green A Sheaths colorless; cells 13-25 mic. in diameter C. turgidus B Sheaths yellowish or brownish; cells 5.8-11 mic. in diameter C. schizodermaticus (2) Sheaths not lamellose A Cells 5-7 mic. in diameter C. minutus B Cells 1.7 mic. in diameter C. multicoloratus C Growing in hot water; cells 1-1.5 mic. in diameter C. thermophilus 2 Cells embedded in a gelatinous mass, not free-floating (i) Sheaths lamellose A Sheaths slightly lamellose; plants 4-8 mic. in diameter C. varius B Sheaths lamellose, finally irregularly peeling off; plants 6-1 1 mic. in diameter C. decorticans (,2) Sheaths not lamellose, sometimes scarcely visible A Plants S mic. in diameter, mostly subquadrate, often triangular, rarely multiangular; sheaths scarcely perceptible C. refractus B Plants 4-7.5, rarely 9 mic, in diameter, spherical C. helveticus C Plant mass pale yellowish; sheaths oblong-elliptical; cells 7.5-13 mic. in diameter; cell contents blue-green, yellowish or orange C. pallidus D Plant mass green, later becoming black; sheaths distinct, ellipsoid; cells 2.7-6.6 mic. in diameter; cell contents blue-green C. cohaerens E Plant mass blue-green or olive; sheaths scarcely visible; plants 3-4 mic. in diameter; cell contents blue-green C. minor F Plant mass lead-colored or green becoming black; sheaths thick, mucous; plants 3-8 mic. in diameter; cell contents blue-green C. membraninus 3 Cells embedded in a gelatinous, free-floating mass (i) Plants 8-13 mic. in diameter, much crowded; cell contents green or blue-green C. limneticus (2) Plants 13 mic. in diameter, usually in groups of two; groups lying apart from each other; cell contents grayish-purple C. purpureas Myxophyceae 5 1. Chroococcus rubrapunctus WoUe. Bull. Torn Bot. Club. 6: i8i. 1877. De Toni. Syll. Algar. 5:8. 1907. Plants 2-2.S mic. in diameter, spherical, single or in masses, aquatic; sheaths thin, gelatinous; cell contents homogeneous, yellowish-orange, sur- rounding a large orange-red area. Pennsylvania. Not infrequent on boarded sides of basins and old tim- bers. (Wolle). 2. Chroococcus macrococcus (Kuetzing) Rabenhorst. Flora Europaea Al- garum. 2: 33. 1865. De Toni. Syll. Algar. 5: 8. 1907. Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sand- censibus a Sv. Berggren 1875 reportatis. 3. 1878. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 614. 1905. Plate I. fig. I. Plant mass more or less extensive, mucous, somewhat thick, yellowish- green; plants 30-80 mic. in diameter, spherical, single or in pairs or fours; sheaths thick, lamellose, colorless, later irregularly peeling off; cells 25-50 mic. in diameter; cell contents homogeneous, yellowish, orange or dark- colored. Greenland. (Boergesen). Hawaii. In stagnant water. Volcano Mauna Kea. Island of Hawaii. (Berggren). 3. Chroococcus turicensis (Naegeli) Hansgirg. Prodr. Algenfl. Bohman. 2:160. f. 58b. 1892. De Toni. Syll. Algar. 5:9. 1907. Plate I. fig. 2. Plant mass gelatinous, smooth, orange-colored; plants spherical, single or in pairs or fours; sheaths moderately thick; cells 19-34 mic. in diameter; cell contents finely granular, orange-colored, rarely blue-green. Greenland. (Boergesen). 4. Chroococcus turgidus (Kuetzing) Naegeli. Gatt. Einz. Alg. 46. 1849. De Toni. Syll. Algar. 5: 11. 1907. Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sandvi- censibus. 3. 1878. Dickie. On the Algae found during the Arctic Expedi- tion. Journ. Linn. Soc. Bot. 17: 9. 1880. Farlow. Marine Algae New Eng- land. 27. 1881. Wolle. Fresh-Water Algae. U. S. 334. pi. 210. f. 40, 41. 1887. Collins. Algae of Middlesex County. 16. 1888; Marine Algae of Nantucket. 4.1888. Bennett. Plants of Rhode Island. 116. 1888. Wolle and Martin- dale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2:612. 1889. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torn Bot. Club, i: 89. 1889. Mackenzie. A Preliminary List of Algae collected in the neighborhood of Toronto. Proceedings of Canadian Institute. III. 7: 270. 1890. Anderson. List of California Marine Algae, with notes. Zoe. 2: 217. 1891. Col- lins. Algae. Rand and Redfield's Flora of Mount Desert Island, Maine. 249. 1894. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30:275. 1895. Setchell. Notes on Cyan- 6 Minnesota Algae ophyceae. III. Erythea 7:54. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 16. no. 751. 1900. Collins. Preliminary Lists of New Eng- land Plants.— V. Marine Algae. Rhodora 2:41. 1900; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 239. 1901. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3:396. 1901. Setchell and Gard- ner. Algae of Northwestern America. Univ. Calif. Pub. Bot. 1 : 179. 1903- Riddle. Brush Lake Algae. Ohio Nat. 5:268. 1905. Lemmermann. Al- genfl. Sandwich-Inseln. Bot. .Tahrb. 34: 614. 1905. Plate L fig. 3. Plants spherical, oblong-ellipsoid or more or less angular from com- pression, single or associated in families of two, four, rarely eight; sheaths thick, usually lamellose, hyaline; cells 13-25, rarely 40 mic. in diameter; ctll wall thin; cell contents homogeneous, pale blue-green, later becoming brownish and granular. Arctic regions. Among Nostoc. Shores of Discovery Bay. (Dickie). Alaska. Distributed through a mass of Microcystis marginata which formed a slimy coating on a perpendicular clifi over which water was trickling. Juneau. (Saunders). Among other algae in pools of fresh water or on dripping rocks. Glacier Valley. Unalaska. (Lawson). Canada. High Park. Toronto, Ontario. (Mackenzie). Maine. Common among various al- gae in lagoon. Little Cranberry Isle. (Collins). Massachusetts. On slimy rocks and piers. Cape Ann. (Davis). On woodwork near high water mark. Everett. Medford. (Collins). On woodwork. County of Nantucket. (Collins). Connecticut. (Collins). Rhode Island. Common. (Bennett). New York. Pier. Stapleton, Staten Island; on rocks in brook near Silver Lake, spring and summer. (Pike). New Jersey. Terrestrial. On moist rocks. Frequent. (Wolle). Ohio. Brush Lake. Champaign County. Fall of 1902. . (Riddle). Washington. In brackish water. Whidbey Island. (Gardner). California. On slimy rocks and cliflfs at high water. (Ander- son). In fresh, brackish and even in somewhat alkaline waters. (Setchell). West Indies. Among various algae. Jamaica. July 1900. (Pease and Butler). Hawaii. In stagnant water. Mauna Kea. Island of Hawaii. (Berggren). Var. fuscescens (Kuetz.) De Toni. Richter. Siisswasseralgen aus deni Umanakdistrikt. Bib. Bot. Heft. 42. 3. 1897. De Toni. Syll. Algar. 5: 13. 1907. Cell contents becoming dark-colored. Greenland. Umanak. (Vanhoffen). 5. Chroococcus schizodermaticus West. Algae of English Lake District. Journ. Roy. Mic. Soc. 742. pi. 10. f. 61, 63. 1892. De Toni. Syll. Algar. 5:13. 1907- West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 275. pi. 16. f. 19. 1895. Plate I. fig. 4. Plants 21-42 mic. in diameter, somewhat globose or triangular, some- Myxophyceae 7 times kidney-shaped associated in colonies of two, three or four; colonies solitary or in small groups; sheaths very thick, straw-colored or dark-col- ored, strongly lamellose, (lamellae 5-10), finally irregularly peeling off; cells S.8-11 mic. in diameter; cell wall somewhat thick; cell contents gran- ular, blue-green. West Indies. On damp wall of dam. Sharp's River. St. Vincent. (El- liott). 6. Chroococcus minutus (Kuetzing) Naegeli. Gatt. Einz. Alg. 46. 1849. De Toni. Syll. Algar. 5:14. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 20. no. 951. 1902. Plants 6-9 mic. in diameter, 10-13 tnic. in length, spherical or oblong, more or less angular, usually united in twos; sheaths somewhat orbicular, hyaline, distinct; cells 5-7 mic. in diameter, 9-10 mic. long; cell contents homogeneous or granular, pale blue-green. Maine. Growing in high pool. Cape Rosier. July 1898. (Collins). 7. Chroococcus multicoloratus Wood. Fresh-Water Algae North America. II. pi. s. f. 6. 1872. De Toni. Syll. Algar. 5:11. 1907. Plate I. fig. S. In a rriucous mass with other algae; plants 3 mic. in diameter, spherical and single, or angular, semi-spherical or irregular and associated in oblong families of from two to four (rarely eight) ; sheaths thick, hyaline, not lamel- lose; cells 1.7 mic. in diameter; cell contents mostly homogeneous, some- times minutely granular, yellowish-green, bluish-green, yellowish, brownish, blackish, sometimes tinged with bright lake. Pennsylvania. On wet rocks. Near Philadelphia. (Wood). 8. Chroococcus thermophilus Wood. Am. Journ. Sci. Arts. 122. 1869; Contr. Hist. Fresh-Water Algae North America. 12. 1872. De Toni. Syll. Algar. 5: 10. 1907. WoUe. Fresh- Water Algae U. S. 335. 1887. Plants subglobose or oblong, angular, single or in twos or fours, associ- ated in families; sheaths very thick, transparent, not lamellose, homogene- ous; cells i-i.S mic. in diameter; cell contents sometimes minutely granular, sometimes homogeneous, greenish. California. In Nostoc colonies. In hot springs (ioo°-i20°F.) Benton's Spring. Owen's Valley, sixty miles southwest from the town of Aurora. (Partz). 9. Chroococcus varius A. Braun in Rabenhorst. Die Algen Europas. no. 246, 248, 2456. 1861-78. De Toni. Syll. Algar. 5:21. 1907. Tilden. American Algae. Century II. no. 198. 1896; Observations on some West American Thermal Algae. Bot. Gaz. 25: 104. pi. 8. f. 21. 1898; Am. Alg. Cent. VI. no. 600. 1902. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 25. no. 1202. 1905. Plant mass gelatinous-mucous, dull brown or olive green; plants 4-8 mic. in diameter, globose, single or in twos or fours, rarely forming larger fam- 8 Minnesota Algae ilies which occur as shapeless bunches; sheaths of medium thickness, hya- line, very slightly lamellose, often pale yellow or orange in color, almost opaque; cells 2-4 mic. in diameter; cell contents pale bluish gray or bluish green, sometimes yellowish. Massachusetts. On walls of greenhouse. Botanic Garden. Cambridge. January 1899. (Collins). Montana. In hot springs. Lo Lo Hot Springs. Lo Lo. September 1898. (Griffiths). Wyoming. On rocks near vent of geyser. Sometimes heated. Norris Geyser Basin. June 1896. In overflow from spring, temperature 41" C. Frying Pan Basin, July 1896. Yellowstone National Park. (Tilden). Forming a green coating on floor of overflow channel. Temperature 49° C. Constant Geyser, Norris Geyser Basin; in acid waters. Green Spring, between Norris Geyser Basin and Beaver Lake. Yellowstone National Park. 1897. (Weed). Dr. Setchell is undoubtedly right in placing the Yellowstone specimens in the genus Pleurocapsa. (See P. c a 1 d a r i a.) 10. Chroococcus decorticans A. Braun. Betracht. ueber die Erschein. Ver- jung. in der Natur. 194. 1851. De Toni. Syll. Algar. 5: 18. 1907. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 181. 1877. Plants 6-1 1 mic. in diameter, single or associated in families of two or four; sheaths distinct, lamellose, finally irregularly peeling off; cell wall solid, colorless; cell contents blue-green. Pennsylvania. Submerged timbers. (Wolle). 11. Chroococcus refractus Wood. Contr. Hist. Fresh- Water Algae North America. 11. pi. 5. f. 5. 1872. De Toni. Syll. Algar. 5:20. 1907. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 10. T908. Plants 5 mic. in diameter, mostly subquadrate, very often triangular, rarely multiangular, closely associated in solid families; families often lobed; sheaths thin, scarcely perceptible, transparent; cell contents finely granular, brownish, olive-green, or yellowish, highly refractive. Pennsylvania. Growing abundantly on wet rocks along the Reading Railroad between Manayunk and the Flat Rock tunnel. (Wood). Iowa. Ames. 1884. (Bessey). 12. Chroococcus helveticus Naegeli. Gatt. Einz. Alg. 46. pi. i. 1849. De Toni. Syll. Algar. 5: 17. 1907. Lagerheim. Ueber einige Algen aus Cuba, Jamaica und Puerto-Rico. Bot. Notiser. 199. 1887. Plants 4-7.5 i"ic., rarely 9 mic. in diameter, spherical, associated in fam- ilies of two, four or eight; sheaths spherical, gelatinous, scarcely visible; cell wall very thin, colorless; cell contents homogeneous or somewhat gran- ular, blue-green or greenish, pale or yellowish in color. West Indies. On Utricularia in stagnant water. Near Fajardo. Porto Rico. April 1885. (Sintenis). Myxophyceae 9 13. Chroococcus pallidus Naegeli. Gatt. Einz. Alg. 46. pi. i. f. 2. 1849. De Toni. Syll. Algar. 5: 19. 1907. Snow. The Plankton Algae of Lake Erie. U. S. Fish Commission Bull, for 1902. 22:392. 1903. Plant mass mucilaginous, pale yellow-ish; plants 7.5-13 mic. in diameter, globose, single or in families of two, four or eight; sheaths oblong-elliptical, colorless; cells 6-1 1 mic. in diameter; cell walls somewhat thick, homogene- ous, hyaline; cell contents finely granular, greenish, yellowish or orange, rarely bluish or blue-green. Ohio. Put-in-Bay. I^ake Erie. Summers of 1898, 1899, 1900. (Snow). 14. Chroococcus cohaerens (Brebisson) Naegeli. Gatt. Einz. Alg. 46. 1849. De Toni. Syll. Algar. 5:21. 1907. WoUe. Fresh-Water Algae U. S. 335. pi. 210. f. 42. 1887. Webber. The Fresh-Water Aljgae of the Plains. Am. Nat. 23: loii. 1889. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 16. pi. i. f. i. 1894. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 275. 1895. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 15. no. 701. 1900. Collins. Phycological Notes of the late Isaac Holden, — II. Rhodora. 7:235. 1905. Plant mass green, or later becoming greenish black, gelatinous; sheaths distinct, hyaline, ellipsoid; cells 2.7-6.6 mic. in diameter, globose or oblong, in twos or fours forming colonies 7-15 mic. in diameter; cell wall thin; cell contents homogeneous or slightly granular, of a turbid, blue-green color. United States. On damp walls, rocks, etc. (WoUe). Maine. On shaded cliffs. Eagle Island. Penobscot Bay. July 1892. (Collins). Con- necticut. Among other algae, on abutment of Factory Pond dam. Decem- ber. (Holden). Nebraska. Stagnant water. Thedford. (Webber, Saun- ders). West Indies. Amongst other algae on trees. Summit of Trois Pitons (4500 ft.). Dominica. November and December, 1892. (Elliott). X5. Chroococcus minor (Kuetzing) Naegeli. Gatt. Einz. Alg. 47. pi. i A. f. 4. 1849. De Toni. Syll. Algar. 5: 23. 1907. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 275. 1895. Bessey, Pound and Clements. Addi- tions to the reported Flora of the State. Bot. Surv. Nebraska. 5:12. 1901. Plate I. fig. 7. Plant mass mucous-gelatinous, dull blue-green or olive green; 3-4 mic. in diameter, rotund, single or in pairs, angular; sheaths mucous, scarcely visible; cell walls very thin, hyaline; cell contents homogeneous, usually pale bluish-green. Nebraska. In aquarium. Lincoln. (Bessey). West Indies. On damp wall of dam. Sharp's River. St. Vincent; on trees. Summit of Trois Pitons (4500 ft.). Dominica. (Elliott). Forma minima W. and G. S. West. loc. cit. 275. pi. 16. f. 18. 1895. Cells 1-1.9 mic. in diameter; families 10-23 mic. in diameter. lo Minnesota Algae West Indies. With the type from the above-named localities. On lime trees. Shanford Estate. Dominica. (Elliott). i6. Chroococcus membraninus (Meneghini) Naegeli. Gatt. Einz. Alg. 46. 1849. De Toni. Syll. Algar. 5: 23. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1201. 1905. Plant mass somewhat membranaceous, mucous, lead-colored to green, becoming blackish; plants 3-8 mic. in diameter, globose or subglobose, sin- gle, or associated in families of twos or fours; families 8-26 mic. in diameter; sheaths thick, mucous, hyaline; cell walls thick, colorless; cell contents minutely granular, blue or blue-green. California. Forming a zone, yellowish red just above, and blue-green just below, the edge of the water, very low, in "The Lagoon," Niles, Ala- meda County. November 1898. (Setchell). 17. Chroococcus limneticus Lemmermann. Beitrage zur Kenntniss der Planktonalgen. Bot. Centralb. 76: 153. 1898. De Toni. Syll. Algar. 5: 16. 1907. Snow. The Plankton Algae of Lake Erie. U. S. Fish Commission Bull, for 1902. 22: 392. 1903. Plate L fig. 8. Plant mass floating free; tegument wide; plants 8-13 mic. in diameter, much crowded, before division globose, after division hemispherical; sheaths hyaline, distinct, lamellose; cell contents greenish or pale blue-green. Ohio. Put-in-Bay. Lake Erie. Summers of 1898, 1899, 1900. (Snow). 18. Chroococcus purpureus Snow. The Plankton Algae of Lake Erie. U. S. Fish Commission Bull, for 1902. 22: 388. 390. 1903. Plate I. fig. 9. Plant mass gelatinous, floating free; tegument wide; plants 13 mic. in diameter, spherical, or just before division elongated, usually arranged two by two in colonies of four or eight; sheaths thin; cell contents grayish-pur- ple, changing to brown under unfavorable conditions. Ohio. Common in the plankton of Lake Erie. Put-in-Bay. (Snow). Genus SYNECHOCYSTIS Sauvageau. Bull. Soc. Bot. de France. 39: cxv. 1892. Plants always globose; sheaths none; cell walls thin not diffluent; cell contents blue-green; reproduction by division of the cells in one direction only. J 9. Synechocystis aquatilis Sauvageau. Sur les Algues d'eau douce recol- tees en Algerie pendant la session de la Societe Botanique en 1892. Bull. Soc. Bot. de France. 39: cxvi. pi. 6. f. 2. 1892. De Toni. SylL Algar. 5; 26. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1206. 1905. Myxophyceae 1 1 Plate I. fig. 10. Submerged; plants 5-6 mic. in diameter, single or in pairs; cell walls hyaline, very thin; cell contents pale blue-green. California. On the outside of a dripping water tank. Berkeley. April 1904. (Gardner). Genus SYNECHOCOCCUS Naegeli. Gatt. Einz. Alg. 56. pi. i. 1849. Plants oblong, cylindrical or ellipsoidal, usually single, occasionally forming families of two or four united in a row or chain; sheaths none; cell walls thin; cell contents blue-green, sometimes yellowish, pinkish or pale orange; reproduction by division of the cells in one direction only. I Cell contents blue-green. 1 Cells 7-15 mic. in diameter, 14-26 mic. in length S. aeruginosas 2 Cells 2 mic. in diameter, 4-6 mic. in length S. racemosus 3 Growing in hot salt water; cells 3 mic. in diameter, 6 mic. in length S. curtus 20. Synechococcus aeruginosus Naegeli. Gatt. Einz. Alg. 56. pi. i E. f. i. 1849. De Toni. Syll. Algar. 5:27. 1907. Farlow. Notes on the Cryptogamic Flora of the. White Mountains. Appalachia. 3:236. 1883. Tilden. Am. Alg. Cent. II. no. 195. 1896; On some Algal Stalactites of the Yellowstone National Park. Bot. Gaz. 24: 198. pi. 8. f. 6. 1897. Observations on some West American Thermal Al- gae. Bot. Gaz. 25: 103. 1898. Collins. Algae of the Flume. Rhodora. 6: 230. 1904. Plate I. fig. II. Plants 7-IS mic. in diameter, 14-26 mic. in length, oblong or somewhat cylindrical, obtusely rotund at both ends, single or in pairs; cell contents homogeneous, light or pale blue-green. Greenland. (Boergesen). New Hampshire. Moist rocks at the Flume. Lake Willoughby. (Farlow). Wyoming. One of the three species of Blue-green algae which formed algal "stalactites." Growing in a small cave made by the cone of a geyser. Valley of the Nez Perces Creek. Lower Geyser Basin. Yellowstone National Park. June 1896. (Til- den). 21. Synechococcus racemosus Wolle. Fresh-Water Algae. V. Bull. Torr. Bot. Club. 8:37. 1881. De Toni. Syll. Algar. 5:28. 1907. Plant mass amorphous, blue-green; plants 2 mic. in diameter, two to four times longer than broad, oblong-cylindrical, with rounded ends, often showing a regular vertical arrangement, densely aggregated; cell contents homogeneous, pale blue-green. Pennsylvania. Glass sides of aquarium. Bethlehem. (Wolle). 22. Synechococcus curtus Setchell in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 1351. 1907. 12 Minnesota Algae Plants 3 mic. in diameter, 6 mic. long just before dividing, slightly elongated, single or united by strands of transparent jelly; cell walls very thin, scarcely visible; cell contents pale bluish-green. California. Floating in myriads in hot salt water, near Key Route power house. Oakland. September 1905. (Gardner). Genus CHROOTHECE Hansgirg. Oesterr. Bot. Zeit. 34: pi. I. 1884. Plant mass somewhat gelatinous, dark-yellowish; plants cylindrical or oblong-conical, with rotund ends, single or in pairs; sheaths wide, lamellose, hyaline, increasing greatly in thickness at one pole; cell contents distinctly granular, bright blue-green or orange-yellow; reproduction by division of the cells in one direction only. I Plants 18-24 mic. in diameter C. richteriana II Plants 1.5 mic. in diameter C. cryptarum III Plants 1 1-12.5 mic. in diameter C. monococca 23. Chroothece richteriana Hansgirg. Bot. Notiser. 128. 1884; Prodromus der Algenflora von Bohmen. 2: 134. f. 45. 1892. De Toni. Syll. Algar. 5:29. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 702. 1900. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37:239. 1901. Plate I. fig. 12. Plant mass somewhat gelatinous, thick, more or less expanded, blue- green or yellowish, becoming darker; plants 18-24 mic. in diameter, once to twice as long as wide, single or in pairs; sheaths up to 6 mic. in diameter, somewhat colorless. Bermudas. On rocks. The Flats. Bermuda. January 1900. (Farlow). West Indies. Among other algae, in small quantity. Montego Bay. (Pease and Butler). 24. Chroothece ? cryptarum Farlow in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 16. no. 752. 1900. De Toni. Syll. Algar. 5:30. 1907. Plant mass irregular, gelatinous, widely expanded, of a pale blue-green or dirty yellow color; plants 1.5 mic. in diameter, 3 mic. in length, oblong or rod-shaped; sheaths gelatinous, colorless, becoming lamellate and devel- oping below into densely branching Urococcu s-like stalks, 7-9 mic. in diameter, 25-50 mic. in length; cell contents blue-green, without definitely shaped chromatophore; cell division usually in one, occasionally in two directions. Bermudas. On calcareous rocks in caves by the seashore. Bermuda. January 1900. (Farlow). 25. Chroothece monococca (Kuetzing) Hansgirg. Prodromus der Algen- flora von Bohmen. 2: 134. 1892. De Toni. Syll. Algar. 5:30. 1907. Plant mass amorphous, gelatinous, blue-green; families 15-20 mic. in diameter; plants 11-12.5 mic. in diameter, up to twice as long as broad, ellip- Myxophyceae 13 soid or oblong, obtusely rounded on both ends, single or in pairs; cells 4-6 mic. in diameter; cell contents blue-green. Var. mellea (Kuetz.) Hansgirg. loc. cit. 135. 1892. De Toni. loc. cit. 31. WoUe. Fresh-Water Algae. II. Bull. Torr. Bot. Club. 6: I37- i877- (Gloeocapsa mellea Kuetz.). Cell contents yellowish-red or yellowish-brown. Colorado. (Wolle). Genus -GLOEOCAPSA Kuetzing. Phyc. Gen. 174. 1843. Plants spherical (or immediately after division oblong), either single or a number associated in families; each cell enclosed in a vesicle-like, strongly thickened, usually distinctly lamellose sheath; sheaths often very thick, colorless or colored, usually lamellose; lamellae often peeling off; cell contents blue-green, bluish, steel-blue, reddish, yellowish, etc.; repro- duction by division of .the cells alternately in three directions. When a cell divides into two daughter-cells, each one secretes a sheath about itself, the two still being enclosed by the sheath of the mother-cell. As division goes on, the sheath of the original cell remains enveloping the entire family, and in fact all the sheaths remain in existence. Therefore, there will always be one less than twice as many sheaths as there are cells in the family (in a family of four cells there will be seven sheaths; in a family of sixteen cells there will be thirty-one sheaths). Later genera- tions of cells are smaller than the first ones. I Sheaths colorless I Sheaths lamellose (i) Sheaths wide A Plant mass steel blue, green, olive or dull yellow; plants 7-8 mic. in diameter; sheaths very wide, indistinctly lamellose; cells 3-5 mic. in diameter G. granosa B Plant mass dull green or olive; plants 3-4.5 mic. in diameter; sheaths very thick, with numerous concentric lamellae G. polydermatica C Plant mass green; plants 7-15 mic. in diameter; sheaths very thick, more or less distinctly lamellose; cells 2.2-3.4 mic. in diameter G. fenestralis D Plant mass somewhat olivaceous; plants 6-17 mic. in diameter; sheaths thick; cells 3.7-6 mic. in diameter G. arenaria (2) Sheaths narrow A Plant mass pale yellow becoming greenish; growing in hot water; plants 19-39 rnic- "n diameter; cells 3-6 mic. in diameter G. montana B Plant mass mucilaginous, dull green or gray becoming blackish, or red becoming brownish; plants 7-11 mic. in diameter; cells 3-4.S mic. in diameter G. quaternata C Plant mass a calcareous crust, light gray or green; plants 6-9 mic. in diameter G. calcarea 14 Minnesota Algae D Plant mass gelatinous, brownish, growing on Z o s t e r a; sheaths numerous, distinct; cells 9-1 1 mic. in diameter, 19-26 mic. in length G. zostericola 2 Sheaths sometimes lamellose (i) Plant mass blue-green or greenish; sheaths not distinctly lamellose A Free-floating; cells .75-2.8 mic. in diameter G. punctata B On wet rocks; plants 4-8 mic. in diameter; cells 2-3 mic. in diameter G. aeruginosa (2) Plant mass olive or green; plants 6.2-10 mic. in diameter; sheaths narrow, lamellose when old; cells 2.5 mic. in diameter G. gelatinosa (3) Plant mass dull olive; plants 7-1 1 mic. in diameter; sheaths thick, not at all or scarcely lamellose; cells 3-6 mic. in diameter G. conglomerata 3 Sheaths not lamellose (i) Plant mass flesh-colored to yellowish; plants 2.5-5.5 mic. in diam- eter; cell contents flesh-colored to honey-colored G. mellea (2) Plant mass black; plants 9-14 mic. in diameter; cells 3.5-4.5 mic. in diameter; cell contents pale blue-green G. atrata II Sheaths yellowish or brownish 1 Sheaths lamellose (i) Plant mass dull olive to brownish-green; sheaths colorless or yel- lowish G. muralis (2) Plant mass grayish-brown to black; sheaths very thick, yellowish or orange, becoming darker G. rupestris 2 Sheaths sometimes lamellose (i) Plants 4.5-5.5 mic. in diameter; sheaths usually not lamellose; cells 1.5-2 mic. in diameter G. fusco-lutea (2) Plants 12 mic. in diameter; sheaths homogeneous or lamellose; cells 3-4.5 mic. in diameter G. sparsa (3) Colonies subglobose; sheaths somewhat lamellose; cells 9-15 mic. in diameter G. gigas 3 Sheaths not lamellose; plant mass olive-green; plants 5-8 mic. in diameter G. crepidinum III Sheaths violet, purple or red. I Sheaths lamellose (i) Plant mass purple, sometimes becoming black A Sheaths deep purple or copper-brown; plants 6-12 mic. in diameter G. magma B Sheaths violet or reddish-purple; plants 7.5-12 mic. in diameter; cells 2-4.5 mic. J" diameter G. janthina Myxophyceae 15 C Sheaths very thick, opaque, intensely lamellose; plants 10-17 mic. in diameter; cells 4-7 mic. in diameter G. ralfsiana 2 Sheaths sometimes lamellose; plant mass colorless or dark purple, growing in hot water; plants 6-7.8 mic. in diameter; cells 1-2.6 mic. in diameter G. thermalis 3 Sheaths not lamellose (i) Plant mass violet becoming gray or black A Plants 4-8 mic. in diameter; sheaths violet, thick, often opaque; cells 1.8-2.5 mic. in diameter G. ambigua B Plants 10-17 mic. in diameter; sheaths violet or rose-colored; cells 3.5 mic. in diameter G. violacea (2) Plant mass reddish-orange, dark red or black A Plants 11-24 mic. in diameter; sheaths very thick, soon peeling o£E C. dubia B Sheaths intensely blood-red, very wide; cells 3.5-9 mic. in diameter G. sanguinea 26. Gloeocapsa granosa (Berkeley) Kuetzing. Tab. Phyc. i: pi. 36. f. VIII. 1845-1849. De Toni. Syll. Algar. 5: 53. 1907. Wolle. Fresh Water Algae. III. Bull. Torr. Hot. Club. 6: 182. 1877. (Gloeothece granosa Rabenh.). Plate I. fig. 13. Plant mass compact, gelatinous, somewhat cartilaginous, granular, steel blue, green, olive, or dull yellow, more or less spreading; plants 7-8 mic. in diameter, globose or oblong, usually two or four in families 18-60 mic. in diameter; sheaths very wide, many times exceeding the lumen of the cell, indistinctly lamellose, colorless or nearly so; cells 3-5 mic. in diameter; cell contents homogeneous or granular, pale blue-green. Pennsylvania. Wet rocks. (Wolle). 27. Gloeocapsa polydermatica Kuetzing. Tab. Phyc. i : pi. 20. 1845-1849. De Toni. Syll. Algar. 5:51. 1907. Wolle. Fresh-Water Algae U. S. 331. pi. 210. f. 29-31. 1887. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 126. 1896. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 179. 1903. Plate I. fig. 14. Plant mass gelatinous, more or less compact, dull green or dusky olive; plants 3-4.5 mic. in diameter, spherical; sheaths very thick, hyaline, lamel- lose, with numerous concentric firm lamellae; cell contents somewhat homogeneous, blue-green or green. Alaska. On dripping rocks. Near Iliuliuk, Unalaska. (Setchell and Lawson). Massachusetts. On dripping rocks. Cascade, Middlesex Fells. i6 Minnesota Algae (Collins). Pennsylvania. rith age; trichomes 5-12 mic. in diameter, not constricted at joints; apex of trichome slightly tapering, capitate; apical cell showing a depressed conical or rotund calyptra; cells 2-3 mic. in length; transverse walls fre- quentlv granulated. Maine. Growing in a rock'pool reached only by the highest tides. Cape Rosier. July i8go; shore near Seal Harbor; in salt water pools. Ragged Island, near Cape Elizabeth. (Collins). New Hampshire. (Collins). Massachusetts. Wood's Holl. (Farlow). Mystic River salt marshes.. (Col- 1ms). Falmouth. (Nott). Forming light yellow expansions on sandy shore at low water mark. Little Harbor, Wood's Hole. August 1894. (Setchell). Rhode Island. (Bennett, Collins). Connecticut. Growing in large patches on stones and woodwork between tidemarks. Stonington. (Bailey). Noank. (Farlow). New York. Shores of Long Island, Coney Island Creek. Sum- mer. (Pike). New Jersey. Hudson, Hoboken. (Pike). On wharves be- tween tide marks. Atlantic City. (Martindale). Nebraska. In pond. South Bend. (Bessey). Washington. Salt marsh. Whidbey Island. (Gardner). California. Pacific Beach. (Snyder). Mexico. Near Vera Cruz. (Muller). West Indies. Guadeloupe. (Maze). Hawaii. Attached to rocks in tide pool filled at high tide. Waianae, Oahu. May 1900. (Tilden). On marine algae. Laysan. (Schauinsland). 233. Lyngbya confervoides C. Agardh. Syst. Algar. 73. 1824. Gomont. Mon- ogr. Oscill. 156. pi. 3. f. S, 6. 1893. De Toni. Syll. Algar. 5: 271. 1907. Harvey. Nereis Boreali-Americana. Part III. 102. pi. 47. c. 1858. (L. nigrescens Harv.). Schramm and Maze. Essai Class. Algues Guade- loupe. 31, 81. 1865. (Leibleinia littoralis Crouan, L. c a e r u 1 e o- violacea Crouan). Maze and Schramm. Essai Class. Algues Guade- loupe. 21, 23, 26, 28, 30. 1870-1877. (L. c a e r u 1 e o-v i o 1 a c e a Crouan, L. littoralis Crouan, Lyngbya cyanea Crouan, L. rufescens Crouan, L. r u b r o-v i o I a c e a forma crassior Crouan). Farlow. list of Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875; Marine Algae of New England. 35. 1881. (L. 1 u t e o - f u s c a Ag.). Farlow, Ander- son and Eaton. Algae Am. Bor-Exsicc. no. 48. 1876. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 105. 1886. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. (L. cyanea I20 Minnesota Algae Crouan). Collins, Holden and Setdhell. Phyc. Bor.-Am. Fasc. 6. no. 255. 1897. Collins. Preliminary Lists of New England Plants.— V. Marine Algae. Rhodora. 2: 42. 1900. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Hot. Surv. Nebraska. 5: 12. 1901. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23, no. 1106. 1903. Col- lins. Phycological Notes of the late Isaac Holden. — I. Rhodora. 7: 172. ipoS- Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: 55- ipoS- Lemmermann. Algenfl. Sandwich. -Inseln. Bot. Jahrb. 34: 620. 1905. Collins. Notes on Algae. IX. Rhodora. 10: 160. 1908. Plate V. fig. 39. Plant mass about 5 cm. in height, caespitose, extended, fasciculate, mucous, dull yellowish or dark green, when dried becoming violet; fila- ments ascending from a decumbent and tangled base, long, straight, some- v/hat rigid; sheaths up to S mic. in thickness, colorless, later becoming lamellose and roughened on the surface; trichomes 9-25 mic. in diameter, not constricted at joints; apex of trichome not tapering nor capitate; apical cell rotund; calyptra none; cells 2-4 mic. in length; transverse walls usually granulated; cell 'contents olive or blue-green. Maine. Salt marsh. Stover's Point, South Harpswell. (Collins.) Massa- chusetts. Common on Z o s t e r a. Summer. Wood's Holl. (Farlow). Glou- cester. (Davis). Rhode Island. (Collins). Connecticut. On rocks and iron work. Stratford Shoals Light, Long Island Sound, near Bridgeport. October 1891. (Holden). New York. Sea shores or mud. Canarsic Bay, Long Island; on leaves of Z o s t e r a, Peconic Bay. (Hooper, Harvey). Prince's Bay, Staten Island; Canarsie, Bay Ridge, Long Island. (Pike). South Carolina. Charleston. (Farlow, Gibbes). Florida. On sand-cov- ered rocks of a jetty, littoral. Anastasia Island. October 1902. (Howe). Nebraska. In culture from salt basin. Lincoln. (Bessey, Pound and Clem- ents). West Indies. Guadeloupe. (Maze). Havraii. (Farlow). Forma violacea Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. De Toni. Syll. Algar. 5: 703. 1907. Cell contents violet. West Indies. Manchioneal Bay, Jamaica. July 1900. (Pease and Butler). 234. Lyngbya aestuarii (Mertens) Liebman. Bemerkninger og Tillag til den danske Algeflora. Kroyers Tidskrift. 492. 1841. Gomont. Monogr. Oscill. 147. pi. 3. f. I, 2. 1893. De Toni. Syll. Algar. 5: 262. 1907. Harvey. Nereis Boreali-Americana. Part III. 102. pi. 47. B, F. 1858. (L. f e r r u gin e a C. Ag., L. fulva Harv.). Schramm and Maze. Essai Class. Algues Guadeloupe. 32. 1865. (L. congesta Crouan). Far- low. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Farlow, Anderson and Eaton. Algae. Am. Bor. Exsicc. no. 176. 1877. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. (Ph. olivaceum Rab.). Wittrock and Nordstedt. Algae. Aq. Dulc. Exsicc. no. 282. 1879. (L. aestuarii aeruginosa Wolle). WoUe. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. (L. aeruginosa Ag.). Farlow. Marine Algae of New England. 34. 1881. Wolle. Fresh Water Algae. VI. Bull. Torr. Bot. Club. 9: 25. 1882. Pike. Check List of Marine Myxophyceae 12 1 Algae. Bull. Torr. Bot. Club. 13: 105. 1886. WoUe. Fresh- Water Algae U. S. 296. pi. 200. f. 11-16, pi. 202. f. I, 2. 1887. Hay and Mackay. Li^t of the Marine Algae of the Maritime Provinces of Canada, with Notes. Trans. Roy. Soc. Can. 5: 1887. Bennett. Plants of Rhode Island. 114. 188. (L. obscura Kg., L. interrupta Kg.). Collins. Algae of Middlesex County. 14. 1888; Marine Algae of Nantucket. 4. 1888; Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888. Martindale. Marine Algae of the New Jersey coast and adjacent waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Gaol. Surv. N. J. 2: 608, 610. 1889. (Also L. obscura WoUe and O. 1 i 1 1 o r a 1 i s Carm.) Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. (Also L. compacta Crouan). Saunders. Protophyta-Phycophyta. Flora of Nebraska. 21, 22. pi. 2. f. 25, 26. 1894. Collins. Algae. Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894. Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. Minn. Bot. Studies, i: 31. 1894. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. I. no. 6. 1895. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 42. 1900. Tilden. Collecfion of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. 112. 1901; American Algae. Cent. V. no. 488. 1901. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. l: 186, 187. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 26. no. 1255. 1905. Collins. Phycological Notes of the late Isaac Holden. — I. Rhodora. 7: 172. 1905. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: 45. 1905. Lemmermann. Algenfl. Sandwich. -Inseln. Bot. Jahrb. 34: 620. 1905. Collins. Notes on Algae. — VII. Rhodora. 8: 123. 1906. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 13. 1908. Collins. Notes on Algae. IX. Rhodora. 10: 160, 162. 1908. Plate V. fig. 40, 41- Plant' mass widely expanded, either forming a compact woolly layer on moist earth, or a floccose mass floating in water, blackish or dull blue- green; filaments long, flexible, (sometimes branched), strongly twisted and densely crowded, or moderately flexuous or somewhat straight and loosely entangled, sometimes forming erect fascicles in inundated places; sheaths at first colorless, thin, smooth, later becoming thick, roughened on the surface, lamellose, yellowish or brownish, with layers of different colors; trichomes 8-24 mic. in diameter, not constricted at joints; apex of trichome slightly tapering and capitate, truncate, rarely somewhat acute conical; apical cell showing a slightly thickened outer membrane; cells 2.7-5.6 mic. in length; cell contents finely granular, blue-green or olive. Canada. Forming patches on other algae. Malpeque, Prince Edward Island. (Faull). In brackish pond. Pictou Harbor. (Mackay). Maine. Very common in lagoon. Little Cranberry Isle; occasional near Seal Harbor; salt marsh, Stover's Point, South Harpswell; in salt water pools. Ragged Island, near Cape Elizabeth. (Collins). New Hampshire. (Collins). Massachusetts. In quite fresh water, in old claypit. West Cambridge. August 122 Minnesota Algae 190S; common in salt marshes. (Collins). Abundant in summer in shallow, brackish pools, covering exposed algae and Z o s t e r a. Gloucester. (Davis). Rhode Island. Pocasset, Neutakonkanut. (Bennett, Collins). Connecticut. Stonington. (Farlow). On the granite masses composing the breakwater at Stonington. (Bailey). Abundant in quiet brackish water, often forming felt- like sheets. Bridgeport,- Cook's Point, Fresh Pond, June, July, September, October. (Holden). In a brackish pool beside the Thames River. Norwich. September 1892. (Setchell). New York. Shores of Long Island, Fort Hamilton, Bay Ridge. Summer. (Pike). New Jersey. In pools of moist earth subject to inundations from flowing tides; in ponds and pools in salt water marshes, Perth Amboy, Absecon. (Wolle). Brackish ditches at Hoboken. (Bailey). Common on marshes on floating eel-grass. Atlantic City. (Morse). In salt marshes about Newark Bay. (Pike). In salt ditches. Cape May. (Martindale). Pennsylvania. In small ponds. (Wolle). Minnesota. Gull Lake. July 1893. (Tilden). Iowa. In pond amid bladder- wort. Eagle Grove. (Buchanan). Nebraska. In lakes and ponds in the eastern part of the state; in mineral water, Lincoln, Franklin. (Saunders). West Indies. Guadeloupe. (Maze). Near Bridgetown; Bay Estate, Bar- bados. (Howard). In mats on stones. Kingston, Jamaica. April 1893. (Hum- phrey). Port Antonio, Jamaica. July 1891. (Pease and Butler). Near Kings- ton, Jamaica. (Duerden). Hawaii. In ditches between Honolulu and Waikiki, Oahu. 1896-97. (Schauinsland). Forming a skin growing closely attached to sand on rock. Laie Point, Koolauloa, Oahu. June 1900. (Til- den). Forma limicola Gomont. 1. c. 149. De Toni. 1. c. 265. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 19. no. 903. 1902; Fasc. 29. no. 1402. 1907. Plants living on damp soil, subject to inundation; plant mass pannose, compact, somewhat thin; filaments densely crowded and strongly twisted. Massachusetts. Forming thin, black continuous sheets on the mud of a salt marsh. Bay Shore, Eastham. August 1907. (Collins). Washington. On mud in a salt marsh. Snakalum Point, Whidbey Island. (Gardner). Forma natans Gomont. 1. c. 149. De Toni. 1. c. 265. Tilden. Collection of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. 112. 1901; American Algae. Cent. V. no. 489. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 19. no. 904. 1902. Plant mass covered with water, at first attached to wet earth, later floating; filaments long, moderately flexuous or somewhat straight, loosely entangled. Washington. Floating among R u p p i a in a salt water pond. West coast of Whidbey Island. June 1901. (Gardner). Hawaii. In dirty tangled masses, floating in lagoon formed at mouth of river. Kealia River, Kauai. July 1900. (Tilden). Forma symplocoides Gomont. Monogr. Oscill. 149. 1893. De Toni. 1. c. 5: 265. 1907- Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 21. no. 1009. 1903. Myxophyceae 123 Plant mass not covered with water; filaments decumbent and entangled at the base, above forming erect, densely coalesced fascicles. Massachusetts. On a muddy shore near high water mark. Mattapoisett. September 1902. (Collins). Forma ferruginea Gomont. Monogr. Oscill. 150. 1893. De Toni. 1. c. 5: 265. 1907. Harvey. Nereis Boreali-Americana. Part III. 102. pi. 47 B. 1858. (L. ferruginea Ag.). Kemp. A classified List of Marine Algae from the Lower St. Lawrence. Can. Nat. and Geol. 5: 30. i860. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1675. Plant mass dark brown; sheaths thick, lamellose, more or less intensely yellowish-brown. Canada. On top of rocks near low water mark. Lower St. Lawrence. (Kemp). New York. On muddy shores, in tide pools and floating in ditches of salt or brackish water near the sea. Harlem River, close to the High Bridge. (Harvey). Salt ditches at Hoboken and near Greenport. (Bai- ley). Greenport, Long Island. (Farlow). Forma aeruginosa (Ag.) Wolle in Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 282. 1879. Gomont. 1. c. 150. 1893. De Toni. 1. c. 265. Tilden. American Al'gae. Cent. VI. no. 586. 1902. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 19. no. 902. 1902. Plant mass dark blue-green; sheaths somewhat thin, colorless. Nev? Jersey. On ground or in brackish ditches. August 1878. (Wolle). Washington. Floating in a salt water pond. West coast of Whidbey Island. June 1900. (Gardner). Hawaii. In shallow water of taro patch forming s bright blue-green continuous layer. Near Hauula Court House, Makao, Koolauloa, Oahu. June 1900. (Tilden). 235- Lyngbya majuscula (Dillwyn) Harvey in Hooker. English Flora. 5: part I. 370. 1833. Gomont. Monogr. Oscill. 151. pi. 3. f. 3, 4. 1893. De Toni. Syll. Algar. 268. 1907. Harvey. Nereis Boreali-Americana. Part III. loi. pi. 47 A. 1858. Maze and Schramm. Essai Class. Algues Guadeloupe. 15, 22, 23, 24, 25. 1870-1877. (Also O. corallicola Crouan, L. 1 u t e o-f u s c a Crouan, L. showiana Crouan, L. rigidissima Crouan. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Hall. List of the Marine Algae growing in Long Island Sound. Bull. Torr. Bot. Club. 6: 112. 1876. Dickie. Supplemental Notes on Algae collected by H. N. Moseley, M. A., of H. M. S. Challenger, from various Localities. Journ. Linn. Soc. Bot. 15: 489. 1S77. Farlow. Marine Algae of New England. 34. pi. i. f. 4- 1881. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 105. 1886. Hay and Mackay. List of the Marine Algae of the Maritime Provinces of Canada, with Notes. Trans. Roy. Soc. Can. 5: 1887. Moebius. Ueber einige in Portorico gesammelte Siisswasser- und Luft-Algen. Hedwigia. 27: 246. 1888. Hauck. Meeresalgen von Puerto-Rico. Bot. Jahrb. 9: 470. 1888. Bennett. Plants of Rhode Island. 95- 1888. Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 124 Minnesota Algae (Also L. erosa Liebm., L. anguina Mont.). Martindale. Marine Al- gae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 90. 1889. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Anderson. List of California Marine Algae, with Notes. Zoe. 2: 218. 1891. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 202. 1896. Col- lins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 42. 1900. West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898-1900. Col- lins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Til- den. Collection of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. 112. 1901; American Algae. Cent. V. no. 492. 1901. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: SS. 1905- Plate V. fig. 42. Plant mass up to 3 cm. in length, widely expanded, dark blue, dark blue-green, brownish or yellowish green; filaments very long, often curled, sometimes rolled in a circinate manner, rarely moderately fiexuous; sheaths up to II mic. in thickness, colorless, later becoming very thick and rough- ened on the outside; trichomes 16-60 mic. in diameter, not constricted at joints; apex of trichome not tapering; apical cell' rotund; calyptra none; cells 2-4 mic. in length; transverse walls not granulated; cell contents finely granular, dull green, gray or lead-colored. Canada. Pictou Harbor. (Mackay). Floating tufts, attached to other algae or to Zostera. Malpeque, Prince Edward Island. (Faull). New Hampshire. (Collins). Massachusetts. Wood's Hole; during the later summer months forming large tufts upon Zostera and various algae and often found floating free. Cape Cod. (Farlow). Washed ashore in large entangled masses. Wood's Hole. August 1894. (Setchell). Rhode Island. Providence. (Olney). (Collins). Connecticut. (Hall). New York. Can- arsie, College Point, Long Island. Summer. (Pike). Long Island Sound. (Bailey). Peconic Bay. (Hooper). New Jersey. Newark Bay, Hudson River. (Pike). On eel-grass. Atlantic City. (Morse). Cape May. (Martin- dale). Florida. Key West. (Farlow, Harvey, Ashmead). California. On Z o s t e r a. Southern coasts. (Anderson). Mexico. (Liebman). Bermu- das. (Rein). In shallow water. (Dickie). West Indies. (Hohenhacker). Guadeloupe. (Maze). Grenada. (Murray). In warm springs. Los Baiios, near Coamo; in river near Cayey; in Caguitas River, near Caguas, Porto Rico. i88s. (Sintenis). Forming a film on marine algae. Port Antonio, Jamaica. July 1891 (Pease and Butler) and March 1803 (Humphrey). Forming ex- tensive tufts on muddy bottom, near the mouth of a small stream. Man- chioneal Bay, Jamaica. July 1900. (Pease and Butler). Shallow bays, Anguil- la. (Elliott). Barbados. (Vickers). Hawaii. Epiphytic on other algae, at low tide. Waianae, Oahu. May 1900. (Tilden). 236. Lyngbya martensiana Meneghini. Conspectus Algologiae euganeae. 12. 1837. Gomont. Monogr. Oscill. 163. pi. 3. f. 17. 1893. De Toni. Syll. Algar. S: 279. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 31. i86s. (L. Myxophyceae 125 arachnoiidea Crouan). Maze and Schr.amm. Essai Class. Algues Guadeloupe. 28. 1870-1877. (L. t h e r m a 1 is Crouan). Tilden. Collection of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. 112. 1901; American Algae. Cent. V. no. 490. 1901; Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Sta- tion, i: 166. 1902. West. West Indian Freshwater Algae. Journ. of Bot. 42: 291. 1904. Tilden. Notes on a Collection of Al^gae from Guatemala. Proc. Biol. Soc. Wash. 21: 154. 1908; American Algae. Cent. VII. Fasc. i. . no. 637. 1909. j» Plate V. fig. 43. Plant mass caespitose, blue-green, when dried often becoming violet; filaments long, somewhat flexuous, flexible; sheaths Colorless, becoming thickened and roughened with age; trichomes 6-10 mic. in diameter, not con- stricted at joints; apex of trichome not tapering, not capitate, apical cell rotund; calyptra none; cells 1.7-3.3 mic. in length; transverse walls in- conspicuous or marked by protoplasmic granules; cell contents pale blue- green. Central America. On stems of S c i r p u s, dead or dying. Lake Amatit- lan, Guatemala. January 1906. (Kellerman). West Indies. Guadeloupe. (Maze and Schramm). Near Bridgetown; Graeme Hall Swamp, Barbados. (Howard). Hawaii. On twigs under dripping water. Falls four miles from mouth of river. Waialuka River, Hilo. July 1900. (Tilden). Var. calcarea Tilden. American Algae. Cent. II. no. 178. 1896; Some new .species of Minnesota Algae which live in a calcareous or silicious matrix. Bot. Gaz. 23: loi. pi. 9. f. 4. 1897; List of fresh-water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 28. 1898. MacMil- lan. Minnesota Plant Life. 30. f. 8, 10. 1899. De Toni. Syll. Algar. 5: 280. 1907. Plate V. fig. 44- Plant mass forming extended strata throughout upper portions of cal- careous deposit; filaments 6.S-7-5 mic. in diameter, straight, flexible, some- what unequal in size; sheaths very distinct, colorless, smooth or rough; trichomes 5-6.5 mic. in diameter, not constricted at joints, frequently inter- rupted; apex of trichome not or very rarely tapering; cells about 2.5 mic. in length; cell contents dull blue-green, violet or rarely brown. Minnesota. Forming a part of the lime encrustation which covers sides of wooden tank. Minneapolis. October 1895. (Tilden). 237. Lyngbya putealis Montagne. 2e centurie de Plantes cellulaires ex- otiques. Ann. Sci. Nat. Bot. II. 13: 200. 1840. Gomont. Monogr. Oscill. 163. pi. 3. f. 14- 1893- De Toni. Syll. Algar. 5: 277. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 31. 1865. (Also Leibleinia torta Crouan, Lyngbya arachnoidea Crouan, L putealis minor). Maze and Schramm. Essai Class. Algues Guadeloupe. 28, 30, 31- 1870-1877. (Also L. rufescens Crouan, L. b i- color Crouan, L. torta Crouan, L. fusca Crouan, L. font ana 126 Minnesota Algae Crouan, L. fontana crassior Crouan). Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Plate V. fig. 4S. Plant mass up to I dm. in length, caespitose, widely expanded, elongate, penicillate, sometimes becoming dark violet or black; filaments very long, more or less flexuous and entangled at the base, above straight, parallel, rigid; sheaths colorless, thin, papery; trichomes 7.5-13 mic. in diameter, especially constricted at joints; apex of trichome not tapering; apical cell rotund; calyptra none; cells 3-10 mic. in length; transverse walls some- times granulated; cell contents granular, blue or blue-green. West Indies. (Maze and Schramm). Morant Bay, Jamaica. July 1900. (Pease and Butler). 238. Lyngbya major Meneghini. Conspectus Algologiae euganeae. 12. 1837. Gomont. Monogr. Oscill. 164. pi. 3. f. 15. 1893. De Toni. SylK Algar. 5: 279. 1907. WoUe. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. Mur- ray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Bessey, Pound and Clements. Additions to the Re- ported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. West. West Indian Freshwater Algae. Journ. of Bot. 42: 291. 1904. Plate V. fig. 46. Filaments caespitose, elongate, straight, rigid, dark green; sheaths color- less, thick, lamellose, roughened; trichomes 11-16 mic. in diameter, not constricted at joints; apex of trichome slightly tapering, somewhat capi- tate; apical cell showing a slightly thickened outer membrane; cells 2-3.4 mic. in length; transverse walls granulated; cell contents dark blue-green. Florida. St. Lucia River. (Smith). Nebraska. In aquaria. Lincoln. (Bessey, Pound and Clements). West Indies. Guadeloupe. (Maze). Morant Bay, Jamaica. July 1900. (Pease and Butler). Bay Estate, Barbados. (Howard). 239. Lyngbya spirulinoides Gomont. Essai Class. Nostocacees homocystees. Morot. Journ. de Bot. 4: 355. 1890; Monogr. Oscill. 166. pi. 3. f. 18, 19. 1893. De Toni. Syll. Algar. 5: 287. 1907. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 13. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 187. 1903. Plate V. fig. 47. Plant mass floating, olive green; filaments entangled, fragile, forming a regular loose spiral throughout the whole or a portion of their length, or sometimes straight throughout; distance between turns of spiral 73-108 mic; sheaths colorless, thin, somewhat mucous, not lamellose; trichomes 14-16 mic. in diameter, not constricted at joints; apex of trichome not tapering; apical cell rotund; calyptra none; cells 3.4-6.8 mic. in length; Myxophyceae 127 transverse walls sometimes marked by fine granules; cell contents some- what homogeneous or finely granular, pale blue-green. Nebraska. On moist earth. Lincoln. (Bessey, Pound and Clements). Washington. Floating among various filamentous algae. Lake Washington, Seattle. (Gardner). 240. Lyngbya arachnoidea Kuetz. Sp. Algar. 282. 1849. De Toni. Syll. Algar. s: 266. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 31. 1865. Maze and Schramm. Essai Class. Algues Guadeloupe. 28. 1870-1877. Plant mass dark green, becoming brownish or sometimes reddish; filaments 15-19 mic. in diameter, flexible, loosely entangled; sheaths color- less, transparent; trichomes 12.5 mic. in diameter, interrupted in lower por- tions; cells very short; cell contents granular, olive or blue-green. West Indies. In stagnant water. (Schomburgk). Species not well understood. 241. Lyngbya bicolor Wood. Prodromus of a study of the fresh-water Algae of eastern North America. Proc. Am. Phil. Soc. 11: 124. 1869; Cont. Hist. Fresh-Water Algae North America. 22. pi. i. f. 7. 1872. De Toni. Syll. Algar. 5: 290. 1907. Plant mass a blackish or bluish-green mat; filaments variously curved, closely interwoven, simple; sheaths firm, transparent, in old filaments mod- erately thick; trichomes sometimes constricted at joints, often interrupted; cells short; transverse walls usually not visible; cell contents mostly very granular, light blue-green. Pennsylvania. Forming dark waving tufts, a half-inch or more in height, adherent to bottom of stream, or to plants, sticks, etc. In shallow water of the Schuylkill River, near Spring Mills, Philadelphia. (Wood). 242. Lyngbya caeruleo-violacea Crouan in Schramm and Maze. Essai Class. Algues Guadeloupe. 38. 1865. Maze and Schramm. Essai Class. Al- gues Guadeloupe. 21. 1870-1877. De Toni. Syll. Algar. S: 292. 1907. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. "Filamentis 1/2-1 cm. longis, in flocculos basim ad chordae ad instar convolutis, apice liberis, articulis subtiliter granulatis, diam. s-plo brevior- ibus; strato siccitate violaceo-albido." West Indies. Guadeloupe. (Maze). 243. Lyngbya fluitans Hering in Krauss. Pflanzen des Cap- und Natal- Landes, gesammelt und zusammengestellt. Flora. 215. 1846. De Toni. Syll. Algar. 5: 290. 1907. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. "Fills aeruginosis, tenuissimis, flaccidis, in caespitem tripollicarem laxe implicatis." West Indies. Guadeloupe. (Maze). 128 Minnesota Algae 244. Lyngbya hyalina Harvey. Nereis Boreali-Americana. Part III. 104. pi. 47 G. 1858. De Toni. Syll. Algar. 5: 293. 1907. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Bennett. Plants of Rhode Island. 115. 1888. (Microcoleus hyalinus (Kg.) Kirchn.). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Plant mass forming indefinite, very soft and somewhat gelatinous con- tinuous tufts or pilose strata; filaments attached by their bases, erect, straight, very slender, arachnoid, gelatinous-membranaceous, flaccid; trans- verse walls visible in older plants; cell contents granular, very pale yel- lowish green or nearly colorless. Rhode Island. Davisville. (Bennett). Florida. On lime encrusted rocks. Key West. (Harvey). 245. Lyngbya pusilla Harvey. Nereis Boreali-Americana. Part III. 103. pi. 47 E. 1858. De Toni. Syll. Algar. 5: 293. 1907. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Plant mass minute, blackish green; filaments very slender, short, crisped, spreading in small bundles; sheaths very thin, colorless; transverse walls distinct; cell contents pale dull green. South Carolina. Parasitic on small algae. Sullivan's Island. (Harvey). 246. Lyngbya rubra Crouan in Maze and Schramm. Essai Class. Algues Guadeloupe. 29. 1870-1877. De Toni. Syll. Algar. 5: 293. 1907. "Filamentis tenuissimis, in stratus maculiformes vel fasciculatos ad cm. longos consociatis, apice obtusis; articulis subquadratis, contentu subrubro repletis." West Indies. Guadeloupe. (Maze and Schramm). 247. Lyngbya rubro-violacea Crouan in Maze and Schramm. Essai Class. Algues Guadeloupe. 29. 1870-1877. De Toni. Syll. Algar. 5: 293. 1907. "Filamentis in fasciculos penicillatos, plus minusve in spiram con- volutos, 1-2 cm. longos conjunctis; articulis subquadratis, contentu violaceo- obscuro, aetate provecta rubro." West Indies. On madrepores. Guadeloupe. (Maze and Schramm). Genus SYMPLOCA Kuetzing. Phyc. Gen. 201. 1843. Filaments branched, ascending from a prostrate base, agglutinated to- gether in erect or anastomosing fascicles, or wick-like bundles, more or less procumbent, coalescing; false branches solitary; sheaths thin, colorless, firm or somewhat mucous; apex of trichome straight, sometimes a little taper- ing; outer membrane of apical cell slightly thickened in some species. I. Plants living in salt water. I. Fascicles erect (i) Plant mass blackish green; trichomes 4-2 mic. in diameter, con- stricted at joints throughout entire length S. atlantica Myxophyceae 129 (2) Plant mass dull or dark lead-colored; Irichomes 6-14 mic. in diameter, constricted at joints near apices S. hydnoides 2. Fascicles appressed; trichomes 1.5-3-5 mic. in diameter, especially constricted at joints S. laete-viridjs II. Plants living on moist earth, or in fresh or hot water. 1. Trichomes 1-3 mic. in diameter (i) Plant mass deep blue-green; trichomes 1.2-2 mic. in diameter, sometimes constricted at joints S. thermalis (2) Plant mass compact, fibrous; trichomes 1.5-2.5 mic. in diameter, not constricted at joints S. dubia (3) Plant mass blue-green, changing to brown; trichomes 2-3 mic, in diameter S. fuscescens 2. Trichomes 3-8 mic. in diameter (i) Fascicles short, erect, spine-shaped; trichomes 3.4-4 mic. in diame- ter, not constricted at joints; cells somewhat quadrate or shorter than the diameter S. muralis (2) Fascicles tapering from a broad base to a loose, somewhat peni- cillate apex; trichomes 5.6 mic. in diameter; cells a little longer than their diameter, after division shorter S. borealis (3) Fascicles elongate, usually procumbent, spine-shaped; trichomes 5-8 mic. in diameter, not constricted at joints; cells somewhat quadrate or longer than the diameter S. muscorum 348. Symploca atlantica Gomont. Monogr. Oscill. 129. pi. 2. f. 5. 1893. De Toni. Syll. Algar. 5: 302. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 1356. 1907. Plant mass fasciculate-caespitose, blackish green; fascicles up to i cm. in height, erect; filaments very densely entangled, free, unbranched; strongly and angularly twisted; sheaths thin, firm; trichomes 4-6 mic. in diameter, constricted at the joints throughout entire length; outer mem- brane of apical cell thickened into a depressed conical calyptra; cells 2-6 mic. in length; transverse walls conspicuous, pellucid, not granulated; cell contents scarcely granular, greenish yellow. California. On ground moistened by salt water. Bay Farm Island, near Alameda. November 1905. (Gardner). 249. Symploca hydnoides Kuetzing. Spec. Algar. 272. 1849. Gomont. Mon- ogr. Oscill. 126. pi. 2. f. 1-4. 1893. De Toni. Syll. Algar. 5: 300. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 29. 1865. (S. a n- t ill arum Crouan). Maze and Schrjmim. Essai Class. Algues Guade- loupe. 18. 1870-1877. (O. hydrurimorpha Crouan, O. symplocari- o i d e s Crouan). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. 203. 1895. Collins. Preliminary Lists of New England Plants.— V. Marine Algae. Rhodora. 2: 43. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 222. 1905. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: 55. 1903. ^3° Minnesota Algae Plant mass fasciculate-caespitose, dull, rarely dark lead-colored; fas- cicles up to 3 cm. in height, erect, spine-shaped, often lighter colored at base on account of empty sheaths; filaments very densely entangled, some- what agglutinated, sometimes branched, unequally and angularly twisted; shtaths thin, somewhat mucous; trichomes 6-14 mic. in diameter, often constricted at joints near the apices; apical cell slightly inflated; calyptra none; cells 5-14 mic. in length; transverse walls usually indistinct; cell contents granular, blue-green. Massachusetts. (Collins). Rhode Island. (Collins). Connecticut. In Yellow Mill Pond. August, (flolden). New York. Forming extended patches on mud left bare at low tide in the bottom of a creek. Cold spring Harbor. July 1895. (Johnson). West Indies. Guadeloupe. (Maze). Var. genuina Gomont. 1. c. 127. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 19. no. 905. 1902. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Trichomes 6-8 mic. in diameter; cells equal to or somewhat longer than the diameter. Washington. Growing on old logs in a small cove. Whidbey Island. June 1901. (Gardner). West Indies. On rocks in shallow water, in small patches, not abundant. Montego Bay and Manchioneal Bay, Jamaica. 1900. (Pease and Butler). Var. fasciculata (Kuetz.) Gomont. 1. c. 127. De Toni. 1. c. 302. Farlow. Marine Algae of New England. 184. 1881. (S. fasciculata Kuetz.). Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1 90 1. Trichomes 8-14 mic. in diameter; cells scarcely as long as the diameter. Rhode Island. On rocks between tide marks. Newport. (Farlow). West Indies. Montego Bay and Manchioneal Bay, Jamaica. (Pease and Butler). 250. Symploca laete-viridis Gomont. Monogr. Oscill. 129. pi. 2. f. 6-8. 1893. De Toni. Syll. Algar. 5: 302. 1907. Setchell and Gardner. Algae oi Northwestern America. Univ. Calif. Pub. Bot. 1 : 188. 1903. Plate V. fig. SO. Plant mass thin, fibrillose, light green or yellowish; fascicles up to 1 mm. in height, slender, appressed to substratum; filaments moderately flexuous, somewhat parallel, agglutinated, not branched; sheaths wide, somewhat mucous; trichomes 1. 5-3. 5 mic. in diameter, especially constricted at joints; apical cell conical; calyptra none; cells 2.5-6 mic. in length; cell contents not granular, light green. Alaska. On mud-covered rocks near the upper tide limit. St. Michael. (Setchell). Florida. Key West, Gulf of Mexico. (Farlow). 251. Symploca thermalis (Kuetzing) Gomont. Monogr. Oscill. 134. pi. 2. f. IS, 16. 1893. De Toni. Syll. Algar. 5: 307. 1907. Tilden. American Algae. Cent. III. no. 294. 1898; Observations on some West American Thermal Algae. Bot. Gaz. 25: 98. pi. 9. f. 14. 1898. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 14. no. 652. 1900. Myxophyceae 131 Plate V. fig. SI. Plant mass fasciculate-caespitose, widely expanded, dark blue-green; fascicles up to i mm. in height, erect, approximate, somewhat thick; fila- ments sometimes branched, fragile, twisted and densely entangled at the base, above parallel, curled, closely crowded; sheaths very thin, sometimes mucous; trichomes 1.2-2 mic. in diameter, here and there constricted at joints; apex of trichome not tapering; apical cell rotund; calyptra none, cells 1.7-S mic. in length; transverse walls inconspicuous, sometimes marked by two protoplasmic granules; cell contents homogeneous, rarely slightly granular, pale blue-green. Canada. Forming extensive layers or knob-like masses on bottom of ditch. Natural Sulphur Springs, Banflf, Alberta. August 1897. (Tilden). New York. Adhering to bricks and stones in hot water from condensers of steam engines of the water works. Schenectady. June 1893. (Holden). 252. Symploca dubia (Naegeli) Gomont. Monogr. Oscill. 135. 1893. De Toni. Syll. Algar. 5: 308. 1907. Plate V. fig. 52. Plant mass compact, fibrous, widely expanded, fasciculate on the sur- face, yellowish, blue-green or gray, sometimes reddish on the surface, light- er colored within on account of empty sheaths; filaments coiled, entangled at the base, forming parallel fascicles; sheaths somewhat thick, firm, ir- regular in outline; trichomes 1.5-2.5 mic. in diameter, not constricted at joints; apical cell rotund; calyptra none; cells 3-8 mic. in length; trans- verse walls inconspicuous, sometimes marked by two granules; cell con- tents showing protoplasmic granules arranged in lines, pale blue-green. Mexico. (Miiller). 253. Symploca fuscescens (Kuetzing) Rabenhorst. Fl. Eur. Algar. 2: 153. 1865. De Toni. Syll. Algar. 5: 307. 1907. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879; Fresh- Water Algae U. S. 304. pi. 205. f. 8-12. 1887. Plant mass blue-green, changing to brown; fascicles mucous, penicil- la^fSV'iKe apex, obtuse; filaments agglutinated; sheaths mucous, scarcely ■iijjicUOtt'S;'- tells somewhat quadrate; cell contents homogeneous or finely |1f«la^?^a)e' olive or yellowish blue-green. ^h^ylvania. "Diameter of trichomes 2-3 mic.'' (Wolle). 254. Symploca muralis Kuetzing. Phyc. Gen. 201. 1843. Gomont. Monogr. Oscill. 132. pi. 2. f. 10. 1893. De Toni. Syll. Algar. 5: 304. 1907. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 429. 1895. Collins. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 127. 1896. Plate V. fig. 53- Plant mass continuous, widely expanded, shaggy, dark lead-colored; fascicles up to 2 mm. in height, spine-shaped, somewhat thick, erect; fila- rr.ents elongate, twisted, irregularly entangled, closely crowded, decumbent 132 Minnesota Algae at the base, ascending in less flexuous, somewhat parallel fascicles, not branched; sheaths thin, firm, somewhat mucous below; trichomes 3.4-4 mic. in diameter, not constricted at joints; apex of trichome slightly tapering; apical cell obtuse conical; calyptra none; cells 1.5-4 mic. in length; trans- verse walls hardly visible, not granulateil. Massachusetts. Forming minute green, plush-like patches on ground. Near Black Rock, Middlesex Fells. (Collins). Connecticut. Occurring abundantly on flower pots in greenhouse. New Haven. (Setchell). 255. Symploca borealis Rabenhorst. Fl. Eur. Algar. 2: 156. 1865. De Toni. SylL Algar. 5: 309. 1907. Plant mass fasciculated, bright bluish or blue-green; fascicles 6-8 mm. up to 2.5 cm. in height, tapering from a broad lamelliform base up to a loose, somewhat penicillate apex; filaments 7-10 mic. in diameter, loosely agglutinated by a colorless' mucus; sheaths close, sometimes swollen, homogeneous, very smooth, colorless, often empty in upper portions; trichomes S-6 mic. in diameter, somewhat equal, slightly curved, erect, somewhat parallel, entangled, rarely interrupted; cells a little longer than their diameter, after division shorter; cell contents granular, bright blue- green. Greenland. On Bartramia ithyp h y 1 1 a and B. f o n t a n a. (Breutel). 256. Symploca muscorum (Agardh) Gomont. Essai Class. Nostocacees homocystees. Morot. Journ. de Bot. 4: 354. 1890; Monogr. Oscill. 130. pi. 2. f. 9. 1893. De Toni. Syll. Algar. 5: 303. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 19, 29. 1870-1877. (Ph. spadiceum Crouan, Ph. smaragdinum Crouan, L. grave- o I e n s Crouan). Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877; (Ph. lyngbyaceum Kuetz.). Fresh-Water Algae U. S. 299. pi. 201. f. 22-26. 1887. (L. phormidium Kuetz.). Wolle and Mar- tindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Tilden. American Algae. Cent. I. no. 66. 1894; List of fresh-water Algae collected in Minnesota during 1894. Minn. Bot. Studies. 1 : 235. 1895. West and West. On some Freshwater AJga the West Indies. Journ. Linn. Soc. Bot. 30: 264. 1895. ColliflSn^ and Setchell. Phyc. Bor.-Am. Fasc. 8. no. 3S3. 1897. SetchelkV' Cyanophyceae. III. Erythea. 7: 53. 1899. Collins, H olden . and~%| Phyc. Bor.-Am. Fasc. 21: no. loio. 1903. Setchell and Gardner. Algae Algae of Northwestern America. Univ. Calif. Pub. Bot. i : 188. 1903. West. West Indian Freshwater Algae. Journ. of Bot. 42: 291. 1904. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1208. 1005. Plate V. fig. 54. Plant mass fasciculate or mucous and Phormidium-like, extensive, blackish, dark green or blue-green; fascicles twisted, creeping, rarely erect, filaments flexible, densely crowded, at the base twisted and entangled, in upper portions less twisted, somewhat parallel; not branched; sheaths up to 2 mic. in diameter, firm, tenacious, or more or less mucous; trichomes Myxophyceae 133 5-8 mic. in diameter, not constricted at joints; apical cell rotund or obtuse conical; calyptra slightly thickened; cells S-ii mic. in length; transverse ■walls usually inconspicuous, not granulated; cell contents granular, blue- green. Massachusetts. On moist earth by roadside. Maiden. July 1904. (Col- lins). New Jersey. On marsh bottoms. (Wolle). Pennsylvania. On old logs partially submerged. (Wolle). Maryland. Forming tufts in an old brickyard. Baltimore. November 1896. (Humphrey). Minnesota. On trunk of tree-fern. University greenhouse. Minneapolis. November 1894. (Tilden). Washington. Among mosses on damp ground. Newhall, Orcas Island. (Gardner). California. In a greenhouse. Mount View Cemetery, Oakland. July 1902. (Gardner). West Indies. (Maze and Schramm, Ramon de la Sagra). Bay Estate, Barbados. (Howard). Var. rivularis (Wolle) Tilden. American Algae. Cent. I. no. 67. 1894. (L. phormidium rivularis Wolle). Wolle. Fresh-Water Algae U. S. 299. 1887. De Toni. Syll. Algar. 5: 304. 1907. Johnson and Atwell. Fresh Water Algae. Northwestern University. Report Dept. Nat. Hist. 21. 1890. Tilden. List of Fresh-Water Algae collected in Minnesota during 1894. Minn. Bot. Studies, i: 235. 1895. Plant mass forming dirty aeruginous tufts 25 mm. long; filaments 10 mic. in diameter; cells 2.5-5 mic. in length; cell contents dark steel blue or in portions yellowish green. Pennsylvania. River Lehigh, Bethlehem. (Wolle). Illinois. Running water. Big Wood, Cook County. April. (Johnson and Atwell). Minne- sota. Attached to stones in aquarium in Zoological laboratory. University of Minnesota, Minneapolis. November 1894. (Tilden). Genus PORPHYROSIPHON Kuetzing. Tab. Phyc. 2: 7. pi. 27. f. i. 1850-1852. Filaments unbranched; sheaths firm, solid, lamellose, usually purple or flesh-colored; trichomes solitary within the sheath; apical cell not capitate. 257. Porphyrosiphon notarisii (Meneghini) Kuetzing. Tab. Phyc. 2: 7. pi. 27. f. I. 1850-1852. Gomont. Monogr. Oscill. 69. 1893. De Toni. Syll. Algar. 5: 314. 1907. Tilden. American Algae. Cent. I. no. 65 b. 1894. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 9. no. 402. 1898. West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898-1900. Plate V. fig. 55. Plant mass expanded, cushion-shaped, dark purple; filaments variously curved, densely entangled; sheaths purple, often colorless at the apex, sometimes showing layers of different colors, the outer ones colorless, firm, finally becoming very thick, lamellose, with the apex tapering and fibrillose; trichomes 8-19 mic. in diameter, usually constricted at joints; 134 Minnesota Algae apical cell tapering, obtuse; cells 4.5-12 mic. in length; cell contents gran- ulated, blue-green. North America. (Trecul, Anderson). South Carolina. On clayey- soil in damp "Black-jack" woods. Chester. January 1898. (Green). West Indies. (Lenormand). Genus HYDROCOLEUS Kuetzing. Phyc. Gen. 196. 1843. Plant mass forming a caespitose cushion, very rarely hardened with calcium carbonate, or caespitose but somewhat indefinite, or even not at all caespitose, but Phormidium-like; sheaths always colorless, cylindri- cal, somewhat lamellose, more or less mucous or somewhat amorphous, later entirely diffluent; trichomes few within the sheath, often loosely aggregated; apex of trichome straight, more or less tapering, capitate; outer membrane of apical cell thickened into a calyptra; cells shorter than the diameter of the trichome, in some species very short. I Plants living in salt water. 1 Plant mass caespitose (i) Plant mass green becoming violet; sheaths cylindrical, moderate- ly mucous; trichomes 14-21 mic. in diameter H. comoides (2) Plant mass blackish green; sheaths irregular in outline, strongly mucous; trichomes 18-24 ™ic. in diameter H. cantharidosmu; 2 Plant mass caespitose or forming an expanded mucous stratum, blackish green; sheaths irregular in outline, strongly mucous or even entirely diffluent; trichomes 8-16 mic. in diameter H. lyngbyaceus 3 Plant mass mucous (i) Plant mass yellowish brown or dull green; sheaths somewhat amorphous or entirely diffluent; trichomes 14-21 mic. in diame- ter H. glutinosus (2) Plant mass pale blue-green; sheaths agglutinated, forming a dif- fluent, amorphous layer; trichomes 25-30 mic. in diameter H. holdenii II Plants living in fresh water 1 Trichomes 6-8 mic. in diameter; apex of trichome gradually taper- ing, evidently capitate; cells somewhat quadrate or one-half the diameter of the trichome in length H. homoeotrichus 2 Trichomes 12 mic. in diameter; cells quadrate or two or three times shorter than the diameter H. ravenelii 3 Trichomes 16-19 mic. in diameter; apex of trichome somewhat taper- ing, scarcely capitate; cells 2-5 times shorter than the diameter H. heterotrichus 258. Hydrocoleus comoides (Harvey) Gomont. Monogr. Oscill. 73. pi. 12. f. 3-5. 1893. De Toni. Syll. Algar. 5: 315. 1907. Myxophyceae 135 Maze and Schramm. Essai Class. Algues Guadeloupe. 22. 1870-1877. (L. mucosa Crouan). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Plate V. fig. 56. Plant mass up to 1.5 cm. in height, cushion-shaped, hemispherical, caespitose, mucous, green becoming violet; filaments erect, often spirally twisted and entangled below, free and somewhat straight in upper por- tions, scarcely branched; sheaths wide, Lyngbya-like, regular in out- line, lubricous, slightly mucous, sometimes lamellose and fibrillose, usually open at the end; trichomes 14-21 mic. in diameter, constricted at joints, few within the sheath, solitary in upper portion of filament; apex of trich- ome tapering, truncate; cells 3-5 mic. in length; transverse walls granu- lated. Bermudas. On thg coast. (Farlow). West Indies. Guadeloupe. (Maze). 259. Hydrocoleus cantharidosmus (Montagne) Gomont. Essai Class. Nos- tocacees homocystees. Morot. Journ. de Bot. 4: 353. 1890; Monogr. Oscill. 74. pi. 12. f. 6, 7. 1893. De Toni. Syll. Algar. 5: 316. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 27. 1870-1877. (L. cantharidosma Montagne, L. agglutinata Crouan, L. 1 a t i- limba Crouan). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. i: 45. 1905. Plate V. fig. 57- Plant mass up to 2 cm. in height, caespitose, lubricous, in dried specimens adhering to paper, olive or dark blue-green; filaments some- what straight, moderately branched; false branches appressed; sheaths sometimes twice as thick as the trichome, very mucous, irregular and roughened in outline, agglutinated when dried,, sometimes lamelloise, usually open at the apex; trichomes 18-24 mic. in diameter, not constricted at joints, few within the sheath, somewhat parallel, solitary in upper por- tion of filament; apex of trichome tapering, truncate; cells 2-4 mic. in length; transverse walls sometimes granulated. West Indies. Guadeloupe. (Maze). Barbados. (Vickers). Hawaii. Growing with other algae below high tide. Hanalei, Kauai. July 1900. (Til- dcn). 260. Hydrocoleus lyngbyaceus Kuetzing. Species Algar. 259. 1849. Go- mont. Monogr. Oscill. 75. pi. 12, f. 8-10. 1893. De Toni. Syll. Algar. s: 3I7- I907- Wolle. Fresh Water Algae. IV. Bull. Torr. Bot. Club. 7: 43. 1880; Fresh-Water Algae U. S. 299. pi. 201. f. 27-29. 1887. (L. arenarium (Kuetz.) Rab.). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Collins. Pre- liminary Lists of New England Plants.— V. Marine Algae. Rhodora. 2: 42. 1900. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: 45- iPOS- 136 Minnesota Algae Plate V. fig. s8. Plant mass caespitose or mucous, widely expanded, dark green; fila- ments adnate, unbranched at base, branched in upper portions; false branches numerous, somewhat appressed; sheaths wide, mucous, roughened in outline, tapering or often open at apex, sometimes entirely diffluent and agglutinated; trichomes 8-16 mic. in diameter, not constricted at joints, numerous at base of filament, spirally • twisted and entangled, solitary in the branches; apex of trichome tapering, truncate; cells 2.5-4.5 mic. in length; transverse walls granulated. Massachusetts. (Collins). New Jersey. On moist low grounds near Atlantic City. (Wolle). Florida. (Smith). Bermudas. (Farlow). West Indies. Barbados. (Vickers). Var. a. Gomont. 1. c. 76. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 89. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. no. 204. 1896. Plant mass caespitose, usually epiphytic; sheaths somewhat firm. Massachusetts. Very abundant on the fronds ofAscophyllum no- dosum in the harbor. Woods Hole. Summer of 1904. (Nott, Setchell). Var. p rupestre Kuetzing. 1. c. 259. Gomont. 1. c. 76. De Toni. 1. c. 318. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 205. 1896. Collins. Notes on New England Marine Algae. — ^VI. Bull. Torr. Bot. Club. 23: I. 1896. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 42. 1900. Plant mass expanded, mucous; sheaths entirely diffluent. Maine. At first forming gelatinous sheaths on Zostera and R u p- p i a, afterwards floating masses, in warm water of tidal basin. Goose Cove, Rosier. July 1895. (Collins). 261. Hydrocoleus glutinosus (Agardh) Gomont. Essai Class. Nostocacees homocystees. Morot. Journ. de Bot. 4: 353. 1890; Monogr. Oscill. 77. 1893. De Toni. Syll. Algar. 5: 318. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 30. 1865. (O. fusco-rubra Crouan). Maze and Schramm. Essai Class. Algues Guadeloupe. 15. 1870-1877. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875. (L. nigrescens Harv.). Murray. Cata- logue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. (O. glutinosa A. Br.). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 10. no. 453. 1898. Collins. Preliminary Lists of New England Plants. — VI. Marine Algae. Rhodora. 2: 42. 1900; Phycolog- ical Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: 45. 1905- Plate V. fig. 59. Plant mass not caespitose, mucous, indefinitely expanded or cylin- drical in shape, yellowish brown or dull or yellowish green; sheaths very irregular in outline and somewhat amorphous, finally entirely diffluent; Myxophyceae 137 trichomes 14-21 mic. in diameter, not constricted at joints; apex of trich- oma tapering, truncate; cells 2.5-3.5 mic. in length; transverse walls gran- ulated. Massachusetts. (Collins). Connecticut. Forming a Phormidium- like coating on iron pillars between tide marks. Black Rock Beacon, near Bridgeport. July 1892. (Holden). New York. Peconic Bay, Long Island. (Farlow). West Indies. Guadeloupe. (Maze). Barbados. (Vick- ers). 262. Hydrocoleus holdenii Tilden. Rhodora. 3: 254. 1901. De Toni. Syll. Algar. s: 319. 1907. Holden. Two new species of Marine Algae from Bridgeport, Con- necticut. Rhodora. i: 197. pi. 9. f. 7, 8. 1899. (H. ma jus Holden). Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 602. 1899. Col- lins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2- 42. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Plate V. fig. 60, 61. Plant mass mucous, tubular, dark blue-green; sheaths agglutinated, forming mostly an amorphous, gelatinous, diffluent mass, from which the outer extermities of the trichomes project, naked or enveloped in broad ragged sheaths, or the trichomes escape entirely and become independent; trichomes 25-30 mic. in diameter, not constricted at joints; apex of trich- ome tapering, truncate; apical cell showing evident calyptra; cells 3-6 mic. in length; transverse walls granulated; cell contents blue-green. Connecticut. Forming gelatinous tubular coatings on old S p a r t i n a stems in ditches of a salt marsh. Bridgeport. May 1896; Cook's Point, May, September. (Holden). 263. Hydrocoleus homoeotrichus Kuetzing. Phyc. Gen. 196. 1843. Gomont. Monogr. Oscill. 82. pi. 13. f. 7-10. 1893. De Toni. Syll. Algar. 5: 323. 1907. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. (H. phormidioides Bulnh.). Setchell. Notes on some Cyanophy- ceae of New England. Bull. Torr. Bot. Club. 22: 429. 1895. Plate V. fig. 62, 63. Plant mass caespitose, floating, indefinite, expanded, lead-colored or black; filaments simple or sparingly branched, flexuous, more or less flex- ible, entangled in tufts; sheaths lamellose, somewhat diffluent, cylindrical, roughened on the surface, transversely wrinkled, with open or pointed apex; trichomes 6-8 mic. in diameter, many within the sheath, parallel or twisted and entangled, sometimes solitary, not constricted at joints; apex of trichome gradually tapering, evidently capitate; apical cell depressed conical; cells 4-5. 5 mic. in length; transverse walls frequently granulated; cell contents blue-green or lead-colored. Connecticut. Growing in small short tufts on the posterior ends of shells of living fresh water mussels (Anodonta). Trading Cove Brook, 138 Minnesota Algae Norwich. (Setchell). Pennsylvania. On stones in rapid water; in sphag- num swamps. (Wolle). 264. Hydrocoleus ravenelii Wolle. Bull. Torr. Bot. Club. 6: 183. 1877. De Toni. Syll. Algar. 5: 322. 1907. Plate V. fig. 64-65. Plant mass dark violet or blue-green; filaments 15 mic. in diameter, those containing two or more trichomes proportionately wider; sheaths of younger plants close and colorless, those of older plants thicker and firmer, golden brown in color, lamellose, with ends usually empty and sharply pointed; trichomes 12 mic. in diameter, of equal thickness, solitary or two or three somewhat twisted together in a common sheath; cells somewhat equal, or two or three times shorter than the diameter; cell contents blue-green changing to golden brown or chestnut. Texas. Pasture grounds. Houston. (Ravenel). 265. Hydrocoleus heterotrichus Kuetzing. Gomont. Monogr. Oscill. 80. pi. 13. f. 3, 4. 1893. De Toni. Syll. Algar. 5: 320. 1907. Wolle. Fresh Water Algae. Bull. Tbrr. Bot. Club. 6: 283. 1879; Fresh- Water. U. S. 307. pi. 205. f. 2-5. 1887. Plate V. fig. 66. Plant mass about 5 mm. in height, caespitose, blackish; filaments ad- nate, short, in basal portion trunk-like, broadening out towards the apex, then divided and repeatedly branched; false branches more or less widely diverging, flexuous; sheaths somewhat close, somewhat mucous, irregu- lar and roughened in outline, broadened out in middle portion of filament, gradually tapering towards the apex, pointed, open or closed, transversely wrinkled; trichomes 16-19 mic. in diameter, many within the sheath, closely aggregated, straight or spirally tangled and twisted, sometimes solitary, not constricted at joints; apex of trichome very slightly tapering, scarcely capitate, truncate; cells 3.4-4.S mic. in length; cell contents finely granular. Pennsylvania. In swamp. Near Bethlehem. (Wolle). Genus HYPHEOTHRIX Kuetzing. Phyc. Gen. 229. 1843. Plants living on moist earth or dripping rocks; filaments prostrate, commonly slightly branched, woven into a more or less compact mass; sometimes hardened with calcium carbonate; sheaths always colorless. I Filaments very much twisted, scarcely flexible, ruptured if disentangled. 1 Plant mass thin, somewhat gelatinous, papery-membranaceous, very hard when dry, not encrusted with calcium carbonate; sheaths firm; trichomes 1-1.7 mic. in diameter, usually one or two within the sheath H. calcicola 2 Plant mass flocculent, waving, light fawn-colored; filaments i. 2-1.8 mic. in diameter; sheaths inconspicuous; transverse walls not visible H. hinnulea Myxophyceae 139 3 Plant mass forming a small mat; filaments 1.5-2 mic. in diameter; sheaths closely adherent, entirely diffluent H. gloeophila 4 Plant mass thin, cushion-shaped, mucous; filaments 1.8-2.2 mic. in diameter; sheaths close H. herbacea 5 Plant mass sometimes expanded, forming loosely interwoven masses or small cushion-shaped clusters; filaments 3.5-4 mic. in diameter; sheaths firm, close H. tenax 6 Plant mass somewhat spherical, hollow, tough, yellowish or light straw-colored; filaments 4-6 mic. in diameter; trichomes 1.5-2 mic. in diameter H. bullosa 7 Plant mass compact, leathery, brick-colored; filaments up to 7.5 mic. in diameter; sheaths wide, membranaceous, firm, homogeneous, smooth; trichomes 3.2-4 mic. in diameter, here and there inter- rupted H. turicensis 8 Plant mass more or less expanded, olive green; filaments 8-1 1 mic. in diameter; sheaths moderately wide; trichomes 3.5 mic. in diame- ter, here and there interrupted, often constricted at joints H. aikensis II Filaments long and flexible, disentangled without rupturing 1 Plant mass encrusted with calcium carbonate; trichomes 1-1.7 mic. in diameter; cells longer than the diameter H. coriacea 2 Plant mass not encrusted with calcium carbonate; trichomes 1.5-2 mic. in diameter; cells longer than the diameter H. lardacea 3 Plant mass not encrusted with calcium carbonate; trichomes 1.5-3 mic. in diameter; cells longer than the diameter H. arenaria 4 Plant mass compact, leathery, roughened; trichomes 2.3-2.8 mic. in diameter; cells a little shorter than the diameter H. vulpina 5 Plant mass membranaceous, firm, smooth, pale rose or dark red; trichomes 5.6-8.3 mic. in diameter; cells somewhat quadrate H. pallida 266. Hypheothrix calcicola (Agardh) Rabenhorst. Fl. Eur. Algar. 2: 78. 1865. Gomont. Monogr. Oscill. 45- pl- 8. f. 1-3. 1893. (S c h i z o- thrix calcicola Gom.). De Toni. Syll. Algar. 5: 327. 1907. Anderson and Kelsey. Common and conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 145. 1891. (Leptothrix calcicola Kg.). Saunders. Protophyta-Phycophyta. Flora of Nebraska. 21. pl. 2. f. 19. 1894 Tilden. American Algae. Cent. II. no. i8o. 1896; (P. purpurascens (Kuetz.) Gom.); On some Algal Stalactites of the Yellowstone National Park. Bot. Gaz. 24: 197. pl. 8. f. 3, 4. 1897; Observations on some West American Thermal Algae. Bot. Gaz. 25: 98. 1898. Collins, Holden and Setchcll. Phyc. Bor.-Am. Fasc. 12. no. 557. 1899. 140 Minnesota Algae Plate VI. fig. 1-4. Plant mass not encrusted with calcium carbonate, somewhat gelatinous, very hard when dry, papery-membranaceous, black or rarely yellowish blue-green; filaments short, very much twisted and entangled, rarely branched; sheaths firm, somewhat cartilaginous, tapering at the apex, at first somewhat close, cylindrical, enclosing one trichome, later becoming thicker, somewhat lamellose, irregular and roughened in outline, en- closing two or rarely many trichomes; trichomes 1-1.7 mic. in diameter, not constricted at joints; cells 2-6 mic. in length; transverse walls some- times marked by two protoplasmic granules; cell contents pale blue-green. Massachusetts. On walls of greenhouse. Botanic Garden, Cambridge. January 1899. (Collins). Nebraska. In greenhouse at the University. (Saunders). Montana. Common everywhere all the year, on damp or dripping rocks. (Anderson and Kelsey). Wyoming. Together with Synechococcus aeruginosus and Gloeocapsa violacea, forming black "stalactites,"' 1-1.5 dm. long and .5 dm. in diameter, or ser- rated, suspended masses or extended sheets. These hung from the top and lined the walls of a small cave in which was the vent of a hot spring. At short intervals they received jets of steam and a spray of hot water. Val- ley of Nez Perces Creek, Lower Geyser Basin, Yellowstone National Park. June 1896. (Tilden). 267. Hypheothrix (?) hinnulea (Wolle). De Toni. Syll. Algar. 5: 336. 1907. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877. (Beggiatoa hinnulea Wolle) ; Fresh-Water Algae U. S. 320. pi. 208. f. s. 1887. Tilden. American Algae. Cent. I. no. 69. 1894. (L y n g b y a hinnulea (Wolle) (Tilden) ; List of fresh-water Algae collected in Min- nesota during 1894. Minn. Bot. Studies, i: 235. 1895. Plant mass flocculent, caespitose, waving, 6 mm. in thickness, light fawn-colored; filaments 1.2-1.8 mic. in diameter, lo-is mm. in length, flexible and contractile; sheaths' inconspicuous; transverse walls not visible; cell contents colorless or light yellowish brown. Pennsylvania. In trenches for warm waste water from steam engines. (Wolle). Minnesota. Collected in masses around the inlet pipe in tanks in Zoological laboratory. University of Minnesota, Minneapolis. Novem- ber 1894. (Tilden). 268. Hypheothrix gloeophila (Kuetzing) Rabenhorst. Fl. Eur. Algar. 2: "JT. 1865. De Toni. Syll. Algar. 5: 331. 1907. Plant mass forming a small mat; filaments 1.5-2 mic. in diameter, some- times solitary, usually slightly curved and entangled; sheaths closely ad- herent, entirely diffluent; cells once and a half longer than their diameter; cell contents pale, almost colorless. Greenland. (Richter). 269. Hypheothrix herbacea Kuetzing. Phyc. Gen. 199. 1843. De Toni. Syll. Algar. 5: 328. 1907. Myxophyceae 141 Wolle. Fresh-Water Algae U. S. 320. pi. 208. f. 13. 1887. (L e p t o t h r i x herbacea Kg.). Plant mass thin, somewhat cushion-shaped, mucous, bright green, more or less faded underneath; filaments 1.8-2.2 mic. in diameter, very slender, slightly flexuously curved, entangled; sheaths very close, color- less; cells here and there distinct. South Carolina. Very abundant on the wood-work around the artesian well. Charleston. (Wolle). 270. Hypheothrix tenax Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 282. 1879; Fresh-Water Algae. U. S. 319. pi. 203. f. 2. 1887. (Leptothrix tenax Wolle). De Toni. Syll. Algar. 5: 329. 1907. Plant mass sometimes expanded, forming loosely interwoven masses i.S dm. or more in diameter, at other times forming small, caespitose, cushion-shaped clusters; filaments 3.5-4 mic. in diameter, slender but strong and tough, often forming firm membranes; sheaths colorless, firm, close; transverse walls not always visible; cells about as long as wide; cell con- tents primarily light blue-green, soon changing to dull yellow or light brown. Pennsylvania. On stones in stagnant water. (Wolle). 271. Hypheothrix bullosa Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877; Fresh-Water Algae U. S. 321. pi. 208. f. 19. 1887. (Leptothrix bullosa Wolle). De Toni. Syll. Algar. 5: 329'. 1907. Plant mass 4-8 mm. in diameter, somewhat spherical or oval, hollow, tough, gregarious, dilute straw color or yellowish white; filaments 4-6 mic. in diameter, unbranched, densely interwoven; sheaths colorless; trich- omes i.S-2 mic. in diameter; cell contents pale blue-green, often faded and contracted. Pennsylvania. Shallow, sluggish water, Susquehanna River, Harris- burgh. (Wolle). 272. Hypheothrix turicensis Naegeli in Kuetzing. Spec. Algar. 269. 1849. De Toni. Syll. Algar. 5: 333. 1907. Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877. Plant mass compact, leathery, irregularly roughened, brick-colored, v/ithin faded or dull green; filaments up to 7.5 mic. in diameter; sheaths wide, membranaceous, firm, homogeneous, colorless, very smooth, taper- ing at apex; trichomes 3.2-4 mic. in diameter, thick, flexuously curved, here and there interrupted; cells a little shorter than the diameter; transverse vifalls sometimes indistinct; cell contents sometimes granular, dark or pale blue-green. Pennsylvania. Moist rocks. (Wolle). 273. Hypheothrix aikenensis Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877. De Toni. Syll. Algar. 5: 329. i907- Plant mass more or less expanded, olive green; filaments 8-1 1 mic. 14^ Minnesota Algae ill diameter, tenacious, curved, very densely entangled; sheaths moderately wide, colorless, pellucid; trichomes 3.5 mic. in diameter, here and there interrupted, often constricted at joints; cells 3.5-7 mic. in length; cell contents pale blue-green. South Carolina. Sluggish water. Aiken. (Ravenel). 274. Hypheothrix coriacea Kuetzing. Spec. Algar. 267. 1849. Gomont. Mon- ogr. Oscill. 47. pi. 8. f. 6, 7. 1893. (Schizothrix coriacea Gom.). De Toni. Syll. Algar. 5: 336. 1907. Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 8. 1880. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 14. no. 654. 1900. (Sch. coriacea (Kg.) Gom.). Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. yj: 240. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 855. 1901. Collins. Phycological Notes of the late Isaac Holden. — 11. Rhodora. 7: 236. 1905. Plate VI. fig. 2. Plant mass up to l.S cm. in thickness; widely expanded, encrusted with calcium carbonate, crustaceous, leathery, roughened on the surface, green becoming reddish, rose- or brick-colored on the outside, faded within; filaments very densely entangled, scarcely to be separated without rup- turing, very long and soft, usually moderately branched; sheaths cylindri- cal, firm, somewhat close, slightly roughened, not lamellose, with very gradually tapering apices; trichomes 1-1.7 mic. in diameter, few within the sheath, somewhat parallel or solitary, constricted at joints; apical cell acute-conical; cells 3-6 mic. in length; transverse walls indistinct; rarely granulated; cell contents pale blue-green. Arctic Regions. Walrus Island, 79° 15' N. (Dickie). Connecticut. Forming a felty stratum of yellowish or orange tint, on moist limestone rocks, shore of Housatonic River, near Gaylordsville. October 1898 and April 1899. (Holden). California. Mixed with other algae, form- ing a thin layer on the side of a watering trough. Dillon's Beach, En- trance to Tomales Bay, Marin County. December 1898. (Setchell and Gibbs). West Indies. In tufts on sides of lily tanks. Botanic Garden, Castleton, Jamaica. April 1893. (Humphrey). Forma meneghinii Kuetzing. 1. c. 268. De Toni. 1. c. 337. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877. Plant mass usually somewhat thick, pale red or flesh-colored; sheaths 2.8-4 mic. in thickness, up to four times thicker than the filaments. New Jersey. Damp earth. (Austin). 275. Hypheothrix lardacea (Cesati) Hansgirg in Dalla Torre und Sarnth. Alg. v. Tyr. Vorarl. u. Liechtenst. 96. Gomont. Monogr. Oscill. 49. pi. 8. f. 8, 9. 1893. (Schizothrix lardacea Gom.). De Toni. Syll. Algar. 5: 340. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. 105. 1895. (S. lardacea (Ces.) Gom.). Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 429. 1895. Tilden. American Myxophyceae 143 Algae. Cent. 11. no. 176. 1896; List of Fresh-Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 28. 1898. Saun- ders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 396. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 20. no. 9SS. 1902. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 236. 1905. Plate VI. fig. 3. Plant mass up to 3 cm. in thickness, expanded, not encrusted with cal- cium carbonate, hard and elastic, composed of layers more or less uniform in color, dull or olive green or reddish; filaments soft, very long, twisted, not or but little branched, separated without rupturing; sheaths cylindrical, firm, contracted or pointed at the apex, at first close and smooth, finally becoming thicker and roughened; trichomes 1.5-2 mic. in diameter, few within the sheath, frequently solitary, somewhat parallel, in living speci- mens not constricted at joints; cells 2-3 mic. in length; transverse walls usually marked by protoplasmic granules; cell contents pale blue-green. Alaska. Prince William Sound. June 1899. (Saunders). Forming blood- red gelatinous' patches on smooth, wet, vertical rocks. Cascades, near Iliuliuk. June 1899. (Setchell and Lawson). Forming bright rose-red tufts on rocks exposed to fresh water spray. Near Orca, Prince William Sound. (Setchell). Connecticut. On vertical surface of dripping rock. East Rock, New Haven. November. (Holden). Forming rather gelatinous, rusty or dirty green patches on wet vertical faces of trap rock. East Rock, New Haven. December i8gi. (Setchell). Minnesota. In a bottle of distilled water left standing for several months. Botanical Laboratory, University of Minnesota. 1896. (Determined by M. Gomont). 276. Hypheothrix arenaria (Berkeley). De Toni. Syll. Algar. 5: 342. 1907. Gomont. Monogr. Oscill. 50. pi. 8. f. 11, 12. 1893. (Schizothrix arenaria Gom.). Plate VI. fig. 4. Plant mass thin, somewhat fragile, not encrusted with calcium car- bonate, blue-green; filaments firm, strongly flexuous, closely entangled, below trunk-shaped, towards the apex divided and branched; false branches strongly twisted and entangled; sheaths firm, roughened in outline, tapering at the apex, thick and lamellose in the lower parts; trichomes 1.5-3 mic. in diameter, few in the lower part of the filament, loosely aggregated, some- what parallel, often solitary in the branches, constricted at the joints (in dried specimens); apical cell acute-conical; cells up to 5 mic. in length; cell contents pale blue-green. United States. (Setchell). 277. Hypheothrix vulpina Kuetzing. Spec. Algar. 267. 1849. De Toni. Syll. Algar. 5: 338. 1907. Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 8. 1880. Plant mass compact, leathery, opaque, roughened, reddish or dull olive, 144 Minnesota Algae becoming darker in color; sheaths close, delicate, colorless; trichomas 2.3- 2.8 mic. in diameter, slightly curved, loosely entangled; cells a little short- er than the diameter; transverse walls distinct, slightly granulated; cell contents pale becoming darker. Arctic Regions. Marshy spots on land, 82° 27' N. (Dickie). 278. Hypheothrix pallida Kuetzing. Spec. Algar. 893. 1849. De Toni. Syll. Algar. 5: 339. 1907. Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 182. 1877; Fresh- Water Algae U. S. 298. pi. 202. f. 26-31. 1887. (L. pallida (Naeg.) Wolle). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Plant mass membranaceous, firm, somewhat smooth, pale rose or dark red in color; filaments 40-80 mic. (?Wolle) in diameter; sheaths very ■vvide, at first homogeneous, finally becoming lamellose and fibrillose; trich- omes S.6-8.3 mic. in diameter, rather straight or sightly curved, some- what parallel or sometimes flexuously curved and interwoven; cells some- what quadrate, here and there slightly swollen; cell contents faded or yel- lowish brown. New Jersey. Forming reddish-brown stratum on dry ground. (Austin). On wet soil and old meadow grounds. (Wolle). Genus SYMPLOCASTRUM Gomont. Monogr. Oscill. 52. 1893. Plants terrestrial or living on damp rocks; filaments twisted and en- tangled, ascending from a prostrate base, agglutinated together in erect fascicles; sheaths colorless. I Plant mass blue-green; trichomes 1.4-2 mic. in diameter, constricted at the joints; cells shorter than the diameter S. fragile II Plant mass flesh-colored or reddish; trichomes 1.6-2 mic. in diameter; cells usually longer than the diameter S. rubrum III Plant mass gray or yellowish; trichomes 1.9-2.3 mic. in diameter; cells longer than the diameter S. cuspidatum IV Plant mass blackish, olive or lead-colored; trichomes 3-6 mic. in diameter; cells somewhat quadrate or longer than the diameter S. friesii 279. Sjrmplocastrum fragile (Kuetzing). De Toni. Syll. Algar. S: 347. 1907. Gomont Monogr. Oscill. 52. pi. 8. f. 13, 14. 1893. (Schizothrix fragilis (Kg.) Gom.). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. 104. 189S. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 429. 1895. Plate VI. fig. 5- Plant mass up to i mm. in thickness, pannose, tomentose, olive or blue-green; filaments flexuous, entangled, more or less, parallel, finally be- coming united into short, erect fascicles; sheaths irregular in outline, some- Myxophyceae 145 what diffluent; trichomes 1.4-2 mic. in diameter, constricted at joints, at the base of the filament often numerous and closely crowded within the sheath; cells 1-2.5 mic. in length; protoplasm fioccose, not granular, pale blue-green. Connecticut. Forming a reddish, closely adherent crust on stones kept moist by the spray from a waterfall, by dam across Still River, Brook- field. May 1892. ("The red color was due to a unicellular organism asso- ciated with it"). CSetchell). 280. Symplocastrum rubrum (Meneghini) De Toni. Syll. Algar. 5: 350. 1907. Gomont. Monogr. Oscill. 53. pi. 8. f. 15, 16. 1893. (S c h i z o- thrix rubra Gom.). Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 189. 1903. Plate VI. fig. 6. Plant mass caespitose, flesh-colored, reddish or becoming dark colored; filaments elongate, divided and branched into numerous appressed por- tions, in Lower parts twisted and entangled, above less flexuous, parallel, forming short, erect, pointed tufts at the apex; sheaths cylindrical, firm, wide, somewhat lamellose, slightly roughened on the surface, frequently transversely wrinkled at the base with a very long, pointed apex; trich- omes 1.6-2 mic. in diameter, constricted at joints (in dried specimens), few or often solitary within the sheath; apical cell rotund; cells 2-3.5 ™ic. in length; transverse walls often granulated; cell contents pale reddish. Alaska. Forming scum on deep pool of fresh water. Glacier Valley, Unalaska. (Lawson). 281. Symplocastrum cuspidatum (West and West). De Toni. Syll. Algar. 5: 349- 1907. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 273. pi. 16. f. 1-7. 1895. (Symploca cuspida- tum W. and W.). Plate VI. fig. 7-9. Plant mass widely expanded, gray or yellowish; fascicles 8-15 mm. in height, erect, narrow, awl-shaped, aggregated, here and there dense, becoming bluish green; sheaths colorless, transparent or forming parallel layers, often roughened in outline, narrower and often branched at the apex; trichomes 1.9-2.3 mic. in diameter, flexuous, entangled, often interrupted, narrower in the mass, at the apex of the fascicles one to three included in the wide sheath, 13.5-25 mic. in diameter; cells 3.8-9 mic. in length; transverse walls distinct; cell contents blue-green. West Indies. Specimens resembling Sphagnum cuspidatum. Occur- ring among mosses on trees. Summit of Trois Pitons (4500 feet), Dominica. (Elliott). Var. luteo-fusca West and West. A Further Confribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898- 1900. De Toni. 1. c. 349. 146 Minnesota Algae Plant mass 1-2 mm. in height; rust-colored, dense; fascicles 4-10 mm. in height; sheaths 15-40 mic. in thickness, often surrounding two, three or many trichomes; trichomes 2.5-3.5 ™ic. in diameter. West Indies. On rocks. Roseau Valley (1000-2000 ft.), Dominica; on bark, windward road to lake, Dominica; on the ground, mostly in old Diablotia holes, Morne Anglais (2300 ft.). (Elliott). 282. Ssrmplocastrum friesii (Agardh) Kirchner in Engler and Prantl. Die natiirlichen Pflanzenfamilien. I. i. a. 68. f. 53. 1900. Gomont. Mon- ogr. Oscill. 54. pi. 9. f. I, 2. 1893. (Schizothrix friesii Gom). De Toni. Syll. Algar. 5: 347. 1907. WoUe. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 138. 1877. (Symploca lucifuga Breb.); Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. (Symploca friesiana Kg.); Fresh- Water Algae U. S. 303. pi. 205. f. 8; 304. pi. 205. f. 13. 1887. Moebius. Ueber einege in Portorico gesammelte Siisswasser- und Luft-Algen. Hedwigia. 2T. 246. 1888. WoUe and Martindale., Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. 503. 1898.' Collins. Notes on Algae. I. Rhodora. i: 10. 1899. Plate VI. fig. 10. Plant mass indefinite, expanded, black or olive or lead-colored; fila- ments in lower portions twisted and entangled, in upper parts somewhat straight, parallel, dichotomously divided and branched into appressed por- tions, forming rigid, erect, spine-shaped tufts 3 cm. or more in height; sheaths cylindrical, firm, pointed at the apex, lamellose, smooth or a little roughened in outline; trichomes 3-6 mic. in diameter, evidently constricted at the joints, few or solitary within the sheath, parallel; apical cell truncate conical; cells 4-1 1 mic. in length; cell contents coarsely gran- ular (except in apical cell). Canada. On old wood. (Macoun). United States. (Farlow). Maine. On ground in woods at the base of Mount Kineo. July 1897. (Col- lins). Massachusetts. On damp ground. August 1898; abundant in paths and by roadsides. Lynnwoods, Middlesex Fells. 1899. (Collins). New Jersey. On shaded clay banks. Bergen. (WoUe). West Indies. Growing upon moss. On Mt. Jimenez, Sierro de Luquillo, Porto Rico. (Sintenis). Genus INACTIS Kuetzing. Tab. Phyc. i: 44. 1845-1849. Plants growing in moist places or in rivers; filaments caespitose, often with numerous false branches, forming cushions which finally often become encrusted with calcium carbonate and hardened, zonate within, or aggregated into penicillate, floating fascicles; sheaths colorless or near- ly so. I Plant mass cushion-shaped, tufted I Plant mass strongly encrusted with calcium carbonate, stony; fila- ments straight, somewhat simple; trichomes 1-2 mic. in diameter; cells somewhat quadrate I. pulvinata Myxophyceae 147 ^- 2 Plant mass strongly encrusted with calcium carbonate, stony; fila- ments slender, simple in basal portions, fasciculately branched above; trichomes 1.4-3 mic. in diameter; cells somewhat quadrate or longer than the diameter I. fasciculata 3 Plant mass cushion-shaped or crustaceous, not hardened with calcium carbonate; filaments forming trunk at base, very much branched in upper portions; trichomes 1-1.5 mic. in diameter; cells longer than the diameter I. lacustris 4 Plant mass somewhat hemispherical, plano-convex; filaments more or less branched, growing in tufts; cells two or three times longer than broad I. austini II Plant mass forming penicillate fascicles, floating. 1 Plant mass submerged, attached; filaments very long; trichomes 1.4-2.4 mic. in diameter, constricted at joints I. tinctoria 2 Plant mass submerged, epiphytic on other algae; trichomes 3-6 mic. in diameter, usually constricted at joints I- simmonsiae 3 Plant mass submerged, attached; filaments very long; trichomes 6 mic. in diameter, constricted at joints I. mexicana III Filaments solitary, growing in gelatinous mass formed by other algae; trichomes 1.5-2 mic. in diameter, not constricted at joints I. hawaiensis 283. Inactis pulvinata Kuetzing. Tab. Phyc. i: 44. pi. yy. f. 3. 1845-1849. Gomont. Monogr. Oscill. 36. 1893. (Schizothrix pulvinata Gom.). De Toni. Syll. Algar. 5: 350. 1907. Plate VI. fig. 11-13. Plant mass cushion-shaped or crustaceous, stony, hardened with cal- cium carbonate, uneven or mammillate, blue-green on the outer surface, zonate within; filaments straight, rigid, parallel, coalesced or closely crowded, moderately branched; false branches entirely appressed; sheaths papery, with pointed apex; trichomes 1-2 mic. in diameter, constricted at joints, more or less numerous within the sheath; cells somewhat quad- rate or twice as long as broad; cell contents pale blue-green. North America. In cataracts. (Anderson). 284. Inactis fasciculata (Naegeli) Grunow in Rabenhorst. Fl. Eur. Algar. 2: 160. 1865. Gomont. Monogr. Oscill. 36. pi. 6. f. 1-3. 1893. (Schi- zothrix fasciculata Gom.). De Toni. Syll. Algar. 5: 351. 1907. Murray. Calcareous Pebbles formed by Algae. Phyc. Mem. Part III. 74. pi. 19. 1895. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 89. 1896. Pennhallow. Note on Calcareous Algae from Michigan. Bot. Gaz. 21: 215. 1896. MacMillan. Minnesota Plant Life. 41. 1899. Tilden. American Algae. Cent. VI. no. 585. 1902. Powell. Observations on some Calcareous Pebbles. Minn. Bot. Studies. 3: 75. pi. 16. f. 8, 9; pi. 17. f. 1-5. 1903- 1^8 Minnesota Algae Plate VI. fig. 14, IS- Plant mass cushion-shaped, stony, hardened with calcium carbonate, becoming confluent into a crustaceous, mammillate layer, blue^green, flesh- colored or brownish on the surface, zonate within; filaments slender, flex- uous, closely entangled, forming a trunk-shaped basal portion narrower at the base, thicker above, branched and divided into many parts at the apex; false branches fasciculate, somewhat appressed; sheaths somewhat thick, with pointed apex; trichomes 1.4-3 inic- in diameter, constricted at the joints, many in the trunk-shaped basal portion, few or solitary in the branches; apical cell acute conical; cells 1.2-3.5 mic. in length; cell con- tents pale blue-green. Connecticut. Mixed with other algae. Twin Lakes, near Salisbury. (Setchell). Michigan. Pebbles found in a pond on the shore of Lake Michigan. (Velie). Minnesota. Forming calcareous pebbles, which were found lying in from four to ten feet of clear water on sand-bars. Clear- water Lake, Wright County. June 1901. (Freeman and Lyon). "These pebbles range in size from that of a small hickory nut to two inches in diameter. Most of them are flattened, and though comparatively smooth in same cases, are often rough, corrugated and wave-worn. All are more or less hollow. In section they have a distinctly stratified appearance." * * * They "were found to be composed of a densely interwoven mass of filaments of which the most common type was that of S. fasciculata Com." — Powell. 285. Inactis lacustris (A. Braun) De Toni. Syll. Algar. 5: 354. 1907. Gomont. Monogr. Oscill. 39. pi. 6. f. 9-12. 1893. (Schizothrix lacustris A. Br.). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 15. no. 712. 1900. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 397. 1901. Plate VI. fig. 16. Plant mass cushion-shaped or crustaceous, not at all or scarcely hard- ened with calcium carbonate, dull yellowish green; filaments flexuous, closely crowded, forming a trunk-shaped basal portion narrower at the base, broadened towards the apex, branched and divided into many parts at the apex; false branches twisted, entangled, or somewhat parallel; sheaths colorless, wide, very wide in the lower part of the filament; trich- omes i-i.S mic. in diameter, constricted at the joints, many in the trunk- shaped basal portion, remote, often spirally twisted, few or solitary in the branches; cells up to 4 mic. in length; cell contents pale blue-green. Alaska. In a fresh water pool. Near Prince William Sound. June 1899. (Saunders). Connecticut. On sandy ground near "Fresh Pond" (brack- ish). Stratford. December 1897. (Holden). Var. caespitosa Gomont. 1. c. 39. De Toni. 1. c. 354. Hauck and Richter. Phyk. Univ. no. 741. 1886-1889. (S. lacustris caespitosa Gom.). Collins. Algae. Flora of the Blue Hills, Middle- sex Fells, Stony Brook and Beaver Brook Reservations of the Metropoli- Myxophyceae 149 tan Park Commission, Massachusetts. 126. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 206. 1896. Filaments forming a' very thick, trunk-shaped basal portion; false branches short. Massachusetts. On stones along the margin of Spot Pond, Middlesex Fells; on stones at the water's edge, Peabody, Suntaug Lake, August iBgo; Tynnfield, Suntaug Lake, September 1890. (Collins). 286. Inactis austini Wolle. Fresh Water Algae. III. Bull. Torr. Hot. Club. 6: 183. 1877. De Toni. Syll. Algar. 5: 351. 1907. Plant mass somewhat hemispherical, plano-convex, 3-7.5 mic. in diame- ter, often aggregated, diffluent, brown becoming blackish green; filament.s firm, cylindrical; more or less branched, growing in tufts; sheaths colorless, very close; cells two or three times longer than broad; transverse walls usually distinct; cell contents dark blue-green. New Jersey. Wet rocks. Little Falls. 1867. (Austin). 287. Inactis tinctoria (Agardh) Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i: 379. 1875. Gomont. Monogr. Oscill. 41. pi. 7. f. 5-7. 1893. (Schizothrix tinctoria Gomont.). De Toni. Syll. Algar. 5: 356. 1907. Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. (Hydrocoleum tinctorium A. Br.); Fresh Water Algae. Bull. Torr. Bot. Club. 6: 282. 1879. (Hypheothrix tinctoria Rabenh.) ; Fresh-Water Algae U. S. 321. pl. 208. f. 16. 1887. (Leptothrix tinc- toria Kg.). Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 13. iQOi. Plate VI. fig. 17- Plant mass continuous, soft, mucous, attached to submerged plants, blue-green or violet; filaments very long, flaccid, floating in free tufts, with penicillate apices, unbranched in lower portions, branched above; sheaths narrow, not lamellose, somewhat diffluent; trichomes 1.4-2.4 mic. in diame- ter, especially constricted at the joints, in basal part of filament numer- ous within the sheath, more or less spirally twisted, in the branches few and straight; apical cell rotund; cells 1.4-3 mic- in length. Pennsylvania. On aquatic plants. (Wolle). Nebraska. On C 1 a d o- phora. Fisher's Lake, Glen Rock. (Bessey, Pound and Clements). 288. Inactis simmonsiae (Collins) De Toni; Syll. Algar. 5: 356. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 15. no. 707. 1900. (Schizothrix simmonsiae Collins). Collins. New Species etc., issued in the Phycotheca Boreali-Americana. Rhodora. 8: 105. 1906. Plants living in salt water; plant mass forming a brownish tufted coating on various algae (showing reddish brown when moistened, pinkish under the microscope); tufts 1-2 cm. long; sheaths thin, distinct; trichomes 3-6 mic. in diameter, much constricted at joints, usually single within the sheath, but often several in basal portion, sometimes irregularly swollen 150 Minnesota Algae and distorted as if doubling up in the sheath; cells .6-2 mic. in length; cell contents pale green. Rhode Island. On algae in high rock pool. Easton's Point, Newport. December 1897. (Simmons). 289. Inactis mexicana (Gomont) De Toni. Syll. Algar. 5: 356. 1907. Go- mont. Monogr. Oscill. 42. 1893. (Schizothrix mexicana Gom.). Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Plant mass continuous, soft, attached to submerged plants; filaments very long, flaccid, floating in free tufts, with penicillate apices, twisted, entangled, unbranched in lower portions, fasciculately branched above; false branches somewhat appressed; sheaths very thin, papery, not lamel- lose, somewhat roughened in outline; trichomes 6 mic. in diameter, con- stricted at joints, in basal part of filament numerous within the sheath, densely crowded, often twisted into a cord, in the branches few or solitary; apical cell scarcely tapering, rotund; cells 2-5 mic. in length; transverse v/alls commonly inconspicuous; cell contents showing scattered protoplas- mic granules, pale violet (in dried specimens). Mexico. In Guatulco River. (Gomont). West Indies. On rock in "Wag Water,'' Castleton, Jamaica. April 1893. (Humphrey). 290. Inactis hawaiensis (Lemmermann) De Toni. Syll. Algar. 5: 357. 1907. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 620. pi. 8. f. 19. 1905. (Schizothrix havaiensis Lemm.). Plate VI. fig. 18. Filaments 8-38 mic. in diameter, solitary, growing in gelatinous mass formed by other algae; false branches present; sheaths colorless, lamellose. v/ith pointed apices; trichomes 1.5-2 mic. in diameter, not constricted at joints, parallel or flexuous, one to four within the sheath; cells S-6 mic. in length; transverse walls not granulated, almost invisible; cell contents filled with vacuoles, pale blue-green. Hawaii. With other algae in hot water. Volcano Mauna Kea, Island of Hawaii. (Schauinsland). Genus SCHIZOTHRIX Kuetzing. Phyc. Gen. 230. 1843. Plants living on moist earth or in water, or in inundated places, rarely entirely aquatic; filaments forming erect or prostrate, Symploca-like fas- cicles or a pannose stratum, rarely floating free; sheaths in the beginning colorless, finally becoming yellowish brown, purplish pink or bluish. I Cells somewhat quadrate or shorter than the diameter. 1 Plant mass thin, encrusted, often widely expanded or in tangled tufts among other algae; sheaths colorless, very transparent; trichomes 1-1.5 mic. in diameter, constricted at joints; cells some- what quadrate S. hyalina Myxophyceae 151 2 Plant mass caespitose or appressed, semiorbicular; sheaths very thick, lamellose; trichomes 4-9 mic. in diameter, usually solitary within the sheath S. thelephoroides 3 Plant mass indefinite, sheaths purple, orange or rose-colored; trich- omes 6-8 mic. in diameter, many within the sheath S. purpurascens 4 Plant mass indefinite, woolly, lead-colored; sheaths very thick, lamellose; trichomes 7.5-8.5 mic. in diameter S. chalybea 5 Plant mass not caespitose; sheaths yellowish orange; trichomes 7-13 mic. in diameter; cells somewhat quadrate or twice as short as the diameter S. muelleri II Cells longer than the diameter 1 Filaments very long; sheaths dark lead-colored, irregular in out- line; trichomes 1.7 mic. in diameter S. braunii 2 Filaments forming a loose, cobwebby mass within sandstone rock; sheaths cylindrical, rough, usually colorless and not lamellose, sometimes brownish and lamellose; trichomes 3.5-4.8 mic. in diameter; cells quadrate or a little longer than the diameter S. rupicola 291. Schizothrix hyalina Kuetzing. Spec. Algar. 320. 1849. De Toni. Syll. Algar. 5: 360. 1907. Wolle. Fresh-Water Algae U. S. 307. pi. 203. f. 3, 4. 1887. (M i c r o c o- leus hyalinus (Kg.) Kirchn.). Bennett. Plants of Rhode Island. 115. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. Plant mass thin, encrusted, often widely expanded or in tangled tufts among other algae, blue-green or green; filaments 8 mic. in diameter; sheaths colorless, very transparent; trichomes 1-1.5 mic. in diameter, con- stricted at joints, very slender, curved and entangled, few within the sheath; apex of trichome awl-shaped, pointed; cells somewhat quadrate; c«ll contents pale green. Rhode Island. Davisville. (Bennett). New Jersey. In ponds on Sphagnum. (Wolle). Pennsylvania. Wet rocks. (Wolle). South Carolina. Wet ground. (Wolle). 292. Schizothrix thelephoroides (Montagne) Gomont. Monogr. Oscill. 57. pi. 10. f. 1-4. 1893. De Toni. Syll. Algar. 5: 359- I907- Moebius. Ueber einige in Portorico gesammelte Siisswasser- und Luft- Algen. Hedwigia. 27: 247. pi. 9. f. 7- 1888. Plate VI. fig. 19. Plant mass pannose, caespitose or appressed, semiorbicular, rust- colored; filaments .5 cm. in height, divided and branched into appressed, somewhat dichotomous divisions, forming more or less spirally twisted tufts; sheaths firm, very thick, lamellose, the inner layers rust-colored, the outer ones colorless, very frequently dilated below the pointed apex, slightly roughened on the surface, transversely wrinkled; trichomes 4-9 mic. in diameter, usually solitary sometimes two within the sheath, parallel. 1 52 Minnesota Algae remote, evidently constricted at the joints; apical cell scarcely tapering, rotund; cells in lower portion of trichome up to double the diameter in length, in the upper portion somewhat quadrate, 6-14 mic. in length; cell contents coarsely granular, blue-green. West Indies. Wet rocks. Summit of Mount Junque, Sierra de Luquillo, Porto Rico. (Sintenis). 293. Schizothrix purpurascens (Kuetzing) Gomont. Monogr. Oscill. 58. pi. 9. f. 6-8. 1893. De Toni. Syll. Algar. 5: 361. 1907. Plate VI. fig. 20, 21. Plant mass indefinite, expanded, dark violet; filaments moderately long, somewhat dichotomously divided and branched into more or less divaricate portions, in lower portions entangled, in upper parts forming somewhat parallel and twisted creeping tufts; sheaths purple, orange or rose-colored, transparent at the apex, firm, solid, very thick and especially lamellose, irregular and roughened in outline, with pointed apex; trich- omes 6-8 mic. in diameter, usually constricted at the joints, numerous within the sheath, somewhat remote and parallel; apical cell conical, often sharply pointed; cells 3-8 mic. in length; cell contents coarsely granular (except in apical cell). Var. cruenta (Lespinasse) Gomont. 1. c. S9- De Toni. 1. c. 362. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. 504. 1898. Collins. Notes on Algae. — I. Rhodora. i: 10. 1899. Sheaths purplish pink or peach-colored; trichomes usually constricted at joints. Massachusetts. On moist ground near Winchester Reservoir, Middle- sex Fells. August, September 1898. (Collins). South Carolina. (Raven- el). 294. Schizothrix chalybea (Kuetzing) Gomont. Monogr. Oscill. S7- pl- 9- f- 3-S. 1893- De Toni. Syll. Algar. 5: 359. 1907. Plate VI. fig. 22. Plant mass indefinite, woolly, lead-colored; filaments moderately long, branched, waving, loosely coalesced in erect tufts 2 mm. long; false branches somewhat dichotomous, appressed; sheaths very thick, lamellose, the inner layers pale lead-colored, the outer ones transparent, firm, cylin- drical, smooth or a little roughened on the outside; trichomes 7.5-8.5 mic. in diameter, very much constricted at joints; few and parallel within the sheath, or often solitary; apical cell up to 11 mic. in length, obtuse cr acute conical; cells 3-8 mic. in length; cell contents coarsely granular (except in apical cell), dark green in color. Mexico. On mossy ground, near the Volcano of Orizaba. (Mueller). 295. Schizothrix muelleri Naegeli in Kuetzing. Spec. Algar. 320. 1849. Gomont. Monogr. Oscill. 59. pl. 10. f. 5-7. 1893. De Toni. Syll. Algar. 5: 362. 1907. Wolle. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 138. 1877. Myxophyceae ^53 (Hydrocoleum versicolor Rabenh.). Farlow. Notes on the Gryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. (Microcoleus versicolor Thur.). Collins. Algae of Middle- sex County. 15: 1888. Collins, Holden and Setchell. Phyc. Bor.-Ara. Fasc. I. no. 7. 1895. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 126. 1896. Setchell. Notes on Cyano- phyceae. III. Erythea. 7: 45. 1899. Collins. The Algae of the Flume. Rhodora. 6: 230. 1904. Plate VI. fig. 23. Filaments long, moderately ilexuous, divided and branched into ap- pressed portions, woven into an indefinite, expanded, dark or blackish green mass, or forming decumbent tufts attached to mosses, or floating free; sheaths yellowish orange, firm or somewhat diffluent, irregular in outline, with pointed apex, trichomes 7-13 mic. in diameter, slightly con- stricted at joints, solitary or few within the sheath; apical cell obtuse conical; cells 4-9 mic. in length; cell contents coarsely granular. New Hampshire. Mt. Tumble-Down Dick. (Farlow). In thin black sheets on wall of the "Flume." (Collins). Massachusetts. Forming a black coating on wet rocks. Middlesex Fells; on perpendicular cliffs, form- ing sheets of considerable size, Saugus, April 1890, 1893. (Collins). Con- necticut. Mount Carmel. (Setchell). California. Along the banks of a small stream on Howell Mt., near St. Helena, Napa County. February 1896. 296. Schizothrix braunii Gomont. Monogr. Oscill. 63. pi. 11. f. 9-13. 1893. De Toni. Syll. Algar. S: 365. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 189. 1903. Plate VI. fig. 24. Plant mass crustaceous-floccose, adhering to paper when dried, black- ish; filaments very long, densely tangled and twisted into cords, moderate- ly branched; sheaths dark lead-colored, firm, slightly irregular in outline, not fringed, with very gradually tapering apex; trichomes 1.7 mic. in diame- ter, constricted at joints, few within the sheath, often solitary, distant, parallel; apical cell tapering, obtuse; cells 2-5 mic. in length; transverse walls granulated; cell contents pale blue-green. Alaska. On dripping rocks. Near Iliuliuk. (Setchell and Lawson). Orca. (Jepson). "Most of the sheaths are colorless, but some are of the characteristic blue-black color of this species." — Setchell and Gardner. 297. Schizothrix rupicola Tilden. American Algae. Century II. no. 175. 1896; Some New Species of Minnesota Algae which live in a Cal- careous or Silicious Matrix. Bot. Gaz. 23: 103. pi. 9. f. 9. 1897; List of Fresh-Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 28. 1898. Plate VI. fig. 25. Filaments 9.6-16 mic. in diameter, forming a loose, cobwebby mass 154 Minnesota Algae within sandstone rock, as far at least as 10-15 mm. from surface; sheaths cylindrical, rough, usually colorless and not lamellose, but sometimes brownish and lamellose; trichomes 3.5-4.8 mic. in diameter, not constricted at the joints, one to many in a sheath; apical cell truncate conical; cells 5-8 mic. in length; transverse walls usually invisible. Minnesota. In bare and dry sandstone cliffs. Soldiers' Home, Minne- haha Falls. September 1896. (Hall). Genus DASYGLOEA Thwaites. Eng. Bot. pi. 2941. 1848. Sheaths very wide, colorless or yellowish brown; trichomes very few within the sheath, very loosely aggregated; apex of trichome straight, not capitate; cells often longer than the diameter. 298. Dasygloea amorpha Berkeley in English Botany, pi. 2941. 1848. Go- mont. Monogr. Oscill. 84. pi. 13. f. 11, 12. 1893. De Toni. Syll. Algar. 5: 368. 1907. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877; Fresh-Water Algae U. S. 304. pi. 204. f. 1-9. 1B87. (M icrocoleus amorpha (Thwaites) Wolle). Plate VI. fig. 26. Plant mass amorphous, gelatinous; filaments twisted, entangled, divid- ed into fringes at the apex; sheaths transparent throughout, or dull yel- low within, very irregular in outline, mucous, sometimes somewhat lamel- lose; trichomes 4-6 mic. in diameter, constricted at joints; apex of trichome sometimes very gradually tapered; apical cell truncate conical; cells 4-13 mic. in length; cell contents coarsely granular. Pennsylvania. Forming a thin olive or dark blue-green membrane, skin-like, on trickling rocks in mountain ravine. Glen Onoko. (Wolle). Genus MICROCOLEUS Desmazieres. Cat. des Plantes omises dans la Botanographie Belgique. 7. 1823. Plants living on soil, in fresh water or sometimes in salt water; fila- ments pimple or vaguely branched, creeping on the ground, sometimes growing among other algae; sheaths colorless, more or less regularly cylindrical, not lamellose, in many species finally diffluent; trichomes many within the sheath in well developed filaments, closely crowded, often twisted into rope-like bundles; apex of trichome straight, tapering; apical cell acute, rarely obtuse conical, in one species capitate. I Plants living in salt water; apical cell not capitate, pointed. 1 Trichomes 1.5-2 mic. in diameter, constricted at joints M. tenerrimus 2 Trichomes 2.5-6 mic. in diameter, constricted at joints M. chthonoplastes II Plants living on soil; apical cell capitate. M. vaginatus Myxophyceae 155 III Plants living in fresh water; apical cell not capitate 1 Sheaths mucous, diffluent; trichomes 4-5 mic. in diameter, especially constricted at joints M. lacustris 2 Sheaths somewhat mucous, not or scarcely diffluent; trichomes 5-7 mic. in diameter, not constricted at joints M. paludosus 3 Plant mass large, cushion-like; trichomes 5-6 mic. in diameter M. pulvinatus 4 Sheaths very mucous and agglutinated; trichomes 6-10 mic. in diameter, especially constricted at joints M. subtorulosus 299. Microcoleus tenerrimus Gomont. Monogr. Oscill. 93. pi. 14. f. 9-1 1. 1893. De Toni. Syll. Algar. 5: 373. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 30. 1865. Maze and Schramm. Essai Class. Algues Guadeloupe. 20. 1870-1877. (M. o 1 i o g o- thrix Crouan). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Collins, Holden and Setch- ell. Phyc. Bor.-Am.. Fasc. 15. no. 706. 1900. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901; Notes on Algae. — VI. Rhodora. 5: 233. 1903. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 188. 1903. Plate VI. fig. 27. Filaments simple or slightly branched, densely entangled in a gray or blue-green mass, or mixed with various algae; sheaths wide, irregular in outline, pointed or open at the apex, sometimes entirely diffluent; trich- omes 1-5-2 mic. in diameter, especially constricted at the joints, long, flexuGus, usually loosely aggregated, more or less numerous within the sheath; apex of trichome often gradually tapering; apical cell not capi- tate, very acute conical; cells 2.2-6 mic. in length; transverse walls pellu- cid, sometimes granulated. Maine. In rather small quantity. At Southwest Harbor, Mount Desert Island. (Holden). Louisiana. Forming a blue-green coating on an old wooden pier. Lake Pontchartrain. November 1898. (Saunders). Wash- ington. In a salt marsh. Whidbey Island. (Gardner). West Indies. Brackish water. Guadeloupe. (Maze). In company with M. chthonoplas- t e s. March 1893. (Humphrey). 300. Microcoleus chthonoplastes (Flora danica) Thuret. Essai Class. Nos- tochinees. Ann. Sci. Nat. Bot. VI. i: 378- 1875. Gomont. Monogr. Oscill. 91. pi. 14- f- 5-8. 1893- De Toni. Syll. Algar. 5: 371. 1907. WoUe. Fresh Water Algae. IV. Bull. Torr. Bot. Club. 7: 44. 1880. (M. gracilis Hass.). Farlow. Marine Algae of New England. 33. pi. 2. f. 3. 1881. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 105. 1886. WoUe. Fresh-Water Algae U. S. 306. pi. 203. f. 10, 11. 1887. (M. gracilis Hass, M. anguiformis Harv). Bennett. Plants of Rhode Island. 115. 1888. Collins. Algae of Middlesex County. 14. 1888; Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Jorr. Bot. Club, i: 90. 1889. WoUe and Martin- IS6 Minnesota Algae dale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. i88g. (C h t ho n o b 1 a s t u s 1 y n g b e i Kg.). Johnson and Atwell. Fresh Water Algae. Northwestern University. Report Dept. Nat. Hist. 21. 1890. Collins. Algae. Rand and Redfield's Flora of Mount Desert Island. Maine. 247. 1894. Collins, Hoi den and Setchell. Phyc. Bor.-Am. Fasc. 4. no. 153. 1896. Collins. Pre liminary Lists of New England Plants. — ^V. Marine Algae. Rhodora 2: 42. 1900. Bessey, Pound and Clements. Additions to the Reported Flora o: the State. Bot. Surv. Nebraska. 5: 13. igoi. Collins. The Algae o Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 19. no. 906. 1902. Collins. Notes on Algae. VI. Rhodora. 5: 233. 1903. Setchell and Gardner. Algae of North- western America. Univ. Calif. Pub. Bot. i: 188. 1903. Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Tilden. American Algae. Cent. VII. Fasc. i. no. 635. 1909. Plate VI. fig. 28. Filaments twisted, rarely branched, forming a dull or dark green, pan- riose, broadly expanded, compact, stratified mass, made up of layers of different colors, or growing sparsely among other algae; sheaths cylindrical, more or less unequal and roughened in outline, with apex usually open, sometimes entirely diffluent; trichomes 2.5-6 mic. in diameter, constricted at joints, short, somewhat straight, many within the sheath, usually dense- ly aggregated into bundles, rarely twisted into cords; apex of trichome tapering; apical cell not capitate, acute conical; cells 3.6-10 mic. in length; transverse walls not granulated. Canada. Mixed with other algae. Malpeque, Prince Edward Island. (Faull). Maine. Very common in lagoon. Little Cranberry Isle. (Col- lins). Shore west of Bracy Cove. (Holden). New Hampshire. (Col- lins). Massachusetts. Mixed with other algae, common along the New England coast. Wood's Holl. (Farlow). Salt marshes. (Collins). Growing on sand between tide marks, salt marsh. Wood's Hole. July 1895. (Oster- hout). Rhode Island. Geneva. (Bennett). Connecticut. Forming a thick coating on turf near high water mark. Seaside Park; in sheets on sandy bottom between tide marks. Cook's Point, September, October. (Holden). New York. Shores of Long Island, Fort Hamilton, Green- port. Summer. (Pike). New Jersey. In brackish pools. Atlantic City. (Morse, Martindale). On moist earth. (Wolle). Texas. 1902. (Fanning). Ohio. Plankton. Put-in-Bay, Lake Erie. (Snow). Illinois. Running water. Big Woods, Cook County. April. (Johnson and Atwell). Dakota. (Hobby). Washington. Growing on the mud in a salt marsh. Pen's Cove, Whidbey Island. (Gardner). West Indies. In turfs of algae. St. Ann's Bay, Jamaica. March 1893. (Humphrey). Cuba. (R. de la Sagra). 301. Microcoleus vaginatus (Vaucher) Gomont. Essai Class. Nostocacees homocystees. Morot. Journ. de Bot. 4: 353. 1890; Monogr. Oscill. 93. pi. 14. f. 12. 1893. De Toni. Syll. Algar. 5: 374. 1907. Myxophyceae ^57 Wolle. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 138. 1877. (M. terrestris Desmaz.); Fresh-Water Algae U. S. 305. pi. 203. f. 7-9; pi. 205. f. 16, 17. 1887. Collins. Algae of Middlesex County. 15. 1888. Ben- nett. Plants of Rhode Island. 115. 188. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 20. pi. 2. f. 21. 1894; The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 397. 1901. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Setchell and Gardner. Algae of Northwestern America, Univ. Calif. Pub. Bot. i: 189. 1903. Collins, Holden and Setchell. Phyc, Bor.-Am. Fasc. 21. no. loii. 1903. Buchanan. Notes on the Algae of Iowa. Proc. Iowa. Acad. Sci. 14: 12. 1908. Plate VI. fig. 29. Filaments creeping, rarely entangled and twisted, sometimes branched; forming a black, glistening sheet; sheaths cylindrical, more or less un- equal in outline, agglutinated, pointed and closed at the apex, or open and gradually disappearing, at times entirely diffluent; trichomes 3.5-7 mic. in diameter, not constricted at joints, many within the sheath, closely crowded, usually twisted into cords, the portion extruding from the sheath straight; apex of trichome gradually tapering and capitate; outer membrane of apical cell thickened into a depressed conical calyptra; cells 3-7 mic. in length; transverse walls frequently granulated. Alaska. Forming, with other algae, a thin coating on damp ground, recently covered by snow. Glacier Bay. (Saunders). Massachusetts. Newton. (Farlow). Melrose. (Collins). Rhode Island. Common. (Ben- nett). New Jersey. On moist earth. (Wolle). Iowa. Damp ground. Grinnell. (Fink). On flower pots in greenhouse. Ames. (Buchanan). Ne- braska. On damp earth in greenhouses. University. (Saunders). Wash- ington. La Conner, Skagit County. (Gardner). California. In a gutter. Berkeley. February 1902. (Gardner). West Indies. On moist rock. Rio Cobre, Bog Walk, Jamaica. April 1893. (Humphrey). 302. Microcoleus lacustris (Rabenhorst) Farlow in Farlow, Anderson and Eaton. Algae. Am. Bor. Exsicc. no. 227. 1877. Gomont. M-onogr. Oscill. 97. 1893. De Toni. Syll. Algar. 5: 376. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 7. no. 307. 1897. Setchell. Notes on Cyanophyceae. III. Erythea. 7: 52. 1899. Riddle. Brush Lake Algae. Ohio Nat. 5: 268. 1905. Filaments simple or vaguely branched, forked at the apex, twisted and entangled forming a black or blue-green layer; sheaths somewhat thin, mucous and agglutinated, sometimes diffluent, often gradually disappear- ing at the apex; trichomes 4-5 mic. in diameter, especially constricted at joints, somewhat parallel, the portion extruding from the sheath very straight; apical cell more or less obtuse conical, not capitate; cells 6-12 mic. in length; transverse walls not granulated; cell contents showing scat- tered coarse granules, pale blue-green. Massachusetts. Newton. (Farlow). Connecticut. In tangled felty strata and disseminated among Scytonema crispum, in pool. North 158 Minnesota Algae Haven. November 1896. (Holden). Pennsylvania. "Distributed by WoUe under name ofPhormidium congestum * * * probably col- lected in Pennsylvania." — Setchell. Ohio. Brush Lake, Champaign Coun- ty. (Riddle). 303. Microcoleus paludosus (Kuetzing) Gomont. Monogr. Oscill. 96. pi. 14. f. 13. 1893. De Toni. Syll. Algar. 5: 376. 1907. Setchell. Notes on Cyanophyceae. III. Erythea. 7: 53. 1899. Bessey, Pound and Clements. Additions to the Reported Flo'ra of the State. Bot. Surv. Nebraska. 5: 13. 1901. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 17. no. 802. 1901. Tilden. American Algae. Cent. VII. Fasc. I. no. 634. 1909. Plate VI. fig. 30. Filaments entangled, twisted, simple or forked at the apex, growing among other algae or forming a blackish or blue-green stratum; sheaths moderately mucous, open and disappearing at the apex or closed and pointed; trichomes 5-7 mic. in diameter, not constricted at joints, parallel, straight, or twisted into cords; apical cell not capitate; cells 4-13 mic. in length; transverse walls not granulated; cell contents light blue-green. Rhode Island. (Osterhout). Nebraska. On wet soil in greenhouse. Lincoln. (Bessey). California. In southern part of the state. (Parish). In conservatory. Golden Gate Park, San Francisco. September 1900. (Gard- ner). In greenhouses. University of California, Berkeley. (Setchell). Ha- v/aii. With other algae forming a layer covering rocks on bottom and sides of basin of "warm spring." Temperature at 7 a. m. 31 + ° C. Puna, Island of Hawaii. July 1900. (Tilden). 304. Microcoleus pulvinatus Wolle. Fresh-Water Algae U. S. 305. pi. 204. f. 10-14. 1887. De Toni. Syll. Algar. 5: 379. 1907. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. Plate VI. fig. 31. Plant mass large, cushion-like, often 1.5 dm. in diameter, about S cm. in thickness, somewhat hollow in the center, dark olive brown, gelatinous- membranaceous; filaments 12-30 mic. in diameter; trichomes 5-6 mic. in diameter, one, two or three in a sheath. New Jersey. "The thalli', of all possible sizes from one to ten inches in diameter, are attached to stones and grasses, looking like boulders in ths bottom of a mill race with rapidly running water.'' Baraber. (Wolle). 305. Microcoleus subtorulosus (Kuetzing) Gomont. Essai Class. Nosto- cacees homocystees. Morot. Journ. de Bot. 4: 352. 1890; Monogr. Oscill. 98. pi. 14. f. 14, IS. 1893. De Toni. Syll. Algar. 5: 378. 1907. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. (Ph. subtorulosum Breb.) ; Fresh- Water Algae U. S. 300. pi. 202. f. 3, 4. 1887. (Lyngbya subtorulosa (Breb.) Wolle). Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 13; 1908. Myxophyceae 159 Plate VI. fig. 32. Plant mass lead-colored, spreading over aquatic plants and damp soil; filaments somewhat amorphous, fragile; sheaths very mucous, agglutinated; trichomes 6-10 mic. in diameter, especially constricted at joints, usually numerous within the sheath, parallel, straight; apex of trichome very gradually tapering; apical cell conical or cylindrical conical, not capitate; cells S-io mic. in length; cell contents showing scattered protoplasmic granules. Florida. Moist ground. (Smith). Iowa. (Hobby). Genus CATAGNYMENE Lemmermann. Planktonalg. Ergebn. einer Reise n. d. Pacific. 354. 1899. Filaments multicellular, floating free, surrounded by thin, close sheaths, enclosed in widely expanded, gelatinous diffluent envelopes, separating easily into fragments through the death of cells. I Gelatinous envelope 93-100 mic. in diameter; trichomes up to 16 mic in diameter, straight or curved. C. pelagica II Gelatinous envelope 150-168 mic. in diameter; trichomes 20-22 mic. in diameter, spirally coiled C. spiralis 306. Catagnymene pelagica Lemmermann. Planktonalgen. Ergebnisse einer Rcise nach dem Pacific. Abhandl. d. naturw. Verein in Bremen. 16: 354- pl. 3. f. 38-40, 42. 1899; Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 619. 1905. De Toni. Syll. Algar. 5: 381. 1907. Outer envelope 93-100 mic. in diameter, gelatinous, colorless; trich- omes up to 16 mic. in diameter, straight or curved; apical cell rotund or possessing a calyptra; cells very short, 3-4 mic. in length. Hawaii. In plankton, between the islands of Laysan and Hawaii. 1896- 97. (Schauinsland). Var. major Wille. Die Schizophyceen der Plankton-Expedition. 51. pl. I. f. 7. 1904. De Toni. Syll. Algar. 5: 382. 1907. Plate VI. fig. 33. Gelatinous envelope 100-165 mic. in diameter; trichomes 21-27 mic. in diameter. Bermudas. Plankton. Atlantic Ocean. (Wille). 307. Catagnymene spiralis Lemmermann. Plaftktonalgen. Ergebnisse einer Reise nach dem Pacific. Abhandl. d. naturw. Verein in Bremen. 354. pl. 3. f. 41, 47-49. 1899; Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 619. 1905. De Toni. Syll. Algar. 5: 382. 1907. Outer envelope 150-168 mic. in diameter, gelatinous, colorless; trich- omes 20-22 mic. in diameter, spirally coiled; apical cell rotund; cells 3-4 mic. in length. Hawaii. In plankton, between the islands of Laysan and Hawaii. 1896-97. (Schauinsland). i6o Minnesota Algae According to Wille, Oscillatoria capitata West should be made a variety of this species: Var. capitata Wille. Die Schizophyceen der Plankton-Expedition. 52. pi. I. f. 8, 9. 1904. Plate VI. fig. 34- Filaments irregularly wound or twisted within an oval gelatinous en- velope; trichomes 10-14 mic. in diameter. West Indies. Lat. 23° 44' N.; long. 45° 30' W. (Murray and Black- man). Genus HALIARACHNE Lemmermann. Planktonalg. Ergebn. einer Reise n. d. Pacific. 353. 1899. Filaments multicellular, floating free, in somewhat globose or elon- gate, gelatinous colonies, arranged in two layers, radiating from the cen- ter, hooked at the apex; reproduction by division of the colony. 308. Haliarachne lenticularis Lemmermann. Planktonalgen. Ergebnisse einer Reise nach dem Pacific. Abhandl. d. naturw. Verein in Brem- en. 353. pl. 2. f. 22-24. 1899; Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 619. 1905. De Toni. Syll. Algar. 5: 385. 1907. Colony lenticular, 450-700 mic. in diameter; apical cell possessing a calyptra; cells about 8 mic. in diameter, 4-7 mic. in length; cell contents showing gas vacuoles. Hawaii. In plankton, between the islands of Lay'san and Hawaii. 1896- 97. (Schauinsland). Family II. NOSTOCACEAE Sheaths forming a more or less distinct mucous, gelatinous or mem- branaceous tegument, mostly confluent, often not present; trichomes con- sisting of a single row of uniform cells, with heterocysts, usually twisting and entangled, not branched, showing no differentiation of base and apex, reproduction by means of vegetative division, hormogones and gonidia. I. Sheaths inconspicuous, or mucous and diffluent, or gelatinous, firm and thick 1 Trichomes flexuous and contorted, forming a plant mass or colony of definite shape (i) Colony usually of a rounded or expanded character, gelati- nous, made up of dissolved individual sheaths, attached to the substratum or floating free in water; heterocysts intercalary Nostoc (2) Colony tubular, cylindrical; filaments somewhat straight, parallel, agglutinated WoUea • 2 Trichomes more or less straight, free, or forming a thin mucous layer of indefinite shape Myxophyceae i6l (i) Heterocysts and gonidia intercalary A Trichomes free; cells disc-shaped; shorter than their diameter; gonidia seriate, remote from the heterocysts Nodularia B Trichomes naked, or with a thin mucous sheath, free or ag- gregated without order to form a flocculent mass; cells equal to or longer than their diameter; gonidia solitary, in pairs or in short series Anabaena C Trichomes short, aggregated in parallel bundles to form thin, feathery, plate-like masses Aphanizomenon (2) Heterocysts terminal and the* gonidia always contiguous to them Cylindrospermum II Sheaths thin, membranaceous, persistent; filaments free or agglutinated in a parallel manner 1 Sheaths not present; trichomes single, endophytic; heterocysts termi- nal Richelia 2 Trichomes single within the sheath; heterocysts intercalary Aulosira 3 Trichomes single within the sheath; heterocysts intercalary and terminal Microchaete 4. Trichomes usually many within the sheath, forming a membranaceous or filamentous mass Hormothamnion Genus NOSTOC Vaucher. Hist. Conferves. 203. 1803. Plant mass or colony at first globose or oblong, afterwards assuming various forms (globose, foliose, filiform, buUose) in the different species, solid or hollow, mucous, gelatinous or leathery, made up of tangled trich- omes and their more or less dissolved sheaths; filaments flexuous, curved, entangled, coalesced; sheaths sometimes distinct, sometimes invisible; trichomes often torulose; cells depressed spherical, barrel-shaped or cylin- drical; heterocysts intercalary and (in younger plants) terminal; gonidia spherical or oblong, developed centrifugally in series between the hetero- cysts. I Plants living in fresh water; forming minute, disc-shaped specks or patches on aquatic plants; plant mass growing at the periphery; filaments closely contorted. N. cuticulare II Plants living in fresh water, microscopic, granular, aggregated, hav- ing the appearance of Aphanocapsa; filaments very closely en- tangled; trichomes scarcely distinct. N. punctiforme III Plants living in fresh water, very minute; trichomes 2-3.5 rnic. in diameter, distinct. I Plant mass very minute, punctiform; filaments loosely flexuous; trichomes 3-3.5 mic. in diameter; gonidia about 4 mic. in diameter, 6-8 mic. in length, oblong N. paludosum x62 Minnesota Algae 2 Plant mass small, adherent, somewhat globose; orange or green; trichomes 2-2.5 mic. in diameter, very^ short, strongly curved N. aureum 3 Plant mass small, gelatinous, membranaceous, soft, green, blue-green or brownish; trichomes 3-4 mic. in diameter, flexuously curved, somewhat densely entangled N. comminutum IV Plants living in fresh water; plant mass large, gelatinous, fragile, at first spherical, afterwards becoming torn and irregularly ex- panded. 1 Filaments numerous, abruptly contorted, entangled; trichomes 3.5-4 mic. in diameter; gonidia 6-7 mic. in diameter, 7-8 mic. in length N. linckia 2 Filaments flexuous, loosely entangled (i) Gonidia 6-7 mic. in diameter, spherical; wall of gonidium smooth; trichomes 4 mic. in diameter N. piscinale (2) Gonidia oblong; wall of gonidium smooth A Trichomes 4-4.2 mic. in diameter; gonidia 6-8 mic. in diameter, 7-10 mic. in length, contiguous; wall of gonidium becoming brownish or colorless N. rivulare B Trichomes 3.5-4 mic. in diameter; gonidia 6 mic. in diameter, 8-10 mic. in length, not contiguous; wall of gonidium colorless N. carneum C Trichomes 4 mic. in diameter; cells different in shape, some cylindrical, others barrel-shaped or spherical depressed; gonidia 6-7 mic. in diameter, 10-12 mic. in length, not contiguous; wall of gonidium colorless or becoming yellowish N. spongiaeforme V Plants living on soil; colonies gelatinous, soft, at first spherical, soon confluent and flattened, attached to soil or mosses 1 Cells cylindrical; trichomes 4 mic. in diameter; gonidia 6-8 mic. in diameter (i) Gonidia 14-19 mic. in length; wall of gonidium smooth N. ellipsosporum (2) Gonidia 8-14 mic. in length; wall of gonidium furnished with short spines N. gelatinosum 2 Cells oval, spherical or spherical depressed (i) Trichomes 3-4 mic. in diameter; gonidia 4-8 mic. in diameter, 8-12 mic. in length, oblong, in a catenate series N. muscorum (2) Trichomes 2.2-3 mic in diameter; gonidia 4 mic. in diameter, 6 mic. in length, oval N. humifusum VI Plants living on soil, sometimes submerged; colonies free, at first spherical, then expanding symmetrically or irregularly; cells somewhat globose. I Colonies gelatinous, spongy, lacunose, somewhat pellucid, green, olive or brownish; trichomes 4 mic. in diameter; gonidia 7 mic. in diame- Myxophyceae 163 ter, 7-10 mic. in length, often oval; wall of gonidium smooth, colorless N. foliaceum 2 Colonies expanded, irregular or orbicular, very thin, small, mem- branaceous, pellucid, blue-green; trichomes 4 mic. in diameter N. punctatum 3 Colonies at first spherical, afterwards becoming flattened and finally- spreading out into irregular, membranaceous sheets; surrounded by a firm outer layer; trichomes 4-5.6 mic. in diameter N. commune 4 Colonies free, spherical, becoming irregularly plicate-tuberculate, thick, solid, surrounded by a firm outer layer; trichomes 4-5 mic. in diameter; gonidia S mic. in diameter, 7 mic. in length, oval; wall of gonidium thick, smooth, becoming brownish N. sphaericum 5 Colonies spherical, finally becoming flattened, membranaceous; trich- omes 2.5-3 rnic. in diameter N. minutum 6 Plants living in hot water; colonies indefinitely expanded, laciniate; filaments 2 mic. (?) in diameter N. calidarium 7 Colonies somewhat spherical, small, very hard, sometimes soft, with surface often corrugated; trichomes 6.5-8.2 mic. in diameter N. austinii VII Plants living on soil or in fresh water; colonies spherical, surrounded by a firm outer layer. 1 Plants living on soil (i) Colonies small; trichomes 8-9 mic. in diameter; gonidia some- what spherical, two or three times larger than the cells; wall of gonidium thin, very smooth N. macrosporum (2) Colonies spherical or oblong, rarely beyond i cm. in diameter, somewhat pellucid; trichomes 5-8 mic. in diameter; gonidia 6-7 mic. in diameter, 9-15 mic. in length, oval N. microscopicum (3) Colonies small or of medium size, spherical; trichomes 4-7 mic. in diameter; gonidia 6-7 mic. in diameter, exactly spherical; wall of gonidium somewhat thick, rough N. sphaeroides 2 Plants living in fresh water (i) Colonies irregularly somewhat orbicular, gregarious and some- times aggregated; trichomes 5 mic. in diameter N. depressum (2) Colonies spherical, usually aggregated in grape-like clusters; trich- omes 3.5-4 mic. in diameter N. glomeratum (3) Colonies gregarious, pellucid, sky blue or blue-green; trichomes 5-7 mic. in diameter; cells barrel-shaped N. caeruleum (4) Colonies spherical, surrounded by a leathery outer layer; trich- omes 4-6 mic. in diameter N. pruniforme VIII Plants living in fresh water, attached; colonies somewhat spherical, bullate, rarely disc-shaped, surrounded by a firm outer layer; trich- omes slender. 164 Minnesota Algae 1 Trichomes 3-3.5 mic. in diameter, especially cylindrical; gonidia S mic. in diameter, 7 mic. in length; wall of gonidium smooth N. verrucosum 2 Trichomes 2-3 mic. in diameter, distinctly torulose; gonidia 3-4 mic. in diameter, 5-6 mic. in length; wall of gonidium smooth, brown N. amplissimutn 3 Filaments radiating from the center, flexuous, very densely twisted and entangled near the surface; trichomes 4-4.5 mic. in diameter; gonidia 4-5 mic. in diameter, 7-8 mic. in length, oval; wall of go- nidium smooth, yellowish N. parmelioides 309. Nostoc cuticulare (Brebisson) Bornet and Flahault. Revision des Nostocacees heterocystees contenues dans des principaux herbiers de France. Ann. Sci. Nat. Bot. VII. 7: 187. 1888. De Toni. Syll. Algar. s: 387. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 7. no. 308. 1897. Plant mass flattened, adnate, forming thin, orbicular, confluent, dark blue-green patches; filaments closely entangled, here and there forming denser clusters; sheaths more or less distinct, wide, gelatinous, trans- parent; trichomes 3.8-4 mic. in diameter, torulose; cells barrel-shaped, equal to or a little longer than the diameter; heterocysts barrel-shaped, equal to or a little larger than the cells; cell contents blue-green. New York. On leaves of Potamogeton. Ithaca. (Atkinson). 310. Nostoc punctiforme (Kuetzing) Harlot. Le Genre Polycoccus Kuet- zing. Morot. Journ. de Bot. 5: 29. i8gi. Reinke. Zwei parasitische Algen. Bot. Zeit. 37: 473. pi. 6. f. 1-5. 1879. (Anabaena cy- cadearum Reinke). Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot' VII. 7: 189. 1888. (N. hederulae Menegh.). Sauvageau. Sur le Nostoc punctiforme. Ann. Sci. Nat. Bot. VIII. 3: 367. pi. 17. 1897. Pampaloni. II Nostoc punctiforme nei suoi rap- porti coi Tubercoli Radicali delle Cicadee. Nuovo Giornale Bot. Ital. N. S. 8: 6z6. pi. 5. 1901. De Toni. Syll. Algar. 5: 388. 1907. Schneider. Mutualistic Symbiosis of Algae and Bacteria with Cycas revoluta. Bot. Gaz. 19: 25. pi. 3, 4. 1894. Tilden. American Algae. Cent. II. no. 171. 1896; List of Fresh-Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 27. 1898. Life. The Tuber-like Rootlets of Cycas revoluta. Bot. Gaz. 31: 265. 1901. Lemmermann. Al- genfl. Sandwich. -Inseln. Bot. Jahrb. 34: 622. 1905. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 12. 1908. Plate VI. fig. 35-37- Colonies small, somewhat globose, scattered or confluent, adnate; filaments flexuous, very densely entangled; sheaths close, transparent, mu- cous; trichomes 3-4 mic. in diameter; cells depressed spherical or elliptical; heterocysts 4-6.5 mic. in diameter, transparent; gonidia somewhat spherical or oblong, 5-6 mic. in diameter, 5-8 mic. in length, with thick, smooth, outer membrane; cell contents finely granular, light olive green. Minnesota. In roots of Cycas revoluta. University Plant House, Myxophyceae 165 Minneapolis. December 1896. (Tilden). Iowa. In nodular thickenings on the roots of Cycas revoluta. Greenhouse. Ames. (Buchanan). Hawaii. "Sandwich Islands." 1896-97. (Schauinsland). 311. Nostoc paludosum Kuetzing. Tab. Phyc. 2: i. pi. i. f. 2. 1850. Janc- zewski. Observations sur la Reproduction de quelques Nostochi- nees. 'Ann. Sci. Nat. Bot. V. 19: 125. pi. 9. f. B. 1874. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 191. 1888. De Toni. Syll. Algar. 5: 390. 1907. Plate VI. fig. 38. Lemmermann. Algenfl. Sandwich.-Inseln. 'Bot. Jahrb. 34: 621. 1905. Plant mass very minute, scarcely visible to the naked eye, punctiform, gelatinous; filaments loosely flexuous; sheaths wide, bullose; trichomes 3-3.5 mic. in diameter; cells barrel-shaped, ' equal in length to the diame- ter; heterocysts a little larger than the vegetative cells, light-colored; go- nidia 4-4.5 mic. in diameter, 6-8 mic. in length, oval, 'blue-green, with a very thin, smooth, transparent outer membrane. Hawaii. In ditches and pools between Honolulu and ' Waikiki, Oahu. 1896-97. (Schauinsland). 312. Nostoc aureum Kuetzing. Tab. Phyc. 2: i. pi. i. f. 4. 1850. De Toni. Syll. Algar. 5: 391. 1907. Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 9. 1880. Colonies small, adherent, somewhat globose, orange or green, soft, somewhat elastic, mucous within; trichomes 2-2.5 niic. in diameter, very short, strongly curved, loosely entangled, sometimes nearly straight; cells sometimes crowded, sometimes separated, often continuous, somewhat globose or oblong, blue-green; heterocysts 3-4.5 mic. in diameter, spherical, single and scattered or in series. Arctic Regions. Among mud from Floeberg, 82° 27' N. (Moss). "It must have been conveyed by currents from the land, or blown off shore with dust from a dried-up pool." — Dickie. 313. Nostoc comminutum Kuetzing. Tab. Phyc. 2: 3. pi. 10. f. 2. 1850. De Toni. Syll. Algar. 5: 393. 1908. WoUe. Fresh-Water Algae U. S. 282. 1887. Harvey. The Fresh- Water Algae of Maine.— I. Bull. Torr. Bot. Club. 15: 161. 1888. Britton. Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Plant mass small, gelatinous-membranaceous, soft, sometimes green or blue-green, sometimes becoming dull brownish; trichomes 3-4 mic. in diameter, fiexuously curved, somewhat densely entangled; cells spherical or depressed spherical, strongly compressed, closely or loosely connected; heterocysts exactly spherical, up to twice the diameter of the cells, inter- calary, rarely terminal; cell contents homogeneous, pale blue-green. United States. Floating in ditches and smaller ponds. (Wolle). Maine. Abundant in a gathering made from a pool in the Penobscot at Great Works. (Merrill). New Jersey. On pond waters, frequent. (Wolle). i65 Minnesota Algae 314. Nostoc linckia (Roth) Bornet in Bornet and Thuret. Notes Algol- ogiques. 86. pi. 18. f. 1-12. 1880. Janczewski. Observations sur la Reproduction de quelques Nostochinees. Ann. Sci. Nat. Bot. V. 19: 127. pi. 9. f. C. 1874. (N. minutissimum Jancz.). Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 192. 1888. De Toni. Syll. Algar. 5: 391. 1907. Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sand- vicensibus a Sv. Berggren 1875 reportatis. 5. 1878. (N. intricatum Menegh.). Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 89. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. 507. 1898. Bes- sey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. Setchell and Gardner. Algae of Northwest- ern America. Univ. Calif. Pub. Bot. i: 189. 1903. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 622. 1905. Plate VII. fig. I. Colonies of various sizes, sometimes punctiform, expanded, at first globose, soon becoming enlarged and finally clathrate-fenestrate and ir- regularly torn, sometimes into filiform portions, gelatinous, blue-green or violet in color, or becoming darker; filaments numerous, abruptly twisted and flexuous; sheaths distinct near the surface of the mass, within con- fluent and transparent; trichomes 3.5-4 mic. in diameter, pale gray-green; cells short, depressed globose; heterocysts S-6 mic. in diameter, somewhat spherical; gonidia 6-7 mic. in diameter, 7-8 mic. in length, somewhat glo- bose, with a smooth outer membrane becoming darker with age. Connecticut. Occurring in Lake Saltonstall, near New Haven. (Setch- ell). "It forms thickish sheets of a pale green color and very much crum- pled. Occasionally some trace of its original globular shape is preserved and it forms large imperfect bladders several inches in diameter." — Setchell. South Dakota. In clear running spring water. Roberts County. (Saunders). "At first forming small, solid spherical masses, attached to stones, weeds, etc., finally becoming detached and forming hollow, torn, warty, dark brown masses, sometimes 10 cm. in diameter." — Collins, Holden and Setchell. Nebraska. In ponds. South Bend. (Bessey). Washington. Floating, intermingled with other algae, on ponds of fresh water. Near Coupeville, Whidbey Island. (Gardner). Hawaii. With Conferva sandvicensis and other algae in ponds. Paoa Valley, Oahu. 1875. (Berggren). 315. Nostoc piscinale Kuetzing. Phyc. Gen. 208. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 194. 1888. De Toni. Syll. Algar. 5: 393. 1907. McClatchie. Proc. Southern Calif. Acad, i: 346. 1897. (N. rivulare). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 8. no. 355. 1897. Richter. Susswasseralgen aus dem Umanakdistrikt. Bib. Bot. Heft. 42. 5. 1897. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 11 11. 1903. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 622. 1905. Myxophyceae 167 Plate VII. fig. 2. Colonies at first globose, light blue-green, afterwards becoming bullose and variously tuberculate, mucous or gelatinous, dark blue-green; filaments flexuous, moderately entangled; sheaths distinct near the surface of the mass, dark-colored, those in the interior confluent, transparent; trichomes 4 mic. in diameter, pale olive green; cells depressed spherical or about twice as long as the diameter; heterocysts 4-5.6 mic. in diameter, some- what spherical or oblong; gonidia 6-7 mic. in diameter, globose, in a long- catenate series, approximate, with a smooth, transparent outer layer grown together with the sheath. Greenland. Karajak. (Richter). Canada. Pool near Bow River, Lag- gan. Alberta. July 1901. (Butler and PoUey). California. In stagnant pool. Near Pasadena. May 1896. (McClatchie). Hawaii. In ditches and pools between Honolulu and Waikiki, Oahu. 1896-97. (Schauinsland). 316. Nostoc rivulare Kuetzing. Tab. Phyc. 2: 3. pi. 10. f. 3. 1850. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 195. 1888. De Toni. Syll. Algar. 5: 395. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 189. 1903. Colonies at first globose, of various sizes, soon becoming bullate, tuberculate, hollow, then irregularly torn and perforated, lobed, fragile, at first light green, when older becoming yellowish or of various colors; filaments loosely entangled, moderately flexuous; sheaths distinct, yellow- ish at the surface of the mass, those in the interior transparent and con- fluent; trichomes 4-4.2 mic. in diameter; cells spherical oblong, a little longer than the diameter; heterocysts 5-6 mic. in diameter, oblong; go- nidia 6-8 mic. in diameter, 7-10 mic. in length, oblong or barrel-shaped, contiguous when mature, with smooth, transparent or dark-colored outer membrane. Alaska. Forming floating masses of light brown jelly in springs and pools. Near Huntville, Unalaska. (Setchell and Lawson). Washington. Near Green Lake, Seattle. (Gardner). 317. Nostoc carneum Agardh. Syst. Algar. 22. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Bot. VII. 7: 196. 1888. De Toni. Syll. Algar. s : 395- I907- Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 190. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 29. no. 1403- I907- Plate VII. fig. 3- Colonies globose when young, later bullose, tuberculate, hollow, after- wards becoming irregular in form, expanded, diffluent into a gelatinous mucus, flesh-colored, dark-colored or pale blue-green; filaments loosely entangled, moderately flexuous; sheaths indistinct, transparent; trichomes <(.S-4 mic. in diameter; cells oblong cylindrical, about twice as long as wide; heterocysts 6 mic. in diameter, oblong; gonidia 6 mic. in diameter, 8-10 i68 Minnesota Algae mic. in length, oval or elliptical, separated when mature, with a smooth, transparent thin outer membrane. Alaska. Forming brown, floating masses of jelly on surface of streams. Glacier Valley, Unalaska. (Lawson). Connecticut. Floating in a spring, in irregularly rounded masses, from the size of a pin head to S cm. in diameter. Mount Carmel. October 1907. (Graves). Washington. Green Lake, Seattle. (Gardner). 318. Nostoc spongiaeforme Agardh. Syst. Algar. 22. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 197. 1888. De Toni. Syll. Algar. 5: 397. 1907. Tilden. American Algae. Cent. I. no. 83. 1894; List of Fresh-water Algae collected in Minnesota during 1894. Minn. Bot. Stud, i: 236. 1895. Rich-^ ter. Siisswasseralgen aus dem Umanakdistrikt. Bib. Bot. 8: Heft. 42. A. 5. 1897. Tilden. Am. Alg. Century VI. no. 579. 1902. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 22. no. 1064. 1903. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 190. 1903. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 622. 190^. Tilden. American Algae. Cent. VII. Fasc. I. no. 633. 1909. Plate VII. fig. 4, 5. Colonies gelatinous, at first globose, afterwards expanded, verrucose, bullose, pale blue-green-violet, or reddish; filaments flexuous, loosely en- tangled; sheaths in the interior confluent, those near the outside of the mass more or less distinct, yellowish or dark-colored; trichomes about 4 mic. in diameter, blue-green or violet; cells different in shape, some cylin- drical, up to 7 mic. in length, others barrel-shaped or depresed-spherical; heterocysts 7-8 mic. in diameter, somewhat globose or oblong; gonidia 6-7 mic. wide, 10-12 mic. long, oblong, separated; wall of gonidium smooth, later becoming dark-colored. Greenland. Ikerasak. Very abundant. (Richter). Minnesota. Floating on surface of water in tank. State Fish Hatcheries, St. Paul. September 1894; on mosses and weeds in stagnant pond and on muddy ground. Wood- land Park, Duluth. (Tilden). Washington. Floating in a small pool of fresh water. Edge of Green Lake, Seattle. (Gardner). California. Lake Chabot, San Leandro, Alameda county. June 1902. (Osterhout and Gard- ner). Hawaii. In bogs in Nuanu, Oahu. (Schauinsland). 319 A. Nostoc ellipsosporum (Desmazieres) Rabenhorst. Fl. Eur. Algar. 2: 169. 1865. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 198. 1888. De Toni. Syll. Algar. 5: 398. 1907. Schramm and Maz6. Essai Class. Algues Guadeloupe. 29. 1865. (Hormosiphon antillarum S. and M.). Maze and Schramm. Essai Class. Algues Guadeloupe. 14. 1870-1877. (L. antillarum Crouan). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 59. 1895. Plate VII. fig. 6-10. Plant mass gelatinous, expanded, adhering by under surface, irregular- ly mammillary, reddish or dark-colored; filaments flexuous, laxly en- tangled; trichomes 4 mic. in diameter, pale blue-green or olive; cells Myxophyceae 169 similar in form, cylindrical, 6-14 mic. in length; heterocysts somewhat spherical or oblong, 6-7 mic. wide, 6-14 mic. long; gonidia 6-8 mic. in diameter, 14-19 mic. long, elliptical or oblong-cylindrical; wall of gonidia smooth, transparent or yellowish. Michigan. Growing over grass and moss, on wet clay bank, forming reddish-brown gelatinous masses, irregularly lobed and fusing into layers. Ann Arbor. September 1892. (Johnson). Minnesota. On wet rocks. Min- nehaha Falls, Minneapolis. August 1883. (Farlow). West Indies. Guade- loupe. (Maze). 319 B. Nostoc gelatinosum Schousboe in Bornet. Deuxieme Note sur les Gonidies des Lichens. Ann. Sci. Nat. Bot. V. 19: 318. 1874. Bornet and Flahault. Revis. des Nostoc. VII. 7: 199. 1888. De Toni. Syll. Algar. s: 399. 1905. Plate VII. fig. II. Colonies more than a centimeter in diameter, gelatinous, irregularly ex- panded, buUate-tubercuIate, brownish; filaments flexuous, loosely entangled; sheaths near the outside of colony distinct, those in the interior hyaline and confluent; trichomes 4 mic. in diameter; cells 5-10 mic. in length, oblong- cylindrical; heterocysts $ mic. in diameter, 6-10 mic. in length, elliptical; gonidia 6-8 mic. in diameter, 8-14 mic. in length, with truncate apices, pale brownish in color; wall of gonidium furnished with minute spines. Minnesota. With Anthoceros on bank of ditch. Near Minneapolis. September 1904. (Hillesheim). 320. Nostoc muscorum Agardh. Dispositio. Algar. Sueciae. 44. 1812. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 200. 1888. De Toni. Syll. Algar. 5: 400. 1907. Dickie. In Hooker, J. D. An Account of the Plants collected by Dr. Walker in Greenland and Arctic America, etc. Journ. Linn. Soc. Bot". 5: 86. 1861; Notes on a collection of Algae procured in Cumberland Sound by Mr. James Taylor, etc. Journ. Linn. Soc. Bot. 9: 241. 1867. Farlow. Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. Wolle. Fresh-Water Algae U. S. 282. pi. 197. f. 35. 1887. Collins. Algae of Middlesex County. 163. 1888. (Also N. collinum). Anderson and Kelsey. Common and conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 18. 1894. Tilden. American Algae. Cent. IV. no. 394. 1900. West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898-1900. Tilden. American Algae. Cent. VI. no. 580. 1902. Setchell and Gardner. Algae of North- western America. Univ. Calif. Pub. Bot. i: 190. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. mo. 1903. Collins. Algae of the Flume. Rhodora. 6: 230. 1904; Phycological Notes of the late Isaac Holden. — II. Rhodora 7: 242. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 121 1. 1905. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 11. 1908. 170 Minnesota Algae Plate VII. fig. 12-14. Plant mass gelatinous-membranaceous, irregularly expanded, adhering by under surface, tuberculose, dull olive or dark-colored; filaments flex- uous, densely entangled; trichomes 3-4 mic. in diameter, similar, olive; cells spherical or barrel-shaped, or cylindrical, about twice as long as broad; heterocysts somewhat globose, 6-7 mic. in diameter; gonidia 4-8 mic. in diameter, 8-12 mic. in length, oblong, in a catenate series, numerous; wall of gonidium smooth, yellowish. Arctic Regions. Fresh water. Port Kennedy. (Lat. 72° N.) (Walker). Alaska. Near Iliuliuk, Unalaska. July 1899; forming soft gelatinous lumps and masses of various shapes, on rocks among mosses, Amaknak Cave, Amaknak Island, Bay of Unalaska. (Setchell and Lawson). Canada. Cumberland Sound, Davis Strait. (Taylor). In brown bunches on sides of rock among moss. Just above high tide. Baird Point. Minnesota Sea- side Station, Vancouver Island, British Columbia. August 1898. (Tilden). Newfoundland. Signal Hill, St. Johns. July 1897. (Holden). Maine. On sand by roadside, near seashore, in company with Microcoleus vagi- natus Harpswell. July 1904. (Collins). New Hampshire. On mosses. Berlin Falls, near Shelburne. 1882, 1883. (Farlow). Massachusetts. Maiden swamp in Middlesex Fells, Newton. (Farlow). Minnesota. On moist ground, among mosses and liverworts. St. Louis Park, Minneapolis. October 1901. (Hone). Iowa. On the stems of mosses. Fayette. 1905. (Fink). Nebraska. On wet rocks and on the moss covering them. (Saunders). Montana. Abundant on moss under dripping rocks. (Ander- son and Kelsey). Washington. Moist ground just above high watei mark. Whidbey Island. (Gardner). West Indies. Growing on sides ot road. Fort Charlotte, St. Vincent Island. 321. Nostoc humifusum Carmichael sec. Harvey in Hooker's British Flora. 2: 399. 1833. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 201. 1888. De Toni. Syll. Algar. 5: 402. 1907. WoUe. Fresh-Water Algae U. S. 280, 282. 1887. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 269. 189s; A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898-1900. Plate VII. fig. IS. Plant mass gelatinous or mucous, irregular, of various sizes, some- times punctiform, sometimes widely expanded from the confluence of many colonies, tuberculate, olive or brownish in color, adherent on under sur- face; filaments twisted and flexuous, densely entangled; sheaths usually yellowish and distinct throughout the mass, sometimes not distinct; trich- omes 2.2-3 mic. in diameter; cells somewhat globose or twice as long as the diameter; heterocysts 3 mic. in diameter, somewhat spherical; gonidia 4 mic. in diameter, 6 mic. in length, somewhat globose or oval, with smooth and yellowish outer membrane; cell contents blue-green. Florida. Colonies "inflated even to the size of a man's head." Island of Anastatia. (Smith). West Indies. On lime-trees. Shanford Estate; on trees, summit of Trois Pitons (4500 feet), November and December Myxophyceae 171 1892; in stream, Wotten Waven, January and February 1896, Dominica. (Elliott). 322. Nostoc foliaceum Mougeot. Stirpes Vogeso-Rhenanae. Fasc. 14. no. 1372. 1854. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 202. 1888. De Toni. Syll. Algar. 5: 403. 1907. Tilden. American Algae. Cent. V. no. 485. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901; Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Station, i: 168. 1902. Plate VII. fig. 16. Plant mass gelatinous, spongy, lacunose, somewhat pellucid, green or olive, becoming brownish; filaments flexuous, entangled, pale blue- green; trichomes 4 mic. in diameter; cells spherical compressed; hetero- cysts 7 mic. in diameter, somewhat spherical; gonidia 7 mic. in diameter, 7-10 mic. in length, often oval; wall of gonidium smooth, colorless. Hawaii. In globules among mosses and liverworts on dripping cliflfs at side of road. South of Laupahoehoe, Hawaii. July 1900. (Tilden). 323. Nostoc punctatum Wood. Contr. Hist. Fresh-Water Algae North America. 32. 1874. De Toni. Syll. Algar. 5: 404. 1907. Plant mass expanded, irregular or orbicular, very thin, small, mem- branaceous, pellucid, blue-green; filaments loosely interwoven, variously curved; cells 4 mic. in diameter, globose or often elliptical, mostly pellucid in the center, loosely connected; heterocysts S mic. in diameter, terminal or intercalary. New Jersey. Damp Ground. September. (Austin). 324. Nostoc commune Vaucher. Histoire des Conferves d'eau douce. 222. pi. 16. f. I. 1803. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 203. 1888. De Toni. Syll. Algar. 5: 404- 1907. Harvey. Nereis Boreali Americana. Part III. 113, 114- Suppl. II. 134. 1858. (N. verrucosum Rabenh., N. arcticum Harv.). Dickie. Algae. Hooker. An Account of the Plants collected by Dr. Walker in Greenland and Arctic America during the Expedition of Sir Francis M'Clintock, R. N., in the Yacht "Fox." Journ. Linn. Soc. Bot. 5: 86. 1861; Notes on a Collection of Algae procured in Cumberland Sound by Mr. James Taylor, and Remarks on Arctic Species in General. Journ. Linn. Soc. Bot. 9: 240. 1867. Wood. Contr. Hist. Fresh-Water Algae North America. 32, 37. 1874. Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 8. 1880. Campbell. Plants of the Detroit River. Bull. Torn Bot. Club. 13: 93. 1886. WoUe. Fresh- Water Algae U. S. 283. pi. 197. f. 8. 1887. Bennett. Plants of Rhode Island. 114. 1888. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geo!. Surv. N. J. 2: 606. 1889. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 890. 1890. Anderson and Kelsey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Smith and Pound. Flora of the Sand Hill Region of 172 Minnesota Algae Sheridan and Cherry Counties. Bot. Surv. Nebraska. 30. 1893. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 1.7. 1894. Nelson. The Cryptogams of Wyoming. Wyoming Experiment Station. Tenth Ann. Re- port. 5. 1900. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 9. no. 403. 1898. Trelease and Saunders. Plants of Yakutat Bay. Harriman Alaska Expedition, no. 502. 1899. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3. 397. 1901. Tilden. Ameri- can Algae. Cent. V. no. 486. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901; Cent. VI. no. 581. 1902; Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Station, i: 169. 1902. Setchell and Gard- ner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 190. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 236. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1210. 1905. Lemmermann. Algenfl. Sandwich. -Inseln. Bot. Jahrb. 34: 622. 1905. Brown. Algal Periodicity in Certain Ponds and Streams. Bull. Torr. Bot. Club 35: 247. 1908. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 11. igo8. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 31. no. 1504. 1908. Plate VIII. fig. I. Plant mass gelatinous, firm, in the beginning spherical, afterwards becoming flattened, finally spreading out into undulating, folded, fleshy or membranaceous, entire or torn, often perforated sheets, leathery on the surface, blue-green, olive or brown in colorj filaments flexuous, entangled; sheaths usually brownish near the- surface of the mass, in the interior more or less distinct, often colorless; trichomes 4.5-6 mic. in diameter; cells depre'ssed spherical or barrel-shaped; heterocysts 7 mic. in diameter, somewhat spli'erical, often up to three or five in number; gonidia not known. Arctic Regions. In several localities and in various stages. From sea level up to 1000 feet. Prevoost Island; shores of Hayes Sound; Floeberg Beach; Egerton Valley. (Dickie). On naked soil in boggy ground. Assist- ance Bay, Lat. 75° 40' N. (Sutherland). Beechey Island. (Lyall). Fresh water. Port Kennedy. (Walker). Alaska. Forming thin leathery thalli of indefinite size and shape, on damp ground. Near Glacier Bay. (Saunders). Hidden Glacier, Yakutat Bay. June 1899. (Trelease). Assuming various shapes, from discoid thalli to flat expansions of considerable extent, on soil or on rocks. St. Michael. (Setchell). Iliuliuk, Unalaska. (Setchell and Lawson). Greenland. On stones in fresh water stream and pools of fresh water. Disko Island. (Lyall). Canada. Various parts of the shores of the Gulf, Cumberland Sound, Davis Strait. (Taylor). Massachu- setts. On steep wet rock near Winchester North Reservoir. June 1904. (Collins). Rhode Island. Common. (Bennett). Connecticut. On lime- stone. Road near Gaylordsville. October. (Holden). New Jersey. On wet ground, common. (Austin). Dripping rocks. Palisades, Bergen. (Wolle). Maryland. On a grassy bank in sandy s^oil. Loch Raven, Baltimore county. July 1897. (Waters). Georgia. On moist ground among various plants. Thomson, McDuffee County. August 1908. (Bartlett). Texas. On mud Myxophyceae 173 flats. Cedar Bayou, Harris County. (Ravenel). Indiana. Near Bloom- ington. (Brown). Michigan. Grosse Isle, near mouth of Detroit River. Summer of 1885. (Campbell). Minnesota. On damp ground on hillside. Mendota. October 1901. (Hillesheim and Lilley). Iowa. A very common alga in the damp margins of marshy places. Iowa City. 1880. (Hobby). Ames. (Bessey, Buchanan). Grinnell. 1904. (Fink). Eagle Grove. 1904. (Bu- chanan). Nebraska. On the ground and in shallow ponds in a pass between two wet valleys. Cherry County. July 1892. (Smith and Pound). Frequent on damp earth and in stagnant or running water. Often found covering the ground for some distance in damp places. (Saunders). Kan- sas. Attached to bare patches of soil. (Parry). Montana. "Common throughout the state. On the high foot-hills (5,000-7,000 feet), on the alkaline plains and in the valleys. In inundated places, where the water is kept warm by the sun's rays, this Nostoc grows with marvelous rapidity, and frequently attains a diameter of ten inches and a half in thickness." (Anderson and Kelsey). Wyoming. Very plentiful in small pools on ledges of rock. Telephone Canon, Albany County. April 1897. (Nelson). New Mexico. Santa Fe. (Fendler). Washington. Whidbey Island. (Gardner). Mexico. On damp soil in autumn; common after rain on dry flats. Rio Bravo (Rio Grande). (Schott). Bermudas. On the ground. Castle Point. February 1898. (Richards). West Indies. In crusts on sandy soil. Constant Spring, Jamaica. April 1893. (Humphrey). Hawaii. In dense forest. Near Halfway House, Kilauea, Hawaii. (Schauinsland). Forming gelatinous, firm, flat wrinkled masses on boards of flume (not covered by water), head of flume. (2,300 feet). Pacific Sugar Mill, Hama- kua, Hawaii. July 1900. (Tilden). Var. flagelliforme (Berkeley and Curtis) Bornet and Flahault. 1. c. 206. Wright. Plantae Texanae. no. 3809. Harvey. 1. c. 115. Wood. 1. c. 226. De Toni. 1. c. 408. Farlow, Anderson and Eaton. Algae Am.-Bor. Exsicc. no. 100. 1878. Anderson and Kelsey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 31. no. 1505. 1908. Plant mass filiform, up to 3-4 mm. in width, firm; trichomes parallel. Texas. On naked aluminous soil. San Pedro. (Wright). Montana. Very common on the alkali plains about Helena. It has the appearance of "small weather-beaten, entangled tufts of black horsehair.'' (Anderson and Kelsey). Mexico. On sandy soil. Mazapil, Zacatecas. (Lloyd). 325. Nostoc sphaericum Vaucher. Histoire des Conferves d'eau douce. 223. pi. 16. f. 2. 1803. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 208. 1888. De Toni. Syll. Algar. 5: 409. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 30. 1872. Campbell. Plants of the Detroit River. Bull. Torr. Bot. Club. 13: 93. 1886. Wolle. Fresh-Water Algae U. S. 283. pi. 197. f. 18-20. 1887. Collins. Algae of Middlesex County. 14. 1888. Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: .606. 1889. Anderson and Kel- sey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 174 Minnesota Algae i8: 144. 1891. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 269. 1895. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reser- vations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Tilden. American Algae. Cent. III. no. 291. 1898. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 16. no. 755. igoo. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Ne- braska. 5: 12. 1901. Tilden. American Algae. Cent. VI. no. 582. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 30. no. 1453. 1908. Buchanan. Notes on the Algae of Iowa. Proc. Iowa. Acad. Sci. 14: 11. igo8. Plate VIII. fig. 2. Colonies free, spherical 1-15 mm. in diameter, finally becoming ir- regularly plicate-tuberculate, thick, sometimes 6-7 cm. in diameter, solid, surrounded by a firm outer layer, olive green, yellowish or violet, be- coming brownish; filaments flexuous, densely entangled; trichomes 4 rarely 5 mic. in diameter; cells spherical compressed or barrel-shaped; heterocysts 6 mic. in diameter, somewhat spherical; gonidia 5 mic. in diaineter, 7 mic. in length, oval; wall of gonidium thick, smooth, becoming brownish. Alaska. On dripping rocks among mosses. Amaknak Island, Bay of Unalaska. (Setchell and Lawsonj. Maine. Minute colonies free, among various algae, in salt marsh pools. Harpswell. July 1905. (Collins). Massachusetts. In minute blackish or greenish rounded masses on wet rocks, near the Cascade. Melrose, Middlesex Fells. (Collins). Rhode Island. Providence. (Bennett). New Jersey. Abundant on wet rocks. (Wolle). Pennsylvania. Adhering to mosses and twigs in the water. Spring Mills, near Philadelphia. (Wood). North Carolina. On wet rocks with moss. Tryon. March 1897. (Green). Michigan. Grosse Isle. Near mouth of the Detroit River. Summer of 1885. (Campbell). Minnesota. Among mosses on cliff overhanging stream. Dalles of the St. Louis River, Fond du Lac, near Duluth. August 1901. (Tilden). Iowa. Iowa City. (Hobby). Ames. (Bessey). Nebraska. On soil in greenhouse. Lincoln. (Bessey). Montana. Damp rocks in shady ravines. (Anderson and Kel- sey). West Indies. On damp wall of dam in Sharp's River, St. Vincent. May 1892.' (Elliott). 326. Nostoc minutum Desmazieres. Plantes Cryptog. de France, ist Ed. Fasc. II. no. 50. 1831. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 209. 1888. De Toni. Syll. Algar. S: 4ii. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191, 1903. Plant mass minute, gregarious, spherical, finally becoming flattened, membranaceous, up to 10 mm. in diameter; filaments densely entangled; trichomes 2.5-3 ™'c. in diameter; cells barrel-shaped; heterocysts 4-5 mic. in diameter; gonidia unknown. Myxophyceae 175 Alaska. On dripping rocks, much mixed with other algae of a gelatinous nature. Iliuliuk, Unalaska. (Setchell and Lawson). 327. Nostoc calidarium Wood. Contr. Hist. Fresh-Water Algae North America. 34. pi. 2. f. 2. 1872. De Toni. Syll. Algar. 5: 409, 423. 1907. Plate VIII. fig. 3. Plant mass indefinitely expanded, either membranaceous coriaceous oi- gelatinous, bright or dull olive green or olive brown, irregularly and deeply sinuate, finally neatly laciniate; filaments 2 mic. (?) in diameter, unequal, sometimes flexuously curved but mostly straight and closely joined, occurring in two forms; the one small, with cylindrical cells, scattered heterocysts and diffluent sheaths, if any; the other form very large, with globose or oblong cells and heterocysts not different from the other cells. California. In hot springs. Temperature 110-120° and 124-135°. F. Benton's Spring, Owen's Valley, sixty miles southwest from Aurora. (Partz). 328. Nostoc austinii Wood. Contr. Hist. Fresh-Water Algae North Amer- ica. 27. 1872. De Toni. Syll. Algar. 5: 411. 1907. Colonies somewhat spherical, small, mostly the size of fish eggs, but reaching the diameter of nearly 4 mm., sometimes very hard, sometimes much softer, with surface often corrugated, brownish or blackish; filaments variously curved, densely entangled or distantly and loosely interwoven, greenish, brownish, lead-colored or yellowish brown; sheaths often dis- tinct in smaller colonies, those in larger ones indistinct or not visible; trichomes 6.5-8.2 mic. in diameter; cells spherical, often in pairs; hetero- cysts equal to diameter of cells or a little larger, spherical, intercalary or terminal, cell contents coarsely granular. New Jersey. Growing amidst mosses on rocks. Near Gloucester. (Austin). 329. Nostoc macrosporum Meneghini. Monographia Nostochinearum ital. 116. pi. 14. f. 2. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 209. 1888. De Toni. Syll. Algar. 5: 412. 1907. Farlow. Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. Wolle. Fresh-Water Algae U. S. 284. 1887. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. Plate VIII. fig. 4- Colonies small, solid, spherical or oblong, blue-green or olive, be- coming brownish; filaments loosely entangled, flexuously curved, or spi- rally rolled; sheaths often distinct, yellowish; trichomes 8-9 mic. in diame- ter, especially cylindrical; cells short, disc-shaped, or equalling the diame- ter in length, closely connected; heterocysts 9-10 mic. in diameter, some- what spherical; gonidia (according to Borzi) "globose, angular from mutual pressure, or globose-compressed, two or three times larger than the cells; wall of gonidium thin, very smooth"; cell contents pale blue-green or olive green. 176 Minnesota Algae New Hampshire. Mixed with other algae. The "Flume,'' Shelburne, Lake Willoughby. (Farlow). Nebraska. On pots in greenhouse. Lincoln. (Bessey). 330. Nostoc microscopicum Carmichael. Harvey in Hooker's British Flora. 5: 399. 1833. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VIL 7: 210. 1888. De Toni. Syll. Algar. 5: 413. 1907. . Harvey. Nereis Boreali-Americana. Part IIL 115. 1858. Dickie. Notes on a Collection of Algae procured in Cumberland Sound by Mr. James Taylor. Journ. Linn. Sec. Bot. 9: 241. 1867. Farlow. Notes on the Cryp- togamic Flora of the White Mountains. Appalachia. 3: 236. 1883. (N. rupestre Kg.). Harvey. The Fresh-Water Algae of Maine. L Bull. Torr. Bot. Club. 15: 161. 1888. Bennett. Plants of Rhode Island. 114. 1888. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Collins, Holden and Setch- ell. Phyc. Bor.-Am. Fasc. 6. no. 256. 1897. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 1109. 1903. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Collins. Algae of the Flume. Rhodora. 6: 230. 1904. West. West Indian Freshwater Algae. Journ. of Bot. 42: 291. 1904. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 236. 1905. Plate VIII. fig. 5- Colonies spherical or oblong, rarely beyond i cm. in diameter, soft, at first glistening, finally becoming olive or brownish; filaments loosely entangled; sheaths more or less distinct, yellowish, "contrasting with the generally uncolored jelly" (Cooke); trichomes S-8 mic. in diameter; cells somewhat spherical; heterocysts 7 mic. in diameter, somewhat spherical; gonidia 6-7 mic. in diameter, 9-15 mic. in length, oval, olive; wall of go- nidium smooth; cell contents sky blue or violet-green. Canada. On stones in a small stream. Baffin's Bay. (Sutherland). Cum- berland Sound. (Taylor). Maine. In a lake near Houlton. (Harvey). New Hampshire. On rocks. The "Flume." (Farlow). Vermont. On wet rocks. Ripton Gorge. September 1896. (Farlow). Massachusetts. On pebbles in rather shallow water. Suntaug Lake, Peabody. September 1892. (Collins). Rhode Island. Providence. (Bennett). Connecticut. Sage's Ravine, Salisbury, below First Falls. October. (Holden). New Jersey. Frequent on moist rocks. (WoUe). Washington. Floating, intermingled with other algae. Whidbey Island; Seattle. (Gardner). West Indies. On steps into reservoir. Constant Spring. April 1893. (Humphrey). "Chan- cery Lane Estate," Barbados. (Howard). 331. Nostoc sphaeroides Kuetzing. Tab. Phyc. 2: 2. pi. 4. f. i. 1850. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII 7: 212. 1888. De Toni. Syll. Algar. 5: 415. 1907. Hall. List 04 the Marine Algae growing in Long Island Sound within 20 miles of New Haven. Bull. Torr. Bot. Club. 6: 112. 1876. Collins. Algae of Middlesex County. 14. 1888. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 10. no. 454. 1898. Saunders. The Algae. Harriman Alaska Myxophyceae 'i-77 Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Colonies of medium size, spherical, green becoming bluish; trichomes 4-7 mic. in diameter, tapering at the apices; gonidia (>-^ mic. in diameter, exactly spherical, angular from mutual pressure, orange becoming brown- ish; wall of gonidium somewhat thick, rough. Alaska. Forming a soft, bluish green coating on rocks near Juneau. (Saunders). Massachusetts. Cambridge. (Farlow). Fresh Pond, Cam- bridge. (Richards). Connecticut. Pools. Whitneyville and Beaver Mead- ows. (Eaton). 332. Nostoc depressum Wood. Contr. Hist. Fresh-Water Algae North America. 30: 1872. De Toni. Syll. Algar. 5: 415. 1907. Colonies irregularly suborbicular, gregarious and sometimes aggregated, elastic, surrounded by a firm, translucent outer layer, about the size of a mustard seed or smaller, adhering to submerged mosses, blackish in color; filaments mostly loosely interwoven; sheaths not present; trichomes 3 mic. in diameter; cells spherical, generally rather closely connected, rarely distant: heterocysts, 7 mic. in diameter, rather larger than the cells. New Jersey. Attached to a brook moss, growing in a rapid rivulet in the northern part of the state. (Austin). 333. Nostoc glomeratum Kuetzing. Tab. Phyc. 2: 2. pi. 3. f. 5. 1850. De Toni. Syll. Algar. 5: 415. 1907. Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. Plate VIII. fig. 6, 7. Colonies spherical, usually aggregated in grape-like clusters, lead- colored or becoming somewhat purplish, with inconspicuous outer layer; trichomes 3.S-4 mic. in diameter, more or less densely entangled, somewhat equal in thickness; cells spherical, crowded; heterocysts ^-^.^ mic. in diameter. California. On filaments of old Cladophora. (Anderson). 334. Nostoc caeruleum Lyngbye. Hydrophytologia danica. 201. pi. 68. f. B. 1819. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 213. 1888. De Toni. Syll. Algar. 5: 416. 1907. Wood. Contr. Hist. Freshwater Algae. North America. 31. 1872 Wolle. Fresh-Water Algae U. S. 284. 1887. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Tilden. American Algae. Cent. I. no. 84. 1894; List of Fresh- Water Algae collected in Minnesota during 1894. Minn. Bot. Studies. i: 236. 1895. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1166. 1904. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 11. 1908. Plate VIII. fig. 8. Colonies very small, up to S-6 mm. in diameter, spherical, solid. 178 Minnesota Algae separate or aggregated, sometimes proliferated, surrounded by a firm, tenacious outer layer, blue-green, sky blue, or becoming brownish, pellucid; filaments densely interwoven, flexuously twisted; sheaths usually indistinct; trichomes 5-7 mic. in diameter, twisted; cells barrel-shaped; heterocysts 8-10 mic. in diameter, spherical or depressed spherical; go- nidia unknown. New Jersey. Growing attached to moss. Northern part of state. (Aus- tin). Minnesota. In small stagnant pools at edge of lake. Parker's Lake, Hennepin County. July 1894. (Tilden). Floating in great quantities. Lake Zumbra. September 1903. (Butler). Iowa. Ames. 1884. (Bessey). Washington. In a ditch of fresh water. Near Seattle. (Gardner). 335. Nostoc pruniforme (Linn.) Agardh. Dispositio Algar. Sueciae. 45. 1812. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 215. 1888. De Toni. Syll. Algar. 5: 418. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 28. 1872. Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. Rab- enhorst. Die Algen Europas. no. 2530. 1878. Twitchell. Remarks on a Variety of Nostoc pruniforme. Journ. Cin. Soc. Nat. Hist. 9: 253. 1886. Wolle. Fresh- Water Algae U. S. 284. 1887. Atwell. A Deep-Water Nos- toc. Bot. Gaz. 14: 291. 1889. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Johnson and Atwell. Fresh Water Algae. Northwestern University. Report Dept. Nat. Hist. 21. 1890. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 18. pi. i. f. 4. a, b. 1894. Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. Minn. Bot. Studies, i: 31. 1894; Amer- ican Algae. Cent. I. no. 85. 1894; List of Fresh-Water Algae collected in Minnesota during 1894. Minn. Bot. Studies, i: 236. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 58. 1895; 1. c. Fasc. 14. no. 657. 1900. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Collins. Phycological Notes of the late Isaac Holden. II. 7: 237. 1905. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 11.^ 1908. Plate VIII. fig. 9, 10. Colonies spherical, attaining the size of a hen's egg, soft and watery within, at length hollow, surrounded by a leathery outer layer, olive or dark blue-green, finally becoming brownish or blackish; filaments loosely entangled, radiating from the center; sheaths often distinct, colorless, rarely yellowish; trichomes 4-6 mic. in diameter, cells spherical compressed or a little longer than the diameter; heterocysts 6-7 mic. in diameter, somewhat spherical. Maine. (Leidy). Connecticut. In a stagnant pool connected with the lower of "Twin Lakes," mostly resting on the bottom, but attached when young to sticks, etc., growing to the diameter of about 5 cm. Salis- bury, Litchfield County. August 1895. (Holden). New Jersey. In ponds, frequent. (Wolle). Pennsylvania. In stagnant water. Bethlehem. 1877. (Wolle). Illinois. "With the first gales of November and March each year there appears upon the shore of Lake Michigan, an abundance of Myxophyceae 179 an interesting form of Nostoc. It was first observed in 1864 by Professor Oliver Marcy. Thrown out upon the shore by the waves, it appears as small, purple and green balls or thalli." (Atwell). Thrown up in extensive "windrows" on the shore of Lake Michigan. Evanston. August 1894. (John- son). Minnesota. Lake Kilpatrick. June 1893; floating free or attached to water plants in artificial lake, Minneapolis, August 1894. (Tilden). Iowa. Nodules often reaching the size of a plum. (Fink). Very small, in pool near Ontario, Ames. (Buchanan). Nebraska. In still water. (Saunders). Idaho. (Twitchell). Washington. In ditches of fresh water. Near Seattle. (Gardner). 336. Nostoc verrucosum (Linn.) Vaucher. Histoire des Conferves d'eau douce. 225. pi. 16. f. 3. 1803. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 216. 1888. De Toni. Syll. Algar. S: 419- 1907. Harvey. Nereis Boreali-Americana. Part III. 114. 1858. Dickie. Al- gae. Hooker. An Account of the Plants collected by Dr. Walker in Green- land and Arctic America during the expedition of Sir Francis M'Clintock, R. N., in the Yacht "Fox," 21 Je. i860. Journ. Linn. Soc. Bot. S: 79. 1861; Notes on a Collection of Algae procured in Cumberland Sound by Mr. James Taylor. 1. c. 9: 241. 1867. Harvey. Determinations of Algae in Rothrock's Sketch of the Flora of Alaska. Ann. Rept. Bd. Regents. Smiths. Inst, for 1867. Wood. Contr. Hist. Fresh-Water Algae North America. 28. 1874. WoUe. Fresh-Water Algae. U. S. 284. pi. 197. f. i, 2. 1887. Johnson and Atwell. Fresh Water Algae. Northwestern University. Report. Dept. Nat. Hist. 21. 1890. Anderson and Kelsey. Common and Conspicu- ous Algae of Montana. Bull. Torr, Bot. Club. 18: 144. 1891. Millspaugh. Contribution III. to the Coastal and Plain Flora of Yucatan. Field Colum- bian Museum. Bot. i : 347. 1898. Tilden. American Algae. Cent. V. no. 393. 1900. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Tilden. Collection of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. 112. 1901; American Algae. Cent. V. no. 487. 1901; Cent. VI. no. 583. 1902; Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Station, i: 170. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Brown. Algal Periodicity in Certain Ponds and Streams. Bull. Torr. Bot. Club. 35: 242, 247. 1908. Plate VIII. fig. 11-16. Colonies often gregarious, up to 10 cm. in diameter, at first solid, gelatinous, firm, spherical or rotund and plicate-undulate, afterwards be- coming hollow, vesicular, softer, and torn, when young olive-blackish, be- coming brownish green when older; filaments flexuously twisted, densely entangled near the surface; sheaths thick, often indistinct, colorless or yellowish brown; trichomas 3-3.5 mic. in diameter, especially cylindrical; cells spherical depressed, shorter than the diameter; closely connected; heterocysts 6 mic. in diameter, somewhat spherical; gonidia 5 mic. in diameter, 7 mic. in length; oval; wall of gonidium smooth, yellowish. i8o Minnesota Algae Arctic Regions. Beechey Island. (Lyall). Port Kenedy. (Walker). Alaska. Fresh water pools. Port Clarence. (Harvey). Greenland. On stones in fresh water streams; in pools of fresh water, Island of Disko. (Lyall). Canada. Freshwater. Cumberland Sound. (Taylor). Pennsyl- vania. Growing in great abundance in very cold, large, limestone spring. Centre County. Summer of 1869. (Wood). Indiana. Attached to the stone bottom of a small stream, flowing across University Campus. Jordan Branch. Bloomington. (Brown). Wisconsin. Attached to rocks in water- fall. Burkhardt. September 1899. (Tilden). Illinois. Bowmanville. July. (Johnson and Atwell). Minnesota. On rocks in falls in river. Lester River, Lester Park, Duluth. August 1901. (Tilden). Nebraska. In cul- ture in greenhouse. Lincoln. (Bessey). Montana. "Common at the Falls of the Missouri and in spring water impregnated with lime. In the fall of the year this species is torn from its hold on submerged rocks in the upper Missouri River, rises to the surface and floats to the shore in la,rge numbers. Sometimes watery, hollow specimens, the size of bantam eggs, are picked up." (Anderson and Kelsey). New Mexico. Santa Fe. (Fend- Icr). Nevada. Attached to rocks in running water. Humboldt River, Winnemucca. July 1901. (Griffiths). Mexico. "Found in the aguada Chulubmay, nine miles east of Izamal. March." (Millspaugh). West In- dies. On rocks in "Wag Water" and in a trough in running water. Castle- ton, Jamaica. April 1893. (Humphrey). Hawaii. Forming small, black, "shot-like" balls, covering sides of pools in falls and rapids. Head waters of flume (2,300 feet). Pacific Sugar Mill, Hamakua, Hawaii. July 1900. (Tilden). 337. Nostoc amplissimum Setchell. Notes on Cyanophyceae. III. Erythea. 7: so. pi. 2,' 3. f. I, 2. 1899. De Toni. Syll. Algar. 5: 421. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 12. no. SS8. 1899. Plate VIII. fig. 17-19. Colonies at first spherical, very early becoming hollow and lobulated, expanding until they become irregular, verrucose, brownish yellow sacs, measuring up to 60x30 cm.; membrane of sack of varying thickness, 2-10 mm., composed of one to several layers of jelly in which trichomes are embedded, also containing abundant small lumps of lime; filaments very numerous, arranged somewhat variously, near upper and lower surfaces much contorted, in middle more nearly horizontal and parallel; sheaths of outer filaments conspicuous, wide, brown, those of inner filaments dis- tinct, colorless, usually wanting in case of central filaments; trichomes 2-3 mic. in diameter, more or less torulose; cells 3.5-5 mic. in length, de- pressed spherical or short cylindrical; heterocysts usually about 4 mic. in diameter; gonidia 3-4 mic. in diameter, 5-6 mic. in length, ellipsoidal, usu- ally beginning to form in outer layer, wall of gonidium smooth, brown. California. On stones in streams. Near Pasadena. May 1896. (Mc- Clatchie). Floating and attached to the sides of a watering trough, sup- plied from an artesian well. Near Hollister. April 1897. (Setchell). Dr. Setchell calls attention to the fact that this is the largest species belonging to the Cyanophyceae. Myxophyceae i8i 338. Nostoc parmelioides Kuetzing. Phyc. Gen. 206. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 219. 1888. De Toni. Syll. Algar. 5: 422. 1907. Harvey. Nereis Boreali-Americana. Part III. 114, 134. 1858. (N. c r i s- t a t u m Bailey, N. Sutherland! Dickie). Schramm and Maze. Essai Class. Algues Guadeloupe. 29. 1865. (Hydrococcus guadelupensis Crouan). Maze and Schramm. Essai Class. Algues Guadeloupe. 13. 1870- 1877. (Oncobyrsa guadelupensis Crouan). Wood. Contr. Hist. Fresh-Water Algae North America. 29. 1872. N. alpinum Wood). WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877; Fresh- Water Algae U. S. 285. pi. 197. f. 33, 34. 1887. Setchell. Notes on some- Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 428. 1895. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 57. 1895. Tilden American Algae. Cent. II. no. 168. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 236. 1896. Tilden. American Algae. Cent. VI. no. 584. 1902. Plate VIII. fig. 20. Colonies attached, disc-shaped or tongue-shaped, hard, sometimes, somewhat spherical, of various sizes, up to 2 cm. in diameter; filaments •radiating from the center, somewhat straight at the center, parallel, en- tangled, those near the surface densely twisted and entangled; "sheaths of cuter filaments yellowish, distinct, those of the inner, colorless, often con- fluent; trichomes 4-4.5 mic. in diameter; cells spherical or spherical de- pressed, closely connected; heterocysts 6 mic. in diameter, somewhat spherical; gonidia 4-5 mic. in diameter, 7-8 mic. in length, oval; wall of gonidium smooth, yellowish. Canada. South side of harbor in winter quarters. Baffin's Bay. July 1851. (Sutherland). Connecticut. Attached at one point to smooth sand- stone bed of a mountain rivulet. Mt. Carmel. September 1893. (Setchell).. Goshen. August 1895. (Green). New York. In mountain rivulets, at- tached to stones under water. Near West Point. (Bailey). Crumelbow Creek, Hyde Park, New York City. (Harvey). Palisades. (Wolle). Penn- sylvania. Abundant on stones on rocky bottom of river. Susquehanna River,, at Harrisburgh. (Wolle). Near Harrisburgh. (Kelley). Wyoming. At- tached to granitic rocks in creek about four miles from the melting snovv^ which feeds the creek. (9,000 feet). North Fork, Clear Creek, Big Horn Mountains. August 1898. (Williams and Griffiths). Nevada. In cold streams. Clover Mountains. (11,000 feet). (Watson). Genus WOLLEA Bornet and Flahault. Revis. des Nostoc. 223. 1888. Plant mass or colony tubular, cylindrical, somewhat membranaceous^ soft; filaments somewhat straight, parallel or slightly curved, agglutinated; sheaths confluent; heterocysts intercalary; gonidia catenate, contiguous to- the heterocysts or remote from them. 339. WoUea saccata (Wolle) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 223. 1888. Wolle. Fresh Water Algae. IV. i82 Minnesota Algae Bull. Torr. Bot. Club. 7: 44. 1880. (Sphaerozyga saccata Wolle). Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 397. 1880. Wolle. Fresh- Water Algae N. S. 290. pi. 199. f. I. 1887. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. De Toni. Syll. Algar. 5: 432. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. i. no. 30. 1895. Plate VIII. fig, 21, 22. Colonies 2-6 mm. in diameter, up to i dm. in length, consisting of elongated, vertical, somewhat membranaceous, soft tubes, closed at the apex, cylindrical or variously constricted, more or less aggregated; trich- omes 4-5 mic. in diameter, numerous, erect, parallel or slightly curved; cells oblong or cylindrical, closely connected; heterocysts 6 mic. in diame- ter, oval or somewhat spherical, yellow or pale orange; gonidia 7 mic. in diameter, 15-22 mic. in length, numerous, cylindrical, catenate. New Jersey. At first attached, afterwards floating free. Along the shores and in the shallow water of Cranberry Pond. (Wolle). Genus NODULARIA Mertens. Jiirgens, Alg. Aquat. Dec. XV. no. 4. 1822. Filaments free; sheaths colorless, close, usually thin, mucous, some- times diffluent; trichomes more or less straight; cells short, depressed, disc-shaped; heterocysts depressed; gonidia spherical, somewhat spherical or disc-shaped, developed in series between the heterocysts; wall of go- nidium smooth. I Trichomes less than 8 mic. in diameter. 1 Filaments 4-6 mic. in diameter; gonidia 6-8 mic. in diameter, some- what spherical N. harveyana 2 Filaments 6-7 mic. in diameter; gonidia 7-10 mic. in diameter, spheri- cal depressed N. sphaerocarpa 3 Trichomes 6-8 mic. in diameter; cells short, about half as long as wide N. paludosa II Filaments more than 8 mic. in diameter. 1 Trichomes 7.5-9.5 rnic. in diameter; cells nearly as long as broad before division N. hawaiiensis 2 Filaments lo-ii mic. in diameter; gonidia 10-12 mic. in diameter, 9 mic. in length, spherical depressed, in series N. armorica 3 Filaments 8-18 mic. in diameter; gonidia 12-15 niic- in diameter, 6-10 mic. in length; somewhat spherical or elliptical N. spumigena 4 Trichomes (?) 33-38 mic. in diameter; cells short N. mainensis 340. Nodularia harveyana (Thwaites) Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i: 378. 1875. Bornet and Flahault. Revis. Myxophyceae 183 des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 243. 1888. De Toni. Syll. Algar. 5: 432. 1907. Farlow. Marine Algae New England. 31. 1881. Collins. Algae of Middlesex County. 14. 1888. Martindale. Marine Algae of the New Jer- sey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i; 92. 1889. Collins. Preliminary Lists of New England Plants. V. Marine Algae. Rhodora. 2: 42. 1900. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 21. no. 1013. 1903; Ease. 22. no. 1062. 1903. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 192. 1903. West. West Indian Fresh- water Algae. Journ. of Bot. 42: 291. 1904. Tilden. Notes on a Collection of Algae from Guatemala. Proc. Biol. Soc. Wash. 21: 155. 1908. Plate IX. fig. I, 2. Filaments 4-6 mic. in diameter, tapering at the ends, terminated by an obtuse conical cell; sheaths thin, colorless, distinct; cells before division about as long as broad or a little longer; gonidia 8 mic. in diameter, some- what spherical, yellowish brown. Maine. In a high pool, exposed to spray only. Ragged Island, Casco Bay. July 1903. (Collins). New Hampshire. (Collins). Massachusetts. Found in small quantities, mixed with Sphaerozyga, in company with Rhizoclonium. Charles River, Cambridge; also in salt marshes. (Farlow). Connecticut. (Collins). New York. Mariners' Harbor. Staten Island. (Pike). Nebraska. In ponds and running water. South Bend. (Bessey). Washingfton. On mud by the roadside. Near La Con- ner, Skagit County. May 1901. (Gardner). Central America. Associated with Phormidium valderianum. Laguna Lake, Amatitlan (3,950 feet). February 1905. (Kellerman). 341. Nodularia sphaerocarpa Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 245. 1888. De Toni. Syll. Algar. 5: 433. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 22. no. 1063. 1903. Plate IX. fig. 3. Filaments 6-j mic. in diameter, entangled; sheaths thin, colorless, finally diffluent; cells 6 mic. in diameter, 4 mic. in length; heterocysts about as large as the cells; gonidia 7-10 mic. in diameter, depressed spherical, brown- ish, two to twelve in series. California. Forming a thin layer on the moist shady side of a sandy clifif. Bolinas, Marin County. May 1903. (Gardner). 342. Nodularia paludosa Wolle. Fresh-Water Algae U. S. 291. pi. 198. f. 3, 4. 1887. De Toni. Syll. Algar. 5: 435. 1907. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 4: 24. 1896. Plate IX. fig. 4. Filaments single or in small clusters;, sheaths rarely present, soon diffluent; trichomes 6-8 mic. in diameter, nearly straight; cells short, about 184 Minnesota Algae hair as long as wide; heterocysts nearly spherical, yellowish; cell contents granular, bright blue-green. Colorado. (WoUe). Pennsylvania. (Wolle). Nebraska. In salt lake, Lincoln. According to some authorities this species may belong to Anabaena cupressaphila or to N. harveyaiia. 343. Nodularia hawaiiensis Tilden. American Algae. Cent. V. no. 484. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901. Plate IX. fig. s. Plant mass stringy, dark blue-green; sheaths not evident; trichomes 7.5-9.5 mic. in diameter; cells before division nearly as long as broad, de- pressed spherical; heterocysts 10 mic. in diameter, spherical or a little longer than broad; gonidia not known. Hawaii. In tufts attached to other algae, on reef constantly washed over by waves. Waianae, Oahu. May 1900. (Tilden). The filament has neither the distinct sheath and small diameter of that of N. harveyana nor the short Oscillatoria-like cells of N. s p u m i- g e n a, the only marine forms of Nodularia described by Bornet and Flahault. Until gonidia are found in the plant its affinities cannot be dis- covered. 344. Nodularia armorica Thuret. Notes Algologiques. 2: 122. pi. 29. 1880. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 245. 1888. De Toni. Syll. Algar. 5: 433. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 193. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 22. no. 1061. 1903. Plate IX. fig. 6. Filaments lo-ll mic. in diameter, entangled; sheaths very thin; cells compressed, one half as short as the diameter; heterocysts compressed, d little larger than the cells; gonidia 10-12 mic. in diameter, 9 mic. in length, depressed spherical, yellowish brown, arranged in series; end walls of gonidia firm, biconcave, transversely truncate. Washington. Floating on the surfaces of quiet ponds. Near Coupeville, Whidbey Island; Port Townsend. (Gardner). California. In a shallow ditch. Oakland. May 1902. (Osterhout and Gardner). 345. Nodularia spumigena Mertens in Jurgens. Algae Aquaticae. Dec. XV. no. 4. 1822. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 245. 1888. De Toni. Syll. Algar. 5: 433. 1907. Filaments entangled in a mucous mass, or scattered, sometimes float- ing free, somewhat straight or curled; sheaths sometimes thin, or in other cases quite thick; cells very short, disc-shaped, three or four times shorter than the diameter; heterocysts a little larger than the cells; Myxophyceae 185 gonidia not contiguous to the heterocysts, often numerous, yellowish brown. Var. genuina Bornet and Flahault. 1. c. 246. De Toni. 1. c. 433. Riddle. Brush Lake Algae. Ohio Nat. 5: 268. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 27. no. 1307. 1906. Filaments 8-12 mic. in diameter; gonidia usually 12 mic. in diameter, 8-9 mic. in length. Maine. Among Cladophora expansa, etc., in marsh pools. Stover's Point, Harpswell. July 1906. (Collins). Ohio. Brush Lake, Champaign County. 1902. (Riddle). Var. litorea (Kuetzing) Bornet and Flahault. 1. c. 246. De Toni. 1. c. 434- Collins. Notes on New England Marine Algae. IV. Bull. Torr. Bot. Club. 11: 130. 1884; Preliminary Lists of New England Plants. V. Marine Algae. Rhodora. 2: 42. 1900. Plate IX. fig. 7, 8. Filaments 12-16 mic. in diameter; gonidia about 14 mic. in diameter. 10 mic. in length. Maine. (Collins). New Hampshire. A few filaments among other algae in marshes. Hampton. (Collins). Massachusetts. (Collins). Var. major (Kuetzing) Bornet and Flahault. 1. c. 247. De Toni. 1. c. 435- Collins. Preliminary Lists of New England Plants V. Marine Algae. Rhodora. 2: 42. 1900. Setchell and Gardner. Algae of Northwestern Amer- ica. Univ. Calif. Pub. Bot. i: 193. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 21. no. 1012. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Filaments 12-18 mic. in diameter; gonidia 14-15 mic. in diameter, 6-7 mic. in length. Connecticut. Scattered filaments among other blue-green algae. In marsh pool. Cook's Point. (Holden). Washington. In a pond of slight- ly brackish water. Penn's Cove, near Coupeville, Whidbey Island. June 1901. (Gardner). 346. Nodularia mainensis F. L. Harvey. The Fresh-water Algae of Maine. II. Bull. Torr. Bot. Club. 16: 188. 1889. De Toni. Syll. Algar. 5: 435- 1907- Sheaths distinct but close; trichomes 33-38 mic. in diameter; cells 2-6 mic. in length; heterocysts compressed, oval, orange yellow or brownish j-ellow. Maine. Found intermingled with Vaucheria sessilis in Pushaw Stream, a tributary of the Penobscot, near Orono. July 1888. (F. L. Harvey). Genus ANABAENA Bory. Diet. Class, i: 307. 1822. Sheaths not present or when present often diffluent; trichomes equal throughout or tapering at the apices, usually rigid and fragile, sometimes 1 86 Minnesota Algae circinate, free or aggregated without order to form a flocculent mass; cells equal to or longer than their diameter; apical cells sometimes conical; heterocysts numerous and intercalary; gonidia variously disposed, sometimes solitary, sometimes lying on each side of a heterocyst, rarely in short catenate series. I Gonidia oval or spherical. 1 Gonidia oval or barrel-shaped, remote from the heterocysts in cate- nate series (i) Wall of gonidium smooth A. variabilis (2) Wall of gonidium papillose A. hallensis 2 Gonidia spherical, contiguous to heterocysts, solitary or in short series, 12-20 mic. in diameter A. sphaerica II Gonidia variously disposed, sometimes contiguous to heterocysts, some- times remote from them, cylindrical, straight or curved. 1 Trichomes usually circinate; gonidia curved, obliquely truncate at the apices (i) Gonidia 7-13 mic. in diameter, 20-50 mic. in length, curved, obliqite, inequilateral, contiguous to or rarely remote from the hetero- cysts; wall of gonidium smooth, colorless or yellowish; trich- omes 4-8 mic. in diameter A. flos-aquae (2) Gonidia 16-18 mic. in diameter, up to 30 mic. in length, curved, oblique or cylindrical, the younger ones somewhat spherical, usually remote from the heterocysts; wall of gonidium smooth, colorless; trichomes 8-14 mic. in diameter A. circinalis 2 Trichomes straight; gonidia cylindrical, straight, usually remote from the heterocysts, solitary or in series (i) Trichomes 4-5 mic. in diameter; sheaths sometimes present; go- nidia 14-17 mic. in length A. inaequalis (2) Trichomes S-8 mic. in diameter; sheaths occasionally present; gonidia 7-10 mic. in diameter, up to 30 mic. and more in length A. catenula (3) Trichomes 4.2-6 mic. in diameter; sheaths present; gonidia 6 mic. in diameter, 14-20 mic. in length A. laxa III Gonidia contiguous to heterocysts on each side, developed centripe- tally, cylindrical or somewhat cylindrical 1 Gonidia 7-12 mic. in diameter, 18-28 mic. in length, short, somewhat cylindrical, often slightly constricted in the center; apical cell con- ical A. torulosa 2 Gonidia 8-10 mic. in diameter, 20-40 mic. in length, especially cylin- drical; apical cells obtuse A. oscillarioides 3 Gonidia 15-20 mic. in diameter, 50-90 mic. in length, cylindrical or more commonly tapering slightly from the middle to the rounded ends A. bornetiana Myxophyceae 187 Species not well understood A. azollae A. confervoides A. cupressophila A. gelatinosa A. subrigida 347. Anabaena variabilis Kuetzing. Phyc. Gen. 210. 1843. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 226. 1888. De Toni. Syll. Algar. 5: 437. 1907. WoUe. Fresh-Water Algae U. S. 287. pi. 198. f. 29-32. 1887. Bennett. Plants of Rhode Island. 114. 1888. (Sp h a e r o z y g a polysperma Rab.). WoUe and Martindale. Algae. Britten's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Anderson and Kelsey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 429. 1895. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 3. no. 107. 1895. Tilden. American Algae. Cent. II. no. 169. 1896. Richter. Siisswasseralgen aus dem Umanakdistrikt. Bib. Bot. 7: Heft. 42. 5. 1897. Setchell. Notes on Cyanophyceae. III. Erythea. 7: SI. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. is. no. 709. 1900. Collins. Preliminary Lists of New England Plants. V. Marine Algae. Rhodora. 2: 41. 1900. Tilden. Collection of Algae from the Hawai- ian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901; American Al- gae. Cent. V. no. 483. 1901; American Algae. Cent. VI. no. 678. 1902; Algae Collecting in the Hawaiian Islands. Postelsia. i: 168. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 190s. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2S. no. 1209. 1905. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 622. 190S. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 31. no. 1507. 1908. (A. variabilis brachyspora Collins). Plate IX. fig. 9. Plant mass gelatinous, spreading on damp soil or floating free, dark green; sheaths usually not present; trichomes 4-6 mic. in diameter, flexuous, slightly constricted at joints; apical cell obtuse conical; cells 2.S-6 mic. in diameter, somewhat quadrate; heterocysts 6 mic. in diameter, 8 mic. in length, spherical or oval; gonidia 7-9 mic. in diameter, 8-14 mic. in length, oval, truncate at the apices, numerous in catenate series, remote from heterocysts, developed centrifugally; wall of mature gonidium smooth, yellowish brown. Greenland. Umanak. (Vanhofifen). Maine. Among various floating Algae in a warm pool above high water mark. Ragged Island, Casco Bay. July 1908. (Collins). Rhode Island. Spectacle Pond. (Bennett). Forming a brownish or bluish green, gelatinous layer on the floating leaves of Ruppia maritima, in brackish water. Watch Hill Pond, Watch Hill. September 1894. (Setchell). Connecticut. Fresh Pond. (Collins, Holden). l88 Minnesota Algae New Jersey. Fresh water. Somerset. (Setchell). In pools, Bound Brook. (Wolle). Minnesota. In stagnant water in popls made by high waves and seepage on beach. Oatka Beach. Minnesota Point, Duluth. August 1901. (Tilden). South Dakota. Artesian water into which sewage runs. Aberdeen. August 1895. (Griffiths). Floating in large light blue-green masses on the surface of a pond supplied with artesian water. September 1898. (Saunders). Montana. Common in open, muddy pools heated by the sun's glare; rising to the surface in small, frothy scummy masses. Ponds and semi-stagnant mud-bottomed parts of streams in the mountains and on the plains. June to November. (Anderson and Kelsey). Wyoming. On surface of water in ditch. Seven miles north of Lake Hotel, Yellowstone National Park. July 1896. (Tilden). Idaho. Standing water. Near Lewis- ton, Nez Perces County. (800 feet). 1896. (A. A. and E. G. Heller). Washington. In ditches and ponds. Whidbey Island; Seattle. (Gardner). California. San Francisco. (Setchell). In masses ofRuppia maritima in salt marsh pool. West Berkeley. August 1904. (Gardner). Hawaii. On bottom of irrigation ditches in sugar cane field. Water turned on about once a week. Ewa Plantation, Oahu. June 1900. (Tilden). Maluhia, Oahu. (Schauinsland). 348. Anabaena hallensis (Janczewski) Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 7: 227. 1888. De Toni. Syll. Algar. S: 440. 1907. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 12. 1901. Plate IX. fig. 10-13. Plant mass mucous, floating; sheaths gelatinous; trichomes 4-5 mic. in diameter, somewhat straight, with tapering apices; c6lls depressed spherical or somewhat quadrate; heterocysts S mic. in diameter, barrel- shaped; gonidia 7-8 mic. in diameter, 10-12 mic. in length, oblong-elliptical, truncate at the apices, usually remote from the heterocysts, developed cen- trifugally; wall of gonidium colorless, minutely papillose; cell contents granular; blue-green. Nebraska. In aquaria. Lincoln. (Bessey). 549. Anabaena sphaerica Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 228. 1888. De Toni. Syll. Algar. 5: 440. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 192. 1903. Plant mass floccose, blue-green; sheaths not distinct; trichomes 5-6 mic. in diameter, moniliform, straight, agglutinated together in parallel bundles; cells spherical or spherical-truncate; heterocysts 6-7 mic. in diameter, nearly spherical; gonidia 12 mic. in diameter, 12-18 mic. in length, spherical or somewhat oval, contiguous to heterocysts, in short series; wall of gonidium smooth, brownish yellow. Washington. Floating on the surfaces of small ponds. Whidbey Island; Port Townsend. (Gardner). Var. macrosperma Bornet and Flahault. 1. c. 228. De Toni. 1. c. 440. Myxophyceae 189 Gonidia 20 mic. in diameter, spherical. West Indies. Santa Cruz. (Hornemann). 350. Anabaena Hos-aquae (Lyngbye) Brebisson in Brebisson and Godey. Algues des Environs de Falaise. 36. 1835.- Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 228. 1888. De Toni. Syll. Algar. S: 441. 1907. WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. (Trichormus incurvus Allm.). Farlow. Notes on Fresh- Water Algae. Bot. Gaz. 8: 225. 1883. Wolle. Fresh-Water Algae U. S. 286. 1887. Bennett. Plants of Rhode Island. 114. 1888. Trelease. The "Working" of the Madison Lakes. Trans. Wis. Acad. Sci. Arts and Letters. 7: 122. pi. 10. f. 4. 1889. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Saunders. Proto- phyta-Phycophyta. Flora of Nebraska. 18. 1894. Tilden. List of Fresh- Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 27. 1898; American Algae. Cent. III. no. 292. 1898. Fanning. Observations on the Algae of the St. Paul City Water. Minn. Bot. Studies. 2: 609. pi. 45. f. 21. 1901. Tilden. American Algae. Cent. VI. no. 576. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. 1 : 192. 1903. Nelson. Observations upon some Algae which cause "Water Bloom." Minn. Bot. Studies. 3: 56. pi. 14. f. 3. 1903. Moore and Kellerman. A Method of Destroying and Preventing the Growth of Algae and Certain Pathogenic Bacteria in Water Supplies. U. S. Dept. Agric. Bureau of Plant Industry. Bull. 64. 20. 1904. Riddle. Brush Lake Algae. Ohio Nat. 5: 268. 1905. Clark. The Holophytic Plankton of Lakes Atitlan and Amatitlan, Guatemala. Proc. Biol. Soc. Wash. 21: 98. 1908. Tilden. Notes on a Collection of Algae from Guatemala. Proc. Biol. Soc. Wash-. 21: 155. igo8. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 12. 1908. Plate IX. fig. 14. Plant mass frothy, gelatinous, lubricous, floating, bluish in color; sheaths not present; trichomes 4-8 mic. in diameter, circinate; cells 6-8 mic. in length, compressed spherical; heterocysts a little wider and longer than the cells; gonidia 7-13 mic. in diameter, 20-50 mic. in length; curved, oblique, inequilateral, contiguous to or rarely remote from the heterocysts, often surrounded by a wide gelatinous sheath; wall of gonidium smooth, colorless or yellowish. Greenland. (Borgesen). Rhode Island. Very common. (Bennett). Nevy Jersey. Common on stagnant fresh water. (Wolle). District of Colum- bia. Washington. (Moore and Kellerman). Ohio. Brush Lake, Cham- paign County. Fall of 1902. (Riddle). Wisconsin. Forming a part of a greenish yellow scum which occurs every season in greater or less quantity on Third and Fourth Lakes (Mendota and Monona) during the hot weather of summer. (Trelease). Minnesota. (Farlow). Floating in abundance on surface of water. Cedar Lake, Hennepin County. October 1897. (Fanning and Humphrey). City water supply, St. Paul. (Fanning). Forming a pale, bluish green scum. Spring Park, Lake Minnetonka, Hennepin County. October 1901. (Nelson). Iowa. "One of the most common of the con- IQO Minnesota Algae stituents of the plankton of many of our lakes at some seasons of the j'ear. Occurs frequently in the sloughs in the northern part of the state also." Jenning's Pond, near Boone River; slough, Eagle Grove, 1904. (Buchanan). Nebraska. Free-swimming, membranaceous, blue-green. (Saunders). Washington. Floating in great abundance on quiet water. Lake Union, Seattle. (Gardner). Central America. Very common in all the phyto-plankton from Lake Amatitlan, Guatemala. Winter of 1905-1906. (Meek). Very abundant, collected with a surface net. Lake Amatitlan. Temperature of water TZ° ■ January 1906. (Kellerman, Meek and Smith). Var. treleasei Bornet and Flahault. 1. c. 230. De Toni. 1. c. 443. Trelease. The "Working'' of the Madison Lakes. Trans. Wis. Acad. Sci. Arts and Letters. 123. pi. 10. f. 5. 1889. (A. mendotae Trelease). Cells 4 mic. in diameter; heterocysts 5 mic. in diameter, 10 mic. in length; gonidia 6 mic. in diameter, 40 mic. in length, slightly curved. Wisconsin. Forming a copious water bloom on Lake Mendota, at Madi- son, especially abundant in the fall. (Farlow). 351. Anabaena circinalis Rabenhorst. Alg. Eur. Exsicc. no. 209. 1852. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Hot. VIL 7: 230. 1888. De Toni. Syll. Algar. 5: 443- 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 38. pi. 3. f. 5. 1874. (A. gigantea Wood). Farlow. Notes on Fresh- Water Algae. Bot. Gaz. 8: 225. 1883. (A. flos-aquae circinalis Kirchn.). Arthur. Some Algae of Minnesota supposed to be Poisonous. Bull. Minn. Acad. Nat. Sci. 2: (App.) 1-12. 1883. Bennett. Plants of Rhode Island. 114. 1888. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 18. pi. i. f. 12. 1894. Tilden. List of Fresh-Water Algae collected in Minnesota during 1894. Minn. Bot. Studies, i: 236. 1895. Jackson and EUms. On Odors and Tastes of Surface Waters, with Special Reference to Anabaena, a Microscopical Organism found in Certain Water Supplies of Massachu- setts. Review Am. Chem. Research. 8: 410. 1897. Nelson. Observations upon some Algae which cause "Water Bloom." Minn. Bot. Studies. 3: 56. pi. 14. f. 2. 1903. Moore and Kellerman. A Method of Destroying or Pre- venting the Growth of Algae and Certain Pathogenic Bacteria in Water Supplies. U. S. Dept. Agric. Bureau of Plant Industry. Bull. 64. 20. 1904. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 27. no. 1308. 1906. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 12. 1908. Plate IX. fig. IS. Plant mass frothy; sheaths often not present; trichomes 8-14 mic. in diameter, usually circinate, sometimes straight; cells a little shorter than the diameter, spherical compressed; heterocysts 8-10 mic. in diameter, somewhat spherical; gonidia 16-18 mic. in diameter, up to 30 mic. in length, curved, oblique or cylindrical, the younger ones somewhat spherical, usually remote from the heterocysts; wall of gonidium smooth, colorless. Massachusetts. Horn Pond, Woburn; South Framingham, November 1882. (Farlow). Ludlow Reservoir, Springfield. Fall of 1895. (Jackson and Ellms). Forming a scum on a small pond. Medford. June 1906. (Collins). Myxophyceae 191 Rhode Island. Providence. (Lathrop). R. W. Park. (Bennett). New York. Chautauqua Lake. (Wolle). Pennsylvania. Floating upon a brick pond, forming a part of a thick, dirty green, "pea-soup" colored, almost pulverulent scum. (Wood). District of Columbia. Washington. (Moore and Kellerman). Minnesota. Lake Tetonka, Waterville. 1882. (Arthur). Floating on a pond. Union Park, Minneapolis. August 1882. (Butler). Floating in large quantities at edge of lake. Lake Calhoun, Hennepin County. October 1894. (Tilden). Spring Park, Lake Minnetonka. October 1901. (Nelson). Iowa. Very common in the lakes. East Okoboji Lake; Upper Gar Lake. October 1904. (Buchanan). Nebraska. Gives a bluish green color to stagnant water, or in age forms a blue-green scum on the surface. (Saunders). 352. Anabaena inaequalis (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VIL 7: 231. 1888. De Toni. Syll. Algar. 5: 446. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1165. 1904. Plate IX. fig. 16. Plant mass floccose, floating or climbing to other algae, blue-green; sheaths distinct, especially around the gonidia; trichomes 4-5 mic. in diame- ter, straight, parallel, sometimes free, sometimes surrounded by a firm mucus; apex of trichome scarcely tapering; apical cell obtuse; cells spheri- cal-truncate; heterocysts 6 mic. in diameter, spherical; gonidia 6-8 mic. in diameter, 14-17 mic. in length, remote from the heterocysts, developed centrifugally, two or three in a series; wall of gonidium smooth, yellowish. California. Lake Chabot, San Leandro. June 1902. (Osterhout and Gardner). 353. Anabaena catenula (Kuetzing) Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 7: 232. 1888. De Toni. Syll. Algar. 5. 447. 1907. Wolle. Fresh- Water Algae U. S. 290. pi. 199. f. 17-24. 1887. (S p h a e r o- zyga smithii (Thw.) Wolle). Bessey. Miscellaneous Additions to the Flora of the State. Bot. Surv. Nebraska. 46. 1893. Saunders. Proto- phyta-Phycophyta. Flora of Nebraska. 18. pi. i. f. 9, 10. 1894. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. S06. 1898. Collins. Notes on Algae.— I. Rhodora. i: 10. 1899. Setchell and Gardner, Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 192. 1903. Plate IX. fig. 17- Plant mass gelatinous, floating, blue-green; sheaths difiluent in mature plants; trichomes 5-8 mic. in diameter, flexuous; apical cell rotund; cells barrel-shaped, usually a little shorter than the diameter; heterocysts 6-9 mic. in diameter, 9-13 mic. in length, somewhat spherical or oblong; gonidia --10 mic. in diameter, 16-30 mic. in length, cylindrical, often slightly con- 192 Minnesota Algae stricted in the center, with round-truncate apices, contiguous to the heterocysts or remote from them, developed centrifugally, usually in catenate series; wall of gonidium smooth, pale smoke-colored. Alaska. Floating on shallow ponds or sluggish streams. Huntville, Unalaska. (Setchell and Lawson). Glacier Valley, Unalaska. (Lawson). Maine. In a ditch just above the beach. Eagle Island, Penobscot Bay. July 1896. (Collins). Massachusetts. On dead leaves, in swamp near Bear's Den Path, Middlesex Fells; Penny Brook, Lynn Woods, July 1905. (Col- lins). Nebraska. In moist places in greenhouses. (Bessey, Saunders). Washington. Near Coupeville, Whidbey Island; Green Lake, Seattle. (Gard- ner). Hawaii. In stagnant water. Kauai. July igoo. (Tilden). Var. americana Collins. New Cyanophyceae. Erythea. 4: 119. 1896. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Ease. g. no. 207. 1896. Collins. Notes on Algae. — I. Rhodora. i: 10. 1899. De Toni. 1. c. 448. Gonidia 30-60 mic. in length, strictly cylindrical. Massachusetts. In company with other algae, forming a scum in pools and ditches. Middlesex Eells. June 1893. (Collins). 354. Anabaena laxa (Rabenhorst) A. Braun in Bornet and Flahault. Note sur le Genre Aulosira. Bull. Soc. Bot. de France. 32: 120. pi. 4. f. 2, 3. 1885; Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 233. 1888. De Toni. Syll. Algar. 5: 451. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 30. no. 1454. 1908. Plate IX. fig. 18. Sheaths colorless, scarcely conspicuous; filaments 7 mic. in diameter; trichomes 4.2-6 mic. in diameter; cells barrel-shaped, about as long as broad; gonidia 6 mic. in diameter, 14-20 mic. in length, cylindrical, with rotund apices; wall of gonidium smooth, colorless. Massachusetts. Penny Brook, Lynn Woods. July 1905. (Collins). 355. Anabaena torulosa (Carmichael) Lagerheim. Bidrag till Sveriges Algflora. Oefversigt af K. Vet.-Akad. Forhandl. 47. 1883. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 236. 1888. De Toni. Syll. Algar. 5: 455. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 42. pi., 3. f. 3. 1872. (Dolichospermum polysperma (Kg.) Wood). Far- low. Marine Algae United States. Proc. Am. Acad. Arts Sci. 10: 380. 1875. (Sphaerozyga carmichaelii Harv.) ; Report of the U. S. Fish Commission for 1875. 715. 1876; Marine Algae of New England. 30. pi. I. f. 3. 1881. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 105. 1886. Wolle. Fresh-Water Algae U. S. 289. pi. 198. f. 37, 38. 1887. (Sphaerozyga polysperma Rab.). Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888; Algae of Middlesex County. 14. 1888; Marine Algae of Nantucket. 4. 1888. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i : 92. 1889. Wolle and Martindale. Algae. Brit- ton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 18. pi. i. f. 8. 1894. Myxophyceae 193 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 8. no. 354. 1897. Col- lins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. igoo; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Plate IX. fig. 19. Plant mass mucous, thin, blue-green; trichomes 4.2-5 mic. in diameter; apical cell acute conical; cells barrel-shaped, equal to or a little shorter than the diameter; heterocysts 6 mic. in diameter, 6-10 mic. in length, some- what spherical or ovoid; gonidia 7-12 mic. in diameter, 18-28 mic. in length, short, somewhat cylindrical, often slightly constricted in the center, con- tiguous to the heterocysts, developed centripetally; wall of gonidium smooth, pale smoke-colored in mature specimens. Maine. On Z o s t e r a. Goose Creek marshes. Cape Rosier. July i8q6. (Collins). New Hampshire. (Collins). Massachusetts. On decaying algae, looking like a shining emerald-green film. Wood's Hole; Gloucester; Cambridge; salt marshes, Everett. (Farlow). Not uncommon on mud in the harbor; on decaying Zostera marina, Mattapoisett, September 1906. (Collins). Rhode Island. (Collins). Connecticut. Noank. (Far- low). On mud on margin of marsh pools. Cook's Point; on muddy sand, near high water mark, among S p a r t i n a, shore of The Gut, June. (Hol- den). New York. On decayed algae. Fort Hamilton; Greenport. (Pike). Fresh water. Somerset; in pools. Bound Brook. (Wolle). New Jersey. With other algae, forming a brownish jelly, in a poo! east of Camden. (Wood). Newark Bay. (Pike). Atlantic City. (Morse, Martindale). Ne- braska. In stagnant water, usually among other algae; also on damp earth, on flower pots, in greenhouses at the University. Lincoln. (Saunders). 356. Anabaena oscillarioides Bory. Dictionnaire Classique d'Histoire Natu- relle. i: 308. 1822. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 233. 1888. De Toni. Syll. Algar. 5: 45,1. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 40. pi. 3. f. i. a, b. 1872. (Cylindrospermum flexuosum Rab.). Wolle. Fresh-Water Algae U. S. 292. pi. 199. f. 13. 1887. Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Britton's Cata- logue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Til- den. American Algae. Cent. I. no. 87. 1894. Saunders. Protophyta-Phyco- phyta. Flora of Nebraska. 19. 1894. Tilden. List of Fresh-Water Algae collected in Minnesota during 1894. Minn. Bot. Studies, i: 236. 189s. Col- lins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Setchell. Notes on Cyanophyceae. III. Erythea. 7: 51. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 14. no. 656. 1900; Fasc. 19. no. 907. 1902. Kellerman. Proposed Algological Survey of Ohio. Ohio Nat. 2: 222. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 192. I903- Collins. Phycological Notes of the late Isaac Holden.— II. Rhodora. 7: 236. 1905. 194 Minnesota Algae Plate IX. fig. 20. Plant mass gelatinous, dark green; trichomes 4.2-6 mic. in diameter, with rotund apical cells; cells barrel-shaped, equal to the diameter in length, or a little shorter or longer; heterocysts 6-8 mic. in diameter, spherical, or 6 mic. in diameter and 10 mic. in length, ovoid; gonidia 8-10 mic. in diameter, 20-40 mic. in length, when young ovoid, finally becoming espe- cially cylindrical, solitary or in series, with rounded apices, contiguous to the heterocysts, developed centripetally; wall of gonidium smooth, in ma- ture specimens very pale soot-colored. Massachusetts. On dead leaves, in swamp near Bear's Den Path, Middle- sex Fells. (Collins). Wood's Hole. (Humphrey and Miyabe). In still water. West Falmouth. August 1896. (Humphrey). Rhode Island. Roger Williams Park. (Bennett). Connecticut. Pool below Factory Pond, Bridgeport. (Holden). New Jersey. In brackish ditches. (Wolle). Pennsylvania. "In a dark little grotto, formed by shelving rocks." Reading Railroad, just above the Flat Rock tunnel; on wet ground by a horse-trough, near west end of upper bridge at Manayunk; on banks of Schuylkill River, in vicinity of Philadelphia. (Wood). On dripping rocks and on wet ground. (Wolle). Ohio. (Kellerman). Illinois. Evanston. (Johnson). Min- nesota. Second Creek, Lake City, Wabasha County. September 1894. South Dakota. In a slough. Elm River, eight miles north of Aberdeen. May 1896. (Griffiths). Nebraska. In a small creek near Lincoln. (Saunders). Montana. Helena. (Kelsey). Washington. On moist bank near bicycle path. Madrona Park, Seattle. May 1901; floating on pools and lakes, or on moist ground, Coupeville, Whidbey Island; Port Townsend. (Gardner). California. San Francisco. (Setchell). Var. elongata (Kuetzing) Bornet and Flahault. 1. c. 236. De Toni. 1. c- 453- Tilden. American Algae. Cent. III. no. 293. 1898. Heterocysts 7-9 mic. in diameter, very long, 6-18 mic. in length; go- nidia up to 70 mic. in length. South Dakota. Floating in stagnant water on prairie. Columbia. June 1897. (Griffiths). Var. stenospora Bornet and Flahault. 1. c. 236. De Toni. 1. c. 454. Tilden. American Algae. Cent. II. no. 172. 1896; Cent. VI. no. 577. 1902. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 31. no. 1506. 1908. Trichomes more slender; apical cell acute conical; gonidia S-io mic. in diameter, 16-40 mic. in length, often two to eight in a chain; wall of go- nidium smooth, colorless. Massachusetts. Forming rather thin films on plants and boards in a ditch. Eastham. August 1908. (Collins). Minnesota. Floating on surface of shallow pool on sandy or muddy beach. Minnesota Point, Duluth. August 1901. Colorado. On aquatic plants in slowly flowing stream in swamp. Five miles southeast of Port Collins. July 1896. (Cowen). Myxophyceae 195 357- Anabaena bornetiana Collins. New Cyanophyceae. Erythea. 4: 120. 1896; in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 208. 1896. De Toni. Syll. Algar. 5: 457. 1907. Trichomes 12 mic. in diameter, straight or somewhat flexuous; cells spherical or slightly shorter than their diameter; heterocysts 13-14 mic. in diameter, 13-20 mic. in length, spherical or occasionally oblong; go- nidia 15-20 mic. in diameter, 50-90 mic. in length, cylindrical or more com- monly tapering slightly from the middle to the rounded ends, contiguous to heterocysts on each side; wall of gonidium smooth, translucent. Massachusetts. Occurring usually in isolated filaments among other al- gae in ditches and pools, often with other species of Anabaena. Maiden, Medford, Middlesex Fells. May, June 1896. (Collins). 358. Anabaena azoUae Strasburger. Das Botanische Practicum. 352. f. 124. 1884. De Toni. Syll. Algar. 5: 457. 1907. Tilden. American Algae. Cent. II. no. 170. 1896; List of Fresh-Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 27. 1898. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 16. no. 754. 1900. Sheaths not present; trichomes snake-like in shape, aggregated in small bundles; cells 5 mic. in diameter, 8 mic. in length, usually somewhat spherical or ellipsoidal, cylindrical, with rotund apices; heterocysts up to 10 mic. in diameter, oval, easily distinguished from the olive contents and polar nodules ("cellulose buttons"); cell contents lead-colored-green; go- nidia unknown. Minnesota. In chambers in the leaves of Azolla Carolinian a. University Plant House, Minneapolis. September 1896. (Tilden). Cali- fornia. Endophytic in Azolla Carolinian a, growing in pools in the bed of Los Angeles River, Los Angeles. November 1900. (Monks). 359. Anabaena confervoides Reinsch. On Fresh-Water Algae from Ker- guelen's Island. Journ. Linn. Soc. Bot. 15: 208. 1877. De Toni. Syll. Algar. 5: 461. 1907. Tilden. American Algae. Cent. V. no. 482. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901. Plate IX. fig. 21. Plant mass thin; trichomes 2.2-2.8 mic. in diameter, slender, extremely long, very straight, parallel, surrounded by a common mucus; cells very distinct, rectangular, slightly longer than broad; heterocysts a little larger than the cells, elliptical; cell contents finally granular, pale blue-green; gonidia unknown. Hawaii. Floating at edge of taro patch. Near Hauula Courthouse, Hauula, Koolauloa, Oahu. June 1900. (Tilden). 360. Anabaena cupressophila Wolle. Fresh-Water Algae U. S. 288. pi. 198. f. I, 2. 1887. De Toni. Syll. Algar. 5: 458. I907- Wolle and Martindale. Algae. Britton's Catalogue of Plants found in 196 Minnesota Algae New Jersey. Geol. Surv. N. J. 2: ^7. 1889. Plate IX. -fig. 22. Plant mass gelatinous, somewhat membranaceous, deep blue-green; filaments 7-8 mic. in diameter; sheaths delicate; trichomes moniliform, .slightly curved or nearly straight, more or less parallel; cells about half as long as wide, sometimes separated; heterocysts compressed globose, homo- geneous, brownish yellow; cell contents granular, light blue-green. New Jersey. On the trunks of trees, low down near the water's edge in swamps. (Wolle). 361. Anabaena gelatinosa Wood. Contr. Hist. Fresh-Water Algae North America. 38. pi. 2. f. 4. 1872. De Toni. Syll. Algar. 5: 461. 1907.- Plant mass gelatinous, mucous, indefinitely expanded, somewhat pellu- cid, with a brownish tinge; sheaths not present; trichomes somewhat curved, rather distant, not entangled; cells globose; heterocysts about equal to the cells in diameter, spherical or rarely oblong; cell contents homo- geneous, light golden yellow or light blue-green; gonidia spherical, termi- nal. Pennsylvania. Near Philadelphia. (.Wood). 362. Anabaena subrigida (Wood) De Toni. Syll. Algar. 5: 461. 1907. Wood. Contr. Hist. Fresh- Water Algae North America. 42. pi. 3. f. 2. 1872. (Dolichosperm um subrigidum Wood). Plant mass floating; trichomes single, straight or nearly so, very small; cells cylindrical or somewhat spherical, distinct; heterocysts cylindrical, short, single, distinct; gonidia single or in pairs, slightly constricted in the center, not contiguous to heterocysts; cell contents light green. Pennsylvania. In scum floating on ditches. Near Philadelphia. (Wood). ' ' Genus APHANIZOMENON Morren. Hist. Genre Nouv. Conf. 11: 11. 1838. Colonies thin, feathery, plate-like or spindle-shaped bundles, blue- green, floating; sheaths not present; trichomes short, tapering at the ends, agglutinated; heterocysts scattered; gonidia cylindrical, much elongated, solitary, developed sparingly between the heterocysts. 363. Aphanizomenon flos-aquae (Linn.) Ralfs. On the Nostochineae. Ann. Mag. of Nat Hist. 5: 340. pi. 9. f. 6. 1850. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 241. 1888. De Toni. Syll. Algar. $: 468. 1907. Arthur. Some Algae of Minnesota Supposed to be Poisonous. Bull. Minn. Acad. Nat. Sci. 2: (App.) i. 1883. Wolle. Fresh- Water Algae U. S. 291. pi. 198. f. 7, 8. 1887. Tilden. American Algae. Cent. II. no. 173. 1896; List of Fresh-Water Algae collected in Minnesota during 1895. Minn. Bot. Studies, i: 599. 1896. Riddle. Algae from Sandusky Bay. Ohio Nat. 3: 317. 1902. Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Myxophyceae 197 Fasc. 23. no. 1107. 1903. Nelson. Observations upon some Algae which cause "Water Bloom." Minn. Bot. Studies. 3: 53. pi. 14. f. i. 1903. Riddle. Brush Lake Algae. Ohio Nat. 5: 268. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 1359. 1907. Plate X. fig. I. Colonies small, aggregated in membranaceous flakes, fragile, blue-green; trichomes 5-6 mic. in diameter, rigid, tapering at the ends; cells somewhat quadrate, 5-15 mic. in length; heterocysts 6-7 mic. in diameter, 15-20 mic. in length, somewhat cylindrical; gonidia 7-8 mic. in diameter, 60-80 mic. in length, cylindrical, elongate, containing granular protoplasm; wall of go- nidium smooth, colorless. Massachusetts. Floating on quiet water. Medford. October 1906. (Lam- bert). Ohio. Sandusky Bay; Brush Lake. (Riddle). Plankton. Put-in-Bay, Lake Erie. (Snow). Minnesota. Lake Tetonka, Waterville. 1882. (Ar- thur). Lake of the Woods. July 1894. (MacMillan). Lake Minnetonka. 189S. (Crocker). On surface of water around edges in quiet bays during summer and early autumn. Long Lake, Hennepin County. September 1895. (Shaver and Tilden). In a shallow lake in the depressions of the Fergus Falls moraine, Fergus Falls. August 1900. (Ballard). California. Floating on Lake Chabot, San Leandro. June 1902. (Gardner). Genus CYLINDROSPERMUM Kuetzing. Phyc. Gen. 211. 1843. Plant mass expanded, indefinite, mucous; sheaths not present; trich- omes equal, short, embedded in an amorphous mucus; cells cylindrical, longer than their diameter; heterocysts terminal, solitary; gonidia devel- oped from the cell or cells next the heterocyst, generally solitary, rarely seriate. I Gonidia solitary. 1 Gonidia cylindrical, up to 40 mic. in length (i) Gonidia 10-16 mic. in diameter, 32-40 mic. in length C. stagnale (2) Gonidia 11-12 mic. in diameter, 23-24 mic. in length 1 C comatum 2 Gonidia oblong or ventricose-elliptical (i) Wall of gonidium punctate A Gonidia 10-15 mic. in diameter, 20-38 mic. in length, ventricose- elliptical; wall of mature gonidium rough, punctate C. ma jus B Gonidia 6-6.5 mic. in diameter, 16-19 inic. in length, elliptical; wall of gonidium very finely granular C. minutum (2) Wall of gonidium smooth A Gonidia 8-9 mic. in diameter, 18-20 mic. in length C. minutissimum B Gonidia 9-12 mic. in diameter, 18-20 mic. in length C. muscicola 198 Minnesota Algae C Gonidia 12-14 niic. in diameter, 20-38 mic. in length C. licheniforme II Gonidia seriate C. catenatum 364. Cylindrospermum stagnale (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 250. 1888. De Toni. Syll. Al- gar. 5: 472. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 40. pi. 2. f. 7. •1872. (C. macrospermum Kg., Anabaena stagnalis Kg.) WoUe. Fresh-Water Algae U. S. 292. pi. 199. f. 6-8. 1887. Wolle and Martindale. Algae. Britten's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Anderson and Kelsey. Common and Con- spicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 145. 1891. Tilden. List of fresh-water Algae collected in Minnesota during 1893. Minn. Bot. Studies. 1:31. 1894. (Cylindrospermum limnicola Kuetz.) Col- lins. Notes on Algae. — IV. Rhodora. 3: 289. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 856. 1901. Tilden. American Algae. Cent. V. no. 481. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901; Algae collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Sta- tion, i: 168. 1902. Kellerman. Proposed Algological Survey of Ohio. Ohio Nat. 2: 222. 1902. Clark. The Holophytic Plankton of Lakes Atit- lan and Amatitlan, Guatemala. Proc. Biol. Soc. Wash. 21: 97. 1908. Bu- chanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 12. 1908. Plate X. fig. 2. Plant mass floccose, expanded, attached or floating; trichomes 3.8-4.5 mic. in diameter, slightly constricted at joints; cells up to three or four .times longer than their diameter; heterocysts 6-7 mic. in diameter, up to 16 mic. in length, somewhat spherical, often oblong; gonidia 10-16 mic. in diameter, 32-40 mic. in length, cylindrical, with rotund apices; wall of gonidium smooth, yellowish brown; cell contents pale blue-green. Maine. Forming a dense bluish green or brownish scum on the surface of an artificial pond at the Pogy Oil Factory, Bristol, near Round Pond Village. July 1901. (Collins). New Jersey. Frequent in wet places on dead wood. (Wolle). South Carolina. "In bottom of shallow, slowly running streams, adhering to ground or fallen leaves, etc., gelatinous, green." Near Aiken. September. (Ravenel). Ohio. (Kellerman). Minnesota. Irving Chase Lake. July 1893. (Tilden). Iowa. Iowa City. (Hobby). Montana. Ponds and semi-stagnant, mud-bottomed parts of streams in the mountains and on the plains. Common throughout. June to November. (Anderson and Kelsey). Central America. On surface of water. Lake Amatitlan, Guatemala. February 1906. (Meek). Hawaii. On wet cliffs. Laupahoehoe, Hawaii. July 1900. (Tilden). 36s. Cylindrospermum comatum Wood. Contr. Hist. Fresh-Water Algae North America. 41. pi. 2. f. 1872. Wolle. Fresh-Water Algae U. S. 293. pi. 199. f. 16. 1887. Myxophyceae 199 Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 12. 1908. Plate X. fig. 3. Plant mass gelatinous, blue-green, sometimes tinged on the edges with brown; trichomes 3 mic. in diameter, flexuous, equal, intricate, not spiral; cells short cylindrical, equal to or more than twice as long as the diameter, usually separated; apical cells somewhat spherical; gonidia 10-12 mic. in diameter, 23-24 mic. in length, oblong-cylindrical, granular, yellowish brown; wall of gonidium thick, distinctly granulate; cell contents granular, pale blue-green. Canada. Growing upon the ground in the marshes which border the Niagara River, just above the Canadian Falls. (Wood). Iowa. Frequent on wet soil along brooks. Grinnell. (Fink). 366. Cylindrospermum majus Kuetzing. Phyc. Gen. 212. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 252. 1888. De Toni. Syll. Algar. 5 : 474. 1907. Collins. Algae of Middlesex County. 14. 1888. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 3. no. 106. 1895. Setchell. Notes on Cyano- phyceae. — III. Erythea. 7: 51. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 15. no. 708. 1900; Ease. 23. no. 1108. 1903. Collins. Phyco- logical Notes of the late Isaac Holden.— II. Rhodora. 7: 236. 1905. Plate X. fig. 4. Plant mass widely expanded, mucous, blackish green; trichomes 4-5 mic. in diameter, constricted at joints; cells 5-6 mic. in length, cylindrical; heterocysts a little wider than the cells, up to 10 mic. in length, oblong, pale; gonidia 10-15 mic. in diameter, 20-38 mic. in length, ventricose-ellip- tical; wall of mature gonidium rough, punctate. Maine. Not immersed, but forming gelatinous masses on steep bank above the shore. South Harpswell. July 1903. (Collins). Massachusetts. Newton. (Farlow). On walls of B. and A. R. R. tunnel. (Wood). Con- necticut. Investing grasses, Utricularia, etc., in still water. Pool below Factory Pond, Bridgeport. September 1891. (Holden). California. In a slow stream near Pasadena. (McClatchie). 367. Cylindrospermum minutum Wood. Contr. Hist. Fresh-Water Algae North America. 39. pi. 2. f. 6. 1872. De Toni. Syll. Algar. 5: 475. 1907. Wolle. Fresh-Water Algae U. S. 292. pi. 199. f. 11. 1887. (C. 1 i m n i- c o 1 a Wolle). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Bessey. Miscellaneous Additions to the Flora of the State. Bot. Surv. Nebraska. 46. 1893. Saunders. Protophyta-Phycophyta. Flora of Nebraska. 19. pi. i. f. II. 1894. Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. Minn. Bot. Studies, i: 31. 1894. 200 Minnesota Algae Plate X. fig. s- Plant mass rust-colored, gelatinous; trichomas 2.8 mic. in diameter, gen- erally curved and entangled, sometimes straight, more or less constricted at the joints; cells cylindrical; heterocysts hirsute, spherical; gonidia 6-6.5 mic. in diameter, 16-19 niic. in length, elliptical, very minutely granulate; cell contents homogeneous or granular, light blue-green. New Jersey. Forming, with other algae, a ferruginous brown, gelatinous mass, growing in a deep, shaded, very stagnant pool. Spring Garden. (Wood). In wet places on dead wood. (Wolle). Minnesota. Irving Chase Lake. July 1893. (Tilden). Nebraska. Lincoln. (Bessey). Forms light green, slimy strata on pots in greenhouse. Lincoln. (Saunders). 368. Cylindrospermum minutissimum Collins. New Cyanophyceae. Erythea. 4: 120. 1896; Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 26. no. 1256. 1905. De Toni. Syll. Algar. 5: 472. 1907. Plant mass loose, blue-green; trichomes 2-2.5 mic. in diameter, straight, not constricted at joints; cells cylindrical, very slender, 4-5 mic. in length; heterocysts 4 mic. in diameter, 7-8 mic. in length, cylindrical-oblong; go- nidia 8-9 mic. in diameter, 18-20 mic. in length; wall of gonidium smooth, translucent (in not quite ripe gonidia). Massachusetts. Among other algae 'in a scum in a ditch. Maiden. Octo- ber 1890. (Collins). 369. Cylindrospermum muscicola Kuetzing. Phyc. Germ. 173. 1845. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 254. 1888. De Toni. Syll. Algar. 5: 477. 1907. Collins. Algae of Middlesex County. 14. 1888. Tilden. American Algae. Cent. II. no. 174. 1896. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. ZT. 240. 1901. Setchell and Gardner. Algae of Northwestern Amer- ica. Univ. Calif. Pub. Bot. i: 193. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 27. no. 1306. 1906. Plate X. fig. 6. Plant mass expanded, mucous, blackish green; trichomes 3-4.7 mic. in diameter, cylindrical, slightly constricted at joints; cells 4 mic. in length; heterocysts 4 mic. in diameter, 5-7 mic. in length, oblong; gonidia 9-12 mic. in diameter, 10-20 mic. in length, oval, orange brown; wall of go- nidium smooth; cell contents pale blue-green. Maine. On steep, wet clay bank. Harpswell. July 1906. (Collins). Massachusetts. Cambridge. (Farlow). On moist ground, Medford. Septem- ber 1906. (Lambert). Washington. In a small stream of running water. Orcas Island. (Gardner). California. In slowly running water. Pasadena. December 1895; (McClatchie). West Indies. On sides of basin. Constant Spring; on sand at edge of river, Castleton, April 1893. (Humphrey). 370. Cylindrospermum licheniforme. (Bory) Kuetzing. Diagnosen und Be- merkungen. Bot. Zeit. 5: 197. 1847. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 253. 1888. De Toni. Syll. Algar. s: 476. 1907. Myxophyceae 201 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 7. no. 309. 1897. Setchell. Notes on Cyanophyceae. III. Erythea. 7: 52. 1899. Tilden. American Algae. Cent. VI. no. 575. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 193. 1903. Plant mass mucous, orbicular-confluent, finally becoming widely ex- panded, very deep blackish green; trichomes 4.2 mic. in diameter, slightly constricted at joints; cells 4-5 mic. in length; heterocysts 5-6 mic. in diame- ter, 7-12 mic. in length, oblong; gonidia 12-14 ^c. in diameter, 20-38 mic. in length, oblong or ventricose-elliptical, with truncate apices; wall of go- nidium smooth, brownish or reddish; cell contents pale blue-green. New York. Ithaca. (Atkinson). Minnesota. On stones at edge of river, near quarry. St. Louis River, Fond du Lac, near Duluth. August 1901. (Tilden). Washington. On mud or moist sand. Near Oak Harbor, Whid- bey Island; near Mt. Vernon, Skagit County; near Seattle. (Gardner). California. Growing upon a bank within reach of salt spray. Bolinas, Marin County. (Setchell). 371. Cylindrospermum catenatum Ralfs. On the Nostochineae. Ann. and Mag. of Nat. Hist. S: 338. 1850. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 254- 1888. D^ Toni. Syll. Algar. S: 477. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. 505. 1898. Collins. Notes on Algae. — I. Rhodora. i : 9. 1899. Tilden. American Al- gae. Cent. IV. no. 395. 1900. Setchell and Gardner. Algae of Northwest- ern America. Univ. Calif. Pub. Bot. i: 193. 1903. Plate X. fig. 7. Plant mass mucous, orbicular-confluent, indefinite, blackish green; trich- omes 4 mic. in diameter, constricted at joints; cells 4-5 mic. in length; heterocysts 4 mic. in diameter, 6-7 mic. in length, oblong; gonidia 7-10 mic. in diameter, 13-18 mic. in length, oblong, two to eight in series; wall of go- r.idium smooth, orange brown. Massachusetts. Forming a dark thin coating on the ground, looking as if a little black paint had been spilled and dried. On moist earth near S-^ot Pond. Middlesex Fells. August and September 1897. (Collins). Wash- ington. Floating in stagnant place in stream. Tracyton, Kitsap County. July 1898. (Tilden). Hawaii. At edge of mountain stream. Kaliuwaa Stream, Makao, Koolauloa, Oahu. June 1900. (Tilden). Genus RICHELIA Johs. Schm. Vid. Medd. Nat. Foren Kjob. 147. 1901. Sheaths not present; trjchomes single, endophytic; heterocysts solitary, situated at the base of the trichome. X72. Richelia intracellularis J. Schm. Plankton fra det Rode Hav og Adenbugten. Vid. Medd. fra. d. Nat. Foren. Kjob. 147. 1901. De Toni. Syll. Algar. 5: 480. 1907. 202 Minnesota Algae Plate X. fig. 8. Trichomes S.6-9.8 mic. in diameter, So-ioS mic. in length, short, straight or nearly straight, thickened at the apices, living as endopkytes in the cells of Rhizosoleniae styliformis; heterocysts 9.8- II. 2 mic. in diameter, spherical or somewhat spherical, single, basal; cells somewhat spherical or barrel-shaped; apical cell often a little larger than the others, somewhat spherical; cell contents finely granular, or showing a few large granules, pale blue-green. Hawaii. Plankton. On Rhizosolenia and Hemiaulus deli- catulus Lemm. (Schauinsland). Genus AULOSIRA Kirchner. Krypt. von Schles. Algen. 238. 1878. Filaments free, equal, scattered or in fascicles; sheaths membranaceous, close; cells cylindrical or barrel-shaped; heterocysts intercalary; gonidia developed at intervals between the heterocysts, remote from or contiguous to them, cylindrical, in catenate series. 373. Aulosira schauinslandii Lemmermann. Die Algenflora der Sandwich- Inseln. Bot. Jahrb. 34: 622. pi. 7. f. 9-11. 1905. De Toni. Syll. Al- gar. 5: 482. 1907. Plate X. fig. 9. Filaments lo-ii mic. in diameter, flexuous or spiral; sheaths firm, colorless; trichomes 9.5 mic. in diameter, slightly constricted at joints; apical cell hemispherical, about 8 mic. in length, containing coarse gran- ules; cells 3 mic. in length, short; heterocysts usually 9.5 mic. in diameter, II mic. in length, always intercalary, somewhat spherical or cylindrical; gonidia not known. Hawaii. On Turbinaria. Laysan. (Schauinsland). Genus MICROCHAETE Thuret. Essai Class. Nostochinees. 7. 1875. Plants small, living in fresh or salt water, aggregated into star-shaped or cushion-shaped tufts; filaments unbranched, erect, attached at the base; sheaths present; trichomes single within the sheath; heterocysts basal and intercalary; gonidia developed from the lower cells. I Plants living in fresh water; heterocysts basal and intercalary. I. Filaments 4.4-S-i mic. in diameter; sheaths colorless, wide M. tenuissima 2 Filaments 10 mic. in diameter; sheaths simple, thin, close M. tenera 3 Filaments 16-18 mic. in diameter; sheaths at first thin, later be- coming lamellose, colorless M. robusta Myxophyceae 203 H Plants living in salt water; heterocysts basal. 1 Plant mass densely caespitose; filaments 6-7 mic. in diameter, thick- ened into a bulb at the base M. grisea 2 Plant mass loosely caespitose; filaments 7-9 mic. in diameter, flex- uous, scarcely thickened at base M. vitiensis 374. Microchaete tenuissima W. and G. S. West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 269. pi. 14. f. 7-1 1. 1895. De Toni. Syll. Algar. 5: 484. 1907. West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 286. 1899. Plate X. fig. 10. Filaments 4.4-5.1 mic. in diameter, very slender, somewhat entangled, twisted; sheaths transparent, colorless, wide; trichomes 1-1.8 mic. in diameter; cells elongate, 5-16 mic. in length, the younger cells shorter and wider; heterocysts 2-2.4 ™ic. in diameter, 3.5-6.5 mic. in length, some- what quadrate or oblong, intercalary. West Indies. Amongst Symploca cuspidata on trees, summit of Trois Pitons (4,500 feet). November and December 1892; on rocks, Castle Bruce River (2,000-3,000 feet), Dominica. January and February 1896. (Elliott). 375. Microchaete tenera Thuret. Essai Class. Nostochinees. 7. 1875. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 84. 1887. De Toni. Syll. Algar. 5: 482. 1907. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 427. 1S95. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 194. 1903. Plate X. fig. II. Plant mass small, star-shaped; filaments 6-7 mic. in diameter, i mm. in length, curved at the base, slightly flexuous; sheaths thin, close, uni- form, colorless; trichomes 5 mic. in diameter; lower cells twice as long as their diameter, upper cells equal in length to their diameter; heterocysts basal, oblong, cylindrical, intercalary. Alaska. Forming gray tufts on dripping rocks. Walls of Amaknak Cave, Amaknak Island, Bay of Unalaska. (Setchell and Lawson). Con- necticut. Mixed with various, gelatinous algae, occurring upon dripping rocks near Norwich and New Haven. (Setchell). 376. Microchaete robusta Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 194. 1903. De Toni. Syll. Algar. S: 483. 1907. Plant mass forming a tuft or star-shaped cluster on water weeds; fila- ments 16-18 mic. in diameter, elongate and extremely cylindrical, decum- bent at the very base, but scarcely thickened; sheaths at first thin, later becoming lamellose, colorless; trichomes 12 mic. in diameter, composed 204 Minnesota Algae of cells which are quadrate or slightly longer than broad in the lower por- tion and shortened to one-third as long as broad in the upper part; cells 0-16 mic. in length; heterocysts basal and intercalary, the former being spherical or nearly so, while the latter are elongated and rectangular; cell contents finely granular, blue-green. Washington. In ponds of fresh water, near Seattle. (Kincaid). 377. Microchaete grisea Thuret. Essai Class. Nostochinees. 7. 1875. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 85. 1887. De Toni. Syll. Algar. 5 : 485. 1907. Collins. Notes on New England Marine Algae IV. Bull. Torr. Bot. Club. 11: 130. 1884. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 4. no. 158. 1896. Collins. Preliminary Lists of New England Plants. V. Marine Algae. Rhodora. 2: 42. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Plate X. fig. 12. Plant mass densely caespitose, tomentose, orbicular, dull green, be- coming violet when dried; filaments 6-7 mic. in diameter, i mm. in length, curved at the bulbous base, soon becoming erect, densely crowded; sheaths thin, close, continuous, colorless; trichomes 5-6 mic. in diameter; cells shorter than their diameter; heterocysts basal, hemispherical. Ceuiada. Forming patches on Fucus evanescens. Malpeque, Prince Edward Island. (Faull). Maine. On Zostera marina Goose Creek, Cape Rosier. July 1895. (Collins). Massachusetts. On an old pecten shell in company with Calothrix Crustacea. West Falmouth. (Collins). Connecticut. On stranded stump. Seaside Park. November. (Holden). 378. Microchaete vitiensis Askenasy in Bornet and Flahault. Tableau synopt. des Nostochacees filamenteuses heterocystees. 22. 1885. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 85. 1887. De Toni. Syll. Algar. S: 485. 197. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 624. 1905. Plant mass loosely caespitose, tomentose^ short; filaments 7-9 mic. in diameter, scarcely attaining i mm. in length, curved and slightly thick- ened at the base, above slightly tapering, erect, flexuous; sheaths thin, close, colorless; trichomes 5-6 mic. in diameter; cells a little shorter than their diameter; heterocysts basal. Hawaii. Growing on Liagora coarctata. Laysan. 1896-1897. (Schauinsland). Genus HORMOTHAMNION Grunow. Reise d. Freg. Novara. 31. 1867. Plant mass formed from filaments growing together in a longitudinal manner, sometimes developing as an expanded layer, sometimes erect, filiform, torn and branched, not surrounded by a common gelatinous tegu- ment; sheaths membranaceous, thin, often diffluent, colorless; trichomes Myxophyceae 205 moniliform; usually many within the sheath; heterocysts intercalary; go- nidia not known. I Plant mass floccose, entangled; trichomes 9-12 mic. in diameter. H. solutum II Plant mass erect, caespitose, resembling Symploca; trichomes 6-7 mic. in diameter H. enteromorphoi- des. 379. Hormothamnion solutum Bornet and Grunow in Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 259. 1888. De Toni. Syll. Algar. 5: 486. 1907. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 624. 1905. Plant mass floccose, entangled, mucous, green or blue-green; filaments 12-15 iti'c. in diameter, 5-6 mm. in length, soft, flaccid, free or coalesced in numerous fascicles, erect; sheaths membranaceous, firm, colorless; trichomes 9-12 mic. in diameter, constricted at joints; cells disc-shaped, depressed, three or four times shorter than their diameter; heterocysts somewhat quadrate. Hawaii. (Grunow). 380. Hormothamnion enteromorphoides Grunow. Reise seiner Majestat Fregatte Novara um die Erde. Bot. Theil. i: 31. 1867. Bornet and Thuret. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 260. 1888. De Toni. Syll. Algar. 5: 486. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 29. 1865. (S p h a e- rozyga microcoleiformis Crouan). Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. i88g. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 56. 1895. Col- lins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Vickers. Liste des Algues Marines de la Barbade. Ann. Sci. Nat. Bot. VIII. i: SS- 1905- Plate X. fig. 13. Plant mass at first mucous, confluent, agglutinated, green or blue-green, when older caespitose, formed from simple, erect, soft fascicles, rising from a prostrate base, fastigiately branched; branches tapering at the apices; filaments 7-9 mic. in diameter; sheaths mucous, colorless, delicate; trich- omes 6-7 mic. in diameter, 7-10 mic. in length. Florida. Key West, Tortugas. (Farlow). West Indies. Guadeloupe. (Duchassaing). In tufts from sandy bottom in shallow water. St. Ann's Bay. March 1893; on coral reef, Navy Island, Jamaica. July 1897. (Hum- phrey). Near Kingston, Jamaica. May 1901. (Duerden). Barbados. (Vick- ers). Family III. SCYTONEMACEAE Filaments branched; false branches formed by the perforation of the sheath by the trichome which thereupon issues as one or two long, flex- 2o6 Minnesota Algae uous branches each developing a sheath of its own; sheaths homogeneous and colorless, or lamellose and yellowish or brownish, firm, tubular; trich- omes consisting of a single row of cells, one or more included in a sheath; heterocysts and gonidia variously disposed; reproduction by means of vegetative division, homogones and gonidia. I Trichomes single within the sheath 1 Heterocysts not present; filaments free or forming felt-like masses, branched; false branches often in pairs Plectonema 2 Heterocysts present (i) False branches usually arising between two heterocysts, single or 1, in pairs; sheaths delicate or very thick, parallel, or more or less diverging towards the apex Scytonema (2) False branches usually arising in the immediate region of the heterocysts, single; sheaths somewhat thin, flexible, more or less fragile Tolypothrix II Trichomes or filaments several within the sheath. 1 Filaments straight, associated in tufts; sheaths thin; trichomes two or more within the sheath; heterocysts basal Desmonema 2 Filaments several contorted within a common tegument, associated in a gelatinous stratum; trichomes single within the sheath Diplocolon Genus PLECTONEMA Thuret. Essai Class. Nostochinees. 375, 375). 1875. Filaments free or forming felt-like masses, branched; false branches solitary or in pairs; sheaths firm, colorless or rarely yellowish orange; trichomes frequently constricted at the joints; apex of trichome straight, very rarely tapering; calyptra none. I Plants large, caespitose; trichomes 3 mic. and more in diameter. 1 Plant mass caespitose, rotund, light green; trichomes S-io ™ic. in diameter, here and there constricted at joints P. tenue 2 Plant mass caespitose, indefinite, brownish green; trichomes 11-22 mic. in diameter P. tomasinianum 3 Plant mass widely expanded, indefinite, blackish, rarely yellowish green; trichomes 28-47 ni'c. in diameter, not constricted at joints P. woUei II Plant mass very thin, not caespitose; trichomes 1-4 mic. in diameter. 1 Filaments somewhat flexuous, immersed in dead shells; trichomes .9-1.5 mic. in diameter, not constricted at joints P. terebrans 2 Filaments somewhat straight, growing among various gelatinous al- gae; trichomes 1-1.5 mic- 'n diameter P. nostocorum 3 Filaments usually strongly flexuous, densely entangled in a rose- colored membrane; trichomes i. 2-1.8 mic. in diameter P. roseolum Myxophyceae 207 . 4 Filaments long, entangled, flexuous, much branched, forming a rose- colored or reddish brown mass adhering to rocks or larger algae; trichomes 1.2-2 mic. in diameter P. golenkinianum 5 Filaments very long, entangled in dense balls; trichomes 2-2.5 mic. in diameter P. calothrichoides 6 Filaments long, flexuous, much branched, forming a black or brown- ish green mass; trichomes 2-3.5 mic in diameter P. battersii 381. Plectonema tenue Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i: 380. 1875. Gomont. Monogr. Oscill. 121. pi. i. f. 5, 6. 1893. De Toni. Syll. Algar. 5: 492. 1907. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission. 127. 1896. Plate XI, fig. I, 2. Plant mass caespitose, rotund, light green; filaments graceful, elongate, much branched; false branches usually in pairs; sheaths at first colorless and very thin, later becoming thick, and yellowish orange in color; trich- omes 5-10 mic. in diameter, here and there constricted at joints, tapering at the apex; apical cell tapering, obtuse conical; cells 2-6 mic. in length; transverse walls not granulated; cell contents finely granular, pale blue- green. Massachusetts. Spot Pond, Middlesex Fells. (Collins). 382. Plectonema tomasinianum (Kuetzing) Bornet. Les Nostocacees he- terocystees du Systema Algarum de C. Agardh (1824) et leur Synonymie actuelle. (1889). Bull. Soc. Bot. de France. 36: 155. 1889. Gomont. Monogr. Oscill. 119. 1893.. De Toni. Syll. Algar. 5: 490. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 59. pi. 8. f. 6. 1872. (Scytonema nagelii (Kg.) Wood). Rabenhorst. Die Algen Europas. no. 2493. 1877. (P. mirabile Thur.). Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 285. 1879. (Calothrix mirabilis Ag.). Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 391. 1880. Wolle. Fresh Water Algae. VII. Bull. Torr. Bot. Club. 10: 20. 1883; Fresh- Water Algae U. S. 266. pi. 181. f. 12-15. 1887. Bennett. Plants of Rhode Island. 114. 1888. (Scytonema natans Breb.). Wolle and Martin- dale. Algae. Britten's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. (Calothrix brebissonii Kg.). Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903- Plate XI. fig. 3. Plant mass caespitose, more or less expanded, brownish green or rarely dull blue-green, up to 2 cm. in height; filaments entangled, flexible, usually flexuous, repeatedly branched; false branches often in pairs, issuing in an erect, spreading or oblique manner; sheaths at first thin, colorless, with age 2o8 Minnesota Algae .becoming lamellose, yellowish brown and up to 3 mic. in thickness; trich- omes 11-22 mic. in diameter, constricted at the joints; apical cell rotund; cells 3-9 mic. in length; transverse walls sometimes granulated; cell con- tents often filled with coarse granules, blue-green. Rhode Island. Quidnessett. (Bennett). New Jersey. Frequent on stones in ponds or floating. Hammonton. (Wolle). Pennsylvania. Form- ing little dark green mats, growing attached to mosses in large spring that supplies Belief onte with water. (Wood). In spring. Bethlehem. (Wolle). Maryland. Falls of Deep Creek. (Smith). Ohio. Plankton. Lake Erie. Put-in-Bay. (Snow). Minnesota. Minneapolis. (Wolle). 383. Plectonema woUei Farlow. Remarks on some Algae found in the Water Supplies of the City of Boston. Bull. Bussey Inst. yT. 1875. Gomont. Monogr. Oscill. pi. i. f. i. 118. 1893. De Toni. Syll. Algar. S: 489. 1907. Rabenhorst. Die Algen Europas. no. 2440. 1876. (Lyngbya wollei Farlow). Farlow, Anderson and Eaton. Algae Am. Bor. Exsicc. no. 46. 3877-1889. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 279. 1879. Farlow. On some Impurities of Drinking-Water caused by Vege- table Growths. Supp. First Ann. Rep. Mass. State Bd. Health. 131. 1880. Wolle. Fresh- Water Algae U. S. 297. pi. 200. f. 6-8. 1887. Collins. Algae of Middlesex County. 14. 1888. Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Collins, Holden and Setch- ell. Phyc. Bor. -Am. Fasc. 2. no. 55. 1895. Tilden. American Algae. Cent. II. no. 177. 1896; List of Fresh-Water Algae collected in Minnesota dur- ing 1895. Minn. Bot. Studies, i : 599. 1896. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901. Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903. Collins. Phyco- logical Notes of the late Isaac Holden. — II. Rhodora. 7: 236. 1905. Plate XI, fig. 4, s. Plant mass caespitose, floating, blackish, rarely yellowish green; fila- ments woolly, entangled, fragile (in dried specimens), somewhat straight or variously curved, slightly branched; false branches solitary, rarely in pairs, issuing in an oblique manner; sheaths colorless, sometimes yellowish orange, lamellose with age, roughened in outline, up to 10 mic. in thickness; trichomes 28-47 mic. in diameter, not constricted at joints; apical cell rotund; cells 4-9 mic. in length; transverse walls not granulated; cell con- tents finely granular, blackish or blue-green. Massachusetts. Attached to stones in rivers. (Wolle). Washed ashore in large quantities. Horn Pond, Woburn; August 1890; Lake Quannapowitt, Wakefield. (Collins). Rhode Island. Providence. (Bennett). Con- necticut. Attached to stones in swift water. Housatonic River, below Great Falls, near New Milford. October 1890. (Holden). New Jersey. "The floating mass was fully ten yards long, 2-3 yards wide, a foot or more in thickness, and so densely matted, it was impossible to break through with a row-boat." In pond near Stanhope; Sussex; Lake Hopatcong, Swarts- Myxophyceae 209 wood Pond. (Wolle). Pennsylvania. Bethlehem. (Wolle). Florida. (WoUe). South Carolina. Strouds. August, October 1896. (Green). Ohio, Plankton. Lake Erie, Put-in-Bay. (Snow). Minnesota. Forming large masses, dark, nearly black in color, on surface of stagnant lake. Long Lake, Hennepin County. September 1895. (Shaver and Tilden). Central America. Nicaragua. (Agardh). West Indies. In rapid current of stream. "Roar- ing River,'' St. Ann's, Jamaica. March 1893. (Humphrey). Morant Bay. August 1894. (Pease and Butler). 384. Plectonema terebrans Bornet and Flahault. Sur quelques Plantes vivant dans le Test Calcaire des Mollusques. Bull. Soc. Bot. de France. 36: CLXIII. pi. 10. f. s, 6. 1889. Gomont. Monogr. Oscill. 123. 1893. De Toni. Syll. Algar. 5: 497. 1907. Collins. Some Perforating and other Algae on Fresh-Water Shells. Erythea. 5: 95. 1897. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 7. no. 306. 1897. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 42. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 1357. 1907. Plate XL fig. 6. Filaments slender, elongate, flexuous, branched; false branches often solitary; sheaths very thin, colorless, cylindrical; trichomes .9-1. S mic. in diameter, not constricted at joints; cells 2-6 mic. in length; apical cell ro- tund; transverse walls marked by two refringent granules; cell contents pale blue-green. Maine. In live shells of L i 1 1 o r i n a, in company with H y e 1 1 a caeSpitosa. Cape Rosier. July 1901. (Collins). Rhode Island. (Col- lins). Connecticut. In Unio shells. Twin Lakes', Salisbury, Litchfield County. August 1895. (Setchell and Holden). "Very abundant all through the shells, and when the latter were decalcified, formed a dense mat which made it rather difficult to distinguish the other algae that grew in company with it." — Collins. In marine shells with other algae. Harbor. September, October. (Holden). 585. Plectonema nostocorum Bornet in Bornet and Thuret. Notes Algolo- giques. 2: 137. 1880. Gomont. Monogr. Oscill. 122. pi. i. f. 11. 1893. De Toni. Syll. Algar. 5: 495. 1907. Collins. Notes on Algae. — III. Rhodora. 3: 133. 1901; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 240. 1901; Algae of the Flume. Rhodora. 6: 230. 1904. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1164. 1904. Lemmermann. Algenfl. Sandwich. -Inseln. Bot. Jahrb. 34: 624. 1905. Plate XL fig. 7. Filaments graceful, elongate, somewhat straight, at first much branched, later sparingly branched; false branches solitary or in pairs; sheaths color- less, very thin, cylindrical; trichomes 1-1.5 mic. in diameter, constricted at 210 Minnesota Algae joints; apical cell rotund; cells 2-2.5 mic^ in length; transverse walls not granulated. Maine. In the gelatine of a small N o s t o c, growing in a watering trough by the side of the road from Seal Harbor to Jordan Pond, Mount Desert. July 1900. (Collins). New Hampshire. In a gelatinous mass on a wet cliflf. Wanalancet Falls, Tamworth. August 1903; with other algae in masses of translucent gelatine, on walls of the "Flume," September 1904. (Collins). West Indies. Among Gloeocapsa quaternata. Bath, Jamaica. July 1900. (Pease and Butler). Hawaii. In hot water. Kilauea, Hawaii. (Schauinsland). 386. Plectonema roseolum (Richter) Gomont. Monogr. Oscill. 122. pi. i. f. 9, 10. 1893. De Toni. Syll. Algar! 5: 494. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 188. 1903. Plate XL fig. 8. Plant mass gelatinous, rose-colored, when dried becoming papery, adhering to the paper; filaments densely entangled, strongly tortuous and abundantly branched, sometimes less tortuous and sparingly branched; false branches solitary or in pairs; sheaths colorless, usually thick, firm, irregular in outline; trichomes 1.2-1.8 mic. in diameter, not constricted at joints; apical cell rotund; transverse walls marked by two protoplasmic granules; cell contents very pale rose-color. Alaska. On dripping rocks. West shore of Amaknak Island. Bay of Unalaska. (Setchell and Lawson). 387. Plectonema golenkinianum Gomont. Sur quelques Oscillariees Nou- velles. Bull. Soc. Bot. de France. 46: 35. pi. i. f. 11. 1899. De Toni. Syll. Algar. 5: 494. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 603. 1899. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rho- dora. 2: 42. 1900; Notes on Algae. — VI. Rhodora. 5: 233. 1903. Plate XL fig. 9. Forming a rose-colored or reddish brown mass, adhering to rocks or larger algae; filaments entangled, elongate, flexuous, abundantly and re- peatedly branched; false branches spreading, elongate, in pairs, more slender than the primary filament; sheaths colorless, somewhat thick; trich- omes 1.2-2 mic. in diameter, constricted at joints; apical cell rotund; cells shorter than their diameter; cell contents homogeneous, rose-colored. Maine. Forming a reddish brown coating on wet cliffs, and especially in "grottoes." Eagle Island, Penobscot Bay. July 1893. (Collins). 388. Plectonema calothrichoides Gomont. Sur quelques Oscillariees Nou- velles. Bull. Soc. Bot. de France. 46: 30. pi. i. f. 6-10. 1899. De Toni. Syll. Algar. 5: 496. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 604. 1899. Myxophyceae 211 Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rho- dora. 2: 42. 1900. Plate XI. fig. 10. In a crust formed by various blue-green algae; filaments scarcely elongate, entangled in dense balls, radial because of pressure, strongly tortuous, tapering at the apices, branched; false branches in pairs, spread- ing, often parallel; sheaths thick and orange brown in the middle portion of the filament, gradually becoming thinner and faded at the ends; trich- omes 2-2.5 m'c. in diameter, constricted at joints; apical cell rotund; cells shorter than their diameter, cell contents pale blue-green. Massachusetts. Marblehead. January 1889; with other algae, on rocks near high water mark, Nahant, June 1889. (Collins). 389. Plectonema battersii Gomont. Sur quelques Oscillariees Nouvelles. Bull. Soc. Bot. de France. 46: 36. 1899. De Toni. Syll. Algar. 5: 495. 1907. Collins. An Algologist's Vacation in Eastern Maine. Rhodora. 4: 177. 1902; Notes on Algae. — VI. Rhodora. 5: 233. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 22. no. 1060. 1903. Plant mass blackish or brownish green; filaments elongate, flexuous, abundantly and repeatedly branched; false branches usually in pairs, more slender than the main filaments; sheaths colorless, somewhat thick in the main filaments; trichomes 2-3.5 ™'c. in diameter, constricted at joints, with somewhat tapering apices; apical cell rotund; cells shorter than their diameter; cell contents homogeneous, pale blue-green. Maine. In a runway on rocks from upper pools. Brownie Island, Jones- port. July 1902; Harpswell. (Collins). Massachusetts. Marblehead Neck. August 1902. (Collins). Genus SCYTONEMA Agardh. Syst. Algar. 26. 1824. Filaments branched; false branches usually arising between two hetero- cysts, solitary or in pairs, formed by the lateral perforation of the sheath by the trichome; trichomes single within the sheath, straight; hormogones terminal, solitary; gonidia spherical or oval, observed in a few species; wall of gonidium thin, smooth. I Sheaths homogeneous or formed of parallel layers. 1 Plants living in fresh water (i) Filaments 5-8 mic. in diameter S. conchophilum (2) Filaments 12-16 mic. in diameter S. arcangelii (3) Filaments 18-24 mic. in diameter S. coactile (4) Filaments about 30 mic. in diameter S. rivulare (5) Filaments 36 mic. in diameter S. occidentale (6) Filaments 16-36 mic. in diameter S. crispum 2 Plants living in warm water (i) Filaments 16 mic. in diameter S. caldarium 212 Minnesota Algae (2) Filaments 25 mic. in diameter S. azureum 3 Plants living on soil, rocks, or bark, not submerged (i) Filaments 7-15 mic. in diameter S. hofmanni (2) Filaments 9-15 mic. in diameter S. varium (3) Filaments 12-15 mic. in diameter S. javanicum (4) Filaments 10-18 mic. in diameter S. ocellatum (5) Filaments up to 20 mic. in diameter S. intertextum (6) Filaments 15-20 mic. in diameter S. austinii (7) Filaments 15-21 mic. in diameter; cells compressed S. millei (8) Filaments 15-21 mic. in diameter; cells somewhat quadrate or elongate S. guyanense (9) Filaments 19-24 mic. in diameter S. amplum (10) Filaments 20-25 mic. in diameter S. woUeanum (11) Filaments 16-30 mic. in diameter S. stuposum II Sheaths lamellose, with diverging layers; plants usually living on soil or rocks, not submerged. 1 Filaments 10-15 ""ic. in diameter S. tolypotrichoides 2 Filaments 12-18 mic. in diameter S. flavo-viride 3 Filaments 15-21 mic. in diameter S. mirabile 4 Filaments 18-36 mic. in diameter S. myochrous 5 Filaments 40-75 mic. in diameter S. badium III Sheaths thick, lamellose, forming wings or membranaceous expan- sions (ocreae); branches in basal portion of filament issuing in pairs, those in the upper portion solitary. 1 Plants living in water (i) Plants living in salt water; filaments 28-50 mic. m diameter S. fuliginosum (2) Plants living in fresh water, on dripping rocks or submerged S. alatum 2 Plants' living on damp rocks or en bark (i) Filaments 12-16 mic. in diameter S. jimipericolum (2) Filaments 15-30 mic. in diameter S, crustaceum (3) Filaments 24-40 mic. in diameter S. densum Species not well understood S. bornetianum S. dubium S. hirtulum S. immersum S. polymorphum S. rubrum S. simplex Myxophyceae 213; 390. Scytonema conchophilum Humphrey in Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Collins, Holden and Setch- ell. Phyc. Bor.-Am. Fasc. 2. no. 52. 1895. Plant mass having the form of gray, postular roughenings on shells; filaments S-8 mic. in diameter, irregularly branched; false branches single or in pairs, with rounded apices; sheaths rather thin, deep yellow, homo- geneous, when old rough on the outside, colorless and thin at growing tips; trichomes 2.7-4.5 mic. in diameter; cells two-thirds to twice as long as. broad; heterocysts 5 mic. in diameter, spherical or slightly elongated, rarely two or three together, intercalary; cell contents pale bluish green. West Indies. On old conch shell, Mastigocoleus testarum oc- curring on inside of same shell. Port Antonio. March 1893; Kingston, Jamaica. June 1897. (Humphrey). 391. Scytonema arcangelii Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VH. S: 92. 1887. De Toni. Syll. Algar. 5: 502. 1907. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901.. Plant mass cushion-shaped, 3-4 mm. in height, expanded, gray or greenish; filaments 12-16 mic. in diameter, entangled in fascicles; false branches long, flexuous; sheaths membranaceous, thin, colorless; trichomes. 10-14 mic. in diameter; cells disc-shaped or somewhat quadrate; hetero- cysts somewhat quadrate, colorless or yellowish. West Indies. On moist rocks by spring. Castleton, Jamaica. April 1893.. (Humphrey). 392. Scytonema coactile Montagne in Kuetzing. Spec. Algar. 305. 1849. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VIL. 5: 90. 1887. De Toni. Syll. Algar. 5: 501. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 32. 1865. Maze and Schramm. Essai Class. Algues Guadeloupe. 34-36. 1870-1877. (S. c o a c- tile radians Crouan, S. elegans antillarum Crouan, T o 1 y p o- thrix guadelupensis Crouan). Murray. Catalogue of the Marine. Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. Plant mass caespitose, woolly, silky, radiately expanded, green or blue- green, up to IS cm. in diameter; filaments 18-24 mic. in diameter, 4 cm. and more in length; false branches long, erect, spreading; sheaths firm, mem- branaceous, colorless or yellowish; trichomes 12-18 mic. in diameter; cells somewhat quadrate or longer than the diameter; heterocysts somewhat rare,. somewhat quadrate. West Indies. At first attached, finally floating free in stagnant water (Perrottet, Montagne). 393. Scytonema rivulare Borzi. Morfologia e Biologia delle Alghe Fico- cromacee. Nuovo Giorn. Bot. Ital. 11: 373. 1879. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 91. 1887. De Toni. Syll. Algar. 5: 501. 1907. Tilden. American Algae. Cent. V. no. 479. 1901; Collection of Algae from the Hawaiian Islands. Haw. Almanac and Annual for 1902. iii. 1901.. 214 Minnesota Algae Plate XL fig. II, 12. Plant mass widely expanded, woolly, blackish, verging towards red; filaments about 30 mic. in diameter, sparingly branched, variously flexuous or curved; sheaths firm, close, homogeneous, "glassy," up to S mic. in thickness; cells quadrate or shorter than wide; heterocysts having the form and size of the vegetative cells, orange or yellowish; gonidia spheri- cal, blackish or lead-colored; wall of gonidium firm, smooth; cell con- tents distinctly granular, lead-colored becoming purple. Hawaii. Forming dark brownish or purplish red cushions on stones in mountain stream. Kaliawaa stream, Makao, Koolauloa, Oahu. June 1900. (Tilden). 394. Scytonema occidentale Setchell. Notes on Cyanophyceae. — III. Ery- thea. 7: 49. 1899. De Toni. Syll. Algar. 5: 503. 1907. Plate XI. fig. 13, 14. Forming tufts of a somewhat rigid consistency and of a black color; filaments 36 mic. in diameter, decumbent at base, branched; false branches 21-27 inic. in diameter, usually in pairs, erect, flexuous, free or included for a longer or shorter distance within a common sheath; sheaths thick, gelatinous, roughene'd, made up of parallel layers; trichomes 18-30 mic. in diameter; cells 9-12 mic. in length, those in the hormogones much shorter, 3 mic. in length; cell contents grayish violet. California. Growing upon bare smooth rock bed of La Jota Creek, just above the Falls, on Howell Mt., near St. Helena, Napa County. (Setchell). 395. Scytonema crispum (Agardh) Bornet. Les Nostocacees heterocystees du Systema Algarum de C. Agardh (1824) et leur Synonymic actu- elle (1889). Bull. Soc. Bot. de France. 36: 156. 1889. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 89. 1887. (S. cincinnatum Thur.) De Toni. Syll. Algar. 5 : 498. 1907. Dickie. Fresh-water Algae. Brown's Florula Discoana. Contributions to the Phyto-Geography of Greenland within the Parallels of 68° and 70° North Latitude. Trans. Bot. Soc. Edinburgh. 9: 464. 1868. (L. cincinnata Kg.) Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. Nord- stedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sandvicensibus a Sv. Berggren 1875 reportatis. 6. 1878. Wolle. Fresh Water Algae. V. Bull. Torr. Bot. Club. 8: 38. 1881; Fresh- Water Algae U. S. 254. pi. 185. f. 8-10. 1887. Johnson and Atwell. Fresh Water Algae. Northwestern Uni- versity. Report Dept. Nat. Hist. 20. 1890. Setchell. Notes on some Cyan- ophyceae of New England. Bull. Torr. Bot. Club. 22: 428. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 60. 1895; Fasc. 14. no. 655. 1900. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: 14. 1901. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Tilden. American Al- gae. Cent. V. no. 480. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Lemmer- Myxophyceae 215 mann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 624. 1905. Tilden. American Algae. Cent. VII. Fasc. i. no. 632. 1909. Plate XI. fig. IS. Plant mass caespitose, entangled, woolly, green, becoming brown or olive; filaments 16-36 mic. in diameter, 3 cm. and more in length, curled, branched; sheaths firm, membranaceous, colorless, rarely becoming brown- ish; trichomes 14-30 mic. in diameter; cells three times shorter than their diameter; heterocysts depressed or quadrate, sometimes numerous, some- times almost none. Greenland. Abundant in "Lyngemarken Spring, September." (Dickie). Rhode Island. In abundance near Providence. (Osterhout). Connecticut. Near Lanesville; on rock below Factory Pond; ditch at North Haven. September, November. (Holden). Forming extensive dark green woolly masses in stagnant water. North Haven. October 1891. (Setchell). Penn- sylvania. In a pond near Bethlehem. (Wolle). Florida. (Coe). Illinois. Lakeside, Cook County. May (Johnson and Atwell). Minnesota. Lily Lake, near Stillwater, Washington County. August 1908. (Tilden). Ne- braska. In ponds. Nebraska City. (Bessey). Colorado. (Brandegee). West Indies. In reservoir. Botanic Garden, Castleton, Jamaica; on sides of trough, Constant Spring; in basin, Kingston. April 1893. (Humphrey). Hawaii. In ponds. Nuanu, Oahu. (Berggren). Floating in mats on surface of stagnant water among roots of Water Hyacinth, on beach. Meheiwa, Makao, Koolauloa, Oahu. June 1900. (Tilden). "The filaments vary very much. Sometimes both branches and hetero- cysts are rare and the species looks very much like a Lyngbya, very often the scanty branches occur single and adjacent to a heterocyst and it resembles greatly a Tolypothrix, while the geminate branches mid- way between two heterocysts, characteristic of Scytonema are generally found only after long and careful search." — Setchell. 396. Scytonema caldarium Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 48. pi. 3. f. 3. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 12. no. 559. 1899. Plate XII. fig. I. Plant mass forming more or less extended tufts; filaments 16 mic. in diameter, decumbent or even horizontal at base, more or less entangled, branched; false branches in pairs, erect, twisted together into Symploca- like tufts, 8-lS mm. high; erect filaments 12-16 mic. in diameter, seldom or only singly branched; sheaths firm, lamellose, with parallel layers, colorless, soon becoming a deep yellowish brown; trichomes 4-8 mic. in diameter; cells 3-12 mic. in length; heterocysts discoid to quadrate in the younger portions of the filaments, cylindrical in older portions, colorless; cell con- tents uniformly coarsely granular, olive or yellowish green. California. Growing on cooler portions of the rocks from which the hot water drips. Temperature of the tufts 27° C. Waterman Hot Springs, near San Bernadino. April 1897. (Parish). 2i6 Minnesota Algae .397. Scytonema azureum Tilden. American Algae. Cent. VII. Fasc. i. no. 630. 1909. Plate XII. fig. 2, 3. Filaments 25 mic. in diameter, flexuous, sparingly branched; false branches usually in pairs, occasionally originating at the heterocysts as in Tolypothrix; sheaths narrow, straight, smooth; trichomes 17 mic. in diameter, often constricted at joints; cells quadrate or shorter than broad; hetero.cysts somewhat spherical or quadrate, yellowish green; cell contents more or less deep bluish purple (cyaneus, azureus) in color. Hawaii. With other algae forming a layer covering rocks on bottom and sides of basin of "warm spring." Temperature at 7 a. m. 31 + ° C. Puna, Hawaii. July 1900. (Tilden). 398. Scytonema hofmanni Agardh. Synopsis Algar. Sueciae. 117. 1817. Bor- net and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 97. 1887. De Toni. Syll. Algar. 5: 513. 1907. Wood. Prodromus of a Study of the Fresh-Water Algae of Eastern North America. 130. 1869. Maze and Schramm. Essai Class. Algues Guadeloupe. 32. 1870-1877. (S. j u 1 i a n u m Menegh., S. c i n e r e u m Crouan). Wood. Contr. Hist. Fresh-Water Algae North America. (S. cortex Wood). 64. 1872. Farlow. Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. (Symphyosiphon hofmanni Kg.). WoUe. Fresh- Water Algae U. S. 262. pi. 189. f. 3. 1887. Moebius. Ueber einige in.Portorico gesammelte Siisswasser- und Luft-Algen. Hedwigia. 27: 245. 1888. Wolle and Martindale. Algae. Brit- ton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Bessey. Additions to the Reported Flora of Nebraska, made dur- ing 1893. Bot. Surv. Nebraska. 5. 1894. Saunders. Protophyta-Phycophyta. Flora of Nejjraska. 24. 1894. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 9. no. 404. 1898. West and West. A Further Contribution to the Fresh-water Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 287. 1898-1900. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 17. no. 803. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 195. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1903. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 26. no. 1258. 1905. Plate XII. fig. 4. Plant mass cushion-shaped, widely expanded, 1-3 mm. in thickness, blackish or blue-green, sometimes impregnated with calcium carbonate, then purple or green or bluish gray; filaments 7-15 mic. in diameter, coa- lesced in vertical fascicles; false branches aggregated; sheaths firm, mem- branaceous; trichomes 5-10 mic. in diameter, olive or blue-green; cells un- equal in length; heterocysts oblong. Alaska. On dripping rocks. Iliuliuk, Unalaska. (Setchell and Lawson). New Hampshire. On rocks near the brook. Tuckerman's Ravine, near Shel- Myxophyceae 217 burne. (Farlow). Massachusetts. Newton. (Farlow). On shaded rocks. High Ledge, Melrose. April 1892. (Collins). Connecticut. On old stumps. Shore of upper Twin Lake, Salisbury. October. (Holden). New Jersey. On moist earth, wood and rocks. (WoUe). Nebraska. On damp wood, in greenhouses. State University, Lincoln. (Bessey, Saunders). California. On rocks. North side of Bolinas Ridge, Marin County. June 1896. (Setch- ell). West Indies. Forming violet-colored masses among mosses on lime- stone rocks in mountains near Utuado, Porto Rico. (Moebius). On steps of Court House, Port Antonio. April 1893; on leaves of trees, Bath, Jamaica. (Humphrey). Head of Castle Bruce River, Dominica. January and February 1896. (Elliott). Forma brunnea Wolle. Fresh-Water Algae U. S. 258. 1887; Fresh Water Algae. Bull. Torr. Bot. Club. 6: 284. 1879. (S. cortex bruneum Wolle). De Toni. 1. c. Si5- Plant mass dark brown; filaments covered with apparently "sub-spheri- cal, resinous cells." South Carolina. (Ravenel). Florida. (Ravenel, Smith, Austin). Var. symplocoides (Reinsch) Bornet and Flahault. 1. c. 99. De Toni. I. c. 515. Maze and Schramm. Essai Class. Algues Guadeloupe. 36. 1870-1877. (Calothrix conferta Crouan). Sheaths colorless; cell contents pale blue-green. West Indies. (Maze). Var. calcicolum Hansgirg. Physiologische und Algologische Mittheil- ungen. pi. 3. f. 35. 1890; Prodromus der Algenflora von Bohmen. 2: 33. 1892. De Toni. 1. i;. 516. Plant mass smooth, brown or black, rarely almost soft, gelatinous, often expanded; filaments 6-12 mic. in diameter, more or less branched, curved, often associated in dense floccose masses; false branches somewhat more slender, single or in pairs, approximate, usually issuing between two hetero- cysts, erect; sheaths close, somewhat thickened with age, yellow or yellow- ish orange, rarely almost colorless; trichomes 4-6 mic. in diameter; cells almost inconspicuous, somewhat quadrate or twice as short as wide, hetero- cysts somewhat quadrate, single or in pairs, a little shorter or longer than their diameter; cell contents granular, dull blue-green, green, olive or yel- lowish. South Carolina. (Ravenel). Florida. (Smith, Austin, Ravenel). 399. Scytonema varium Kuetzing. Spec. Algar. 307. 1849. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 97. 1887. De Toni. Syll. Algar. 5: 512. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 34. 1870-1877. Wolle. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 139. 1877. (S. chrysochlorum Kg.) ; Fresh-Water Algae U. S. 253. 1887. Saun- ders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. 2i8 Minnesota Algae Calif. Pub. Bot. i : 195. 1903. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 1905. Plate XII. fig. S. Plant mass 2-3 mm. in height, cushion-shaped, bluish-green or brown- ish; filaments 9-15 mic. in diameter, tortuous, entangled; sheaths gelatinous, below colorless, pellucid, in upper portions yellowish; trichomes 5-7 mic. in diameter; cells somewhat quadrate, scarcely distinct; heterocysts some- what quadrate or longer than the diameter, colorless; cell contents densely granular, blue-green or yellowish. Alaska. On rocks moistened by spray from a waterfall. Near Juneau. (Saunders). Canada. Shaded rocks. Niagara. (Wolle). Florida. Anas- tatia Island, St. Augustine. (Wolle). Hawaii. (Schauinsland). 400. Scytonema javanicum (Kuetzing) Bornet in Bornet and Flahault. Notes Algologiques. 148, 1880. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 1887. De Toni. Syll. Algar. S: 506. 1907. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 269. pi. 14. f. 12-15. 1895. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 428. 1895. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Plate XII. fig. 6. Plant mass cushion-shaped, 2-4 mm. in thickness, deep blue-green or reddish; filaments 12-15 mic. in diameter, coalesced in vertical fascicles; false branches long, flexuous, aggregated; sheaths firm, thin, colorless, be- coming yellowish; trichomes 9-12 mic. in diameter; cells compressed or quadrate; heterocysts somewhat quadrate; cell contents green becoming brown or violet. Massachusetts. Growing on trunks of trees in Middlesex Fells, Mel- rose. (Setchell). West Indies. On lime trees. Shanford Estate; Anguilla; on walls, Roseau, Dominica, November, December 1892. (Elliott). On flower pot in garden. Castleton, Jamaica. Ai^ril 1893. (Humphrey). Var. hawaiiense Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 624. pi. 7. f. 6-8. 1905. De Toni. 1. c. 507. Plate XII. fig. 7. Plant mass cushion-shaped, dark blue-green; filaments 9.5-11 mic. in diameter, coalesced into vertical fascicles; sheaths firm, thin, always color- less; trichomes 5.5-8 mic. in diameter; cells 5.5-14 mic. in length, cylindrical, sometimes quadrate (younger cells compressed) ; heterocysts 7-9.5 mic. in diafneter, 9.5-14 mic. in length, usually cylindrical, rarely somewhat quad- rate, sometimes yellowish; cell contents homogeneous, pale blue-green, the cells in younger branches being filled with reddish bodies (gas vacuoles). Hawaii. Among mosses. Crater of Kilauea, Hawaii. (Schauinsland). 401. Scytonema ocellatum Lyngbye. Hydrophytologia Danica. 97. pi. 28 A. Myxophyceae 219 1819. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 95. 1887. De Toni. Syll. Algar. 5: 509. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 33. 1870-1877. (S. torridum Agardh, S. parietinum Crouan). WoUe. Fresh- Water Algae U. S. 258. pi. 188. f. 1-4, 10-14. 1887. (S. c i n e r e u m Men- egh.). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Saunders. Protophyta- Phycophyta. Flora of Nebraska. 24. pi. 2. f. 24. 1894. Bessey. Additions to the Reported Flora of Nebraska made during 1893. Bot. Surv. Ne- braska. '3: 5. 1894. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 88. 1896. Wittrock, Nordstedt, and Lagerheim. Algae Aq. Dulc. Exsicc. no. 1322. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 210. 1896; Fasc. 15. no. 711. 1900. Bessey, Pound and Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 5: I4- ipoi- Col- lins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901; Algae of the Flume. Rhodora. 6: 230. 1904; Phycological Notes on the late Isaac Holden. — II. Rhodora. 7. 237. 1905. Lemmermann. Algenfl. Sandwich.- Inseln. Bot. Jahrb. 34: 625. 1905. Plate XII. fig. 8. Plant mass cushion-shaped, black or gray becoming bluish; filaments 10-18 mic. in diameter, up to 3 mm. in length, entangled, branched; false branches short; sheaths firm, becoming brownish; trichomes 6-14 mic. in diameter, cells shorter than the diameter or quadrate, heterocysts some- what quadrate, yellowish; cell contents olive green. New Hampshire. One of the three species composing the brown coating on the wall of the "Flume." September 1904. (Collins). Massachusetts, Forming a dark brown felt upon rocks just above the surface of the water. Massapoag Brook, at Sharon. April 1891. (Setchell). Connecticut. On dripping rocks. Sage's Ravine, Salisbury. August. (Holden). New York. (Wolle). New Jersey. On moist rocks. Bergen, Godwinville. (Austin). Pennsylvania. On moist rocks and shaded walls. (Wolle). Florida. (^Wolle). Nebraska. On flower pots in greenhouse. University, Lincoln. (Bessey, Saunders). Bermudas. On sand dunes. Paget. January 1900. CFarlow). West Indies. On bark of trees. Near Constant Spring, Kings- ton, Jamaica. December 1892. (Lagerheim). On old palm stems. Castleton, Jamaica. April 1893. (Humphrey). Hawaii. (Berggren, Schauinsland). 402. Scytonema intertextum (Kuetzing) Rabenhorst. Fl. Eur. Algar. 2: 263. 1865. De Toni. Syll. Algar. 5: 511. 1907. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 284. 1879;. Fresh- Water Algae U. S. 258. pi. 186. f. 10-17. 1887. Plate XII. fig. 9. Plant mass more or less thick, cushion-shaped, compact, dark brown or olive; filaments up to 20 mic. in diameter, ascending; false branches fasciculate, flexuously curved, densely entangled; sheaths somewhat thick, sometimes a little swollen, distinctly lamellose, yellowish or flesh-colored. i>20 Minnesota Algae rarely brownish, the external layers sometimes diffluent into colorless fibrils; trichomes 12-16 mic. in diameter, here and there irregularly con- stricted at joints; cells equal to or a little longer than their diameter; heterocysts oblong or somewhat spherical, very pale brown in color, soli- tary or in pairs at the base of the false branches; cell contents granular. Florida. On old wood. (Smith). 403. Scytonema austinii Wood. Contr. Hist. Fresh-Water Algae North America. 58. 1874. De Toni. Syll. Algar. 5: 511. 1907. WoUe. Fresh-Water Algae U. S. 261. pi. 189. f. 5. 1887. (S y ip p h y o- siphon austinii Wood). WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Plant mass cushion-shaped and somewhat turfy, brown or black; fila- ments 15-20 mic. in diameter, ascending, mostly unbranched, curved; sheaths reddish or yellowish brown at the apex, colorless and transparent, firm, indistinctly lamellose, with rough surface; trichomes 4-10 mic. in diame- ter, blue-green or dark-colored, often very much thickened at the ends; cells shorter or longer than their diameter; heterocysts short, cylindrical, some- what quadrate or spherical, sometimes strongly compressed and much shorter than broad. New Jersey. Forming a sort of miniature turfy cushion upon the rocks. Little Falls. (Austin). Pennsylvania. On rocks. (Wolle) 404. Scytonema millei Bornet in Bornet and Thuret. Notes Algologiques. 147. 1880. Bornet and Flahault. Ann. Sci. Nat. Bot. VII. 5: 93. 1887. De Toni. Syll. Algar. 5: 505. 1907. Hohenacker. Algae Marinae Siccatae. no. 458. 1862. (S. 1 e p r i e u r i i Kg.). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 29. no. 1405. J907. Plant mass cushion-shaped, woolly, widely expanded, 1-5 mm. thick, dark green, becoming brown; filaments 15-21 mic. in diameter, flexuous, entangled, branched; false branches erect, spreading; sheaths firm, brown- ish; trichomes 10-15 ™ic. in diameter; cells compressed; heterocysts com- pressed, brown, shorter than the diameter of the trichome. West Indies. On earth. St. Thomas. (Hohenacker). On earth and rocks. Mavis Bank Road, Jamaica. June 1906. (Lewis). 405. Scj^onema guyanense (Montagne) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 1887. De Toni. Syll. Algar. 5: 506. 1907. Montagne. Histoire de I'lle de Cuba. 10. pi. 2. f. 2. 1838. (S. b y s- soid,eum corticale Mont.). Wood. Prodromus of a Study of the Fresh- Water Algae of Eastern North America. Proc. Am. Phil. Soc. 11: 130. 1869. Maze and Schramm. Essai Class. Algues Guadeloupe. 33: 1870- 77. (Calothrix indica Crouan). Wood. Contr. Hist. Fresh- Water Algae North America. 64. pi. 5. f. 4. 1872. (S. r a v e n e 1 i i Wood). Wood. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 139. 1877. (Symphyo- siphon wollei Born.). Nordstedt. De Algis Aquae Dulcis et de Characeis ex insulis Sandvicensibus a Sv. Berggren 1875 reportatis. (S. Myxophyceae 221 pulvinatum Nordst.). WoUe. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. (M astigonema velutinum Wolle) ; Fresh-Water Algae U. S. 257. pi. 186. f. 1-6. 1887. (S. cortex ravenelii Wolle). Collins. Algae of Middlesex County. 13. 1888. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 624. 1905. Plant mass dense, cushion-shaped, 1-2 mm. in thickness, widely ex- panded, blackish green; filaments 15-21 mic. in diameter, coalesced in vertical fascicles; false branches long, fiexuous, aggregated; sheaths firm, membranaceous, lamellose, yellowish brown; trichomes 10-16 mic. in diameter; cells somewhat quadrate or elongate; cell contents olive green. Massachusetts. In a greenhouse. Newton. (Farlow). New Jersey. Forming an extended olive green stratum, a little above the water level, on the plank sides of a neglected basin of sea water. Perth Amboy. July 1878. (Wolle). Pennsylvania. On calcareous rocks. (Wolle). South Carolina. Forming little turfy spots of a greenish color on bark. Growing on twigs of a C e 1 1 i s and on bark of a willow. (Ravenel). Florida. On trunks of various trees. (Smith). Hawaii. On volcanic gravel, Oahu. (Berggren, Schauinsland). 406. Scytonema amplum West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 270. pi. 16. f. 14-16. 1895; A Further Contribution to the Freshwater Algae of the West In- dies. 1. c. 34: 287. 1900. De Toni. Syll. Algar. 5: 512. 1907. Plate XII. fig. 10, II. Plant mass small, woolly, 3-5 mm. in diameter, brownish; filaments 19-24 mic. in diameter, densely entangled;" false branches 13.5-16 mic. in diameter, rare, usually in pairs but sometimes single, more slender than the main filament; sheaths very wide, formed of parallel layers, in outer portions gelatinous, colorless or somewhat yellowish, in the interior abruptly yellowish or brownish; trichomes 3.5-4 mic. in diameter, narrow; cells up to six times longer than the diameter; heterocysts oblong, several times longer than their diameter; cell contents yellowish green. West Indies. On trees. Summit of Trois Pitons (4,500 feet). Novem- ber, December. 1892; on rocks, Castle Bruce River (2,000-3,000 feet), Do- minica. January, February 1896. (Elliott). 407. Scytonema woUeanum De Toni. Syll. Algar. 5: 513. 1907. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 284. 1879; Fresh- Water Algae U. S. 255. pi. 187. f. 1-3. 1887. (S. m i r a b i 1 e Wolle). Plate XII. fig; 12. Plant mass more or less widely expanded, olive becoming brownish; filaments 20-25 mic. in diameter, strongly curved and fiexuous; false branches 12.5-15 mic. in diameter, numerous, usually in pairs, adhering usually without separation of the trichome at the end; sheaths firm, smooth, olive or yellowish, rarely nearly colorless; trichomes often some- what moniliform; cells two to three times shorter than their diameter. Florida. On bark of Cypress trees. (Ravenel). 408. Scytonema stuposum (Kuetzing) Bornet in Bornet and Thuret. Notes 222 Minnesota Algae Algologiques. 146. 1880. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 92. 1887. De Toni. Syll. Algar. 5: 503. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 34. 1870-1877. (S. cyanescens Crouan). Plate XII. fig. 13, 14- Plant mass cushion-shaped, woolly, widely expanded, blackish violet or becoming reddish; filaments 16-30 mic. in diameter, 5-10 mm. long, free, branched; false branches approximate, solitary or in pairs; sheaths thick, gelatinous; trichomes 12-18 mic. in diameter; cells somewhat quad- rate or two or three times shorter than their diameter; heterocysts equal- ling the cells in diameter; cell contents olive or violet. West Indies. (Maze). 40Q. Scytonema tolypotrichoides Kuetzing. Spec. Algar. 307. 1849. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 100. 1887. De Toni. Syll. Algar. 5: 516. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 61. pi. 6. f. 2. 1872. (S. calotrichoides Wood). WoUe. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 139. 1877; Fresh-Water Algae U. S. 250. pi. 182. f. 4-1 1. 1887. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. 1889. Setchell. Notes on Cyanophyceae. — II. Erythea. 4: 192. 1896. Plate XIII. fig. I. Plant mass caespitose, floating, spherical, one cm. in diameter, brown or green in color, filaments 10-15 mic. in diameter, 5-6 mm. long, radiating from the center, repeatedly branched; sheaths colorless, becoming orange brown, lamellose; the outer layers often colorless; trichomes 8-12 mic. in diameter; cells somewhat quadrate or oblong, scarcely distinct; heterocysts varied, some short, some long, rose-colored; cell contents densely granu- lar, olive or yellowish. New York. In gelatinous masses on dripping rocks. Niagara Falls; on wet or moist earth on the banks of rivers. (Wolle). New Jersey. Frequent on wet rocks. (Wolle). South Carolina. In wet, boggy places, on rotten pine boards. September 1869. (Ravenel). 410. Scytonema flavo-viride (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: loi. 1887. De Toni. Syll. Algar. S: 517- 1907. Plant mass caespitose, entangled, floating, yellowish green; filaments 12-18 mic. in diameter, 2 cm. and more in length, rigid, very sparingly branched; sheaths colorless, thick, lamellose; trichomes 6-10 mic. in di- ameter, cylindrical, equal, constricted at joints; cells twice as long as wide, sometimes up to 15 mic. in diameter and shorter than the diameter; hetero- cysts quadrate or oblong, colorless; hormogones very long; cell contents blue-green. Mexico. In swamps. Near Vera Cruz. (Miller). 411. Scytonema mirabile (Dillwyn) Bornet. Les Nostocacees heterocystees du Systema Algarum de C. Agardh (1824) et leur Synonymie ac- Myxophyceae 223 tuelle (1889). Bull. Soc. Bot. de France. 12. 1889. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5 : loi. 1887. (S. figuratum Ag.) De Toni. Syll. Algar. 5: 517. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 60, 61. pi. 6. 1. I, 2. 1872. (S. therrnale Kg., S. calotrichoides Kg.). Nord- stedt. Die Algis Aquae Dulcis et de Characeis ex Insulis Sandvicensibus a Sv. Berggren 1875 reportatis. 6. 1878. Wolle. Fresh-Water Algae U. S. 351. pi. 183. f. 5-7. 1887; 259. 1887. Wolle and Martindale. Algae. Brit- ton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. 1889. West and West. On some Fresh-water Algae from the West In- dies. Journ. Linn. Soc. Bot. 30: 271. 1895. Setchell. Notes On Cyano- phyceae. — I. Erythea. 4: 89. 1896; Notes on Cyanophyceae. — II. Erythea. 4: 193. 1896. Tilden. American Algae. Cent. III. no. 290. 1898. (S. m y o- chrous (Dillw.) Ag.). West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 287. 1898-1900. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 48. 1899. Tilden. American Algae. Cent. IV. no. 396. 1900. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 857. 1901. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Til- den. Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Station, i: 166. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 195. 1903. Col- lins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 1905. Tilden. American Algae. Cent. VII. Fasc. i. no. 631. 1909. Plate XIII. fig. 2-s. Plant mass woolly, widely expanded, spongy-tomentose, brownish black or blackish green; filaments 15-21 mic. in diameter, tortuous, en- tangled, 2-4 mm. or i cm. in thickness; sheaths lamellose, yellowish brown; layers of the sheath scarcely diverging; trichomes 6-12 mic. in diameter; basal cells long, cylindrical, the upper ones disc-shaped; heterocysts some- what quadrate or longer than the diameter, brownish; cell contents yellow- ish green. Alaska. On moist ground near Glacier Bay; in a freshwater stream emptying into Glacier Bay; on the perpendicular surface of a rock moist- ened by dripping water, Kukak Bay, July 1899. (Saunders). Connecticut. Coating moist limestone rocks. On shore of Housatonic River, near Gay- lordsville. June, October* 1901. (Holden). New York. Forming a dark brown coating on wet rocks. Niagara. (Wolle). New Jersey. Frequent on sub- merged sticks in ponds. (Wolle). South Carolina. Damp surface of hard clay; in wet boggy places on rotten pine boards, September 1869. (Ravenel). Sandy soil near Aiken. (Wolle). Minnesota. On sides of rocks in stone quarry. Minneapolis. May 1899. (Crosby). Iowa. On cliffs. Fayette. 1897. (Fink). Colorado. In pannose layers upon the "Pil- lars of Hercules," South Cheyenne Cafion, near Manitou. (Setchell). Mexico. (Miiller). West Indies. On damp wall of dam. Sharp's River, St. Vincent. May 1892; on trees, summit of Trois Pitons (4,500 feet), No- vember and December 1892; on rocks, Hamstead Valley (850 feet), Do- 224 Minnesota Algae minica, January and February 1896. (Elliott). Hawaii. In stagnant water. Mauna Kea, Hawaii. (Berggren, Schauinsland). Var. leprieurii (Montagne) Bornet and Flahault. 1. c. 103. De Toni. 1. c. 520. Schramm and Maze. Essai Class. Algues Guadeloupe. 32. 1865. Maze and Schramm. Essai Class. Algues Guadeloupe. 34. 1870-1877. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 21. no. 1014. 1903. Outer layers of sheath gelatinous, colorless. Canada. Warm sulphur springs, Banff, Alberta. June 1901. (Butler and Policy). West Indies. (Maze and Schramm). 412. Scytonema myochrous (Dillwyn) Agardh. Dispositio Algar. sueciae. 38. 1812. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 104. 1887. De Toni. Syll. Algar. 5: 521. 1907. Dickie. In Hooker. An Account of the Plants collected by Dr. Walker in Greenland and Arctic America during the Expedition of Sir Francis M'Clintock, R. N., in the Yacht "Fox." Journ. Linn. Soc. Bot. 5: 86. 1861; Notes on a Collection of Algae procured in Cumberland Sound by Mr. James Taylor, and Remarks on Arctic Species in General. 1. c. 9: 242. 1867. Wood. Prodromus of a Study of the Fresh- Water Algae of Eastern North America. Proc. Am. Phil. Soc. 11: 129. 1869. (S. cataractae Wood); Contr. Fresh-Water Algae North America. 62. pi. 7. f. i. 1872. Raben- horst. Die Algen Europas. no. 2492. 1877. Wolle. Fresh-Water Algae. 6: 184. 1877. (S. brandegei Wolle); Fresh-Water Algae U. S. 252, 253. pi. 182. f. 1-3; pi. 183. f. 1-4; pi. 185. f. 1-7. 1887. (S. gracile Kg., S. t u r- fosumKg.). Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. 3. no. 109. 1895. Setchell. Notes on Cyanophyceae. — II. Ery- thea. 4: 192, 193. 1896. Collins. Some Perforating and other Algae on Fresh- Water Shells. Erythea. 5: 96. 1897. Saunders. Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 195. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rho- dora. 7: 237. 1905. Buchanan. Notes on the Algae of Iowa. Proc. Iowa A-cad. Sci. 14: 10. 1908. Plate XIII. fig. 6. Plant mass woolly, widely expanded, spongy-tomentose, brownish black or blackish green; filaments 18-36 mic. in diameter, 2-15 mm. long, tor- tuous, entangled; sheaths lamellose, yellowish brown; layers of the sheath diverging; trichomes 6-12 mic. in diameter; basal cells long, cylindrical, the upper ones disc-shaped; heterocysts somewhat quadrate or longer than their diameter, brown; gonidia spherical, yellowish brown; cell contents yellowish green. Alaska. Forming small tufts on rocks in a brook emptying into Glacier Bay. (Saunders). Greenland. (Borgesen). Canada. Fresh water. Port Kennedy. (Walker). Cumberland Sound. (Taylor). Forming broad turf- Myxophyceae 225 like coating on the rocks below the great cataract. Niagara Falls. (Wood). Dark brown coating on wet rocks. Niagara. (Wolle). Rhode Island. New Providence. (Bennett). Connecticut. Forming dark brownish patches on submerged limestone rocks. Twin Lakes, Salisbury. August, October 1892. (Holden). Growing on outside of Unio shells. Twin Lakes, Salisbury, Litchfield County. August 1895. (Setchell and Holden). New Jersey. On rocky shores of Morris Pond. (Wolle). On moist ground. Closter, Bergen. (Austin). Pennsylvania. Moist ground in extended patches and on dripping rocks. (Wolle). North Carolina. Moist ground. (Ravenel). Iowa. Fayette. 1905. (Fink). Colorado. Wet rocks. (Bran- degee). Bermudas. (Farlow). 413. Scytonema badium Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 184. 1877. De Toni. Syll. Algar. 5: 524. 1907. Plant mass thin, brown (b a d i u s) ; filaments 40-75 mic. in diame- ter, somewhat erect, appressed, short; false branches flaccid, divari- cate, single or in pairs; sheaths wide, yellowish olive; trichomes 2-2.5 mic in diameter, sometimes continuous, sometimes showing distinct transverse walls; cells about as long as wide; heterocysts scattered or situated at the base, somewhat spherical or oblong; cell contents pale blue-green. New York. On old wood. Herkimer County. (Austin). 414. Scytonema fuliginosum Tilden. American Algae. Cent. VII. Fasc. i. no. 629. 1909. Plate XIII. fig. 7, 8. Plant mass thin, bluish green; filaments 28-50 mic. in diameter; sheaths folded into many layers or laminations; layers much dilated, dark brown in thicker parts; trichomes 10-20 mic. in diameter; cells 1.4-5 rnic. in length; heterocysts 12-16 mic. in diameter, spherical, oval or somewhat quadrate; cell contents gray green. Hawaii. Forming a thin layer on bottom of small shallow tide pool just below high tide. Pahala Plantation beach, south shore of Hawaii. July 1900. (Tilden). 415. Scytonema alatum (Carmichael) Borzi. Morfologia e Biologia delle Alghe Ficocromacee. Nuovo Giorn. Bot. Ital. 11: 373- i879- Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: no. 1887. De Toni. Syll. Algar. 5: 528. 1907. Harvey. Nereis Boreali-Americana. Part III. 99. pi. 48- A. f. 1-4. 1858. (Petalonema alatum Berk.). Wood. Contr. Hist. Fresh-Water Algae North America. 66. 1872. Wolle. Fresh-Water Algae U. S. 267. pi. 188. f. IS, 16. 1887. Setchell. Notes on Cyanophyceae. — II. Erythea. 4: 193. 1896. Hone. Petalonema alatum in Minnesota. Minn. Bot. Studies. 3- 47- Pl- 13. 1903. Plate XIII. fig. 9- Plant mass caespitose, mucous, black or brown; 24-66 mic. in diame- ter, 4-8 mm. in length, flexuous, erect or appressed; false branches short, spreading, irregular in outline; sheaths forming lamellose wings or mem- 226 Minnesota Algae branaceous expansions, the outer layers white, somewhat transparent, the internal layers bright yellow, contracted at the heterocysts, very smooth on the surface; trichomes 9-15 mic. in diameter; cells shorter than the diameter; heterocysts spherical, brownish; cell contents blue-green or green. New York. On dripping rocks under Biddle Stairs, Niagara Falls. 1849. (Harvey). "The only locality hitherto discovered for this plant is on the high cliff, near the Cave of the Winds, Niagara Falls. 'Twas found there twenty-five years since and it may be gathered there to-day." (Wolle). Minnesota. On gravel bed of a quiet stream, the outlet of an old tank near the Government Dam works. Near Minneapolis. October 1901. Hone. 416. Scytonema junipericolum Farlow in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 16. no. 756. 1900. De Toni. Syll. Algar. S: 525. 1907. Plant mass forming indefinite, pulvinate, tomentose, black expansions .2-.3 mm. high; basal filaments .14-16 mic. in diameter, nearly prostrate; upper filaments 12-14 ™ic. in diameter; false branches in pairs, numerous, erect, soon dividing into Tolypothrix-like, tortuous, corymbose branch- lets; sheaths about 2 mic. in thickness, lamellose, with diverging layers, with obtuse apex; cells at the base disc-shaped, the upper ones becoming cuboidal and often torulose; heterocysts 11-12 mic. in diameter, 6-7 mic. in length. Bermudas. Common, forming dark velvety patches on the bark of Juniperus bermudiana. "Fairyland." January 1900. (Farlow). 417. Scytonema crustaceum Agardh. Syst. Algar. 39. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 106. 1887. De Toni. Syll. Algar. 5: 525. 1907. Wolle. Fresh-Water Algae U. S. 263. 1887. (Symphyosiphon crustaceus Kg.) Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 1358. 1907. Plate XIII. fig. 10-12. Plant mass cushion-shaped, black, .5-2 mm. in thickness; filaments 15-30 mic. in diameter, thick, short, erect, aggregated, often slightly thick- ened and decumbent, with numerous branches; false branches ascending, short, in pairs, coalesced at the base, finally becoming free; sheaths gelati- nous, yellowish brown, lamellose, the layers diverging; trichomes 6-8 mic. in diameter; cells somewhat quadrate or depressed; heterocysts oblong, blue-green. Connecticut. On limestone rock. Salisbury. November 1906. (Phelps). Pennsylvania. Not infrequent, on wet cliffs. (Wolle). Var. incrustans (Kuetzing) Bornet and Flahault. 1. c. 107. De Toni. 1. c. 526. Wolle. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 139. 1877; (Symphyosiphon incrustans Kg.). A Nostoc the Matrix of Scytonema. Bull. Torr. Bot. Club. 217. 1878. Setchell. Notes on Cyano- phyceae. — II. Erythea. 4: 191. 1896. Myxophyceae 227 False branches in pairs, included within a common sheath as far as the apex; gonidia spherical or oval; wall of gonidium deep brown. New York. Common on rocks exposed to spray. Niagara Falls. (Wolle). 418. Scytonema densum (A. Braun) Bornet in Bornet and Thuret. Notes Algologiques. 152. 1880. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 109. 1887. De Toni. Syll. Algar. 5: 527. 1907. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 271. 1895. Setchell. Notes on Cyanophyceae. — II. Erythea. 4: 191. 1896; Notes on Cyanophyceae. — III. Erythea. 7: 48. 1899. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Plate XIII. fig. 13. Plant mass dense, cushion-shaped, brown or black; filaments 24-40 mic. in diameter, i mm. in length, entangled; false branches erect, appressed; sheaths yellowish brown, gelatinous, lamellose, the younger ones pale yellow; trichomes 6-12 mic. in diameter; heterocysts somewhat quadrate; cell contents green. New York. On rocks. Niagara. August 1876. (Wolle). California. Twin Oaks, San Diego County. (Koch). West Indies. Amongst S. J a V a n i c u m on lime-trees. Shanford Estate, Dominica. November and December 1892. (Elliott). In turfs in moist places. Port Antonio, Jamaica. April 1893. (Humphrey). 419. Symphyosiphon bornetianum Wolle. Fresh-Water Algae U. S. 261. pi. 189. f. 4. 1887. De Toni. Syll. Algar. 5: 536. 1907. Plate XIII. fig. 14. Plant mass thin, with smooth surface, brownish or reddish brown; filaments 12-15 mic. in diameter, short, thick, with the branches forming a close, upright growth; sheaths close; cells somewhat longer or shorter than the diameter; heterocysts scattered, yellowish; cell contents brown or slightly blue-green. South Carolina. On old bricks. Port Royal; on clay cliffs. (Wolle). 420. Scytonema dubium Wood. Contr. Hist. Fresh-Water Algae North America. 63. pi. 6. f. 3- 1872. De Toni. Syll. Algar. 5: 533- i907- Plant mass immersed; filaments 6-10 mic. in diameter, very long, closely interwoven, variously curved, usually sparingly branched; false branches usually single, more or less distant, moderately short, some- times very short, abortive and somewhat crowded; sheaths close, usually rather thick and firm, transparent, colorless; trichomes often contained in distinct, cell-like apartments, sometimes continuous, with indistinct trans- verse walls; heterocysts cylindrical, two to six times longer than broad; cell contents finely granular, usually pale bluish green, sometimes bright blue-green. New Jersey. On leaves of Ranunculus aquatilis. In Shepherd's 228 Minnesota Algae Mill Pond, near Greenwich, Cumberland County. 1869. (Wood). 421. Scytonema hirtulum (Kuetzing) Rabenhorst. Fl. Eur. Algar. 2: 265. 1865. De Toni. Syll. Algar. 5: 531. 1907. WoUe. Fresh-Water Algae U. S. 261. pi. 189. f. 7- 1887. (S y m p h y o- siphon hirtulus Kg.). Plate XIII. fig. IS. Plant mass expanded, cushion-shaped, olivaceous-black, consisting of spine-shaped, wick-like bundles of filaments; filaments and false branches ID-IS mic. in diameter, ascending, slightly curved, parallel and more or less densely agglutinated below, usually free at the apices, obtusely rounded; sheaths colorless or yellowish, transparent, the external layers a little swollen with age, roughened, 20 mic. in thickness; trichomes 8-10 mic. in diameter; transverse walls distinct; cells equal to the diameter or a little shorter; heterocysts both basal and intercalary, single or in pairs, oblong, brown in color. United States. On moist rocks and damp earth. (Wolle). 422. Scytonema immersum Wood. Contr. Hist. Fresh-Water Algae North America. 59. pi. 2. f. 9. 1872. De Toni. Syll. Algar. 5: 530. 1907. Intermingled with other algae and adhering to aquatic plants; fila- ments about 10 mic. in diameter, elongate; false branches mostly in pairs, more or less distant, short or elongate; sheaths wide, transparent, colorless; apex of trichome obtusely rounded; transverse walls sometimes distinct, sometimes invisible; cells quadrate or shorter than the diameter; heterocysts distinct, single, intercalary, somewhat cylindrical, sometimes half as long as broad, sometimes nearly twice as long; cell contents bright blue-green. New Jersey. Forming a flocculent, greenish black, slimy coating to the stems and finely dissected leaves of Ranunculus aquatilis. In Shepherd's Mill Pond, near Greenwich, Cumberland County. 1869. (Wood). 423. Scytonema polymorphum Naegeli. Rabenhorst. Fl. Eur. Algar. 2: 257. i86s. De Toni. Syll. Algar. 5: 532. I907- Moebius. Ueber einige in Portorico gesammelte Siisswasser- und Luft- Algen. Hedwigia. 27: 24s. 1888. Plant mass cushion-shaped, dark blue-green or blackish; filaments 7-27 mic. in diameter, variously curved, loosely entangled, sparingly branched; false branches single or in pairs; sheaths colorless or yellowish brown, transparent, lamellose; trichomes S.8-14.S mic. in diameter; trans- verse walls visible or invisible; cells shorter or up to three times longer than their diameter; heterocysts oblong, colorless or pale brown; cell con- tents light blue-green or lead-colored. West Indies. Porto Rico. (Moebius). 424. Scytonema rubrum Montagne. Premiere Centurie de Plantes Cellu- laires Exotiques. Ann. Sci. Nat. Bot. II. 8: 349. 1837; Histoire de rile de Cuba. 9. 1838. De Toni. Syll. Algar. S: 532. 1907. Myxophyceae 229 Filaments decumbent, reddish, dichotomously branched, entangled; false branches spreading, abruptly bent; cells shorter than their diameter. West Indies. On fallen leaves. Cuba. (Montagne). 425. Scytonema simplex Wood. Contr. Hist. Fresh-Water Algae North America. 57. 1872. Wolle. Fresh-Water Algae U. S. 259. 1887. (S. simplice Wood !!). De Toni. Syll. Algar. 5: 536. 1907. Plant mass moderately thick, somewhat cushion-like, blackish green; filaments 10-15 ™c- in diameter, very long, fiexuously curved, sparingly branched or without branches; false branches in pairs or single, usually elongate; sheaths thick, transparent, often colorless, sometimes pale yel- lowish brown, mostly open and truncate at apex; trichomes 3-6 mic! in diameter; cells equal to seven times as long as broad (?), often separated, apical cells very short; heterocysts cylindrical, scattered, two to five times longer than their diameter; cell contents sparsely granular, pale greenish. South Carolina. Adhering to the wet sides of a wooden gutter leading water from a spring. Aiken. September 1869. (Ravenel). Genus TOLYPOTHRIX Kuetzing. Phyc. Gen. 227. 1843. Filaments branched; false branches usually arising in the immediate region of the heterocysts, rarely between two heterocysts, single; sheaths somewhat thin, flexible, more or less fragile; gonidia spherical, oval or elliptical, often many in a series; wall of gonidium smooth, thin. I Sheaths thin. 1 Plants living in water (i) Filaments 8-10 mic. in diameter T. tenuis (2) Filaments 9-12.5 mic. in diameter T. lanata (3) Filaments 10-15 mic. in diameter T. distorta (4) Filaments 12-17 mic. in diameter T. penicillata 2 Plants living in moist places (i) Filaments 10-15 mic. in diameter T. byssoidea (2) Filaments 15-25 mic. in diameter T. ravenelii II Sheaths thick. 1 Plants living in water (i) Filaments 5-6 mic. in diameter T. setchellii (2) Filaments 12-15 mic. in diameter T. limbata 2 Plants living in moist places; filaments 12-15 mic. in diameter T. rupestris Species not well understood T. glacialis 426. Tolypothrix tenuis Kuetzing. Phyc. Gen. 228. 1843. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 122. 1887. De Toni. Syll. Algar. 5: 545- i907- 230 IVIinnesota Algae WoUe. Fresh-Water Algae. VII. Bull. Torr. Bot. Club. 10: 20. 1883. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. West and West. On some Fresh- water Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 271. 1895. Setchell. Notes on Cyanophyceae. — 11. Erythea. 4: 193. 1896. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 6. no. 257. 1897. Tilden. American Algae. Century IV. no. 397. 1900. Saun- ders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 196. 1903. Tilden. American Algae. Cent. VII. Fasc. I. no. 628. 1909. Plant mass caespitose-floccose, rarely extended in a cushion-like layer, blue-green, becoming brownish with age; filaments 8-10 mic. in diameter, 2 cm. in height, repeatedly branched; false branches erect, spreading, flex- uously curved; sheaths membranaceous, thin, usually inflated at the base of the branches, colorless or yellowish; trichomes 6-8 mic. in diameter, cylindrical; cells equal to or longer than the diameter; heterocysts one to five, often colorless; cell contents blue-green. Alaska. Forming brownish or blue-green tufts, attached to rocks in fresh water. Glacier Bay; Popof Islands. (Saunders). Massachusetts. On mosses and various small plants. Spot Pond, Middlesex Fells. (Collins). New Jersey. Often very abundant, in ponds. (Wolle). Plainfield. (Balen). Maryland. On grasses in pools in abandoned brickyard. Baltimore. October 1896. (Humphrey). Michigan. Ann Arbor. (Reighard). Minnesota. In tank. Botanical Department, University of Minnesota, Minneapolis. March 1909. (Tilden). South Dakota. Forming blue-green tufts or coatings on reeds, finally becoming loosened and floating. Big Stone Lake. August i8g8. (Saunders). Washington. Near Newhall, Orcas Island; Green Lake, Seattle. (Gardner). West Indies. On damp wall of dam. Sharp's River, St. Vincent. May 1892. (Elliott). Forma bryophila Rabenhorst. Fl. Eur. Algar. 2: 273. 1865. De Toni. 1. c. 547- Wolle. Fresh-Water Algae U. S. 265. pi. 181. f. 5-7. 1887. Forming a widely extended, thin, papery layer; trichomes 2.5-3 mic. in diameter. New Jersey. Often very abundant in ponds. (Wolle). Pennsylvania. (Wolle). 427. Tolypothrix lanata (Desvaux) Wartmann in Rabenhorst. Die Algen Sachsens. no. 768. 1858. Bornet and Flahault. Revis. des Nostoc, Ann. Sci. Nat. Bot. VII. 5: 120. 1887. De Toni. Syll. Algar. 5: 542. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 66. pi. 8. f. I 1872. (T. d i s t o r t a var. Wood). Wolle. Fresh Water Algae. IV. Bull. Torr. Bot Club. 7: 44. 1880. (T. aegagropila Kg.); Fresh-Water Algae U. S. 263-265. pi. 180. f. 5-7, 14-16; pi. 181. f. 1-4. 1887. (T. m u s c i c o 1 a Kg., Myxophyceae 231 T. pulchra Kg., T. f 1 a c c i d a Kg.). Collins. Algae of Middlesex County. 13. 1888. Parvey. The Fresh-Water Algae of Maine.— I. Bull. Torr. Bot. Club. 15: 161. 1888. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Anderson and Kelsey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Johnson. Fresh Water Algae. North- western University. Report Dept. Nat. Hist. 22. 1891. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 209. 1896; Fasc. 20. no. 956. 190:.;. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. 1 : 195. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Plate XIV. fig. I. Plant mass caespitose-floccose, rarely extended in a cushion-like layer, blue-green, becoming brownish with age; filaments 9-12.5 mic. in diameter, '^ cm. in height, repeatedly branched; false branches erect, spreading, flex- uously curved, sheaths membranaceous, thin, usually inflated at the base of the branches, colorless or yellowish; trichomes about 10 mic. in diame- ter, cylindrical; cells equal to or longer than the diameter; heterocysts one to four, often colorless; cell contents blue-green. Alaska. Forming blackish brown felt-like mats in shallow, running water. Unalaska. June 1899; forming dark brown, felt-like layers on rocks or on the bottom of shallow, fresh water or dried streams, Iliuliuk. (Setch- ell and Lawson). Maine. Old well. College Farm, near Orono. 1887. (Harvey). Massachusetts. Spot Pond, Stoneham; floating in clay pits, Medford, April 1893. (Collins). Connecticut. Lime Rock. (Adam). Mostly on aquatic mosses in summer and autumn, in quiet water. Pequon- nock River, Bridgeport. November 1890; Lake Saltonstall, near New Haven, September to December. (Holden). New Jersey. Clusters torn from attachment by storm. Budd's Lake. August 1881. (WoUe). Penn- sylvania. Forming little bright green balls, adherent to aquatic plants in an aquarium. Philadelphia. (Wood). In ponds. (WoUe). Indiana. In shallow ponds. Edgemoor, Lake County. August 1890. (Johnson). Mon- tana. On dripping rocks and on wet wood-work of dams, flumes, etc., in springs and streams. July to October. (Anderson and Kelsey). Wash- ington. Near Seattle. (Kincaid). West Indies. (Maze). Var. hawaiiensis Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sandvicensibus a Sv. Berggren 1875 reportatis. 6. 1878. (T. m u s c i- cola). De Toni. 1. c. 545. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 1905. Filaments 9-14 mic. in diameter; trichomes 6-8 mic. in diameter; cells 4-7 mic. in length; heterocysts 9 mic. in diameter, 10-15 mic in length. Hawaii. Adhering to leaves in stagnant water. Mauna Kea, Hawaii. (Berggren). 428. Tolypothrix distorta (Hofman-Bang) Kuetzing. Phyc. Gen. 228. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. S: 119. 1887. De Toni. Syll. Algar. 5: 54i- I907- Wood. Contr. Hist. Fresh-Water Algae North America. 65. 1872. 232 Minnesota Algae Wolle. Fresh- Water Algae U. S. 263. pi. 180. f. 1-3. 1887. Bennett. Plants of Rhode Island. 114. 1888. (Scytonema gracile Kg.). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. Anderson and Kelsey. Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 144. 1891. Tilden. American Algae. Cent. I. no. 82. 1894; List of Fresh-Water Algae collected in Min- nesota during 1894. Minn. Bot. Studies, i: 236. 1895; American Algae. Cent. V. no. 478. 1901; Collection of Algae from the Hawaiian Islands. Hawaiian Almanac and Annual for 1902. iii. 1901; Algae Collecting in the Hawaiian Islands. Postelsia: The Year Book of the Minnesota Seaside Station, i: 153. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 195. 1903. Plate XIV. fig. 2-4. Plant mass caespitose-floccose or extended in a cushion-like layer, blue-green or brownish; filaments 10-15 mic. in diameter, 1-3. cm. in length, repeatedly branched; false branches erect, spreading, flexuously curved; sheaths membranaceous, thin, here and there inflated at the base of the branches, colorless, rarely yellowish; trichomes 9-12 mic. in diameter, some- times constricted at joints; cells equal to or shorter than the diameter; heterocysts solitary, rarely in twos or threes; cell contents blue-green. Alaska. Floating or attached to plants or stones in quiet, fresh water. Cape Nome. (Setchell). Vermont. Pond waters. East Charlotte. (Wolle). Rhode Island. (Thwaites). Warden's Pond. (Wood). North Providence. (Bennett). New York. Reservoir Pond, West Point. (Wood). New Jersey. On rocky shores of Morris Pond, Morris. (Wolle). Wisconsin. Fourth Lake, Madison. (Bailey). Minnesota. Artificial lake. Minneapolis. August 1894. (Tilden). Montana. Everywhere in flowing water, growing caespitose on the rocks. July to October. (Anderson and Kelsey). Wash- ington. Fidalgo Island; Lake Washington, Seattle. (Gardner). Hawaii. Forming tiny bluish green tufts or cushions on rocks in mountain stream. Kaliawaa Stream, Makao, Koolauloa, Oahu. June 1900. (Tilden). 429. Tolypothrix penicillata (Agardh) Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i: 380. 1875. Bornet and Thuret. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 123. 1887. De Toni. Syll. Algar. s: 549. 1907. Farlow. Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. Wolle. Fresh-Water Algae U. S. 252. pi. 183. f. 11-13. 1887. (Scytonema naegelii Kg.). Wolle and Martin- dale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. 1889. Plate XIV. fig. S. Plant mass penicillate-caespitose, deep brown in color; filaments 12-17 mic. in diameter, 2 cm. in length, repeatedly branched; false branches erect at the base, flexuously curved, elongate; sheaths firm, membranaceous, at first colorless, afterwards becoming brownish; trichomes about 10 mic. in diameter, cylindrical; cells 4-12 mic. in length; heterocysts usually soli- tary, yellowish; cell contents blue-green. Myxophyceae 233 New Hampshire. On submerged mosses. Mill Brook, Shelburne. (Far- low). New Jersey, On moist rocks. Closter and Godwinville. (Austin). 430. Tolypothrix byssoidea (Hassall) Kirchner in Engler and Prantl. Nat. Pflanz. I. la. 80. 1900. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 116. 1887. (Hassallia byssoidea Hass.) De Toni. Syll. Algar. 5: 551. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 68. pi. 9. f. I. 1872. (Sirosiphon s c y t o n e m a t o i d es Wood). WoUe. Fresh- Water Algae U. S. 266. pi. 181. f. 8-11. 1887. (T. truncicola (Rab.) Wolle). Collins. Algae of Middlesex County. 13. 1888. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 428. 1895. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Com- mission, Massachusetts. 128. 1896. Collins, Holden and SetcheU. Phyc. Bor.-Am. Fasc. 6. no. 258. 1897. West and West. A Further Contribution to the Freshwater Algae of the West Indies. Journ. Linn. Soc. Bot. 34: 287. 1 898- 1 900. Plate XIV. fig. 6. Plant mass woolly, cushion-like, brownish or black; filaments lo-lS mic. in diameter, i mm. in length, irregularly branched; false branches short, erect, spreading; sheaths close, thin, orange or brown, fragile, tubu- lar, continuous; trichomes 9-1 1 mic. in diameter, constricted at joints; cells two or three times shorter than the diameter; heterocysts, basal, one or two; cell contents olive. Massachusetts. Newton. (Farlow). Among other algae. Cascade, Middle- sex Fells. (Collins). Connecticut. Growing on rocks at the water's edge. Quinebaug River, Lisbon. (Setchell). South Carolina. Growing on the limbs ofMyrica cerifera. February. (Ravenel). West Indies. On leaves. Wotten Waven, Dominica. (Elliott). Forma saxicola Grunow. Bornet and Flahault. 1. c. 117. De Toni. 1. c. 552. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 195- 1903. Filaments 14-18 mic. in diameter; sheaths often striated and corrugated; trichomes 12 mic. in diameter. Alaska. Among mosses on dripping rocks. Amaknak Island, Bay of Unalaska. (Setchell and Lawson). Forma cylindrica Tilden. American Algae. Cent. IV. no. 398. 1900. (Hassallia byssoidea cylindrica). Trichomes 5-6 mic. in diameter, cylindrical; heterocysts basal or inter- calary. Canada. On vertical rocks just above high tide. Baird Point, Strait of Juan de Fuca, Minnesota Seaside Station, Vancouver Island, British Co- lumbia. August 1898. (Tilden). „, . Minnesota Algae 431. Tolypothrix ravenelii Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 285. 1879; Fresh-Water Algae U. S. 265. pi. 180. f. 8-10. 1887. De Toni. Syll. Algar. 5: 542. 1907. Plate XIV. fig. 7- Plant mass thin, more or less expanded, reddish brown; filaments 15-25 mic. in diameter, elongate, false branches elongate; sheaths thin, close, yellowish or dark-colored; trichomes often interrupted; cells equal to or twice as short as their diameter; transverse walls distinct; heterocysts basal or intercalary, usually single, oblong, yellowish; cell contents finely granular, yellowish or reddish. Florida. On sandstone rock. Gainesville. December 1877. (Ravenel). 432. Tolypothrix setchellii Collins. Some Perforating and other Algae on Freshwater Shells. Erythea. 5: 96. pi. 4. 1897. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 7. no. 310. 1897. De Toni. Syll. Algar. 5: 548. 1897. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 196. 1903. Plate XIV. fig. 8. Filaments 5-6 mic. in diameter, up to 7 dm. in length, scattered or ar- ranged in parallel series and forming a layer, flexuous, occasionally thick- ened, repeatedly branched; false branches spreading; sheaths thick, gelati- Jious, refractive, colorless or yellowish; trichomes 4 mic. in diameter, con- stricted at joints; cells equal to or longer than the diameter; heterocysts disc-shaped; cell contents blue-green. Alaska. "A dwarf species.'' On C h a r a. Near Iliuliuk, Unalaska. (Law- son). Connecticut. On shells. Twin Lakes, Salisbury, Litchfield County. August 1897. (Setchell and Holden). 433. Tolypothrix limbata Thuret in Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 5: 124. 1887. De Toni. Syll. Algar. 5: 550. 1907. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. 1 : 196. 1903. Plant mass floccose-caespitose, blue-green; filaments 12-15 mic. in diameter, 2-3 mm. in length, repeatedly branched; false branches erect, spreading, flexuously curved; sheaths refringent, colorless, lamellose, with the outer layers mucous; trichomes 6-9 mic. in diameter, constricted at joints; cells equal to or a little longer than the diameter; heterocysts one to two; cell contents dull blue-green. Washington. Growing on the side of a jar in the botanical laboratory. University of Washington, Seattle. (Gardner). 434. Tolypothrix rupestris Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 185. 1877; in Rabenhorst. Die Algen Europas. no. 2573. 1879; Fresh-Water Algae U. S. 265. pi. 180. f. 11-13. 1887. Myxophyceae " 235 Plate XIV. fig. 9. Plant mass expanded, variously tinged with red, purple and black; filaments 12-15 mic. in diameter, loosely interwoven, much branched; sheaths wide, yellowish, or colorless; cells as long or twice as long as their diameter; heterocysts spherical or oblong, two or three in series; cell contents granular, dull blue-green. Pennsylvania. On dripping, gelatinous, exposed rocks. Delaware Water Gap. July. (Wolle). 435. Tolypothrix glacialis Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 8. 1880. De Toni. Syll. Al- gar. 5: 556. 1907. Plant mass caespitose, brown; filaments 15 mic. in diameter, rigid; sheaths somewhat lamellose; transverse walls indistinct. Arctic Regions. Forming a brownish crust on decayed N o s t o c. Edge of Glacier Lake, Cape Baird. (300 feet), 81° 30' N. (Dickie). Genus DESMONEMA Berkeley and Thwaites. English Botany. 1849. Plant mass caespitose, penicillate; filaments somewhat dichtomously divided, straight; sheaths thin; trichomes two or more within the sheath; heterocysts basal; gonidia large, oval or elliptical, single or in short series; wall of gonidium somewhat thick. 436. Desmonema wrangelii (Agardh) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VIL 5: 127. 1887. De Toni. Syll. Algar. s: 558. 1907. Wolle. Fresh- Water Algae U. S. 237. pi. 168. f. 3, 4. 1887. (C a 1 o t h r i x d i 1 1 w y n i i Hass.) Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. (Also C. radios a (Kg.) Kirchn.). Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 428. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. 108. 1895. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setch- ell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 196. 1903. Plate XIV. fig. 10. Plant mass 5-6 mm. in height, caespitose, formed of penicillate fascicles, gelatinous, dark green; filaments erect, somewhat flexuous, repeatedly sub- dichotomously branched; sheaths thin, continuous, colorless or yellowish; trichomes 9-10 mic. in diameter, constricted at the joints; cells three times shorter than the diameter; heterocysts one, two or none; cell contents tlue-green. Alaska. In a clear brook, emptying into Glacier Bay; in brook, Popof Island. (Saunders). On stones in brooks or lakes, or even in pools on the tundra. St. Michael. (Setchell). Near Iliuliuk, Unalaska. (Setchell and Lawson). Connecticut. Very abundant. Forming small tufts or extended 236 Minnesota Algae patches of a blackish green color on stones in the swiftest currents of Roaring Brook, Cheshire. May 1894. (Setchell). New Jersey. Swamps; Morris Pond, Morris. (Wolle). Maryland. Garrett County. (Wolle). Genus DIPLOCOLON Naegelii in Itzigsohn. Phykologische Studien. Part i. 160. 1857. Plant mass gelatinous, terrestrial; colonies irregular in shape, constrict- ed, somewhat club-shaped; filaments several, contorted within a common tegument, branched; false branches solitary or in pairs, usually arising be- tween two heterocysts, but rarely in the immediate region of the hetero- cj'sts; trichomes single within the sheath. 437. Diplocolon heppii Naegeli in Itzigsohn. Phykologische Studien. Nova Acta Acad. Leopold-Carolin. der Nat. 26: Part i. 160. pi. 11. (excl f. 8-12). 1857. Bornet and Flahault. Revis. des Nostoc. Ann. Sci, Nat. Bot. VII. s: 129. 1887. De Toni. Syll. Syll. Algar. 5: 561. 1907 Wolle. Fresh-Water Algae. II. Bull. Torn Bot. Club. 6: 139. 1877; Fresh Water Algae. U. S. 260. pi. 195. f. 1-9. 1887. (S c y t o n e ma heppii CNaeg.) Wolle). Setchell. Notes on Cyanophyceae. — II. Erythea. 4: 193. 1896. Plate XIV. fig. II. Plant mass caespitose, grumous-gelatinous, brownish becoming black; colonies club-shaped, gelatinous, irregularly dilated, up to i mm. m thick- ness, yellowish brown; common tegument lamellose, yellowish brown; filaments 20-28 mic. in diameter, repeatedly branched within the common tegument, flexuously curved and densely interwoven; trichomes constricted at joints; cells and heterocysts 6-10 mic. in diameter, somewhat spherical; cell contents blue-green. New York. Forming a blackish brown gelatinous stratum upon rocks. Niagara Falls. (Wolle). Florida. On old wood. March 1878. (Wolle). Family IV. STIGONEMACEAE Filaments free, rarely laterally aggregated, scattered, frequently branched; sheaths thick, firm, often irregular; trichomes consisting of one or several rows of cells, with heterocysts; heterocysts often lateral, some- times intercalary; reproduction by means of vegetative division, hormo- gones and gonidia. I Sheaths distinct, definite. I Filaments free (i) Trichomes consisting of one row of cells A Branches of two kinds, the one cylindrical, the other flagelliform; heterocysts terminal or lateral Mastigocoleus B Branches unilateral, usually tapering at the apex; heterocysts in- tercalary Hapalosiphon Myxophyceae 237 C2) Trichomes consisting of one to several rows of cells A Branches unilateral, thin, finally forming hormogones Fischerella B Branches scattered; hormogones formed in the apices of the branches or in special short branches Stigonema 2 Filaments growing together forming a cushion-like mass Capsosira II Sheaths confluent into a gelatinous amorphous mass Nostochopsis Genus MASTIGOCOLEUS Lagerheim. Notarisia. i: 65. 1886. Filaments free, irregularly branched; branches of two kinds, the one cylindrical, the other flagelliform, tapering off into a hair-like apex; sheaths continuous; trichomes, except in the branches, single within the sheath; heterocysts single, rarely in pairs, terminal or lateral, sometimes intercal- ary; gonidia unknown; reproduction by means of hormogones; cell con- tents homogeneous. 438. Mastigocoleus testarum Lagerheim. Note sur le Mastigocoleus, Nou- veau Genre des Algues Marines de I'Ordre des Phycochromacees. Notarisia. i: 65. pl. i. 1886. Hornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Hot. VII. 5: 54- 1887. 'De Toni. Syll. Algar. 5: 564. 1907. Collins. Algae. Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. S- no. 213. 1896. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 47. 1899. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 42. 1900; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901; Phycological Notes of the late Isaac Holden. — II. Rho- dora. 7: 223. 1905. Plate XIV. fig. 12. Filaments 6-10 mic. in diameter, variously curved; sheaths thin, color- less; trichomes 3.5-6 mic. in diameter; cells cylindrical or nearly so; hetero- cysts exceeding the diameter of the trichome, 6-18 mic. wide and long; cell contents greenish. Canada. In oyster shells. Malpeque, Prince Edward Island. (Faull). Maine. Growing in the substance of dead shells. Seal Harbor. (Collins). Massachusetts. In shells ofMya arenariaona sandy beach below low water mark. Quisset. July 1893, 1895. (Setchell). Rhode Island. (Collins). Connecticut. In shells. Fresh Pond. August, September. (Holden). Cal- ifornia. In shells of the Eastern oyster. Near Bay Farm Island, Alameda County. (Setchell). West Indies. In old shells. Kingston, Jamaica. 1897. (Humphrey). Jamaica. (Flahault). Genus HAPALOSIPHON Naegeli in Kuetzing. Spec. Algar. 894. 1849. Plant mass caespitose-floccose, thin, aquatic; filaments free, not grow- 238 Minnesota Algae ing together laterally, branched, consisting of a single row of cells, rarely of twQ rows, enclosed within a sheath; branches erect, usually about the same thickness as the creeping primary filament, commonly unilateral, long, flexuous, very slightly tapering; sheaths continuous, strong, of uniform thickness; sheaths of the branches thinner than those of primary filaments, usually colorless; heterocysts intercalary; wall of gonidium thick, yellowish brown. I Plants living in fresh water. 1 Filaments decumbent, branched on all sides; branches 6-8 mic. in diameter; cells elliptical depressed H. ilexuosus 2 Plant mass caespitose, orange brown; primary filaments 11.5-12.5 mic. in diameter; trichomes 7.5-8 mic. in diameter H. aureus 3 Plant mass floccose, caespitose, dull blue-green; primary filaments 21-24 mic. in diameter H. fontinalis II Plants living in hot water 1 Plant mass cushion-like, irregular or expanded, blue-green; primary filaments 3-6 mic. in diameter H. laminosus 2 Plant mass widely expanded, bright blue-green; trichomes 3-1 1 mic. in diameter H. major III Plants living on bark of trees 1 Plant mass caespitose, small, blue-green; filaments 4-7 mic. in diame- ter H. intricatus 2 Filaments 7-10 mic. in diameter; trichomes 7-9.S mic. in diameter H. arboreus 439. Hapalosiphon flexuosus Borzi. Alghe d'Acqua Dolce della Papuasia. La Nuova Notarisia. 43. 1892. De Toni. Syll. Algar. 5: 570. 1907. West and West. On some Freshwater Algae from the West Indies. Tourn. Linn. Soc. Bot. 30: 272. 1895. Filaments decumbent, branched on all sides, consisting of a single row of cells; branches 6-8 mic. in diameter, about equally thick in all parts, flexuously interwoven; sheaths thin, smooth; cells elliptical depressed; heterocysts similar to vegetative cells in form and size. West Indies. In stream. Grande Soufriere, Dominica. November, De- cember 1892. (Elliott). 440. Hapalosiphon aureus West and West. Welwitsch's African Fresh- water Algae. Journ. of Bot. 241. 1897. De Toni. Syll. Algar. 5: 571. 1907. West. West Indian Freshwater Algae. Journ. of Bot. 42: 291. 1904. Plant mass caespitose, densely interwoven, orange brown, growing among other algae; primary filaments 11. 5-12.5 mic. in diameter, tortuous and interwoven, formed of a single series of cells; sheaths firm, tenacious, thick, orange brown, transparent, finally becoming punctulate; trichomes 7.5-8 mic. in diameter; cells somewhat quadrate or spherical, shorter than the diameter and somewhat ellipsoid, or oblong and seven or eight times as long as broad; branches 6.5-9.5 mic. in diameter, frequently unilateral, Myxophyceae 239 single or in pairs, long and flexuous, more slender than the primary fila- ment, sometimes branched; sheaths thick and usually colorless; cells of the branches variable, 4-6.5 mic. in diameter, similar to those in the primary filament, often indistinct; heterocysts up to 6 mic. in diameter, 7-21 mic. in length, rectangular, oblong, intercalary; gonidia not known; cell con- tents finely granular, pale blue-green. West Indies. Bay Estate, Barbados. (Howard). 441. Hapalosiphon fontinalis (Agardh) Bornet. Les Nostocacees Hetero- cystees du Systema Algarum de C. A. Agardh (1824) et leur Syno- nymic actuelle (1889). Bull. Soc. Bot. de France. 36: 13. 1889. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 61. 1887. (H. pumilus Kirchn.). De Toni. Syll. Algar. 5: 568. 1907. Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sand- vicensibus a Sv. Berggren 1875 reportatis. 7. 1878. (H. braunii Naeg.). WoUe. Fresh-Water Algae. V. Bull. Torr. Bot. Club. 8: 39. 1881. (H. brebissonii Kg.) ; Fresh-Water Algae U. S. 275, 277. pi. 196, f. 2-4, 22, 23. 1887. (H. braunii Kg., H. fucescens Kg.). Harvey. The Fresh- Water Algae of Maine.— I. Bull. Torr. Bot. Club. 15. 161. 1888. Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Brit- ton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. Minn. Bot. Studies, i: 30. 1894. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metro- politan Park Commission, Massachusetts. 128. i8g6; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Saunders. The Algae. Harri- man Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 196. 1903. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 1905. Tilden. American Algae. Cent. VII. Fasc. i. no. 627. 1909. Plate XIV. fig. 13. Plant mass floccose, caespitose, dull blue-green, 3 mm. in height; pri- mary filaments 21-24 mic. in diameter, creeping, interwoven, densely branched on the upper side, containing a single row of cells, rarely two or three, somewhat equal in diameter; sheaths somewhat thick, septate; secondary filaments 9-12 mic. in diameter, long, simple; sheaths continuous; trichomes consisting of a row of single, cylindrical cells; heterocysts inter- calary; hortnogones 6 mic. in diameter, 100-300 mic. in length, made up of from 14-S0 cells. Alaska. In a freshwater pond near Seldovia, Cook Inlet. (Saunders). Maine. Old well. College Farm, near Orono. (Harvey). Massachusetts. On the under side of N u p h a r leaves. Spot Pond and Shiner Pool, Middle- sex Fells. (Collins). Rhode Island. Spectacle Pond. (Bennett). New Jersey. On submerged plants in ponds. Dennisville, Atsion, Hammonton. (Wolle). Minnesota. Lake Kilpatrick. June 1893. (Tilden). On perpen- dicular rocks in stone quarry. Near campus. University of Minnesota, Min- neapolis. September 1904. (Lippold). West Indies. On rock. "Wag 240 Minnesota Algae Water," Castleton, Jamaica. April 1893. (Humphrey). Hawaii. Adhering to leaves, in stagnant water. Mauna Kea, Hawaii. (Berggren). Var. tenuissimus (Grunow) Collins and Setchell. Phyc. Bor.-Am. Fasc. J. no. 212. 1896. De Toni. Syll. Algar. 5: 570. 1907. Wolle. Fresh Water Algae. V. Bull. Torr. Bot. Club. 8: 39. 1881. (H. tenuissimus Grun.); Fresh-Water Algae U. S. 277. pi. 196. f. 20, 21. 1887. Bennett. 1. c. 114. Wolle and Martindale. 1. c. 606. Plant mass floccose; filaments irregularly branched in a squarrose man- ner; branches spreading; sheaths very close, colorless, transparent; trich- omes 3-4.2 mic. in diameter, often interrupted, variously curved, with in- distinct, transverse walls; nearly equal in length to the diameter. Massachusetts. Spot Pond, Medford. September 1890. (Collins). Rhode Island. Blackamore Pond. (Bennett). Connecticut. Attached to under side of N u p h a r leaves. Mill Pond, Lantern Hill, Ledyard. Septem- ber 1892. (Setchell). New Jersey. (Wolle). Pennsylvania. (Wolle). Florida. (Wolle). Minnesota. (Wolle). 442. Hapalosiphon laminosus (Kuetzing) Hansgirg. Ueber den Polymor- phismus der Algen. Bot. Centralblatt. 22: 48. 1885. Bornet and Fla- ^ hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 55. 1887. De i Toni. Syll. Algar. 5: 565. 1907. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 47. 1899. Collins. Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 858. 1901. Setchell. The Upper Temperature Limits of Life. Science. 17: 395. 1903. Plate XIV. fig. 14, IS- Plant mass irregular or expanded, carneous-spongiose or compact, part- ly hardened with calcium carbonate, blue-green; filaments interwoven, showing great variety of form; mature filaments 6 mic. in diameter, with distinct sheath, often constricted at joints, containing a single row of cells, rarely two rows, the cells being spherical depressed, barrel-shaped or cylin- drical, branched; branches unilateral, erect, more slender than the primary filament, composed of long, cylindrical cells; young filaments similar to those of Anabaena, either with or without sheaths, crowded, with a somewhat parallel arrangement, torulose in middle portion, tapering at the ends, sometimes simple, sometimes branched; branches single or in pairs, abruptly bent, with long, narrow cells; heterocysts intercalary, often wider than the vegetative cells, spherical or oblong. California. In long, dark, emerald green, penicillate tufts, waving in a stream of hot water (temperature 49-50° C). Arrowhead Hot Springs, near San Bernadino. April 1898. (Setchell). "Within the strictly thermal limits (waters over 43°-4S° C), only one member of the higher and heterocysted Cyanophyceae has been noted, viz., Hapalosiphon laminosu s." — Setchell. Note. — H. major grows luxuriantly in water of a temperature of 54° C, and even higher. 443. Hapalosiphon major Tilden. American Algae. Century II. no. 167. Myxophyceae 241 1896; Observations on some West American Thermal Algae. Bot. Gaz. 25: 97. pi. 9. f. io-<3. 1898. De Toni. Syll. Algar. 5: 565. 1907. Plate XV. fig. 1-4. Plant mass widely expanded, bright blue-green in color; filaments branched; branches single or in pairs, sometimes abruptly bent; trichomes 3-6 mic. in diameter, sometimes cylindrical with indistinct transverse walls, sometimes consisting of very long cells or short somewhat quadrate cells or even spherical cells, the latter up to 11 mic. in diameter; heterocysts 8 mic. in diameter, 8-16 mic. in length, intercalary, oblong, barrel-shaped. Wyoming. Completely coating bed of very swift mountain rivulet, at vent of hot spring. Temperature of spring 61° C. The growth of the plant begins here and disappears at a distance of fifty-five feet from spring where the temperature is 51° C. The most luxuriant growth is thirty-five feet from the spring at a temperature of 54° C. On a mountain near Lower Geyser Basin, Yellowstone National Park. June 1896. (Tilden). Oregon. In hot spring. Temperature 55° C. Cascade Mountains, lat. 45° 20'. 1895. (Lloyd). "The filaments of H. major are nearly twice the diameter of H. 1 a m i n o s u s Hansg. An important character of the latter plant is its habit of forming crystals of lime, according to Cohn who studied the plant at Carlsbad. The Yellowstone species occurred in silicious waters only, at least it was not discovered at Mammoth Hot Springs, where the waters contain calcium carbonate." — Tilden. 444. Hapalosiphon intricatus West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: -271. 1895; A Further Contribution to the Freshwater Algae of the West Indies. 1. c. 34: 286. 1899. De Toni. Syll. Algar. 5: 571. 1907. Plate XV. fig. S. Plant mass caespitose, small, blue-green; filaments 4-7 mic. in diameter, densely interwoven and variable, sparingly branched, containing a single row of cells; branches single, unilateral, flexuous, similar to the primary filament, with or without a sheath; mature sheaths close, usually distinct; cells variable, up to three times longer than their diameter, often equal and somewhat rotund, or elongate; heterocysts 3.8-5.5 mic. in diameter, one to three times longer than diameter, somewhat quadrate or oblong, scat- tered. West Indies. In little intricate tufts among the leaves of L e u c o- b r y u m, on trees, summit of Trois Pitons (4,500 feet), Dominica. Novem- ber, December 1892; in stream, Wotten Waven, Dominica, January, Feb- ruary 1896. (Elliott). 445. Hapalosiphon arboreus West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 272. 1895. De Toni. Syll. Algar. 5: 572. 1907. 242 Minnesota Algae Plate XV. fig. 6, 7. Primary filaments 7-10 mic. in diameter, flexuous, here and there branched on one side, formed from a single row of cells; sheaths close, thin, colorless; branches short, resembling the primary filaments, but more slender; cells 7-9.5 mic. in diameter, 7-19 mic. in length; heterocysts 6-9 mic. in diameter, 9-1 1 mic. in length, quadrate or oblong, intercalary. West Indies. On trees. Summit of Trois Pitons (4,500 feet), Dominica. November, December 1892. (Elliott). Genus FISCHERELLA (Bornet and Flahault) Gomont. Journ. de Bot. i. 1895. Plant mass forming a continuous, more or less expanded layer, ter- restrial; filaments of two kinds; primary filaments creeping, containing one or two rows of cells, unilaterally very much branched; branches or sec- ondary filaments erect, elongate, more slender than the primary, contain- ing very long hormogones within the sheath. I Plants living in moist places; primary filaments 6-9 mic. in diameter F. ambigua II Plants living in moist places or in hot water; primary filaments 10-13 mic. in diameter F. thermalis 446. Fischerella ambigua (Naegeli) Gomont. Note sur le Scytonema am- biguum Kuetz. Morot. Journ. de Bot. 9: 49. pi. 3. 1895. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. S: 100. 1887. (Scytonema ambiguum Kg.). De Toni. Syll. Algar. 5: 576. 1907. WoUe. Fresh-Water Algae U. S. 262. pi. 189. f. 2. 1887. (Symphyo- siphon ambiguum Naeg.). Collins. Algae of Middlesex County. 13. 1888. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 270. 1895; A Further Contribution to the Freshwater Algae of the West Indies. 1. c. 34: 286. 1899. Setchell and Gardner. Algae of Northwestern America. Univ. CSlif. Pub. Bot. i: 196. 1903. Lemmerman. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 1905. Plate XV. fig. 8, g. Plant mass crustaceous, orbicular, up to i mm. in thickness, brown becoming black; filaments 6-9 mic. in diameter, very slender, densely co- alesced in vertical fascicles; false branches aggregated; sheaths gelatinous, colorless, finally becoming brownish; trichomes 2-3 mic. in diameter, thicker at the apices; cells and heterocysts elongate; hormogones very long; cell contents pale greenish or yellowish brown. United States. Frequently intermingled with larger algae, on moist rocks, wet earth, etc. (Wolle). Massachusetts. Newton. (Farlow). Mexico. (Lenormand). West Indies. On trees, summit of Trois Pitons (4,500 feet). November, December 1892; on the ground, mostly in old "Diablotia" holes, Morne Anglais (2,300 feet), July 1892; on banks near Myxophyceae 243 summit. Couliabon (3,700 feet), Dominica, January, February 1896.- (El- liott). Hawaii. (Berggren). In speaking ofTolypothrix byssoidea cylindrica Tilden, Dr. Setchell states that "although the basal stratum and fasciculi of branch- lets are not well developed, yet the branches seem to indicate this species (F. ambigua) rather than the one to which Miss Tilden has referred it." Further investigation is needed to settle this point. 447. Fischerella thermalis (Schabe) Gomont. Note sur le Scytonema am- biguum Kuetz. Morot. Journ. de Bot. 9: 52. 1895. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 66. 1887. De Toni. Syll. Algar. 5: 574. 1907. Farlow, Anderson and Eaton. Algae Am. Bor. Exsicc. no. 223. 1877. (Scytonema thermale Borzi). Farlow. Notes on the Crypto- gamic Flora of the White Mountains. Appalachia. 3: 236. 1883. (F i s c h e r a thermalis americana Farlow). Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 5. no. 211. 1896. Lemmermann. Algenfl. Sandwich.- Inseln. Bot. Jahrb. 34: 625. 1905. (Stigonema thermale (Schabe) Borzi). Plate XV. fig. 10, II. Plant mass .5 m^m. in thickness, cushion-shaped, woolly, expanded, blackish olive or blue-green; primary filaments 10-13 mic. in diameter, creeping, interwoven, constricted at joints, very much branched on the up- per side; cells somewhat spherical, surrounded by a close, colorless or yel- lowish sheath; branches 7-9 mic. in diameter, erect, cylindrical, or some- times inflated and torulose; cells somewhat quadrate, separated; hormo- gones of three to six cells, showing vacuolar cell contents; sheaths close, continuous; heterocysts intercalary and lateral. New Hampshire. On stone in damp woods. Shelburne, Lake Willough- by; on granite rocks near Shelburne. (Farlow). Hawaii. In hot water. Crater of Kilauea, Hawaii. (Schauinsland). Var. mucosa Lemmermann. 1. c. 626. pi. 8. f. 16-18. 1905. De Toni. 1. c. S7S. Plate XV. fig. 12. Filaments 14-21 mic. in diameter, slightly or not at all constricted at joints, almost regularly dichotomously branched; sheaths wide, transparent, mucous, trichomes constricted at the joints; cells quadrate, cyHndrical or disc-shaped; apical cell hemispherical, with less granular contents; hetero- cysts not known; hormogones consisting of four to six cells, filled with vacuoles, surrounded by a gelatinous sheath; protoplasmic contents (in preserved material) spindle-shaped or spherical, in contact with that of adjoining cells by means of protoplasmic threads passing through the transverse walls. Hawaii. In hot water. Kilauea, Hawaii. (Schauinsland). 244 Minnesota Algae Genus STIGONEMA Agardh. Syst. Algar. 20. 1824. Plants terrestrial or aquatic; plant mass rigid, blackish brown, or cushion-like and soft; filaments free, rarely laterally aggregated, scattered; (richomes, in the larger filaments, consisting of two or several rows of cells; heterocysts often lateral, here and there intercalary, hormogones developed in the apices of vegetative branches or in short special branches. I Trichomes in the mature filaments consisting usually of a single row of cells 1 Filaments 7-15 mic. in diameter; sheaths usually colorless S. hormoides 2 Filaments 25 mic. in diameter; cells 14 mic. in diameter, 6-8 mic. in length S. aerugineum 3 Filaments 24-26 mic. in diameter; sheaths thick, lamellose S. panniforme 4 Filaments 14-38 mic. in diameter; sheaths yellowish brown S. tomentosum 5 Filaments 24-45 mic. in diameter; sheaths thick, lamellose, colorless or yellowish brown S. ocellatum II Trichomes in the mature filaments consisting usually of two or several rows of cells 1 Filaments up to 35 mic. in diameter (i) Filaments 18-28 mic. in diameter; cells often surrounded by a special darker colored envelope S. minutum (2) Filaments 27-37 ™ic- in diameter; cells throughout the entire length of the filament uniformly divided S, turfaceum 2 Filaments 40-90 mic. in diameter (i) Hormogones 45 mic. in length, terminal, solitary or in series S. informe (2) Plants rigid; hormogones 45 mic. in length, lateral S. mamillosum Species not well understood S. brandegeei 448. Stigonema hormoides (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 68. 1887. De Toni. Syll. Al- gar. S: S77- 1907. West and West. On some Freshwater Algae -from the West Indies. Journ. Linn. Soc. Bot. 30: 272. 1895. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 6. no. 259. 1897. West and West. A Further Contribution to the Freshwater Algae of the West Indies. 1. c. 34: 286. 1899. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 47. 1899. Collins. Algae of the Flume. Rhodora. 6: 230. 1904. Plant mass thin, somewhat woolly, brownish black; filaments 7-IS Myxophyceae 245 mic. in diameter, 3 decimill. long, decumbent, slender, densely interwoven, irregularly and sparingly branched; branches erect, flexuous, somewhat toru- lose, equal in diameter to the primary filament; sheaths thick, colorless or yellowish; cells somewhat spherical, loosely arranged in a single row, rarely in two rows; heterocysts scattered; cell contents pale blue-green. New Hampshire. One of the species composing the brown coating on the wall of the "Flume." (Collins). Massachusetts. In gelatinous masses, on dripping rocks. Cascade, Middlesex Fells. A^ril 1896. (Collins). West Indies. On trees. Summit of Trois Pitons (4,500 feet) ; on rocks, Roseau Valley (1,000-2,000 feet), June 1892; abundant on banks, Morne Micotrin; on roadside and on bank near Roseau Lake (2,700 feet) ; on rocks, Castle Bruce River (2,000-3,000 feet), Dominica, January, February 1896. (Elliott). Var. tenue West and West. 1. c. 30: 273. pi. 15. f. 4-8. 1895. De Toni. 1. c. 578. Plate XV. fig. 13. Filaments more slender, 5.5-7 mic. in diameter. West Indies. With the typical form but much more abundant. (Elliott). Var. rhizodes (Kuetzing) Hansgirg. Prodromus der Algenflora von Bohmen. 2: 25. 1892. De Toni. 1. c. 578. Wolle. Fresh- Water Algae U. S. 274. 1887. Plant mass brownish black; filaments 8-12 mic. in diameter; branches unilateral, slightly tapering or thickened at the apices. Vermont. On moist rocks. Charlotte. (Wolle). 449. Stigonema aerugineum n. sp. Plate XV. fig. 14. Plant mass forming a brown, membranous layer; filaments 25 mic. in diameter, rounded at apices, rare, mixed with other algae; branches short, straight, spreading; sheaths thick, homogeneous, colorless; cells 14 mic. in diameter, 6-8 mic. in length, oval or depressed globose, crowded, usually forming a single row; heterocysts 8 mic. in diameter, somewhat spherical; cell contents bright blue-green. Hawaii. Covering bottom of pool. On Puna Road, thirteen miles from Hilo, Hawaii. July 1900. (Tilden). 450. Stigonema panniforme (Agardh) Kirchner. Algen Kryptogamen- Flora von Schlesien. 230. 1878. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VH. 5: 71. 1887. De Toni. Syll. Algar. 5: 580. 1907- Wood. Contr. Hist. Fresh-Water Algae North America. 73. pi. g. f. 3. 1872. (Sirosiphon argillaceus Wood). Wolle. Fresh Water Al- gae. III. Bull. Torr. Bot. Club. 6: 185. 1877; Fresh-Water Algae U. S. 273. 1)1. 193. f. 12, 13. 1887. Bennett. Plants of Rhode Island. 114. 1888. (Sirosiphon pulvinatus Breb.). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. i88g. Hauck and Richter. Phykotheka Universalis. Fasc. 4. no. 645. 3889. West and West. On some Freshwater Algae from the West Indies. 246 Minnesota Algae Journ. Linn. Soc. Bot. 30: 273. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2. no. 61. 1893. Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896; Phycolog- ical Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Plant mass caespitose, expanded, olive-black; filaments 24-36 mic. in • diameter, up to I mm. in length, decumbent, flexuous, intricate, tapering at the apices, irregularly branched; branches erect, agglutinated laterally in fascicles, as thick as the primary filament; sheaths thick, yellowish or yellowish-brown, roughened on the surface; cells short, separated, usually in one series; heterocysts scattered; hormogones terminal, 20 mic. in diame- ter, about 100 mic. in length. Maine. Growing on rocks and moss just above high water mark, but wet by spray in rough weather. Cape Rosier. July 1894. (Collins). New Hampshire. In crevices of rocks. Shelburne. August 1894. (Farlow). Massachusetts. Wet rock. Middlesex Fells. (Collins). Rhode Island. Pocasset Brook. (Bennett). Connecticut. On vertical faces of trap rocks. Sargent's River, Woodbridge. November 1891. (Setchell). On moist rocks. Sage's Ravine, below first falls, Salisbury. October. (Holden). New Jer- sey. Frequent, on moist rocks. (Wolle). Pennsylvania. Wet mountain cliff. Pike County. (Wolle). South Carolina. On a moist clay bank near Aiken. August 1869. (Ravenel). West Indies. On trees. Summit of Trois Pitons (4,500 feet); on rocks, Roseau Valley (1,000-2,000 feet), Dominica. (Elliott). 451. Stigonema tomentosum (Kuetzing) Hieronymus. Bemerkungen ueber einige Arten der Gattung Stigonema Ag. Hedwigia. 34: 166. 189S. De Toni. Syll. Algar. 5: 581. 1907. Wolle. Fresh- Water Algae U. S. 269. pi. 191. f. 1-20; pi. 19S. f. 16. 1887. (Sirosiphon pulvinatus alpinus (Kg.) Wolle). Plant mass compact, woolly, up to 2 mm. in height, often cracked, crus- taceous, brownish black; filaments 14-38 mic. in diameter; primary filaments decumbent, giving off numerous elongate, erect, flexuous branches; branches often densely agglutinated into fascicles; sheaths yellowish or brownish; trichomes for the most part consisting of a single row of cells rarely of two rows; cells of the older filamefits somewhat quadrate or spherical, rarely somewhat cylindrical, each surrounded by a special, deeper colored envelope; cells of the younger filaments 10-12 mic. in diameter, often com- pressed, wider than long, with blue-green contents; heterocysts not rare, lateral or oftener intercalary, somewhat quadrate or spherical, oftener com- pressed, wider than long, yellowish; hormogones lo mic. in diameter, 40-100 mic. in length. West Virginia. Wet rocks. Black Water Creek. (Wolle). 452. Stigonema ocellatum (Dillwyn) Thuret. Essai Class. Nostochinees, 380. 1875. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. s: 69. 1887. De Toni. Syll. Algar. 5: 578. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 36. 1870-1877. (Sirosiphon pluviale Crouan). Wood. Contr. Hist. Fresh-Water Myxophyceae 247 Algae North America. 69, 71. pi. 8. f. 2, 3. 1872. (Sirosiphon pellu- cidulus Wood, S. neglectus Wood). Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 185. 1877. (Sirosiphon crameri Brtigg). Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sandvicensi- bus a Sv. Berggren 1875 reportatis. 7. 1878. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 285. 1879. (Sirosiphon ocellatus Kg.) Farlow. Notes on the Cryptogamic Flora of the White Mountains. Ap- palachfa. 3: 236. 1883. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 668. 1883. Wolle. Fresh-Water Algae U. S. 272. pi. 194. f. i-3. 11-16. 1887. Bennett. Plants of Rhode Island. 114. 1888. Wolle and Martin- dale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 60s. 1889. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 10. no. 455. 1898. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 48. 1899. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. 1901. Setchell and Gardner. Algae of North- western America. Univ. Calif. Pub. Bot. i: 196. 1903. Collins. Algae of the Flume. Rhodora. 6: 230. 1904. Lemmermann. Algenfl. Sandwich.-In- seln. Bot. Jahrb. 34: 625. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 27. no. 1309. igo6. Tilden. Notes on a collection of Algae from Guatemala. Proc. Biol. Soc. Wash. 21: 155. 1908; American Algae. Cent. VII. Fasc. i. no. 626. 1909. Plate XV. fig. 15-17. Plant mass caespitose or cushion-like, woolly, brownish; filaments 3-8 mm. long, erect, decumbent at the base, irregularly branched; branches scarcely more slender than the primary filaments, 35-45 mic. in diameter, elongate, straight, spreading, all bearing hormogones; sheaths thick, lamel- lose, colorless or yellowish brown; trichomes consisting of one, rarely two rows of cells; cells 20-30 mic. in diameter, of various sizes, often wider than long, each surrounded by a special, darker colored envelope; heterocysts rare, lateral; hormogones 15 mic. in diameter, 50-65 mic. in length. Alaska. On rocks in a rapid stream emptying into Glacier Bay; floating in a quiet freshwater pool. Prince William Sound, June 1899. (Saunders). New Hampshire. Common on the wet rocks of the Flume and Berlin Falls. (Farlow). One of the species composing the brown coating on wall of Flume. September 1904; among decaying vegetation on bottom of lake. Lake Chocorua. September 1906. (Collins). Massachusetts. Attached to Sedges in freshwater swamp. Falmouth. August 1897. (Moore). Rhode Island. Quidnessett. (Bennett). New York. Forming, with minute mosses, a blackish, turfy coating to a steep slope of bare rock (s,ooo feet), over portions of which water is continually dripping. Near top of Mount Tahawus, Adirondack Mountains. (Wood). New Jersey. Forming, with various other species of algae, a gelatinous blue-green or brown stratum; in a very stagnant pool; on submerged sticks in swampy places, "in dark brown waving tufts, about one-half inch in length"; Bamber Lake, 1883. (Wolle). Florida. In a marsh pool. Near Hibernia. (Canby). Central America. Growing on edges of steam-holes on side of Volcano Santa Maria, near Lake Atitlan. February 1906. (Kellerman). West Indies. On 248 Minnesota Algae rocks. Castle Bruce River (2,000-3,000 feet), Dominica. January, February T896. (Elliott). Hawaii. In stagnant water. Mauna Kea, Hawaii. (Berg- gren, Lemmermann). 453. Stigonema minutum (Agardh) Hassall. History of the British Fresh- water Algae. 1 : 230. pi. 67. f. 3, 4. 1845. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VH. 5: 72. 1887. De Toni. Syll. Algar. s: 582. 1907. Wood. Prodromus of a Study of the Freshwater Algae of Eastern North America. 133. 1869; Contr. Hist. Fresh-Water Algae North America. 72, 74. pi. 9. f. 2. 1872. (Sirosiphon acervatus Wood, S. 1 i g n i c o- la Wood). WoUe. Fresh-Water Algae U. S. 273. pi. 193. f. i-ii. 1887. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 273. 189S; A Further Contribution to the Freshwater Algae of the West Indies. 1. c. 34: 286. 1899. Collins, Holden and Setch- ell. Phyc. Bor.-Am. Ease. 15. no. 713. 1900. Saunders. The Algae. Harri- man Alaska Exped. Proc. Wash. Acad. Sci. 3: 399. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i : 197. 1903. Collins. Algae of the Flume. Rhodora. 6: 230. 1904; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Lemmermann. Al- genfi. Sandwich.-Inseln. Bot. Jahrb. 34: 627. 1905. Plate XV. fig. 18, 19. Plant mass crustaceous or cushion-like, thin, fragile, blackish; filaments 18-28 mic. in diameter, about i mm. in length, decumbent at the base, as- cending, flexuously curved, branched, branches sometimes long, similar to the primary filaments, sometimes very short, bearing hormogones, often very much crowded on one side; sheaths yellowish or yellowish brown, lamellose, the special envelope surrounding each cell frequently of a deep- er color; trichomes in the basal portion of the filament usually consisting of one row of cells, those in the middle and upper portions often composed of two to four rows; heterocysts numerous, lateral or intercalary; hormo- gones 12-15 rnic. in diameter 25-35 mic in length. Alaska. Forming a thin brown coating with Chroococcus rufes- c e n s, on damp rocks, several hundred feet above sea level. Prince William Sound. (Trelease). Greenland. (Borgesen). New Hampshire. One of the species composing the brown coating on wall of the Flume. September 1904. (Collins). Massachusetts. On wet clifif. Cascade, Melrose. April 1900. (Collins). Connecticut. On submerged rocks in Plantain Pond, Salisbury. October. (Holden). South Carolina. On old boards. April; on boards over which spring water was constantly running, August; growing on bark of Ilex opaca; on old wood and on trunks of trees. (Ravenel); West Indies. On damp wall of dam. Sharp's River, St. Vincent; on trees, summit of Trois Pitons (4500 feet); on lime-trees, Shanford Estate; in stream, Wotten Waven, Dominica. (Elliott). Hawaii. On gravelly vol- canic soil. Hilo, Hawaii. (Berggren, Schauinsland). Var. saxicola (Naegelii) Bornet and Flahault. 1. c. 73. De Toni. 1. c. 584. Myxophyceae 249 Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sandvicen- sibus a Sv. Berggren 187S reportatis. 7. 1878. (Sirosiphon saxicola Naeg.). Farlow. Notes on the Cryptogamic Flora of the White Moun- tains. Appalachia. 3 : 236. 1883. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 669. 1884. Plant mass usually thin, crustaceous; filaments 15-21 raic. in diameter; aheaths brown or brownish yellow; cells usually compressed, spherical in the primary filaments, short and often dense in the branches, in the apex truncate and forming a single row. New Hampshire. On exposed rocks and on Stereocaulon. Top of Cabot Mountain, Shelburne. (Farlow). Pennsylvania. (Wolle). Hawaii. On gravelly volcanic soil. Hilo, Hawaii. (Berggren) 454. Stigonema turfaceum (Berkeley) Cooke. British Fresh-Water Algae 272. pi. III. f. 2. 1882-1884. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 74. 1887. De Toni. Syll. Algar. 5: 584. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 75. 1872. (Sirosiphon pulvinatus Breb.). West. The Freshwater Algae of Maine. Journ. of Bot. 27:207. 1889. Richter. Siisswasseralgen aus dem Umanakdistrikt. Bib. Bot. 7: Heft. 42. 4. 1897. Plate XV. fig. 20. Plant mass cushion-like,, deep olivaceous black; filaments 27-37 niic. in diameter, up to i mm. in length, decumbent at the base, ascending, vari- ously curved, much branched; branches resembling the primary filament, erect, bearing hormogones at the apex; sheaths thick, lamellose, yellowish brown; trichomes consisting of from two to four rows of cells; heterocysts collateral; hormogones 12 mic. in diameter, 45 mic. in length. Greenland. East coast. Summers of 1892 and 1893. (Vanhoflfen). Maine. (West). New Jersey. Growing on exposed face of rocks. (Aus- tin). Pennsylvania. On rocks. Near Philadelphia. (Wood). Var. parvus Wood. Contr. Hist. Fresh-Water Algae North America. 75. pi. 10. f. I. 1872. De Toni. 1. c. 585. Filaments closely interwoven into a deep olive black, turfy mass, very thick, irregularly and frequently branched, yellowish brown; branches poly- morphous, their apices usually obtusely rounded, containing from one to four rows of cells; sheaths thick, light yellowish brown, sometimes color- less; trichomes consisting usually of several row of cells, cell contents gran- ular, usually deep brown, sometimes light green. Pennsylvania. On the face of dripping rocks along the Wissahickon Creek, near Philadelphia. (Hunt). 455. Stigonema informe Kuetzing. Spec. Algar. 319. 1849. Bornet and Flahault. Revis. des Nostoc. VII. 5: 75. 1887. De Toni. Syll. Algar. 5: 585. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 73. pi. 8. f. 4. 3872. (Sirosiphon guttula Wood). Wolle. Fresh Water Algae. III. 250 Minnesota Algae Bull. Torr. Bot. Club. 6: 183. 1877. (Sirosiphon coralloides Kg., S.^ lacu'stris Rab.) ; Fresh-Water Algae U. S. 270. pi. 191. f. 21; pi. 192. f. 9-12. 1887. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. West and West. On some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30. 273. 1895. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 88. 1896; Notes on Cyanophyceae. — II. Erythea. 4: 191. 1896. Plate XV. fig. 21. Plant mass expanded, caespitose or crustaceous, somewhat mucous, brownish or black; filaments 40-70 mic. in diameter, 1-2 mm. in length, erect from a decumbent base, irregularly branched; branches 45 mic. in diameter, straight or bent, branched on upper side, all bearing hormogones; sheaths thick, lamellose, yellowish brown; cells 15-18 mic. in diameter; heterocysts numerous, collateral; hormogones 18 mic. in diameter, 45 mic. in length, solitary or in series. Vermont. Wet rocks. Mt. Mansfield. (Wolle). Connecticut. In small quantity in Long Pond, Lantern Hill, Ledyard. (Setchell). New Jersey. On stones constantly washed by the waves, along the rocky shores of Green Pond, Morris. (Wolle). On dry rocks and on moist rocks. (Austin.) South Carolina. Growing on the bark ofTaxodiumdistichum. Aiken. (Ravenel). West Indies. On trees. Summit of Trois Pitons (4500 feet). Dominica. (Elliott). 456. Stigonema mamillosuni (Lyngbye) Agardh. Syst. Algar. 42. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. S: ^^. 1887. De Toni. Syll. Algar. 5; 587. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. ^^. 1872. Farlow. Marine Algae New England. 40. 1882; Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 236. 1883. Collins. Algae. Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894; Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massachusetts. 128. 1896. Collins, Holden and Setchell. Phy. Bor.-Am. Fasc. 8. no. 356. 1897. Collins. Algae of the Flume. Rhodora. 6: 230. 1904; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237, 243. 1905. Plate XV. fig. 22. Plant mass cushion-like, woolly, up to 12 mm. in thickness; filaments up to 65 mic. in diameter, erect, rigid, interwoven, very much branched at the base; branches 45-50 mic. in diameter, gradually tapering at the ends, erect, spreading, with numerous branchlets; some branchlets sterile, long and thick, others bearing hormogones, mammilliform, short, spreading, shorter than the diameter of the branch, 24 mic. in diameter; sheaths thick, lamellose, often torulose, yellowish brown; hormogones short, 15 mic. in diameter, 45-50 mic. in length; heterocysts collateral. Newfoundland. On submerged stones in a pond at the foot of Windsor Lake, near St. John's. July 1897. (Holden). Maine. On rocks in outlet of Hadlock Lower Pond. (Holden). New Hampshire. On submerged stones Myxophyceae 25 1 in the Androscoggin River, Shelburne. (Farlow). On rocks just outside the Flume. (Collins). Massachusetts. In a brook which empties into the sea at Rafe's Chasm, Magnolia Cove, in Gloucester. (Farlow). On pebbles at margin of Spot Pond, Cascade, Middlesex Fells. (Collins). Connecticut. On damp rocks in Mill River, near Samp Mortar Rock; on stones in Pequon- nock River. July. (Holden). New York. Round Pond, near West Point. (Bailey). 457. Sirosiphon brandegeei Wolle. Fresh-Water Algae U. S. 274. pi. 194. f. 17-27. 1887. De Toni. Syll. Algar. 5: 590. 1907. Filaments 12-20 mic. in diameter, with somewhat pointed apices, red- dish brown; cells in one, two or three rows. Colorado. On "'shores" of a soda spring. Cannon City (Brandegee). Genus CAPSOSIRA Kuetzing. Spec. Algar. 344. 1849. Plant mass hemispherical, cushion-like, attached by lower surface, formed of filaments growing together laterally, aquatic; filaments erect, branched, composed of a single row of cells; sheaths septate; heterocysts intercalary and lateral; hormogones composed of from 10-20 cells; gonidia spherical; wall of gonidium thick, brownish. 458. Capsosira brebissonii Kuetzing. Spec. Algar. 344. 1849. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 79- 1887. De Toni. Syll. Algar. 5: 592. 1907. Wolle. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. Setch- ell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 427. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 26. no. 1257. 1905. Plate XVI. fig. I. Plant mass crustaceous-confluent or hemispherical, 1-3 mm. thick, gelat- inous, hard, blackish green, within showing concentric zones of green and yellowish tints; filaments 7.5 mic. in diameter, straight, densely crowded, irregularly branched, torulose; branches appressed, close, upright, fastig- iate; sheaths thick, gelatinous, not lamellose, colorless or yellowish; cells 4-5 mic. in diameter, somewhat globose, distant; heterocysts lateral. New Hampshire. On shells. Lake Chocorua. September 1904. (Far- low). Connecticut. Growing on a large rock on the eastern side of Round Pond at Lantern Hill, near Mystic. (Setchell). Genus NOSTOCHOPSIS Wood. Prodr. Fresh-Water Alg. N. A. 126. 1869. Plant mass or colony gelatinous, definite, aquatic; trichomes formed of a single row of cells, branched; heterocysts intercalary and lateral, pedi- cellate or sessile. 459. Nostochopsis lobatus Wood. Prodromus of a Study of the Fresh- Water Algae of Eastern North America. 127. 1869; Contr. Hist. Fresh-Water Algae North America. 45. pi. 3. f. 6. 1872. Bornet 252 Minnesota Algae and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 80. 1887. be Toni. Syll. Algar. 5: 592. 1907. Farlow. Notes on Fresh-Water Algae. Bot. Gaz. 8: 225. 1883. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. no. 1895. Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 427. 1895. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Plate XVI. fig. 2. Colony vesicular, lobed, up to 2 cm. in diameter, hollow, blue-green or yellowish green; trichomes 4-9 mic. in diameter, I mm. in length, branch- ed from the base, loose, elongate, fiexuous, often constricted at joints; branches unilateral, fastigiate, cylindrical below, torulose in upper portions, somewhat club-shaped; cells up to twice as long as wide; heterocysts lateral, exserted, or intercalary. Vermont. Forming expansions of several inches in water courses. Fer- risburg. (Faxon and Hosford). Connecticut. Forming irregular, firmly gelatinous balls growing upon stones in more or less rapid water in a brook just west of the "head" of the mountain. Mt. Carmel, about seven miles north of New Haven. September 1893 and 1895. (Setchell). In brook. Mt. Carmel. September. (Holden). Pennsylvania. Floating. Schuylkill River, just above Manayunk. (Wood). Family V. RIVULARIACEAE Filaments tapering from base to apex, ending in a colorless hair, simple or branched; false branches due to development of new trichome from a cell of the main trichome, usually occurring immediately under an inter- calary heterocyst — rarely by the perforation of the sheath between two heterocysts by the trichome, as in Scytonema — either separating immediate- ly and forming a new sheath, or remaining for some time within the origi- nal sheath; heterocysts usually present, usually basal, occasionally inter- calary; reproduction by means of vegetative division, hormogones and gonidia. I Heterocysts not present Amphithrix II Heterocysts present I Filaments free, simple or coalesced into a branched plant mass (i) Sheaths cylindrical A Filaments simple or branched; false branches distinct, free Calothrix B Filaments branched; false branches several (two to six) remain- mg within the original sheath or common tegument Dichothrix C Filaments branched; .false branches many (up to a hundred) re- maining within the original sheath or common tegument Polythrix (2) Sheaths thick, saccate Sacconema Myxophyceae 253 2 Filaments coalesced into a crustaceous, spherical or hemispherical, mucous or gelatinous plant mass or colony (i) Heterocysts basal A Filaments simple, parallel, associated in a crustaceous layer Isactis B Filaments branched, radially arranged, associated in a spherical or hemispherical colony Rivularia (2) Heterocysts intercalary Brachytrichia Genus AMPHITHRIX Kuetzing. Phyc. Gen. 220. 1843. Plant mass crustaceous or caespitose, thin, expanded, of a purple or violet color, consisting of two layers: the lower layer composed of densely interwoven filaments or of minute, radiately disposed series of cells; the upper layer consisting of simple erect filaments, closely packed together and tapering to fine points; sheaths thin, close, continuous; hormogones solitary or in series; heterocysts not present. 460. Amphithrix janthina (Montagne) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 344- 1886. De Toni. Syll. Algar. s: 601. 1907. Collins. Notes on New England Marine Algae.— VI. Bull. Torr. Bot. Club. 23:2. 1896; Preliminary Lists of New England Plants. — ^V. Marine Algae, Rhodora. 2:41. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Plate XVI. fig. 3. Plant mass crustaceous, thin, purple; filaments i.S-2.2 mic. in diameter, 3-5 decimill. in length, erect, close, purplish; sheaths thin, uniform, very close; cells equal to the diameter in length; hormogones 20 mic. in length; cell contents pale blue-green. Massachusetts. On wet cliffs just above high water mark. Rockport. (Collins). Connecticut. Coating stones in Island Brook, below R. R. October. (Holden). Var. torulosa (Grunow) Bornet and Flahault. I. c. 344. De Toni. 1. c. 601. Collins. Notes on New England Marine Algae. VI. Bull. Torr. Bot. Club. 23: 2. i8g6. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 6.' no. 262. 1897. Collins. Preliminary Lists of New England Plants. — ^V. Marine Algae. Rhodora. 2:41. 1900. Filaments up to 5 mm. in length; trichomes torulose. Massachusetts. Forming a purplish coating on stone in ditch in salt marsh near Linden Station, Revere. September 1892. (Collins). 461. Amphithrix violacea (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3:344- 1886. De Toni. Syll. Algar. 5:602. 1907. 254 Minnesota Algae Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 218. 1896. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2:41. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7:223. 1905. Plate XVI. fig. 4. Plant mass caespitose, brownish red or violet; filaments 2-3 mic. in diameter, 1-3 mm. in length, erect, fasciculate; sheaths thin, uniform; trichomes constricted at the joints; cells shorter than their diameter; cell contents granular. Maine. On cliffs at high water mark. Eagle Island, Penobscot Bay. July 1892. (Collins). Rhode Island. (Collins). Connecticut On stones. Fresh Pond. November. (Holden). Genus CALOTHRIX Agardh. Syst. Algar. 24. 1824. Plant mass consisting of penicillate tufts or a soft velvety expansion; filaments simple or slightly branched; heterocysts basal or intercalary, ab- sent in a few species; gonidia basal, seriate. I Heterocysts not present. C. Juliana II Heterocysts present. I Plants living in salt water (i) Heterocysts basal A Plants fasciculate or penicillate, parasitic a Filaments 12-15 mic. in diameter C. confervicola b Filaments 21-29 m'c- in diameter C. consociata B Plants caespitose, often growing on rocks a Filaments 8-12 mic. in diameter; cell contents violet C. fusco-violacea b Filaments 10-18 mic. in diameter; cell contents olive green C. scopulorum c Filaments 9-15 mic. in diameter; cell contents olive green C. contarenii d Filaments 15-20 mic. in diameter; cell contents olive green C. pulvinata e Plants parasitic; filaments 9-15 mic. in diameter, thickened into a bulb at the base; cell contents blue-green C. parasitica (2) Heterocysts basal and intercalary A Filaments 9-12 mic. in diameter, scarcely thickened at base C. aeruginea B Filaments 15-18 mic. in diameter; false branches solitary C. prolifera C Filaments 12-21 mic. in diameter; false branches fasciculate at the apex of the filament C. fasciculata Myxophyceae 255 D Filaments 12-24 mic. in diameter; false branches in pairs, arising between two heterocysts C. vivipara E Filaments 10-40 mic. in diameter, interwoven at base, decumbent C. pilosa F Filaments 12-40 mic. in diameter, not branched; sheaths yellowish brown C. Crustacea 2 Plants living in fresh water (i) Plants epiphytic A Filaments 5-7.5 mic. in diameter; trichomes 3.4-4 mic. in diameter C. epiphytica B Filaments 7-8 mic. in diameter; heterocysts basal, usually in pairs C. scytonemicola C Filaments 8-10 mic. in diameter; trichomes 6-9 mic. in diameter, especially constricted at joints; heterocysts basal, in pairs C. stagnalis D Filaments 10-12 mic. in diameter, curved and bulbous-inflated at the base; trichomes 7-8 mic. in diameter C. fusca E Filaments 5-15 mic. in diameter, sometimes thicker at the base; trichomes 3.5-5.5 mic. in diameter C. sandwicensis F Filaments 15-16 mic. in diameter at base; sheaths thick, lamellose, finally becoming brownish black; cells very short C. breviarticulata G Filaments 15-18 mic. in diameter; sheaths wide, often truncate, almost colorless; trichomes 7-9 mic. in diameter C. violacea H Filaments 18-24 mic. in diameter; sheaths thick, gelatinous, lamel- lose, finally ocreate C. adscendens (2) Plants living in warm or hot water A Filaments 8-10 mic. in diameter; sheaths somewhat thick, uni- form, transparent, sometimes yellowish at base; heterocysts basal, rarely intercalary C. thermalis B Filaments 8-10 mic. in diameter; sheaths close, ocreate, trans- parent, becoming yellowish brown; heterocysts basal and in- tercalary, spherical or quadrate C. calida C Filaments lo-ii mic. in diameter; sheaths close, thick, lamellose, ocreate, transparent and yellowish C. kuntzei (3) Plants living on stones and wood A Filaments 9-10 mic. in diameter; sheaths narrow, close, uniform, colorless; trichomes 6-7 mic. in diameter C. braunii B Filaments 10-12 mic. in diameter; sheaths thick, close, uniform or ocreate, yellowish brown C. parietina C Filaments 12-13 mic. in diameter; sheaths thin, close, uniform, colorless or yellowish C. castellii 21-5 Minnesota Algae Species not well understood C. donnellii M. elongatum M. fertile M. fibrosum M. halos C. lacucola S. obscurus M. pardoxum C. rhizosoleniae M. sejunctum M. turgida 462. Calothrix Juliana (Meneghini) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3:348. 1886. De Toni. Syll. Algar. 5: 60s. 1907- Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 425. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. 1895. Tilden. American Algae. Century II. no. 163. 1896. Col- lins. The Algae of Jamaica. Proc. Am. Acad. 37: 241. 1901. Brown. Algal periodicity in certain ponds and streams. Bull. Torr. Bot. Club. 35:247. 1908. Plate XVI, fig. S- Filaments scattered or forming an interrupted, olivaceous layer, dense- ly crowded, erect, simple, rigid, often thickened at the base, 10-15 niic. in diameter, 2 mm. in length; sheaths thin, close, not lamellose, colorless; trichomes 9-12.5 mic. in diameter, ending in a long, tapering, fragile hair; cells three times shorter than their diameter; hormogones 4 or S times longer than their diameter. United States. (Farlow). Massachusetts. Massopoag Brook, Sharon. (Setchell). Connecticut. Growing on wood and on stones. Trading Cove Brook, Norwich; Quinebaug River, .Lisbon. (Setchell). Forming small iso- lated blackish tufts (1-3 mm. in diameter), on smooth stones in shallow water. Trading Cove Brook, Norwich. September 1892. (Setchell). In- diana. Bloomington. (Brown). California. On stones in stream. Pasa- dena. January 1896. (McClatchie). West Indies. On stones in stream. Roaring River, St. Ann's Bay, Jamaica. March 1893. (Humphrey). 463. Calothrix confervicola (Roth) Agardh. Syst. Algar. 70. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 349. 1886. De Toni. Syll. Algar. 5: 606. 1907. Harvey. Nereis Boreali-Americana. Part III. 105. 1858. Farlow. List Marine Algae United States. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Hall. List of the Marine Algae growing in Long Island Sound within 20 miles of New Haven. Bull. Torr. Bot. Club. 6: 112. 1876. Farlow. Marine Algae of New England. 36. pi. i. f. 6. 1881. Pike. Check List of Marine Myxophyceae 257 Algae. Bull. Torr. Bot. Club. 13: 105. 1886. Bennett. Plants of Rhode Island. 95. 1888. Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888; Marine Algae of Nantucket. S- 1888; Algae of Middle- sex County. 13. 1888. Martindale. Marine Algae of the New Jersey coast and adjacent waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 602. 1889. Anderson. List of California Marine Algae, with notes. Zoe. 2: 218. 1891. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. i. no. 9. 1895. Collins. Preliminary lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900; The Algae of Jamaica. Proc. Am. Acad. 37: 241. 1901. Lemmerman, E. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 627. 1905. Collins. Phycological Notes of the late Isaac Hol- den. — II. Rhodora. 7: 223. 1905. Plate XVI. fig. 6-8. Filaments gregarious, stellately fasciculate, attached to larger algae, rigid, not thickened at the base, blackish green or lead-colored, 12-25 mic. in diameter, 2-3 mm. in length; sheaths close, very often entirely colorless, sometimes yellowish brown in lower parts, homogeneous, soft, gelatinous in upper portions; trichomes 10-18 mic. in diameter; cells four or five times shorter than their diameter; heterocysts one or two, basal; hormogones numerous in the sheath, four to six times longer than their diameter. Canada. On other algae. Malpeque, Prince Edward Island. (FauU). New England. On algae of all kinds. Very common in summer. (Farlow). Maine. (Collins). New Hampshire. (Collins). Massachusetts. On Enteromorpha intestinalis in ditches in salt marshes. Wood's Hole. July 1892. (Setchell). "Parasitic" on various algae at Brant Point; on Ulva in salt water, Medford, Everett. (Collins). Rhode Island. On the filiform marine algae. (Bailey, Olney, Hunt). Connecticut. On R u p- pia. Fresh Pond, August. (Holden). New York. Shores of Long Island. In fresh and salt water. Bay Ridge, Fort Hamilton. Summer. Staten Island. (Pike). New Jersey. On rockweed. Atlantic City. (Morse, Martindale). Hudson: Hoboken and Communipaw. (Pike). New York Bay. (Hooper). California. Common. (Anderson). West Indies. On various algae. Port Antonio. Jamaica. March 1893. (Humphrey). Hawaii. On marine algae. Laysan. 1896-1897. (Schauinsland). Var. purpurea Bornet and Flahault. 1. c. 350. De Toni. 1. c. 607. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 30. no. 1456. 1908. Trichomes purple. Maine. On Cladophora expansa (Kuetz). In marsh pools. Stover's Point. Harpswell. 13 July 1905. (Collins). 464. Calothrix consociata (Kuetzing) Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 3: 3Si- 1886. De Toni. Syll. Algar. 5: 607. 1907. Setchell and Gardner. Algae of Northwestern University. Univ. Calif. Pub. Bot. i: 197. 1903. 21-8 Minnesota Algae Plate XVI. fig. 9- Filaments gregarious and stellately fasciculate, attached to filiform al- gae, curved, decumbent and slightly thickened at the base, blackish green, 21-29 mic. in diameter, .3 mm. in length; sheaths close, membranaceous, brownish, with dilated, funnel-shaped apex, the outside layers colorless; trichomes 12 mic. in diameter; cells three times shorter than the diameter; heterocysts basal; cell contents olive. Washington. On grasses in a salt marsh. Head of Penn's Cove, near Coupeville, Whidbey Island. (Gardner). 465. Calothrix fusco-violacea Crouan in herb. Thuret and Mus. Paris. Bor- net and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 352. 1886. De Toni. Syll. Algar. 5: 608. 1907. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 87. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 217. 1896. Collins. Pre- liminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Plate XVI. fig. 10. Filaments 8-12 mic. in diameter, .5 mm. in length, gregarious, forming a velvety, indefinite or violet mass, bent and thickened at the base; sheaths close, thin, colorless, uniform, gelatinous and diffluent in upper parts; trich- omes 7-8 mic. in diameter, constricted at joints, at first ending in a short hair which falls off when hormogones are formed, leaving apex truncate; cells shorter than their diameter; heterocysts basal, often worn out; hormo- gones many within the sheath, up to ten times longer than their diameter. Massachusetts. Forming orbicular velvety patches, reddish purple to dark blue-green in color, onPunctaria plantaginea. Wood's Hole. Summer of 1895. (Nott). 466. Calothrix scopulorum (Weber and Mohr) Agardh. Syst. Algar. 70. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 3S3. 1886. De Toni. Syll. Algar. 5: 608. 1907. Harvey. Nereis Boreali-Americana. Part III. 105. 1858. Farlow. List Marine Algae United States. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Kjellman. Algae of the Arctic Sea. 322. 1883. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13; 105. 1886. Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888. Bennett. Plants of Rhode Island. 95. 1888. Martindale. Marine Algae of the New Jersey coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. Collins. Algae. — Rand and Red- field's Flora of Mount Desert Island, Maine. 246. 1894. Rosenvinge. Les Algues Marines du Groenland. Ann. Sci. Nat. Bot. VII. 19: 162. 1894; Deuxieme Memoire sur les Algues marines du Groenland. Medd. om Groen- land. 20: 121. 1898. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 17. no. 805. 1901. Setchell and Gard- Myxophyceae 259 ner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 197. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223, 243. 1905. Borgesen and Jonsson. The Distribution of the Marine Algae ci the Arctic Sea and of the Northernmost Part of the Atlantic. Bot. Faeroes. App. XXV. 1905. Plate XVI. fig. II, 12. Plant mass caespitose, velvety, widely expanded, dark green or olive; filaments 10-18 mic. in diameter, up to i mm. in length, twisted and curled, moderately thickened at the base; sheaths somewhat thick, colorless, yel- lowish brown, or forming yellowish and colorless zones, lamellose in the larger filaments, variously dilated and expanded; trichomes 8-15 mic. in diameter, ending in a hair; heterocysts one to three, basal; hormogones numerous in the sheath, four or five times longer than their diameter. Greenland. Forming "in conjunction with several other algae, a thin stratum over stones within the upper part of the littoral zone. It is scarce here (in the Polar Sea), and nowhere occurs in great masses. It has been found both on exposed and sheltered coasts." Greenland Sea; West coast of Spitzbergen. (Kjellman). Forming a gelatinous cushion upon rocks in the littoral region. (Sorenson). East and west portions. (Borgesen and Jonsson). Newfoundland. On rocks between tides. Quidi Vidi. July 1897. (Holden). Maine. Very common on rocks. Seal Harbor; Little Cran- berry Isle (Collins); Sea Wall (Holden). New Hampshire. (Collins). Massachusetts. On rocks near high water mark. Marblehead. June 1901. (Collins). Rhode Island. Rocks near high water mark. (Bailey and Ol- ney.) Connecticut. On rocks. Stratford Shoals. July, September. (Hol- den). New York. Shores of Long Island. Greenport, Little Egg Harbor. Summer. (Pike). Statin Island. (Pike). New Jersey. Hoboken, Beesleys Point. (Pike). On wharves. Atlantic City. (Morse, Martindale). On wood- work. (Morse). New Jersey. Marine. Hudson: Hoboken; Cape May, Beesley's Point. (Pike). On wharves, Atlantic City. (Morse). Washing- ton. In salt water. Puget Sound. (Saunders). 467. Calothrix contarenii (Zanardini) Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 3: 355- 1886. De Toni. Syll. Algar. S: 610. 1907. Collins. Notes on New England Marine Algae. V. Bull. Torr. Bot. Club. 18: 336. 1891; The Algae of Jamaica. Proc. Am. Acad. 37: 241. 1901. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 11 13. 1903. Plate XVI. fig. 13- Plant mass crustaceous, compact, orbicular, smooth, glistening, black- ish green; filaments 9-1S mic. in diameter, up to i mm. in length, very densely crowded, parallel, erect, moderately fiexuous; decumbent and thick- ened at the base; sheaths somewhat thick, colorless or yellowish, dilated into lamellose, funnel-shaped expansions; trichomes 6-8 mic. in diameter, ending in a slender long hair; cells equal to or shorter than their diameter; heterocysts, one to two, basal. 26o Minnesota Algae Massachusetts. On stones more or less embedded in the sand, a little above low water mark. Revere Beach. January and February. (Collins). West Indies. On wreck on beach. Port Morant, Jamaica. March 1893. (Hum- phrey). On Galaxaura, etc. Santurce, Porto Rico. May 1903. (Howe). 468. Calothrix pulvinata (Mertens) Agardh. Syst. Algar. 71. 1824. Borner and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. 3: 356. 1886. De Toni. Syll. Algar. 5: 610. 1907. Farlow. Marine Algae of New England. 37. 1881. Pike. Check List o£ Marine Algae. Bull. Torr. Bot. Club. 13: 106. 1886. Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888. Bennett. Plants of Rhode Island. 95. 1888. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. Collins. Algae. Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894; Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Collins, Hoiden and Setchell. Phyc. Bor.-Am. Fasc. 20. no. 957. 1902. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 197. 1903. Collins. Notes on Algae. — V. Rhodora. 5: 208. 1903; Phycological Notes of the late Isaac Hoiden. — II. Rhodora. 7: 223. 1905. Plate XVI. fig. 14. Plant mass sponge-like, porous, fasciculate, hairy on the surface, dull green, widely expanded; filaments 15-18 mic. in diameter, 2-3 mm. in length, erect, flexuous, scarcely thickened at the base, agglutinated into irregular fascicles, sparingly branched; branches often opposite; sheaths thick, firm, lamellose, colorless or brownish; trichomes 8-12 mic. in diameter, tapering into a short hair; cells two or three times shorter than their diameter; hormogones four to six times longer than broad, often developed within the sheath; cell contents olive. Maine. Growing in extensive sheets on beams and posts under old tide mill. Harpswell. July 1902; on piles of bridge, outlet of Long Pond. "Rare; the most northern station for this species yet reported." (Collins). Massa- chusetts. On wharves. Wood's Hole. (Farlow). Rhode Island. Newport. (Farlow). Connecticut. On woodwork at or above high water mark. Black Rock; Stratford Shoals; on old hulk. Cook's Point, August, October. (Hoiden). New York. Shores of Long Island: Greenport, Little Egg Harbor. (Pike). New Jersey. On wharves. Atlantic City. (Morse, Martin- dale). Washington. In salt marsh on sticks and old wood. Whidbey Island. August 1899. (Gardner). 469. Calothrix parasitica (Chauvin) Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i; 381. 1875. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 357. 1886. De Toni. Syll. Algar. 5: 612. 1907. Farlow. Marine Algae of New England. 37. 1881. Collins. Notes on New England Marine Algae. II. Bull. Torr. Bot. Club. 10: 55. 1883. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 106. 1886. Col- lins, Hoiden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. iii. 1893. Setchell. Myxophyceae 261 Notes on Cyanophyceae. — III. Erythea. 7: 46. 1899. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Plate XVI. fig. 15, 16. Filaments 9-15 mic. in diameter, .5 mm. in length; gregarious, immersed in the outer cells of Nemalion, blue-green, bulbous and curved at the base (bulb up to 24 mic. in diameter) ; sheaths thin, colorless, often dilated and funnel-shaped at the apex; trichomes 7-8 mic. in diameter, ending in a very long, flexuous hair; cells short; heterocysts basal; hormogones many in the sheath, four or five times longer than the diameter. Maine. (Collins). New Hampshire. (Collins). Massachusetts. Completely covering Nemalion multifidum growing at low water mark between the Oak Bluff and the Camp Meeting landings, at Cottage City. (Collins). Epiphytic on the fronds of Nemalion multifidum. Wood's Holl. July 1895. (Nott). Rhode Island. On Nemalion. New- port. (Farlow). Connecticut. On Nemalion. Stratford Shoals. July. (Holden). 470. Calothrix aeruginea (Kuetzing) Thuret. Essai Class. Nostochinees. Ann. Sci. Nat. Bot. VI. i: 10. 1875. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 358. 1886. De Toni. Syll. Algar. S: 612. 1907. Schramm and Maze. Essai Class. Algues Guadeloupe. 30. 1865. (L e i b- leinia flaccida Crouan). Maze and Schramm. Essai Class. Algues Guadeloupe. 20. 1870-1877. (Lyngbya nemalionis Crouan). Collins. Notes on New England Marine Algae. V. Bull. Torr. Bot. Club. 18: 336. 1891; Preliminary Lists of New England Plants. V. Marine Algae. Rho- dora. 2: 41. 1900; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 241. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 17. no. 804. 1901. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 1905. Vickers. Liste des Algues Marines de la Bar- bade. Ann. Sci. Nat. Bot. VIII. i: 55. 1903. Borgesen and Jonsson. The Distribution of the Marine Algae of the Arctic Sea and of the Northern- most Part of the Atlantic. Botany of the Faeroes. Appendix. XXV. 1905. Plate XVII. fig. I. Filaments 9-12 mic. in diameter, .5 mm. in length, forming a somewhat continuous light blue-green layer on the surfaces of larger algae, decumbent and slightly thickened at the base; sheaths somewhat thick, very often entirely colorless, rarely yellowish in lower parts, uniform, soft, and gelati- nous in the upper portions; trichomes 7-9 mic. in diameter, ending in a gradually tapering hair; cells short; heterocysts one or two at the base, few or none intercalary, hormogones numerous within the sheath, four to six times longer than wide. Maine. Cape Rosier. July 1890; among other algae on woodwork of old v-harf, Otter Creek, Mount Desert Island. July 1900. (Collins). Massa- chusetts. (Collins). Connecticut. Forming a coating on iron piles be- tween tide marks. Black Rock Beacon. August, October. (Holden). West Indies. On Dasya arbuscula. Montego Bay, Jamaica. June 1900. 262 Minnesota Algae (Pease and Butler). Rocky Bay, Hastings, Barbados. (Vickers). Hawaii. Growing' on other algae. In pools at half tide. Waianae, Waikiki and Laie Point, Oahu. May and June 1900. (Tilden). 471. Calothrix prolifera Flahault in Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 3: 361. 1886. De Toni. Syll. Algar. S: 615. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1168. 1904. (Calothrix Crustacea forma prolifera (Flah.) Collins). Col- lins. New species, etc., issued in the Phycotheca Boreali-Americana. Rho- dora. 8: 105. 1906. Plant mass expanded, velvety, brownish green; filaments 15-18 mic. in diameter, 2 mm. in length, somewhat flexuous, curved and distinctly thick- ened at the base, here and there branched; branches issuing in the region of the heterocyst as in Tolypothrix; sheaths thick, lamellose, firm, colorless in upper portions, yellowish below, ocreate; ocreae dilated and torn; trich- omes 8-12 mic. in diameter, tapering at the apex into a hair; cells three or four times shorter than their diameter; heterocysts one or two at the base, many scattered through the trichome. California. Among other algae, on boards wet with salt water. Alameda. January 1904. (Gardner). 472. Calothrix fasciculata Agardh. Syst. Algar. 71. 1824. Bornet and Fla- hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 361. 1886. De Toni. Syll. Algar. S: 615. 1907. Collins. Notes on New England Marine Algae. V. Bull. Torr. Bot. Club. 18: 336. 1891. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 6. no. 261. 1897. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Plant mass caespitose, velvety, expanded, blackish green; filaments 12- 21 mic. in diameter, 2-3 mm. in length, erect, somewhat flexuous, a little thickened at the base, when young unbranched, later branched; false branches formed in two ways: sometimes scattered and lateral, solitary or in pairs, sometimes fasciculately crowded on one side of the middle portion of the filament; sheaths moderately thick, lamellose, firm, uniform or di- lated, colorless or with age becoming yellowish brown; trichomes 8-12 mic. in diameter, ending in a hair; cells two or three times shorter than the diameter; heterocysts basal and, in mature filaments, few or numerous throughout the trichome; cell contents blue-green. Maine. On rocks between tide marks. Cape Rosier. July 1889; on dead shells. Cape Rosier, July 1895. (Collins). Massachusetts. (Collins). Rhode Island. (Collins). Forma incrustans Collins. Notes on Algae. — I. Rhodora. i: 13. 1899. De Toni. 1. c. 616. Collins. Notes on New England Marine Algae. V. Bull. Torr. Bot. Club. 18: 336. 1891. (C. contarenii Collins). Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 12. no. 561. 1899. Collins. Notes on Algae. — II. Rhodora. i: 13. 1900; Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Myxophyceae 263 Plant mass crustaceous, flattened; filaments 8-12 mic. in diameter, more slender than in the typical form. Massachusetts. On rocks in littoral zone. Revere Beach. September :89s. (Collins). 473. Calothrix vivipara Harvey. Nereis Boreali-Americana. Part III. 106. 1858. Hornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 362. 1886. De Toni. Syll. Algar. 5: 616. 1907. Farlow. List Marine Algae U. S. Proc. Am. Acad. Arts Sci. 10: 380. 1875; Marine Algae of New England. 37. 1881. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 1307. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. 12. no. 560. 1899. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2 : 41. 1900. Plant mass widely expanded, velvety, blackish green; filaments 12-24 mic. in diameter, 3-5 mm. in length, decumbent and interwoven at the base, becoming erect, somewhat flexuous, branched; false branches in pairs, issuing from the filament as in Scytonema; sheaths thick, gelatinous, uni- form, yellowish brown, somewhat opaque; irichomes 9-15 mic. in diame- ter, tapering very gradually from base to apex, ending in a hair; cells equal to or shorter than their diameter; heterocysts basal and a few scattered through the trichome; cell contents olive green. Massachusetts. Forming patches on rocks and growing also on other algae. Nahant; Wood's HoU. (Farlow). In upper tide pools on smooth rocks. Marblehead. August 1895. (Collins). Rhode Island. (Bailey). Sea- connet Point. (Farlow). 474. Calothrix pilosa Harvey. Nereis Boreali-Americana. Part III. 106. pi. 48 C. 1858. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 363. 1886. De Toni. Syll. Algar. 5: 614. 1907. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. (Scytonema submarinum Crn.). Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 859. 1901. Collins. The Algae of Jamaica. Proc. Am. Acad. 37: 242. 1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1167. 1904. Plant mass caespitose, widely expanded, black or dark blue-green; filaments 10-40 mic. in diameter, 2-10 mm. in length, decumbent and inter- woven at the base, erect at the apices, elongate, rigid, free or growing to- gether laterally in fascicles, distinctly thicker in upper portions; sheaths hard, thick, at first orange, finally yellowish brown, opaque, uniform; trich- omas 10-20 mic. in diameter, briefly tapering at the apex; terminating in a hemispherical cell, here and there interrupted by heterocysts; cell contents olive brown. Florida. Forming blackish or dark brown, pilose strata of indefinite ex- tent. On rocks between tide marks. Key West. (Harvey). California. Forming a black velvety covering on the bottoms of small pools in the rocks above high water mark, but filled with salt water from the spray and higher waves, though often much concentrated by the sun. Near Point Carmel, Monterey County. June 1901. (Setchell). West Indies. Guade- loupe. (Maze). On Bostrychia tenella. Port Antonio, Jamaica. 264 Minnesota Algae August 1894. (Pease and Butler). On rocks, etc., littoral. Porto Rico. May 1903. (Howe). 475. Calothrix Crustacea Thuret. Notes Algologiques. i: 13. pi. 4. 1878. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 359. 1886. De Toni. Syll. Algar. 5: 613. 1907. Maze and Schramm. Essai Class. Algues Guadeloupe. 31. 1870-1877. Farlow, Anderson and Eaton. Algae Am. Bor. Exsicc. no. 49. 1877. Far- low. Marine Algae of New England. 36. 1881. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 105. 1886. Collins. Algae from Atlantic City, N. J. Bull. Torr. Bot. Club. 15: 310. 1888; Algae of Middlesex County. 13. 1888; Marine Algae of Nantucket. 5. 1888. Bennett. Plants of Rhode Island. 95. 1888. Martindale. Marine Algae of the New Jersey coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. WoUe and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 602. 1889. Murray. Catalogue of the Marine Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889.(5 ch i z o- siphon pilosus Crn.). Anderson. List of California Marine Algae, with Notes. Zoe. 2: 218. 1891. Collins, Holden and Setchell. Phyc. Bor.- Am. Fasc. i. no. 10. 1895. Collins. Preliminary Lists of New England Plants.- — V. Marine Algae. Rhodora. 2: 41. 1900. Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 197. 1903. Col- lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1212. 1905. Col- lins. Phycological Notes of the late Isaac Holden. — 11. Rhodora. 7: 223. 1905. Plate XVII. fig. 2-6. Plant mass caespitose, velvety, widely expanded, blackish green or brownish; filaments 12-40 mic. in diameter, 1-2 mm. in length, erect, densely crowded, a little thickened at the base; sheaths somewhat thick, colorless or yellowish brown, in the older filaments lamellose, variously dilated and expanded in upper portions; trichomes 8-15 mic. in diameter, ending in a long hair; cells short; heterocysts one to three at the base, often many scattered through the trichome; hormogones many within the sheath, four 01 five times longer than wide; gonidia oblong, cylindrical, smooth, in series. Canada; On other algae. Malpeque, Prince Edward Island. (FauU). Maine. (Collins). New Hampshire. (Collins). Massachusetts. On Ulva in salt water. Medford; Everett; Brant Point and Polpis. (Collins). On algae of all kinds and on rocks. Wood's Holl. (Farlow). Rhode Island. Narragansett Bay. (Bennett). (Collins). Connecticut. Clothing fronds of Cladophora, Enteromorpha and other algae, also on rocks. Woodmont. July 1892; on algae and rocks, Stratford Shoals; Cook's Point, July, September, October. (Holden). New York. Shores of Long Island: Bay Ridge, Fort Hamilton. Summer. (Pike). New Jersey. On rockweed. Atlantic Ocean. (MorSc, Martindale). Florida. (Harvey, Mel- ville). Washington. Floating, on rocks, clay banks, wood, etc., in brack- ish lagoon. Whidbey Island; Keyport, Kitsap County. (Gardner). Cal- ifornia. Common. On rocks, wharves and other algae. (Anderson). On grass and weeds, salt marsh. Alameda. April 1904. (Gardner). West Myxophyceae 265 Indies. Guadeloupe. (Maze). Hawaii. On other algae. In tide pools at half tide. Waianae, Oahu. May 1900. (Tilden). Forma simulans Collins in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 29. no. 1406. 1907. Filaments stout; color from light blue-green to purple or dull rose. Massachusetts. On Z o s t e r a. Mattapoisett. October 1906. Appearing like C. confervicola (Roth) Ag., but with intercalary heterocysts. (Collins). 476. Calothrix epiphytica West and West. Welwitsch's African Freshwater Algae. Journ. of Bot. 35: 240. 1897. De Toni. Syll. Algar. 5: 621. 1907. West and West. Journ. Linn. Soc. Bot. 34: 285. 1898-1900. Filaments 5-7.5 mic. in diameter at the base, 250 mic. rarely up to 350 mic. in length, minute, attached to larger algae, solitary or somewhat gre- garious, gradually tapering from base to apex; sheaths somewhat thick, transparent and colorless; trichomes 3.5-4 mic. in diameter at the base, ending in ^ very thin hair at the apex; cells equal to the diameter, in length, or at the base a little shorter; heterocysts basal, solitary, small. West Indies. Epiphytic on Tolypothrix. Dominica. (Elliott). 477. Calothrix scytonemicola n. sp. Plate XVII. fig. 7. Filaments 7-8 mic. in diameter, isolated or in small groups, the lower portion attached to host, the remainder erect and free, ending in a hair point; sheaths not distinct; heterocj'Sts 8 mic. in diameter, basal, usually two in number, somewhat globose. Hawaii. Growing on filaments of Scytonema crispum. Very abundant. In stagnant water in pool on beach, among roots of Water hya- cinth. Meheiva, Makao, Koolauloa, Oahu. June 1900. (Tilden). 478. Calothrix stagnalis Gomont. Note sur un Calothrix sporifere. (Calo- thrix stagnalissp. n.). Morot. Journ. de Bot. 9: 197. f. i, 2. 1895. De Toni. Syll. Algar. 5: 619. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 1114. 1903. Collins. Notes on Algae. — VII. Rhodora. 8: 123. 1906. Plate XVII. fig. 8, 9. Filaments 8-10 mic. in diameter in the middle portions, up to i mm. in length, gregarious, radiating, decumbent and thickened at the base, erect, sickle-shaped; sheaths thin, close, papery, transparent; trichomes 6-9 mic. in diameter, especially constricted at joints, gradually tapering into a hair; cells 6-10 mic. in diameter, unequal, usually subquadrate or longer than the diameter; heterocysts in pairs, basal, yellowish, spherical or somewhat quadrate; gonidia lo-li mic. in width (with sheath 12-14 mic wide), 26-40 mfc. in length, yellowish; wall of gonidium smooth. Massachusetts. In stellate tufts, rather sparsely distributed on various filamentous algae, in swamp. Medford. August 1903. (Collins). 479. Calothrix fusca (Kuetzing) Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 3: 364- 1886. De Toni. Syll. Algar. 5: 617. 1907. 266 Minnesota Algae Maze and Schramm. Essai Class. Algues Guadeloupe. 31 . 1877. (M a s- tichothrix longissima Crouan). Wolle. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 138. 1877. (Mastigonema fusca Wolle). Fresh Water Algae III. Bull. Torr. Bot. Club. 6: 184. 1877. (M a s- tigothrix aeruginea Kuetz. Bennett. Plants of Rhode Island. 114. 1888. (Mastigonema aeruginosum (Kg.) Kirchn.). Col- lins. Algae of Middlesex County. 13. 1888. (Mastigonema aerugi- neum Kirchn.). Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. Minn. Bot. Studies. 1 : 30. 1894. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. i. no. 11. 1895. Col- lins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metropolitan Park Commission, Massa- chusetts. 127. 1896. Collins. The Algae of Jamaica. Proc. Am. Acad. 37: 241. 1901. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. igoi. Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903. Setchell and Gardner. Al- gae of Northwestern America. Univ. Calif. Pub. Bot. i: 197. 1903. Col- lins. The Algae of the Flume. Rhodora. 6: 230. 1904. Lemmermann. Al- genfl. Sandwich. -Inseln. Bot. Jahrb. 34: 627. 1905. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 237. 1905. Collins, Hol- den and Setchell. Phyc. Bor.-Am. Fasc. 29. no. 1407. 1907. Plate XVII. fig. 10, 11. Filaments 10-12 mic. in diameter, 2-3 decimill. in length, scattered or gregarious, living within the colonies of gelatinous algae, curved and bul- bous-inflated at the base (bulb 15 mic. in diameter) ; sheaths thick, colorless, gelatinous, diffluent at the apex; trichomes 7-8 mic. in diameter, ending in a long hair; cells short; heterocysts one or two at the base. Alaska. Embedded in the gelatinous coating of Batrachospermum vagum from a freshwater pond. Cook Inlet; Kadiak Island. (Saunders). Occurring singly or few together in the jelly of other species of algae. Near Iliuliuk, Unalaska. (Setchell and Lawson). New Hampshire. On Batra- chospermum vagum. Lake Chocorua. September 1906; on wall of Flume. (Collins). Massachusetts. On Batrachospermum. Billerica. (Faxon). Among other algae on rocks at Cascade, Middlesex Fells. (Collins). Rhode Island. Easton's Pond, Newport. (Bennett). Connecticut. On Batrachospermum vagum. Pool below Factory Pond Dam. Octo- ber. (Holden). New Jersey. October 1892. (Peters). Pennsylvania. (Wolle). Ohio. In plankton. Lake Erie. Put-in-Bay. (Snow). Minne- sota. In pool near Lake Kilpatrick. June 1893. (Ballard). West Indies. Giuadeloupe. (Conquerant). Hawaii. In ditches between Honolulu and Waikiki, Oahu. 1896-1897. (Schauinsland). 480. Calothrix sandvicensis (Nordstedt) Schmidle. Zur Entwickelung einer Zygnema und Calothrix. Flora. 84: 170. pi. 5. f. 12-14. 1897. De Toni. Syll. Algar. 5: 618. 1907. Nordstedt. De Algis Aquae Dulcis et de CharaCeis ex Insulis Sand- vicensibus a Sv. Berggren 1875 reportatis. 5. pi. i. f. 3. 1878. (L o p h o- p odium sandvicense Nordst.). Lemmermann. Algenfl. Sandwich.- Inseln. Bot. Jahrb. 34: 627. 1905. M3^ophyceae 267 Plate XVII. fig. 12. Filaments 5-15 mic. in diameter, sometimes thickened in lower portion; trichomes 3.5-5.5 mic. in diameter; heterocysts equal to or exceeding the basal cells in diameter; gonidia 8 mic. in diameter, 8-10 mic. in length, single, rarely in pairs, somewhat quadrate, angular-convex, rotund. Hawaii. On filaments ofPithophora affinis. Near Hilo, Hawaii. July 1889. (Lauterbach). 481. Calothrix breviarticulata West and West. Welwitsch's African Fresh- water Algae. Journ. of Bot. 35: 240. 1897. De Toni. Syll. Algar. 5: 620. 1907. West. West Indian Freshwater Algae. Journ. of Bot. 42: 293. 1904. Filaments 15-16 mic. at the base, 11.5-12.5 mic. in middle portions, up to 380 mic. in length, solitary or gregarious, gradually tapering from base to apex; sheaths thick, lamellose, becoming brownish black in old plants; trich- omes 8.5 mic. in diameter at the base, 5.5-7.5 mic. in middle portions; cells disc-shaped, four or five times shorter than their diameter; heterocysts soli- tary, basal, hemispherical; cell contents pale blue-green. West Indies. Epiphytic on Vaucheria species. Royal Botanical Gardens, St. Ann's, Trinidad. (Howard). • 482. Calothrix violacea (Wolle) De Toni. Syll. Algar. 5: 619. 1907. WoUe. Fresh Water Algae. II. Bull. Torn Bot. Club. 6: 138. 1877- (M astigonema violacea Wolle). Filaments 15-18 mic. in diameter, parasitic, usually in clusters, ten or twelve arising from each base, "a sort of warty excrescence," when young blue-green, changing when mature to purplish iron or amethyst color, final- ly becoming olivaceous brown; sheaths wide, often truncate, almost color- less; trichomes 7-9 mic. in diameter; lower cells short, two or four times shorter than the diameter, upper cells longer, finally four or six times as long as wide; heterocysts more or less compressed. Pennsylvania. "Parasitic on Plectonema in shallow river waters." < Wolle). 483. Calothrix adscendens (Naegeli) Bornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 3: 365- 1886. De Toni. Syll. Algar. 5: 620. 1907. Wolle. Algae Exsicc. no. 83. (M astigonema parasiticum Wolle). Setchell. Notes on Cyanophyceae. III. Erythea. 7: 46. 1899. Plate XVII. fig. 13, 14- Filaments 18-24 mic. in diameter, i mm. in length, scattered or gre- garious, light blue-green in dried material, tapering from base to apex; sheaths thick, gelatinous, lamellose, finally becoming ocreate, transparent; trichomes 12 mic. in diameter in the middle portions; cells equal to the .Tanular, green tinged with brown; heterocysts 10-12 mic. in diameter. Pennsylvania. Wolle. 528. Rivularia atra Roth. Catalecta Botanica. 3: 340. 1806. Bornet 'and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 4: 353. 1886, De Toni. Syll. Algar. 5: 664. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 50. 1872. (,2. onotrichia minutula Rab.). Farlow. List Marine Algae United States. Proc. Am. Acad. Arts Sci. 10: 380. 1875. Farlow. Marine Algae of New England. 38. pi. 2. f. 2. 1881. Kjellman. Algae of the Arctic Sea. 321. 1883. (Rivularia hemispherica (L.) Aresch). Farlow. Notes on Fresh-Water Algae. Bot. Gaz. 8: 224. 1883. Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 106. 1886. Collins. Marine Algae of Nantucket. 5. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. i88g. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i: 91. 1889. Anderson. List of California Marine Algae, with Notes Zoe. 2: 218. 1891. Collins. Algae. — Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894. Rosenvinge. Les Algues Marines du Groenland. Ann. Sci. Nat. Bot. VII. 19: 162. 1894 Collins, Holden and Setchell. Phyc. Bor.-Am. Fiasc. 8. no. 357. 1897. Ros- envinge. Deuxieme Memoire sur les Algues Marines du Groenland. Medd. om Groenland. 20: 121. 1898. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 43. 1900; Phycological Notes of tho late Isaac Holden.— II. Rhodora. 7: 224. 1905. Borgesen and Jonsson. The Distribution of the Marine Algae of the Arctic Sea and of the North ernmost Part of the Atlantic. Bot. Faeroes. App. XXV. 1905. Plate XX. fig. 10. Colonies up to 4 mm. in diameter, spherical, solitary or -confluent, dark 290 Minnesota Algae green; filaments crowded; sheaths close, narrow, scarcely distinct, above widened, hyaline or yellowish; trichomes 2.5-5 mic in diameter, ending in a thin hair; lower cells scarcely longer than the diameter, upper cells shorj;- er; cell contents blue-green. Greenland. In upper part of littoral zone on sheltered coasts, gregari- ous, but in small numbers. West coast; Baffin Bay, at Tessarmiut, Amera- lik, Pikitsok. (Kjellman). Western part. (Borgesen and Jonsson). Eastern part, south of 70° lat. N. (Rosenvinge). Canada. On rocks and other a^gae. Malpeque, Prince Edward Island. (Faull). New England. Com- mon along the whole coast, on stones, algae and stalks of S p a r t i n a. (Farlow). Maine. Common in upper tide pools. (Collins). Se4 Wall. (Holden). New Hampshire. (Collins). Massachusetts. On shells in harbor; on sides of rock pools, Marblehead, August 1897. (Collins). Rhode Island. (Collins). Connecticut. On turf of S p a r t i n a. Charles Island. September. (Holden). New York. Shores of Long Island. Hell Gate, Flushing Bay. (Pike). New Jersey. Marine. On stones. Atlantic City. (Martindale). California. Common. On stones, algae and other material. (Anderson). ^ I Var. confiuens (Kuetzing) Bornet. Les Algues de Schousboe. 29. 1892. De Toni. 1. c. 666. Colonies confluent forming a layer or mass. Maine. On ground between tide marks. Cape Rosier. July 1897. Con- necticut. On turf of Spartina roots. Charles Island, near Milford. Sep- tember 1896. (Holden). 529. Rivularia haematites (DC.) Agardh. Syst. Algar. 26. 1824. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 4: 350. 1886. De Toni. Syll. Algar. 5: 668. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 49. 1872. (Zo- notricha parcezonata Wood). Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 184. 1877. (Zonotrichia haematites Rabenh.). Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. Soc. Bot. 17: 8. 1880. (Zonotrichia fluviatilis Kuetz.). Campbell. Plants of the Detroit River. Bull. Torr. Bot. Club. 13: 93. 1886. (Rivularia calcarea Eng. Bot.). Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. (Isactis fluviatilis (Rab.) Kirchn.). Saunders. Pro- tophyta-Phycophyta. Flora of Nebraska. 25. pi. 3. f. 31. 1894. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 88. 1896. Tilden. American Al- gae. Cent. III. no. 289. 1898; Observations on some West American Thermal Algae. Bot. Gaz. 25: 96. pi. 9. f. 6-9. 1898. Plate XX. fig. 11-14. Colonies hemispherical, finally confluent and forming a hard, stony crust, up to a centimeter in thickness, green or olive in color, blue-green when dried, zoned in the interior; filaments dense; sheaths close, hyaline or rarely yellowish, fragile, strongly refringent, above ocreate, funnel- shaped, dilated; trichomes 4-7.5 mic. in diameter, ending in a very long Myxophyceae 291 hair; lower cells twice as long as the diameter, those in the middle of ths trichome quadrate, the upper ones half as long as wide. Arctic Regions. "Forming firm, gelatinous bosses on pebbles in running water." In streams from a lake, winter-quarters. 82° 27' N., 61° 22' W. (Moss). Canada. Forming a calcareous crust on botton of ditch. Natural Sulphur Springs, Banfif, Alberta. 13 August 1897. (Tilden). New York. Forming a slippery grayish, or grayish flesh-colored coating on rocks kept wet and glistening with foam and spray. "Cave of the Winds," Niagara Falls. (Wood). "Growing on rocks as glossy blackish, very hard and slippery fronds or masses, which varied in size from that of very small shot to nearly half an inch in length." (Wood). New Jersey. Rocky margins of Green Pond, Morris. (Wolle). Pennsylvania. Stones. Sus- quehanna River. (Wolle). Michigan. Grosse Isle, near the mouth of the Detroit River. Summer of 1885. (Campbell). Nebraska. Minden. (Saun- ders). Colorado. Forming a reddish crust upon dripping rocks. Bridal Veil Falls, Williams Canon, near Manitou. (Setchell). 530. Rivularia dura Roth. Neue Beitrage zur Botanik. 273. 1802. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 4: 347- 1886. De Toni. Syll. Algar. 5: 674. 1907. Wood. Contr. Hist. Fresh-Water Algae North America. 50. pi. 4. f. 5. 1872. (Dasyactis mollis Wood). Campbell. Plants of the Detroit River. Bull. Torr. Bot. Club. 13: 93. 1886. Wolle. Fresh- Water Algae U. S. 249. pi. 179. f. 1-3. 1887. Bennett. Plants of Rhode. Island. 114. 1888. Collins. Algae of Middlesex County. 13. 1888. (R. radians Thur.). Wolle and Martindale. Algae. Britten's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. 1889. Mackenzie. A Preliminary List of Algae collected in the Neighborhood of Toronto. Proc. Can. Inst. III. 7: 270. 1890. Snow. The Plankton Algae of Lake Erie. U. S. Fish Comm. Bull, for 1902. 22: 392. 1903. Plate XX. fig. IS. Colonies small, 5 mm. in diameter, somewhat hard, indurated with cal- cium carbonate, blackish green; filaments dense; sheaths close, not lamel- lose, uniform, hyaline; trichomes 4-9 mic. in diameter, ending in a long, very thin hair; lower cells equal in length to the diameter, upper ones almost three times shorter than wide; cell contents blue-green, sometimes changing to violet when dried. Canada. High Park, Toronto. (Mackenzie). Massachusetts. (Col- lins). Rhode Island. Not uncommon. (Bennett). New Jersey. At- tached to aquatic plants in ponds. (Wolle). Ohio. Plankton. Lake Erie. Put-in-Bay. (Snow). Michigan. Attached to water plants in a small bog near mouth of Carp River in northern part of state. (Wood). Grosse Isle, near the mouth of the Detroit River. Summer of 1885. (Campbell). 531. Rivularia coadunata (Sommerfelt) Foslie. Contributions to Knowl- edge of the Marine Algae of Norway. II. Tromsoe Mus. Aarsheft. 14: 21. 1891. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. 292 Minnesota Algae Bot. VII. 4: 352. 1886. (R. biasolettiana Menegh.). De Toni. Syll. Algar. 5: 667. 1907. Collins. Notes on New England Algae. Bull. Torr. Bot. Club. 9: 69. 1882. (Rivularia warreniae Thur.). Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 427. 1895. Tilden, American Algae. Cent. II. no. 166. 1896. Collins, Holden and Setchell. Pliyc. Bor.-Am. Fasc. 8. no. 358. 1897. Tilden. List of Fresh- Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 27. 1898. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 43. 1900. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 18. no. 860. 1901. Saunders. The Algae. Harriman Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. 1901. Tilden. Ameri- can Algae. Cent. VI. no. S7o. 1902. Setchell and Gardner. Algae of North- western America. Univ. Calif. Pub. Bot. l: 198. 1903. Plate XX. fig. 16, 17. Colonies at first hemispherical, afterwards expanded into an olive or blackish, gelatinous, crustaceous, cushion-like layer, 2^8 mm. in thickness, indurated with calcium carbonate in the interior; filaments about 18 mic. Ill diameter, approximate; sheaths wide, lamellose, colorless or yellowish, or showing transverse zones, ocreate; ocreae dilated, funnel-shaped; trich- omes 5-9 mic. in diameter, ending in a very thin, long, flexuous hair; lower cells a little shorter than the diameter, the upper ones one-third as long as broad; cell contents blue-green; heterocysts oblong, basal, one to three, rarely intercalary. Alaska. On dripping rocks, on roots, etc., in fresh or brackish water. West shore of Amaknak Island, Bay of Unalaska; at mouth of creek, Iliu- liuk, Unalaska. (Setchell and Lawson). Forming minute, hard, dark bluish green thalli, 1-3 mm. in diameter, which finally become agglutinated into iiollow, indefinite masses. On rocks in freshwater streams. Juneau; Glacier Bay. (Saunders). Canada. On sandstone rocks just above high tide, but submerged or at least washed by waves during storms. Minnesota Seaside Station, Port Renfrew, Vancouver Island, British Columbia. December 1901 (Tilden). New Hampshire. (Collins). Massachusetts. Growing on a rock, above high water mark but where the spray formed little pools in rough weather. Marblehead. September 1881; in moist places just above high water mark. Marblehead. June 1901. (Collins). Rhode Island. (Col- lins). Connecticut. Occurring in fairly typical form in perfectly fresh water. Gardner's Lake. Eastern part of the state. (Setchell). South Dakota. On rocks at edge of lake. Big Stone Lake. October 1895. (Grif- fiths). Washington. East Sound, Orcas Island. (Gardner). California. On dripping vertical faces of the cliff, just above high water mark. Carmel Bay, Monterey County. December 1896. (Nott and Setchell). 532. Rivularia bornetiana Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. Bot. Club. 22: 426. 1895. De Toni. Syll. Al- gar. s: 666. 1907. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 4. no. 157. 1896. Myxophyceae 293 Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rho- dora. 2: 43. 1900. Colonies i mm. to more than a centimeter in diameter, solid, spherical, sometimes coalescing into a cylindrical mass S-8 cm. long, rather firm, deep bluish black when young, later becoming light olive green or pale yellow, not incrusted with lime; filaments 8-20 mic. in diameter, radiating from the center, flexuous in older colonies; sheaths wide, conspicuous, colorless to deep brown in color, very much lamellose and ocreate above; trichomes usually 4 mic. in diameter, occasionally reaching 16 mic, very torulose when young, very little so when older; terminal hairs long and slender in jounger plants, almost wanting in the older ones; cells from one-half to five times as long as broad; transverse walls distinct in younger trichomes, very obscure in older specimens; cell contents provided with a few scat- tered granules, light blue; heterocysts 6-8 mic. in diameter, basal, depressed spherical or ellipsoidal in shape. Nova Scotia. (Holden, Setchell). Rhode Island. Forming globular Ihalli on Ruppia maritima in brackish water. Watch Hill Pond, Watch Hill. September 1892. (Setchell). 533^ Rivularia mexicana (Kuetzing) Rabenhorst. Fl. Eur. Algar. 2: 222. 1865. De Toni. Syll. Algar. S: 676. 1907. Colonies soft, gelatinous, somewhat spherical or irregular, pale green, at first attached, finally floating free; trichomes 8-10 mic. in diameter, loose- ly entangled, flagelliform, tapering into a golorless hair at the apex. Mexico. In stagnant water. (Miiller). 534. Rivtilaria microscopica Dickie. Notes on the Algae. Sutherland's Journal of a Voyage in Baffin's Bay and Barrow Straits in the Years 1850-51. 2: 193. 1852. De Toni. Syll. Algar. 5: 677. 1907. Kjellman. Algae of the Arctic Sea. 322. 1883. Arctic Regions. Growing on Enteromorpha com press a. American Arctic Sea; Assistance Bay and "other localities." (Dickie). 535. Zonotrichia minutula Wood. Contr. Hist. Fresh-Water Algae North America. 50. 1872. De Toni. Syll. Algar. 5: 675. 1907. Colonies very small, somewhat spherical, not distinctly zoned, rather soft, not impregnated with calcium carbonate, blackish green; internal fila- ments very distinctly fasciculately branched; sheaths thick, ample, often pale orange brown, with their apices mostly colorless, torn and open; trich- omes 3-5 mic. in diameter; cells short; heterocysts 6 mic. in diameter, ovate to spherical. New York. Forming very small, blackish green, subglobo'se masses, attached to mosses. Clear Pond, Adirondack Mountains. (Wood). 536. Zonotrichia mollis Wood. Contr. Hist. Fresh-Water Algae North America. 48. pi. 4- f- 3- 1872. De Toni. Syll. Algar. 5: 675. ,1907. Colonies somewhat hemispherical, gregarious, often confluent into a mammillose stratum, somewhat soft, grey or flesh-colored, slightly 294 Minnesota Algae zoned; filaments up to 4.2 mic. in diameter, very long, narrow, flexuous; sheaths close, colorless, firm, not fibrous; trichomas up to 2 mic. in diame- ter, often interrupted; transverse walls visible; cells equal to up to four times longer than broad; heterocysts single, spherical. New York. On dripping rocks. Cave of the Winds, Niagara. (Wood). Genus BRACHYTRICHIA Zanardini. Phyc. Indie. Pugillus. 24. 1872. Colonies at first solid, finally becoming hollow, made up of Nostoc- like filaments embedded in gelatin; filaments flexuously curved, parallel, above tapering and drawn out into a hair at the apex, very much branched; sheaths distinct in the young filaments, tubular, finally becoming confluent and invisible; heterocysts intercalary, arranged without any order. 537. Brachytrichia quoyi (Agardh) Hornet and Flahault. Revis. des Nos- toc. Ann. Sci. Nat. Bot. VII. 4: 373. 1886. De Torii. Syll. Algar. 5: 680. 1907. Farlow. List of the Marine Algae of the United States, is. 1876. (Ri vu- laria nitida?). Bornet in Farlow, Anderson and Eaton. Algae Am. Bor. Exsicc. no. 45. 1876. (Hormactis farlowii Born.) ; in Farlow. Marine Algae of New England. 39. pi. 2. f. I. 1881. (Hormactis quoyi (Ag.) Bornet). Pike. Check List of Marine Algae. Bull. Torr. Bot. Club. 13: 106. 1886. Martindale. Marine Algae of the New Jersey Coast and Adjacent Waters of Staten Island. Mem. Torr. Bot. Club, i : 91. 1889. Wolle and Martindale. Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 604. 1889. Hauck and Richter. Phyk. Univ. no. 681. 1890. Schiveley. Hormactis quoyii. Proc. Phil. Acad. 1890: 497. 1891. Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 1197. 1893. Collins, Holden and Setchell. Phyc. Bor.-Am. Ease. i. no. 8. 1895. Col- lins. Preliminary Lists of New England Plants. — V. Marine Algae. Rho- dora. 2: 41. 1900. Plate XX. fig. 18. Colonies up to 5 cm. in diameter, plicate-expanded and buUate, conflu- ent, blackish green. Massachusetts. Growing on F u c u s at half tide. Wood's Holl. (Far- low). Falmouth; Wood's Holl. July 1892. (Collins). Forming bladders on stems of old Fucus vesiculosus L. Quamquisset Harbor, Fal- mouth. August 1890. (Setchell). New York. Shores of Long Island. Greenport. July. (Pike). New Jersey. Atlantic City. (Morse). Cal- ifornia. Pacific Ocean. (Grunow). Families and Genera not well understood. Genus ASTEROTHRIX Kuetzing. Phyc. Gen. 20Q. 1843. Filaments very rigid, nude, with cuspidate, obtuse or acute ends, some- what genuflexuous, branched at right angles; transverse walls usually in- distinct; propagation unknown. Myxophyceae 295 538. Asterothrix creginii Wolle. Fresh-Water Algae U. S. 322. pi. 209. f. 22-25. 1887. De Toni. Syll. Algar. 5: 683. 1907. Bennett. Plants of Rhode Island. 115. 1888. Plate XX. fig. 19, 20. Eilaments 2-4 mic. in diameter, short, pale blue-green; branches given off at right angles, cross-like; trichomes often moniliform; transverse walls usually evident. Rhode Island. Pocasset. (Bennett). Kansas. Norton. (Cregin). Genus GONIOTRICHUM Kuetzing. Phyc. Gen. 244. 1843. Colonies erect, filamentous, dichotomously or rarely unilaterally branched; filaments at first unbranched, finally branched, by the repeated division of cells at right angles; branches more or less regularly branched; cells showing a central star-shaped chromatophore, a central pyr'enoid, and an eccentric nucleus; cell walls diffluent into a gelatinous mucus which forms a thick, gelatinous envelope surrounding each cell. I Colonies filamentous, solid, gelatinous, occasionally branched G. humphreyi II Filaments single or associated in rose-red bundles (colonies), usually thickened at the base, tapering above G. elegans I 539. Goniotrichum humphreyi Collins in Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 9. no. 421. 1898; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 251. 1901. De Toni. Syll. Algar. 5: 688. 1907. Colonies filamentous, solid, gelatinous, occasionally forking or dividing into several branches, the terminal portion consisting of a single series of cells, the older part containing numerous cells irregularly placed near the surface of the filament; lateral branches abundant, simple, issuing nearly at a right angle, composed of a single series of cells. West Indies. On woodwork of wreck. St. Ann's Bay. March 1893. (Humphrey). 540. Goniotrichum elegans (Chauvin) Zanardini. Notizie intorno alle Cel- lulari Marine delle Lagune e dei Litorali de Venezia. Atti R. 1st. Ven. I. 6: 6g. 1847. De Toni. Syll. Algar. 5: 687. 1907. Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 251. 1901. Filaments 20 mic. in diameter, .3-6 mm. in length, single or associated in rose-red bundles or colonies, usually thickened at the base, above taper- ing, rarely unbranched, often somewhat dichotomously branched; cells 7-10 mic. in diameter, in one or many series, spherical or elliptical; cell con- tents violet or reddish changing to green. 296 Minnesota Algae Canada. In tufts onChondrus crispus. Malpeque, Prince Edward Island. (FauII). West Indies. Among other algae on Lauren cia o b- t u s a. Near Kingston. (Duerden.). Genus ASTEROCYTIS Gobi. Kurzer Bericht Algol. Excur. St. Petersb. Gesellsch. Nat. 10: 93. 1879. Colonies erect, filamentous, branched; cells ellipsoid, irregularly ar- ranged, reproduction by means of non-motile, naked gonidia; sexual re- production unknown. . 541. Asterocytis ramosa (Thwaites) Gobi. Kurzer Bericht iiber die im Summer 1878 ausgefuhrte Algologische Excursion. St. Petersb. Gesellsch. d. Naturf. 10: 93. 1879. De Toni. Syll. Algar. S; 690. 1907. Collins. Notes on New England Marine Algae. V. Biill. Terr. Bot. Club. 18: 336. 1891. (G o n i o 1 1 i c hu m ramosum (Thwaites) Hauck). Plate XX. fig. 21. . It; Filaments 12-20 mic. in diameter, i-io mm. long, associated in green or lead-colored fascicles; branching somewhat dichotomous or unilateral; cells 5-8 mic. in diameter, 8-20 mic. in length, in a single series, cylindrical- rotund or elongate; cell contents lead-colored or green. Massachusetts. In small quantity among other algae. Quincy. (Collins). Genus GLAUCOCYSTIS Itzigsohn in Rabenhorst. De Algen Europas. no. 1935. 1866. Cells elliptical, oval, rarely elongate-elliptical, associated in spherical or elliptical, microscopical families of from two to eight cells, surrounded by a colorless, thin and soon diffluent common tegument; cell contents at first blue in color, finally displaying a blue-green or green chromatophore; reproduction by division of cells in one direction. 542. Glaucocystis nostochinearum Itzigsohn in Rabenhorst. De Algen Eu- ropas. no. 1935. 1866. De Toni. Syll. Algar. 5: 693. 1907. Lagerheim. Ueber einige Algen aus Cuba, Jamaica and Puerto-Rico. Bot. Notiser. 199. 1887. Plate XX. fig. 22. Cells 10-18 mic. in diameter, 18-28 mic. in length, solitary or in fami- lies of from two to eight cells; families elliptical or somewhat spherical; cell contents light blue-green or green; cell walls thin. West Indies. Fajardo, Porto Rico. (Sintenis, Moebius). Genus PORPHYRIDIUM Naegeli. Gatt. Einzell. Alg. 139. 1849. Plant mass irregularly expanded, thin, gelatinous, crustaceous; cells numerous, spherical or more or less angular by compression; cell contents . reddish purple, with a central pyrenoid and an eccentric nucleus; individual Myxophyceae 297 sheaths at first thin, becoming thick, finally diffluent into a gelatinous mu- cus; reproduction by cell division in all directions. 543. Porphyridium cruentum (Agardh) Naegeli. Gatt. Einzell. Alg. 139. pi. 4. 1849. De Toni. Syll. Algar. 5: 697. 1907. Buchanan. Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 9. 1908. Plate XX. fig. 23. Plant mass often widely expanded, membranaceous, mucous, of a dark red color, sometimes becoming greenish; cells 6.5-9 mic. in diameter, spheri- cal or angular by mutual pressure; cell contents reddish purple. Iowa. (Buchanan). Family II. CRYPTOGLENACEAE Plants unicellular, blue-green, floating free in water; vegetative cells el- liptical, oval or almost wedge-shaped, bearing two cilia of equal length, not motile; cell walls thin, close, colorless; chromatophores disc-shaped, adher- ing to the wall, enclosing somewhat spherical pyrenoids. Genus CRYPTOGLENA Ehrenberg. Abhandl. Akad. Wiss. zu Berlin. 150. 1832. Cells marked by a conspicuous red pigment spot; cell wall often sepa- rated from the protoplasm, forming a sac. 544. Cryptoglena americana Davis. Notes on the Life History of a Blue- green Motile Cell. Bot. Gaz. 19: pi. 11. 1894. De Toni. Syll. Al- gar. S: 700. 1907. Collins. Preliminary Lists of New England Plants. — V. Marine Algae. Rhodora. 2: 41. 1900. Plate XX. fig. 24, 25. Motile cells S-6 mic. in diameter, 8-10 mic. in length, broadly elliptical, hyaline on one end, slightly truncate, with a depression from which arises a pair of cilia of unequal length, the longer one about as long as the cell is wide; cell contents blue-green, with six to ten disc-shaped chromato- phores arranged around the periphery, and with one or two bright red pigment spots placed on the periphery, near the middle of the cell; non motile cells 6-7 mic. in diameter, 7-9 mic. in length, arranged in groups of twos and fours in a closely packed Polycystis-like colony, almost imiformly colored blue-green, with six to ten disc-shaped chromatophores and one or two brownish red pigment spots near the middle of the cell at the per- iphery; nucleus near the middle of the cell. Massachusetts. On stems of grass and larger algae. Salt marshes of thf Charles River, Cambridge. Autumn. (Davis). GLOSSARY Adherent, clinging to, or united with Adnate, touching closely or broadly Agglutinated, glued together Aggregated, forming a mass or col- lection, but not cohering Amorphous, structureless Anastomose, to run together in a net- like manner Angular, having angles; sharp cor- nered Apex, the end opposite the point of attachment; tip Appressed, pressed closely against Approximate, near, about Aquatic, living in water Arachnoid, cobwebby Articulate, jointed with cells Asexual, without sex Base, the point of attachment Brackish, somewhat salty Bulbous, with a bulb Bullate, swollen Bullose, swollen Caespitose, in tufts or dense bunches Calcareous, composed of or contain- ing lime Calyptra, a cap or lid Capitate, furnished with a globose head Carneous, fleshy Cartilaginous, firm and tough like cartilage Catenate, joined in a continuous se- ries; in a chain Cell, a closed sac, surrounded by a wall of cellulose, containing pro- toplasm and a single nucleus Cell sap, the watery fluid of a cell which separates from the proto- ■ plasm as one or more vacuoles Cell wall, the membrane enclosing the cell contents Cellulose, the cell wall substance of plants Centrifugally, from the center Centripetally, toward the center Chlorophyll, the green coloring mat- ter contained in plants) leaf- green . . Chromatophore, a plastid, contammg a coloring matter Cilium (pi. cilia), one of the vibra- tile, protoplasmic processes which serves to propel zoogonid- ia through the water Circinate, rolled from the end Clathrate, with openings like lattice work Clavate, club-shaped Coalesced, grown together, united Coalescence, the complete union of similar things Collateral, side by side, secondary Colony, a group of independent cells surrounded by a common invest- ment; a mass of plants of more or less definite shape, large enough to be detected by the naked eye Concentric, with a common center Confluent, growing or running to- gether Conidium, gonidium; a gonidium which is abstricted from the apex of a stalk Constricted, narrowed in certain places Contiguous, near or in contact Contorted, twisted Contractile, able to contract Convolute, rolled together Coriacious, leathery, tough Crenate, wavy Crisped, curled Crustaceous, crust-like Cuspidate, pointed, with a tooth Decumbent, lying down Deliquescent, dissolving- Dense, crowded together Depressed-globose, globular, with the poles slightly flattened Dichotomous, two-forked; furcate Dichotomy, division into two branch- es Diffluent, dissolving Disc, any flat circular area Disc-shaped, flat and circular Dissepiment, cross wall Distal, pertaining to the apex Divaricate, spreading Diverging, separating ^ 300 Minnesota Algae Eccentric, without a common center Elongate, lengthened, very long Endophyte, a plant living within an- other organism, usually as a para- site Entire, not toothed Epiphyte, a plant growing upon the outside of another plant, but not nourished by it Equilateral, with equal sides Family, a mass of plants of micro- scopic size and somewhat definite shape quite evidently arising from the division of a single cell Fascicle, bundle Fasciculate) in bundles Fastigiate, tapering to a point Fenestrate, window-like Fibrillae, little threads Fibrillose, made up of small fibers Fibrous, of fibers Filament, the trichome together with its sheath; a fine thread Filamentous, thread-like, composed of filaments Filiform, thread-shaped Fission, splitting; cell division in which the cell separates into two nearly equal portions, especially as a mode of reproduction Flaccid, soft, flabby Flagelliform, whip-like Flexuous, flexible Floccose, composed of matted, woolly hairs Flocculent, woolly Foliaceous, leaf-like Foliose, leaf-like Gelatinous, jelly-like Geminate, paired Geniculate, bent abruptly like a bent knee Genuilexuous, bent abruptly Glaucous, sea-greeri, gray-green Globose, like a ball Globular, spherical or nearly so Gonidangium, the cell in which go- nidia are produced Goriidium, a reproductive cell devel- oped asexually; a specialized re- productive cell capable by itself, of giving rise to a new organ- ism. Granular, with granules Granule, a small grain Granulose, with granules Gregarious, growing in association, but not matted together Grumose, grumous, like a cluster of grains Habit, the general appearance or characteristic manner of growth of a plant Habitat, the locality or region, or the kind of situation in which a plant is naturally found Heterocyst, a cell uniformly larger than its neighbors, but of doubt- ful function ' Hirsute, with coarse hairs Homogeneous, uniform in character or substance. Host, a plant which supports a para- site (or an epiphyte ?) Hyaline, clear and colorless, trans- parent Immersed, sunken below the surface Impregnated, filled with Indurated, hardened Inequilateral, with unequal sides Inflated, swollen ,,, Integument, any outer covering Intercalary, inserted between Intricate, tangled, involved Inundated, flooded Investment, a covering Laciniate, torn Lacunose, hollowed Lamelliform, plate-like Lamellose, with plates or blades Lenticular, lens-shaped Lubricous, slippery, slimy Lumen, cavity Mammillate, mammillose, with nip- ple-like projections Mammilliform, nipple-like Marginal, at the edge Membranaceous, papery Moniliform, chain-like Motile, able to move Mucilaginous, jelly-like Multicellular, of several to many cells Nodule, a little knot or lump Nucleus, a differentiated round or oval body embedded in the proto- plasm of a cell Obovate, ovate, but with the point of attachment at the lower end Ocrea, a sheath Ocreated, sheathed Orbicular, circular Oval, elliptical Ovoid, egg-shaped Pannose, ragged Papillose, with a little point or nipple Glossary 301 Parasite, a plant that lives on or in some other organism from which it derives its nourishment for the whole or a part of its existence Parenchyma, the soft, thin-walled cel- lular tissue of plants Pedicel, a small or delicate supporting stalk Pedicellate, stalked Pellucid, clear Penicillate, like a brush Periphery, edge Phycocyanin, a blue pigment con- tained in the chromatophores of the blue-green algae Pigment spot, a specialised mass of cytoplasm permeated by a red col- oring matter, present in the mo- tile cells of many algae; eye-spot Piliferous, bearing hairs Pilose, hairy Plant, in the coccogoneae a single cell; in the hoemogoneae a single trich- ome " ' Plant mass, the usually shapeless mass of individual plants remaining in close proximity to each other after their formation, either be- cause nothing occurs to separate them or because they are definite- ly held together by a gelatinous excretion Plicate, folded or ridged Polar, at the end Polygonal, many-sided Polyhedral, many-angled Polymorphous, of many forms Proliferated, grown out Protoplasm, the viscid, contractile, semiliquid, more or less granular, substance that forms the principal portion of an animal or vegetable cell Prostrate, flat, lying down Pseudo-parenchymatous, like paren- chyma Pubescent, finely hairy Pulverulent, powdery Pulvinate, cushion-like Punctate, dotted Punctiform, dot-like Pustular, like a swelling Pyrenoid, a small colorless mass of proteid substance seen in many algae, which may be regarded as reserve material Quadrate, square, in fours Radial, pertaining to a radius, as of a circle or sphere Rectilinear, straight Refractive, refringent, bending or turning aside as a light ray Reniform, kidney-shaped Reproduction, the development of one or more new organisms from the whole or from a part of the pro- toplasm of a parent organism Rotund, round Rugose, furrowed, roughened Saccate, sack-like Segment, one of the parts into which an object is naturally divided Septate, divided by partitions Seriate, in a row Sessile, without a stalk Sheath, a gelatinous, usually tubular, envelope surrounding a plant Silicious, containing silica Sinuate, snake-like, twisted Sinus, a gulf or indentation Spatulate, shaped like a spoon Spherical, ball-like Spongiose, spongy Stellate, star-like Stratified, in layers Stratum, a layer Striated,' having fine markings Sub, slightly, somewhat Submerged, sunken Substratum, surface on which the plant grows Superposed, placed one above another Tegument, covering Tenacious, firm, tough Terebriform, screw-like Terminal, end Terrestrial, growing on the ground Thallus, a plant-body without true root, stem or leaf; used incorrect- ly instead of "plant mass" Tomentose, closely hairy Tortuous, twisted Torulcse, chain-like Trichome, the entire number of cells of a multicellular plant, not in- cluding the sheath Truncate, cut off abruptly Tuberculate, tuberculose, warted Tubular, tube-like Ultimate, last, end Uncinate, hooked at the end Undulate, wavy Unicellular, one-celled Unilateral, one-sided Vacuole, a cavity in the protoplasm of a cell containing a watery fluid 302 Minnesota Algae Ventricose, a swelling out on one Vesicular, bladdery side or in the middle Villous, long hairy Verrucose, warted Vesicle, a small bladder-like cavity Zonate, disposed in the form of zones Note: The proper terms to be used in connection with the blue- green algae have not yet become definitely established. The terms and definitions given in this treatise are merely provisional, in case better ones can be found. Some difficulty has been experienced with the terms: "'plant mass," "colony," "family," "thallus," etc. The definition of each, as the author conceives the meaning, is given in the glossary. Plant mass, the usually shapeless mass of individual plants remaining in close proximity to each other after their formation, either because nothing occurs to separate them or because they are definitely held together by a gelatinous excretion Colony, a mass of plants of more or less definite shape, large enough to be detected by the naked eye Family, a mass of plants of microscopic size and somewhat definite shape, quite evidently arising from the division of a single cell Plant, in the coccogoneae a single cell; in the hormogoneae a single trichome. In the latter case it may be thought better by some to consider "plant" and "filament" as synonymous terms. ERRATA Page 8, after line 26 insert Plate I, fig. 6 Page 26, line 23, for Hansirg read Hansgirg Page 27, line 27, for APHANACAPSA read APHANOCAPSA Page 39, line 37, for Coelosphaerium read COELOSPHAERIUM Page 52, line 35, for smaragdinus read smaragdina Page 52, line 37, for olivaceus read olivacea Page 54, line 38, for smaragdinus read smaragdina Page 55, line 4, for olivaceus read olivacea Page 55, line 16, after 2. insert 1904. Page III, line 18, for Chondrocystic read Chondrocystis Page 115, line 19, for sublilis read subtilis Page 122, line 44, for symplocoides read symplocoidea Page 129, after line 25, insert Plate V. fig. 48. Page 130, before first line, insert Plate V. fig. 49 Page 140, first line, for 1-4 read i Page 160, line 3, after capitata insert (E. West Jun.) Page 168, line 25, for depresed- read depressed- Page 170, line 18, for natus Harpswell. read natus. Harpswell Page 180, line 32, for sack read sac Page 181, line 9, before N. insert ( Page 191, line 18, for climbing read clinging Page 265, first line, for Indies read Indies Lists of Hosts and Associates Amphiroa 54 Anodonta 137 Anthoceros i6g Avicennia nitida 287 AzoUa caroliniana 195 Balani 49 Bartramia fontana 132 Bartramia ithyphylla 132 Batrachospermum vagum 266 Bostrychia tenclla 263 Celtis 221 Ceramium rubrum 55 Chaetomorpha aerea 117 Chaetophora calcarea 276 Chantransia 50 Chara 68, 234, 286 Chondrus crispus 295 Cladophora 18, 46, 56, 116, 149, 177, 264 Cladophora expansa 185, 257 Conferva sandvicensis 166 Cycas revoluta 164, 165 Cymopolia barbata 280 Dasya arbuscula 261 Dictyota dichotoma 280 Digenia simplex 280 Enteromorpha 48, 70, 115, 264 Enteromorpha compressa 293 Enteromorpha intestinalis 53, 54, 115, 257 Fucus 54, 294 Fucus evanescens 54, 204 Fucus vesiculosus 282, 294 Galaxaura 260 Gelidium 54, 70 Gigartina 54 Gomontia holdenii 52 Hemiaulus delicatulus 202, 273 Iridaea laminarioides 54 Juniperus bermudiana 226 Laurencia obtusa 295 Leucobryum 241 Liagora coarctata 204 Littorina 209 Mussels 137 Mya arenaria 237 Myrica cerifera 233 Myriophyllum 285 Myriophyllum epiphytica 288 Nemalion multifidum 261 Nuphar 239, 240 Nymphaea 285 Odonthalia 54 Oedogonium 56 Ostraea virginiana 'ii Parmelia saxatilis 22 Phragmites 270 Pithophora affinis 113, 267 Plocamium coccineum 55 Polysiphonia 55, 84 Polysiphonia fastigiata 53 Punctaria plantaginea 258 Ranunculus aquatilis 227, 228 Rhizoclonium 183 Rhizoclonium riparium 50 Rhizoclonium riparium validum 49 Rhizosolenia 202, 273 Rhodochorton 50 Rhodochorton rothii 50 Ruppia 90, 122, 136, 187, 257 Ruppia maritima 99, 188, 293 Sargassum 54 Scirpus I2S, 269 Spartina 137, 193, 287, ago Spermothamnion 50 Sphacelaria 50, 53 Sphagnum 138, 151 Spirorbis 94 Stereocaulon 249 Taxodium distichum 250 Turbinaria 104, 202 Ulya 257, 264 Unio 209 Utricularia 8, 199, 284 Vaucheria 116, 267 Zostera 17, 120, 122, 124, 136, 193, 265 Zostera marina 193, 204 INDEX acervatus Wood (Sirosiphon) 248 acuminata Gomont (Oscillatoria) 60. 78 adscendens (Naeg.) Born, and Flah. (Calothrix) 255, 267 aegagropila Kuetz. (Tolypothrix) 230 aeruginea (Kuetz.) Thur. (Calothrix) 254, 261 aeruginea Kuetz. (Mastigothrix) 266 aerugineo-caerulea (Kuetz.) Gom. (Lyngbya) 109, 116 aerugineum Kirchn. (Mastigonema) 266 aerugineum Breb. (Merismopedium) 42 var. violaceum Rab. 42 aerugineum n. sp. (Stigonema) 244, 245 aeruginosa (Kuetz.) Henfr. (Clathro- cystis) 37 aeruginosa (Carm.) Kuetz. (Gloeocap- sa) 14, 18 aeruginosa C. Ag. (Lyngbya) 120 aeruginosum (Kuetz.) Kirchm (Mas- tigonema) 266 aeruginosus Naeg. (Synechococcus) II, 95, 140 aestuarii (Mertens) Liebm. (Lyng- bya) no, 115, 120 forma aeruginosa Wolle 120 forma aeruginosa. (Ag.) Wolle 123 forma ferruginea Gom. 123 forma limicola Gom. 122 forma natans Gom. 122 forma symplocoidea Gom. 122, agardhii Gom. (Oscillatoria) 58, 62 agglutinata Crouan (Lyngbya) 135 aikenensis Wolle (Hypheothrix) 139, 141 alatum Berk. (Petalonema) 225 alatum (Carm.) Borzi (Scytonema) 212, 225 alpina Clements and Shantz (Eucap- sis) 4S alpinum Wood (Nostoc) t8i ambigua (Naeg.) Gom. (Fischerella) 242 ambigua Naeg. (Gloeocapsa) 15, 22 forma fusco-lutea Naeg. 22 ambiguum Gom. (Phormidium) 92, 103 ambiguum Kuetz. (Scytonema) 242 ambiguum Naeg. (Symphyosiphon) 242 americana Davis (Cryptoglena) 297 amethystea Kolderup - Rosenvinge (Pleurocapsa) 47, 48 amphibia Ag. (Oscillatoria) 59, 73 Amphithrix Kuetzing 252, 253 amplissimum Setch. (Nostoc) 164, 180 amplum W. and G. S. West (Scytone- ma) 212, 221 amoena (Kuetz.) Gom. (Oscillatoria) 60, 77 amorpha Berk. (Dasygloea) 154 amorpha (Thwaites) Wolle (Micro- coleus) 154 Anabaena Bory 161, 185 anguiformis Harv. (Microcoleus) 155 anguina Mont. (Lyngbya) 124 anguina Bory (Oscillatoria) 59, 68 angulosa Rab. (Gloeotrichia) 285 angustissima W. and G. S. West (Os- cillatoria) 60, 76 animalis Ag. (Oscillatoria) 60, 79 antillarum S. and M. (Hormosiphon) 168 antillarum Crouan (Lyngbya) 168 antillarum Crouan (Oscillaria) 64 antillarum Crouan (Symploca) 129 antliaria Juerg. (Oscillaria) 100, 107 Aphanizomenon Morren 161, ig6 Aphanocapsa Naegeli 2, 27 Aphanothece Naegeli 2, 29 aponina Kuetz. (Gomphosphaeria) 38 var. cordiformis Wolle 39 aquatilis Sauv. (Synechocystis) 10 arachnoidea Crouan (Lyngbya) 125 arachnoidea Kuetz. (Lyngbya) iii, 127 arboreus W. and G. S. West (Hapalo- siphon) 238, 241 arcangelii Born, and Flah. (Scytone- ma) 211, 213 arcticum Harv. (Nostoc) 171 arenaria (Hass.) Rab. (Gloeocapsa) 13, 16 arenaria (Berk.) De Toni (Hypheo- thrix) 139, 143 arenaria Gom. (Schizothrix) 143 arenaria (Kuetz.) Rab. (Lyngbya) 13s argillaceus Wood (Sirosiphon) 245 armorica Thur. (Nodularia) 182, 184 Arthrospira Stizenberger 57, 85 articulata Ag. (Echinella) 286 Asterocytis Gobi 296 Asterothrix Kuetzing 294 atlantica Gom. (Symploca) 128, 129 atra Roth (Rivularia) 283, 289 var. confiuens (Kuetz.) Born. 290 3o8 Minnesota Algae atrata (Turp.) Kuetz. (Gloeocapsa) 14, 19 Aulosira Kirchner 161, 202 aureum Kuetz. (Nostoc) 162, 165 aureus W. and G. S. West (Hapalo- siphon) 238 austini Wolle (Inactis) 147, 149 austinii Wood (Nostoc) 163, 17s austinii Wood (Scytqnema) 212, 220 austinii Wood (Symphyosiphon) 220 autumnale (Ag.) Gom. (Phormidium) 93. 94, 107 azollae Strasb. (Anabaena) 187, 195 azureum Tilden (Scytonema) 212, 216 badium Wolle (Scytonema) 212, 225 battersii Gom. (Plectonema) 206, 211 baueriana (Grun.) Born, and Thur. (Dichothrix) 274, 275, 276 bauerianum Grun. (Schizosiphon) 276 beccariana (De Not.) Born, and Flah. (Rivularia) 288 biasolettiana Menegh. (Rivularia) 292 bicolor Crouan (Lyngbya) 1 11, 125 bicolor Wood (Lyngbya) 127 bonnemaisonii Crouan (Oscillatoria) 59, 68 borealis Rab. (Symploca) 129, 132 borealis Richt. (Rivularia) 283, 288 bornetiana Collins (Anabaena) 186, 19.=; bornetiana Setchell (Rivularia) 283, 292 bornetianum Wolle (Symphyosiphon) 212, 227 boryana Bory (Oscillatoria) 61, 83 bostrychicola Crouan (Lyngbya) 118 botryoides (Kuetz.) Kirchn. (Proto- coccus) forma caldarius Tilden 47 Brachytrichia Zanardini 253, 294 brandegei Wolle (Sirosiphon) 244, 251 brandegei Wolle (Scytonema) 224 braunii Born, and Flah. (Calothrix) 2SS, 269 braunii Kuetz. (Hapalosiphon) 239 braunii Naeg. (Hapalosiphon) 239 braunii Gom. (Schizothrix) 153 brebissonii Kuetz. (Calothrix) 207 brebissonii Kuetz. (Capsosira) 251 brebissonii Kuetz. (Hapalosiphon) 239 breviarticulata W. and G. S. West (Calothrix) 255, 267 brevis Kuetz. (Oscillatoria) 60, 79 var. neapolitana' (Kuetz.) Gom. 80 brunnea Naeg. (Aphanocapsa) 28, 29 bullosa Wolle (Hypheothrix) 139, 141 bullosa Wolle (Leptothrix) 141 byssoidea Hass. (Hassallia) 233 var. cylindrica Tilden 233 byssoidea (Hass.) Kirchn. (Tolypo- thrix) 229, 233 forma cylindrica Tilden 233, 243 forma saxicola Grun. 233 byssoideum Ag. (Scytonema) var. corticale Mont. 220 caeruleo-violacea Crouan (Leibleinia) 119 caeruleo-violacea Crouan (Lyngbya) III, 127 caeruleum Lyngb. (Nostoc) 163, 177 caespitosa Born, and Flah. (Hyella) SI, 209 caespitosa (Kuetz.) Wolle (Isactis) 269 forma tenuior viridis Rab. 267 caespitosum Kuetz. (Mastigonema) 269 calcarea Tilden (Dichothrix) 274, 275, 280 calcarea Tilden (Gloeocapsa) 13, 17 calcarea Eng. Bot. (Rivularia) 290 calcicola (Ag.) Rab. (Hypheothrix) 96, 138, 139 calcicola Kuetz. (Leptothrix) 139 calcicola Gom. (Schizothrix) 139 caldaria (Tilden) Setchell (Pleurocap- sa) 8, 47 caldaria Tild. (Spirulina) 86, 8g caldarium Setchell (Scytonema) 211, 215 calida P. Richter (Calothrix) 255, 268 calidarium Wood (Nostoc) 163, 175 calidum Gom. (Phormidium) 93, 105 Calothrix Agardh 17, 252, 254 calotrichoides Gom. (Plectonema) 206, 210 calotrichoides Kuetz, (Scytonema) 223 calotrichoides Wood (Scytonema) 222 cantharidosma Mont. (Lyngbya) 134, 13s cantharidosmus (Mont.) Gom. (Hy- drocoleus) 135 capitata W. West Jun. (Oscillatoria) 59, 70, 160 Capsosira Kuetzing 237, 251 carmichaelii Harv. (Sphaerozyga) 192 carneum Ag. (Nostoc) 162, 167 cartilaginea Wood (Rivularia) 284 castagnei (Breb.) Rab. (Aphanothece) 30, 31 . castellii (A. Massalongo) Born, and Flah. (Calothrix) 255, 271 castellii Mass. (Scytonema) 271 Catagnymene Lemmermann 58, 159 cataractae Nae?. (Schizosiphon) 275 cataractae Wood (Scytonema) 224 Index 309 catenatum Ralfs (Cylindrospermum) 198, 201 catenula (Kuetz.) Born, and Flah. (Anabaena) 186, 191 var. americana Collins 192 centrifuga Bornet (Isactis) 281, 282 cesatiana Rab. (Oncobyrsa) 45 chalybea Mert. (Oscillatoria) 61, 82 var. genuina Collins, Holden and Setchell 82 chalybea (Kuetz.) Gom. (Schizothrix) IS2 Chamaesiphon Braun and Grunow 46, 55 Chamaesiphonaceae 2, 46 chlorina Kuetz. (Oscillatoria) 60, 75 Chlorogloea Wille 3, 46 Chondrocystis Lemmermann 2, 24 Chroococcaceae i, 2 Chroococcus 2, 3, 31 Chroothece Hansgirg 2, 12 chrysochlorum KuiCtz. (Scytonema) 217 chthonoplastes (Fl. Dan.),Thur. (Mi- crocoleus)' 155 cincinnata Kuetz. (Lyngbya) 214 cincinnatum Thur. (Scytonema) 214 cinereum Crouan (Scytonema) 216 cinereum Menegh. (Scytonema) 219 circinalis Rab. (Anabaena) 186, 190 cladophorae n. sp. (Lyngbya) 109, 116 Clathrocystis Henfrey 3, Z7 coactile Mont. (Scytonema) 211, 213 var. radians Crouan (Scytonema) 213 coadunata (Sommerfelt) Foslie (Rivu- laria) 283, 291 Coccogoneae i Coelosphaeriopsis Lemmermann 3, 41 Coelosphaerium Naegeli 3, 39 cohaerens (Breb.) Naeg. (Chroococ- cus) 4, 9 collinum Kuetz. (Nostoc) 169 comatum Wood (Cylindrospermum) 197, 198 comminutum Kuetz. (Nostoc) 162, 165 commune Vaucher (Nostoc) 163, 171 var. flagelliforme (Berk, and Cur- tis) Born, and Flah. 173 comoides (Harv.) Gom. (Hydroco- leus) 1.34 compacta (Ag. ?) Born, and Flah. (Dichothrix) 274, 277 compacta Crouan (Lyngbya) I2t compacta Collins (Rivularia) 283, 288 concharum Hansg. (Pleurocapsa) 47 conchophilum Humph. (Scytonema) 211, 213 conferta Richt. (Aphanothece) 29, 30 conferta Crouan (Calothrix) 217 confervicola (Roth) Ag. (Calothrix) 254, 256, 26s var. purpurea Born, and Flah. 257 confervoides Reinsch (Anabaena) 187, I9S confervoides C. Ag. (Lyngbya) no, 119 forma violacea Collins 120 confluens Naeg. (Gloeothece) 25 congesta Crouan (Lyngbya) 120 congestum Rab. (Phormidium) 118, 158 conglomerata Kuetz. (Gloeocapsa) 14, 18 consociata (Kuetz.) Born, and Flah; (Calothrix) 254, 257 contarenii (Zanard.) Born, and Flah. (Calothrix) 254, 259 contarenii Collins (Calothrix) 262 contortum Wille (Trichodesmium) 84, 85 convolutum Breb. (Merismopedium) 42, 44 corallicola Crouan (Oscillaria) 123 corallinae Gom. (Oscillatoria) S9, 7o coralloides Kuetz. (Sirosiphon) 250 coriacea Kuetz. (Hypheothrix) 139, 142 forma meneghinii Kuetz. 142 coriacea Gom. (Schizothrix) 142 coriacea (Kuetz.) Gom. (Schizothrix) 142 cerium (Ag.) Gom. (Phormidium) 92, loi cortex Wolle (Scytonema) 221 forma ravenelii Wolle 221 cortex Wood (Scytonema) 216 cortiana Menegh. (Oscillatoria) 61, 71, 81 corymbosa (Harv.) Grun. (Polythrix) 280 corymbosus Harv. (Microcoleus) 280 crameri Brugg. (Sirosiphon) 247 creginii Wolle (Asterothrix) 29s crepidinum (Rab.) Thur. (Gloeocap- sa) 14, 20 crepidinum Collins (Pleurocapsa) 47, 49 crispum (Ag.) Born. (Scytonema) 157, 211, 214, 26s cristatum Bailpy (Nostoc) 181 crosbyanum Tilden (Phormidium) 91, 96 cruenta Grun. (Oscillatoria) 60, 80 cruentum (Ag.) Naeg. (Porphyridi- um).296 Crustacea Thur. (Calothrix) 50, 204, 255, 264 forma prolifera (Flah.) Collins 262 forma simulans Collins 26s 310 Minnesota Algae crustaceum Ag. (Scytonema) 212, 226 var. incrustans (Kuetz.) Born, and Flah. 226 crustaceus Kuetz. (Symphyosiphon) 226 crustifprmis Naeg. (Schizosiphon) 269 cryptarum Farl. (Chroothece ?) 12 Cryptoglena Ehr. 297 Cryptoglenaceae 297 cupressophila Wolle (Anabaena) 184, 187, 195 curtus Setchell (Synechococcus) 11 curvatus Nordst. (Chamaesiphon) 55, S6 curviceps Ag. (Oscillatoria) 59, 67 cuspidata W. and G. S. West (Sym- ploca) 14s cuspidata (Symploca) 203 cuspidatum (.W. and G. S. West) De Toni (Symplocastrum) 144, 145 var. luteo-fusca W. and G. S. West 145 cuticulare (Breb.) Born, and Flah. (Nostoc) 161, 164 cyanea Crouan (Lyngbya) iig cyanescens Crouan (Scytonema) 222 Cyanophyceae i cycadearum Reinke (Anabaena) 164 Cylindrospermum Kuetz. 161, 197 cystifera (Hass.) Rab. (Gloeothece) 26 Dasygloea Thwaites 58, 154 decorticans A. Br. (Chroococcus) 4, 8 densum (A. Br.) Born. (Scytonema) 212, 227 depressum Wood (Nostoc) 163, 177 Dermocarpa Crouan 46, 52 Desmonema Berk, and Thwaites 206, detersa Stiz. (Oscillaria) 98 Dichothrix Zanard. 252, 274 diffusa Farlow (Oscillaria) 61 digueti Gom. (Lyngbya) 109, iis dillwynii Hass. (Calothrix) 23s Diplocolon Naeg. 206, 236 distincta (Nordst.) Schmidle (Lyng- bya) 109, 113 distorta (Hofman-Bang) Kuet^. (To- lypothrix) 229, 231 distorta var. Wood (Tolypothrix) 230 donnellii (Wolle) (Calothrix) 256, 271 donnellii Wolle (Mastigonema) 271 donnellii Wolle (Microcystis) 33, 34 dubia Wartm. (Gloeocapsa) 15, 23 dubia (Naeg.) Gom. (Symploca) 129, .131 dubium Grun. (Coelosphaerium) 39, 40 dubium Wood (Scytonema) 212, 227 duplex Wolle (Spirulina) 87, 90 dura Roth (Rivularia) 283, 291 echinata Eng. Bot. (Rivularia) 284 echinulata (Smith) Born, and Flah. (Rivularia) 283, 286 elabens (Menegh.) Kuetz. (Microcys- tis) 33. 35 elabens Kuetz. (Polycystis) 35 elachista W. and G. S. West (Aphano- capsa) 27, 28 elegans (Chauv.) Zanard. (Goniotri- chum) 295 elegans A. Br. (Merismopedium) 42, 43 elegans Ag. (Oscillatoria) 96 elegans Kuetz. (Scytonema) var. antillarum Crouan 213 ellipsosporum (Desm.) Rab. (Nos- toc) 162, 168 elongatum Wood (Mastigonema) 256, 271 enteromorphoides Grun. (Hormo- thamnion) 205 Entophysalis Kuetz. 2, 23 epiphytica West and West (Calo- thrix) 2SS, 26s erosa Liebm. (Lyngbya) 124 erythraeum Ehr. (Trichodesmium) 84 Eucapsis Clements and Shantz 3, 45 farlowii Born. (Hormactis) 294 fasciculata Ag. (Calothrix) 234, 262 forma incrustans Collins 262 fasciculata (Naeg.) Grun. (Inactis) 147 fasciculata Gom. (Schizothrix) 147, 148 favosum (Bory) Gom. (Phormidium) 93, 104 fenestralis Kuetz. (Gloeocapsa) 13, 16 ferruginea C. Ag. (Lyngbya) 109, 120, 123 ferruginea G. S. West (Lyngbya) 114 fertile Wood CMastigojiema) 256, 271 fibrosum (Wood) Wolle (Mastigone- ma) 256, 272 figuratum Ag. (Scytonema) 223 Fischerella (Born, and Flah.) Gom. 237, 242 flaccida Crouan (Leibleinia) 261 flaccida Kuetz. (Tolypothrix) 231 flavo-viride (Kuetz.) Born, and Flah. (Scytonema) 212, 222 flexuosum Rab. (Cylindrospermum) 193 flexuosus Borzi (Hapalosiphon) 238 flos-aquae (Lyngb.) Breb. (Anabae- na) 186, 189 Index 311 flos-aquae (Linn.) Ralfs (Aphanizo- menon) 196 var. treleasei Born, and Flah. 190 var. circinalis Kirchn. 190 flos-aquae (Wittr.) Kirchn. (Micro- cystis) 33/35 fluitans Her. (Lyngbya) iii, 127 fluitans Cohn (Rivularia) "286 fluviatilis (Rab.) Kirchn. (Isactis) 290 fluviatilis Kuetz. (Zonotrichia) 290 foliaceum Moug. (Nostoc) 163, 171 fontana Huber and Jadin (Hyella) SI, 52 . fontana Crouan (Lyngbya) 125 forma crassior Crouan 126 fontinalis (Ag.) Born. (Hapalosi- phon) 238, 239 var. tenuissimus (Grun.) Collins and Setchell) 240 formosa Bory (Oscillatoria) 60, 80 foveolarum (Mont.) Gom. (Phormid- ium) 91, 94 fragile (Menegh.) Gom.. (Phormid- ium) 91, 93 fragile (Kuetz.) De Toni (Symplo- castrum) 144 fragilis (Kuetz.) Gom. (Schizothrix) . 144 friesiana Kuetz. (Symploca) 146 friesii Gom. (Schizothrix) 146 friesii (Ag.) Kirchn. (Symplocastrum) 144, 146 froelichii Kuetz. (Oscillaria) 65 fucicola Saunders (Dermocarpa) 52, 54 fucicola (Kuetz.) Born, and Flah. (Dichothrix) 274, 279 fuliginosa Hauck (Pleurocapsa) 47, 48 fuliginosum Tilden (Scytonema) 212, 22s fulva Harv. (Lyngbya) 120 fusca (Kuetz.) Born, and Flah. (Calo- thrix) 25s, 265 fusca Crouan (Lyngbya) 125 fusca Wolle (Mastigonema) 266 fuscescens Kuetz. (Hapalosiphon) 239 fuscescens (Kuetz.) Rab. (Symploca) 129, 131 fusco-lutea (Naeg.) Kuetz. (Gloeocap- sa) 14, 19 fusco-lutea Naeg. (Gloeothece) 25, 27 fusco-rubra Crouan (Oscillatoria) 136 fusco-violacea Crouan (Calothrix) 254. 258 gelatinosa Wood (Anabaena) 187, 196 gelatinosa Kuetz. (Gloeocapsa) 14, 18 gelatinosum Schousb. (Nostoc) 162, 169 geminata Menegh. (Oscillatoria) 59, 74, 75 gigantea Wood (Anabaena) 190 gigas W. and G. S. West (Gloeocap- sa) 14, 20 glacialis Dickie (Tolypothrix) 229, 235 glauca Wolle (Anacystis) 35 Glaucocystis Itzig. 296 glaucum (Ehr.) Naeg. (Merismope- dium) 42, 43 var. fontinale Hansg. 44 Gloeocapsa Kuetz. 2, 13 gloeophila (Kuetz.) Rab. (Hypheo- thrix) 139, 140 Gloeothece Naeg. 2, 25 glomeratum Kuetz. (Nostoc) 163, 177 glutinosa A. Br. (Oscillaria) 136 glutinosus (Ag.) Gom. (Hydrocoleus) 134, 136 golenkinianum Gom. (Plectonema) 206, 210 gomontiana Setch. (Arthrospira) 85, 86 Gomphosphaeria Kuetz. 3, 38 Goniotrichum Kuetz. 295 gracile Kuetz. (Scytonema) 224, 232 gracilis Rab. (Calothrix) 269 gracilis (Menegh.) Rab. (Lyngbya) 89, no, 117 gracilis Hass. (Microcoleus) 155 gracillima Kuetz. (Oscillaria) 76 granosa (Berk.) Kuetz. (Gloeocapsa) 13, 15 granosa Rab. (Gloeothece) 15 granulosa Kuetz. (Entophysalis) 24 graveolens Crouan (Lyngbya) 132 grevillei (Hass.) Rab. (Aphanocapsa) 27, 28 grisea Thur. (Microchaete) 203, 204 guadelupensis Crouan (Hydrococcus) 181 guadelupensis Crouan (Oncobyrsa) 181 guadelupensis Crouan (Tolypothrix) 213 guttula Wood (Sirosiphon) 249 guyanense (Mont.) Born, and Flah. (Scytonema) 212, 220 gypsophila Kuetz. (Calothrix) 278 gypsophila (Kuetz.) Born, and Flah. (Dichothrix) 274, 277, 278, 280 haematites (DC.) Ag. (Rivularia) 283, 290 haematites Rab. (Zonotrichia) 290 Haliaracbne. Lemm. 58, 160 hallensis (Jancz.) Born, and Flah. (Anabaena) i86, 188 312 Minnesota Algae halophila Lemm. (Coelosphaeriopsis) 41 halos Wood (Mastigonema) 256, 272 Hapalosiphon Naeg. 236, 237 harveyana (Tliwaites) Thur. (Nodu- laria) 99, 182, 184 hawaiensis Lemm. (Schizothrix) 150 hawaiensis (Lemm.) De Toni (Inac- tis) 147, ISO hawaiiensis Tilden (Nodularia) 182, 184 hederulae Menegh. (Nostoc) 164 helveticus Naeg. (Chroococcus) 4, 8 hemisphaerica (L.) Aresch. (Rivulfl- ria) 289 heppii Naeg. (Diplocolon) 236 heppii (Naeg.) Wolle (Scytonema) 236 herbacea Kuetz. (Hypheothrix) 139, 140 herbacea Kuetz. (Leptothrix) 141 heterotrichus Kuetz. (Hydrocoleus) 134. 138 hindsii Mont. (Trichodesmium) 84 hinnulea Wolle (Beggiatoa) 140 hinnulea (Wolle) De Toni (Hypheo- thrix ?) 138, 140 hinnulea (Wolle) Tilden (Lyngbya) 140 hirtulus Kuetz. (Symphyosiphon) 228 hirtulum (Kuetz.) Rab. (Scytonema) 212, 228 hofmanni Ag. (Scytonema) 212, 216 forma brunnea Wolle 217 var. calcicolum (Hansg.) 217 var. symplocoides (Reinsch) Born. and Flah. 217 hofmanni Kuetz. (Symphyosiphon) 216 holdenii Tilden (Hydi-ocoleus) 134, 137 holdenii De Toni (Lyngbya) 109, 115 homoeotrichus Kuetz. (Hydrocoleus) 134, 137 Hormogoneae i, 56 hormoides (Kuetz.) Hornet and Flah. (Stigonema) 244 var. rhizodes (Kuetz.) Hansg. 24s var. tenue West and West 245 Hormothamnion Grun. 161, 204 hosfordii Wolle (Calothrix) 278 hosfordii (Wolle) Born. (Dichothrix) 274, 278 hospita Thur. (Rivularia) 287 humifusum Carm. (Nostoc) 162, 170 humphreyi Collins (Goniotrichum) 29s hyalina Harv. (Lyngbya) iii, 128 hyalina Kuetz. (Schizothrix) 150, 151 hyalinus (Kuetz.) Kirchn. (Micro- coleus) 128, 151 hydnoides Kuetz. (Symploca) 129 var. fasciculata (Kuetz.) Gom. 130 var. genuina Gom. 130 Hydrocoleus Kuetz. 57, 134 hydrurimorpha Crouan (Oscillaria) 129 Hyella Bornet and Flahault 46, Si Hypheothrix Kuetzing S7. 138 ichthyoblabe Kuetz. (Microcystis) 33, 34 icthyoblabe Kuetz. (Polycystis) 34 immersutn Wood (Scytonema; 212, 228 imperator Wood (Oscillaria) 62 Inactis Kuetzing S7. 146 inaequalis (Kuetz.) Born, and Flah. (Anabaena) 186, 191 incrustans Grun. (Chamaesiphon) S5 incrustans Kuetz. (Symphyosiphon) 226 incrustata Wood (Gloeotrichia) 285 incrustata (Wood) De Toni (Rivula- ria) ^83, 28s incrustatum (Naeg.) Gom. (Phormid- ium) 92, 99 var. cataractarum (Naeg.) Gom. 100 incurvus Allm. (Trichormus) 189 indica Crouan (Calothrix) 220 informe. Kuetz. (Stigonema) 244, 249 interrupta Kuetz. (Lyngbya) 121 interruptum Kuetz. (Phormidium) 92, 102 intertextum (Kuetz.) Rab. (Scytone- ma) 212, 219 intracellularis J. Schm. (Richelia) 201 intricatum Menegh. (Nostoc) 166 intricatus West and West (Hapalo- siphon) 238, 241 inundata Kuetz. (Lyngbya) 100 inundatum Kuetz. (Phormidium) 92, 100 Isactis Thuret 253, 281 itzigsohnii Born. (Gloeocapsa) 22 janthina (Mont.) Born, and Flah. (Amphithrix) 253 var. torulosa (Grun.) Born. an4 Flah. 2S3 janthina Naeg. (Gloeocapsa) 14, 22 javanicum (Kuetz.) Born, and Flah. (Scytonema) 212, 218 var. hawaiiense Lemm. 218 jenneri (Kuetz.) Stiz. (Arthrospira) 8S jenneri Kuetz. (Spirulina) 85 joannianum Kuetz. (Phormidium) 106 Juliana (Menegh.) Born, and Flah. (Calothrix) 254, 2s6 iulianum Rab. (Phormidium) 114 julianum Menegh. (Scytonema) 216 junipericolum Farl. (Scytonema) 212, 226 Index 313 kerneri Hansg. (Xenococcus) 49, 50 tcuetzuigianum ISi aeg. (Coelospnaeri- umj 39, 40 kuetzmgii schraidle (Lynbya) var. distincta (Nordst.) Lemm. 113 kuntzei P. Richter (.Calothrix) 255, 2oe lacucola WoUe (Calothrix) 256, 272 lacustns (A. Jrfr.) De Toni (Inactis) 147, 14s var. caespitosa Gom. 148 lacustris (Kab.) Farlow (.Microcole- us) 157 lacustris A. Br. (Schizothrix) 148 lacustns Kab. (Sirosiphon) 250 laetevirens Crouaii (Oscillatoria) 60, 78 laete-viridis Gom. (Symploca) 129, 130 lagerheitnii (Mob.) Gom. (Lyngbya) 106, III laminosum (Ag.) Gom. (Phormidi- um) 92, 96, 98 forma weedii Tilden 97 laminosus (Kuetz.) Hansg. (Hapalo- siphon) 238, 240, 241 lanata (Desv.) Wartm. (Tolypothrix) 229, 230 var. hawaiensis Nordst. 231 lardacea (Cesati) Hansg. (Hypheo- thrix) 142 lardacea (Ces.) Gom. (Schizothrix) 139, 142 latilimba Crouan (Lyngbya) 135 laxa (Rab.) A. Br. (Anabaena) 186, 192 laysanense Lemm. (Phormidium) 93, 104 laysanensis Lemm. (Xenococcus) 49 leibleiniae (Reinsch) Born€t (Dermo- carpa) var. pelagica Wille 52, 55 lenticularis Lemm. (Haliarachne) 160 leprieurii Kuetz. (Scytonema) 220 leptotrichia Kuetz. (Oscillaria) 76 licheniforme (Bory) Kuetz. (Cylm- drospermum) 198, 200 lignicola Wood (Sirosiphon) 248 limbata Thur. (Tolypothrix) 229, 234 limneticus Lemm. (Chroococcus) 4. 10 , limnicola Wolle (Cylindrospermum) 199 limosa Ag. (Oscillatoria) 58, 64, 65, 72 var. badia Tilden 66 var. chalybea Crouan 69 linckia (Roth) Born. (Nostoc) 162, 166 , ^ linearis Naeg. (Gloeothece) 25 littoralis Crouan (Leiblemia) 119 littoralis Carm. (Oscillatoria) 121 lobatus Wood (Nostochopsis) 251 longissima Crouan (Mastichothrix) 266 lucifuga Breb. (Symploca) 146 lunata W. and G. S. West (Gloe- othece) 25, 26 luridum (Kuetz.) Gom. (Phormid- ium) 91, 95 lutea (Ag.) Gom. (Lyngbya) 53, 109, 114 luteo-fusca Ag. (Lyngbya) 118, 119 luteo-fusca Crouan (Lyngbya) 123 Lyngbya C. Ag. 50, 57, 108, 215 lyngbyei Kuetz. (Chthonoblastus) 156 lynbyaceum Kuetz. (Phormidium) 132 lyngbyaceus Kuetz. (Hydrocoleus) 134, 13s var. a Gom. 136 var. p rupestre Kuetz. 136 macrococcus (Kuetz.) Rab. (Chroo- coccus) 3, S macrospermum Kuetz. (Cylindrosper- mum) 198 macrosporum Menegh. (Nostoc) 163, 175 magma (Breb.) Kuetz. (Gloeocapsa) 14, 21 var. itzigsohnii (Born.) Hansg. 21 magna Wolle (Gloeothece) 25, 27 magnoliae Farlow (Entophysalis) 24 mainensis F. L. Harv. (Nodularia) 182, 18s major Tilden (Hapalosiphon) 238, 240 major Menegh. (Lyngbya) no, 126 major Vauch. (Oscillatoria) 59, 67 major Kuetz. (Spirulina) 86, 87, 97 majus Kuetz. (Cylindrospermum) 197, 199 majus Hold. (Hydrocoleus) 137 majuscula (Dillw.) Harvey (Lyng- bya) no, 123 mamillosum (Lyngbye) Ag. (Stigo- nema) 244, 250 margaritifera Kufetz. (Oscillatoria) 59. 69 marginata Menegh. (Anacystis) 34 marginata (Menegh.) Kuetz. (Micro- cystis) 6, 33, 34 marginata Naeg. (Microcystis) 34 martensiana Menegh. (Lyngbya) no, 124 var. calcarea Tilden 125, 276 var. distincta Nordst 113 Mastigocoleus Lagerh. 236, 237 mellea Kiietz. (Gloeocapsa) 13 mellea Kuetz. (Gloeocapsa) 14, 18 membranacea (Rab.) Born. (Gloeo- thece) 25, 26 membranacea (Kuetz.) Thur. (Lyng- bya) IDS 314 Minnesota Algae membraninus (Menegh.) Naeg. (Chroococcus) 4, 10 mendotae Trelease (Anabaena) 190 meneghiniana Kirchn. (Calothrix) 277 meneghiniana (Kuetz.) De Toni (Dichothrix) 274, 277 meneghiniana (Kuetz.) Gom. (Lyng' bya) no, 117 meneghiniana Zan. (Spirulina) 86, 87 meneghinianus Kuetz. (Schizosiphon) 277 Merismopedium Meyen. 3, 41 mexicana (Gom.) De Toni (Inactis) 147, ISO mexicana (Kuetz.) Rab. (Rivularia) 284, 293 mexicana Gom. (Schizothrix) 150 Microchaete Thuret 161, 202 microcoleiformis Crouan (Sphaerozy- ga) 205 Microcoleus Desmazieres 58, 154 Microcystis Kuetz. 3, 33 microscopica Naeg. (Aphanothece) 29, 31 microscopica Dickie (Rivularia) 284, 293 microscopicum Carm (Nostoc) 163, 176 microspora (Menegh.) Rab. (Aphano- thece) 30, 31 millei Born. (Scytonema) ^'2, 220 miniata Hauck (Oscillatoria) 59, 68 minnesotensis Tilden (Oscillatoria) 59, 75 minor (Kuetz.) Naeg. (Chroococ- cus) 4, 9 forma minima W. and G. S. West 9 minutissimum Collins (Cylindrosper- mum) 197, 200 minutula Kuetz. (Limnactis) 288 minutula (Kuetz.) Born, and Flah. (Rivularia) 283, 288 minutula Rab. (Zonotrichia) 284, 289 minutula Wood (Zonotrichia) 293 minutum Wood (Cylindrospermum) 197, 199 minutum Desm. (Nostoc) 163, 174 minutum (Ag.) Hass. (Stigonema) 244, 248 var. saxicola (Naeg.) Born, and Flah. 248 minutus (Kuetz.) Naeg. (Chroococ- cus) 4, 7 mirabile Thur. (Plectonema) 207 mirabile (Dillw.) Born. (Scytonema) 212, 222 var. leprieurii (Mont.) Born, and Flah. 224 mirabile Wolle (Scytonema) 221 mirabilis Ag. (Calothrix) 207 mollis Wood (Dasyactis) 291 mollis Wood (Zonotrichia) 284, 293 monococca (Kuetz.) Hansg. (Chroo- thece) 12 var. mellea (Kuetz.) Hansg. 13 montana Tilden (Dichothrix) 274, 275 montana Kuetz. (Gloecapsa) 13, 16 var. caldarii Sur. 16 montana Harv. (Sorospora) 21 mucicola Lemm. (Lyngbya) 108, in mucosa Crouan. (Lyngbya) 135 muelleri Naeg. (Schizothrix) 152 multicoloratus Wood (Chroococcus) 4. 7 muralis Kuetz. (Gloeocapsa) 14, 19 muralis Kuetz. (Symploca) 129, 131 muscicola Kuetz. (Cylindrospermum) 197, 200 muscicola Kuetz. (Tolypothrix) 230 muscorum Ag. (Nostoc) 162, 169 muscorum (Ag.) Gom. (Symploca) 129, 132 var. rivularis (Wolle) Tilden 133 myochroum (Dillw.) Ag. (Scytonema) 212, 224 Myxophyceae i naegelii Wartm. (Aphanothece) 30, 32 naegelii Kuetz. (Scytonema) 232 naegelii (Kuetz.) Wood (Scytonema) 207 nana Tild. (Lyngbya) 109, 112 natans Kuetz. (Oscillaria) 72 natans (Hedw.) Welw. (Rivularia) 283, 28s natans Breb. (Scytonema) 207 naveammi Grun. (Fhormidium) 92, 102 neglecta Wood (Oscillatoria) 64 ueglectus Wood (Sirosiphon) 247 nemalionis Crouan (Lyngbya) 261 nigra Vauch. (Oscillatoria) 59, 70 nigrescens Harv. (Lyngbya) 119, 136 nigro-viridis Thw. (Oscillatoria) 59, 69 nitida Ag. (Rivularia) 283, 287 nitida ? (Rivularia) 294 Nodular'ia Mertens 161, 182 nordstedtii Gom. (Spirulina) 86, 88 Nostoc Vaucher 7, in, 160, 161, 210, 23s Nostocaceae 56, 160 nostochinearum Itzig. (Glaucocystis) 296 Nostochopsis Wood 237, 251 nostocorum Born. (Plectonema) 206, 209 ' notarisii Kuetz. (Porphyrosiphon) 269 notarisii (Menegh.) Kuetz. (Porphy^ rosiphon) 133 Index 315 novum Wood (Merismopedium) 42, 43 numidica Gom. (Oscillatoria) 61, 81 obscura Dickie (Hypheothrix) 104 obscura Kuetz. (Lyngbya) 121 obscura Wolle (Lyngbya) 121 obscurus Dickie (Schizosiphon) 256, occidentale Setch. (Scytonema) 211, 214 ocellatum Lyngb. (Scytonema) 212, 218 ocellatum (Dillw.) Thur. (Stigonema) 244, 246 ccellatus Kuetz. (Sirosiphon) 247 ochracea (Kuetz.) Thur. (Lyngbya) 109, 113 okeni Ag. (Oscillatoria) 61, 81 oligothrix Crouan (Microcoleus) 155 olivacea (Hooker) Born, and Flah. (Dichothrix) 274, 276 olivacea (Reinsch) nob. (Dermocar- pa) 52, SS olivaceum Rab. (Phormidium) 120 olivaceus Reinsch (Sphaenosiphon) SS Oncobyrsa Ag. 3, 45 ornata Kuetz. (Oscillatoria) 59, 67 orsiniana Thur. (Calothrix) 275 brsiniana (Kuetz.) Born, and Flah. (Dichothrix) 274, 275 orsinianum Kuetz. (Mastigonema) 27s oscillarioides Bory (Anabaena) 186, 193 var. elongata (Kuetz.) Born, and Flah. 194 . var. stenospora Born, and Flah. 194 Oscillatoria Vaucher 57, s8, 90 Oscillatoriaceae 56, 57 packardii (Farlow) nob. (Microcys- tis) 33, 36 packardii Farlow (Polycystis) 36 pallida (Kuetz.) Rab. (Aphanothece) 30, 31 . , pallida Kuetz. (Hypheothrix) 139, 144 pallida (Naeg.) Wolle (Lyngbya) 144 pallida (Farlow) Lemm. (Microcys- tis) 34, 36 pallida (Kuetz.) Farlow (Polycys- tis) 36 pallidus Naeg. (Chroococcus) 4, 9 paludosa Wolle (Nodularia) 182, 183 paludosum Kuetz. (Nostoc) 161, 165 paludosus (Kuetz.) Gom. (Microco- leus) 158 panniforme (Ag.) Kirchn. (Stigone- ma) 244, 245 papyraceum (Ag.) Gom. (Phormidi- um) 92, lOI papyrina Kirchn. (Lyngbya.) 102 paradoxa (Wolle) De Toni (Rivula- ria) 283, . 289 paradoxa Wolle (Zonotrichia) 289 paradoxum Kuetz. (Mastigonema) 256, 273 parasitica (Chauvin) Thur. (Calo- thrix) 254, 260 parasiticum Wolle (Mastigonema) 267 parcezonata Wood (Zonotrichia) 290 parietina (Naeg.) Thur. (Calothrix) 2SS, 269, 280 parietinum Crouan (Scytonema) 219 parmelloides Kuetz. (Nostoc) 164, 181 parvula Rab. (Gloiotrichia) 285 pelagica Lemm. (Catagnymene) 159 var. major Wille 159 pellucidulus Wood (Sirosiphon) 247 penicillata Zanard. (Dichothrix) 27s, 280 penicillata Kuetz. (Lyngbya) 109, 115 penicillata (Ag.) Thur. (Tolypothrix) 229, 232 percursa Kuetz. (Oscillatoria) 61, 83 perelegans Lemm. (Lyngbya) 108, III persicinum (Reinke) Gom. (Phormi- dium) 91, 94 phormidio.ides Bulnh. (Hydrocoleus) 137 Phormidium Kuetzing. 57, 91 phormidium Kuetz. (Lyngbya) 132 phormidium Rab. (Lyngbya) var. rivularis Wolle 133 pilosa Harv. (Calothrix) 255, 263 pilosus Crouan (Schizosiphon) 264 piscinale Kuetz. (Nostoc) 162, 166 piscinalis (Briigg.) De Toni (Micro- cystis) 34, 36 piscinalis (Briigg.) (Polycystis) 36 pisum Thur. (Gloeotrichia) 284 pisum (Ag.) Thur. (Gloeotrichia) 284, 286 pisimi Ag. (Rivularia) 283, 284, 286 plana (Harv.) Thur. (Isactis) 281 var. fissurata Born, and Flah. 282 plana Rab. (Mastigonema) 281 Plectonema Thuret 206, 267 Pleurocapsa Thuret 46, 47 plicata Carm. (Rivularia) 287 pluviale Crouan (Sirosiphon) 246 polydermatica Kuetz. (Gloeocapsa) 13, IS polymorphum Naeg. (Scytonema) 212, 228 polyotis (Ag.) Born, and Flah. (Riv- ularia) 283, 286 polysperma Rab. (Sphaerozyga) 187, 192 3i6 Minnesota Algae polyspermum (Kuetz.) Wood (Do- lichospermum) 192 Polythrix Zanardini 252, 280 Porphyridium Naegeli 296 Porphyrosiphon Kuetzing S7, I33 prasina A. Br. (Aphanothece) 30, 32 prasina (Reinsch) Born, and Thuret (Dermocarpa) 52 princeps Vauch. (Oscillatoria) 58, 62, 72 forma purpurea Collins 63 proboscidea Gom. (Oscillatoria) 58, 64 prolifera Flah. (Calothrix) 254, 262 prolifica (Grev.) Gom. (Oscillatoria) S8, 61 pruniforme (Linn.) Ag. (Nostoc) 163, 178 pulchra Kuetz. (Tolypothrix) 231 pulverea (Wood) De Toni (Microcys- tis) 33. 35 pulvereus (Wood) Wolle (Anacystis) 35 pulvereus Wood (Pleurococcus) 35 pulvinata (Mert.) Ag. (Calothrix) 254, 260 pulvinata Kuetz. (Inactis) 146, 147 pulvinata Gom. (Schizothrix) 147 pulvinatum Nordst. (Scytonema) 221 pulvinatus Wolle (Microcoleus) 158 pulvinatus Breb. (Sirosiphon) 245, 249 forma alpinus (Kuetz.) Wolle 246 punctata Naeg. (Gloeocapsa) 14, 17 punctatum Wood (Nostoc) 163, 171 punctiforme (Kuetz.) Har. (Nostoc) 161, 164 purpurascens (Kuetz.) Gom. (Phor- midium) 91, 95 purpurascens (Kuetz.) Gom. (Phor- midium) 139 purpurascens (Kuetz.) Gom. (Schizo- thrix) 152 var. cruenta (Lesp.) Gom. 152 purpureus Snow (Chroococcus) 4, 10 pusilla Harv. (Lyngbya) iii, 128 putealis Mont. (Lyngbya) no, 125 var. minor Crouan 125 quaternata (Breb.) Kuetz. (Gloeo- capsa) 13, 17, 210 quoyi (Ag.) Born, and Flah. (Bra- chytrichia) 294 quoyi (Ag.) Born. (Hormactis) 294 racemosus Wolle (Synechococcus) II radians Thur. (Rivularia) 288 var. minutula Kirchn. 288 radiosa (Kuetz.) Kirchn. (Calothrix) 235 ralfsiana (Harv.) Kuetz: (Gloeocap- sa) 15, 22 ramosa (Thwaites) Gobi (Asterocy- tis) 296 ramosum (Thwaites) Hauck (Gonio- trichum) 296 ravenelii Wolle (Hydrocoleus) 134, 138 ravenelii Wood (Scytonema) 220 ravenelii Wolle (Tolypothrix) 229, 234 refractus Wood (Chroococcus) 4, 8 retzii Ag. (Lyngbya) 102 retzii (Ag.) Gom. (Phormidium) 92, 102 forma fasciculatum Gom. 103. forma rupestris (Kuetz.) Gom. 103 rhizosoleniae Lemm. (Calothrix) 256, 273 Richelia Jobs. Schm. 161, 201 richteriana Hansg. (Chroothece) 12 rigidissima Crouan (Leibleinia) 123 rivulare Kuetz. (Nostoc) 166 rivulare Kuetz. (Nostoc) 162, 167 rivulare Borzi (Scytonema) 211, 213 Rivularia (Roth) Agardh. 253, 283 Rivulariaceae 57, 252 rivulariarum Gom. (Lyngbya) 108, III rivularis (Carm.) Rab. (Aphanocap- sa) 27, 28 rivularis (Kuetz.) Menegh. (Oncobyr- sa) 45 robusta Clark (Clathrocystis) 37, -38 robusta Setchell and Gardner (Micro- chaete) 202, 203 rosea -(Reinsch) Batters (Dermocar- pa ?) 52, S3 rosea (Snow) Lemm. (Gomphosphae- ria) 38, 39 roseolum (Richter) Gom. (Plectone- ma) 206, 210 rubra Crouan (Lyngbya) in, 128 rubra Gom. (Schizothrix) 145 rubrapunctus Wolle (Chroococcus) 4, 5 rubro-violacea Crouan (Lyngbya) in, 128 forma crassior Crouan 119 rubrum Tild. (Phormidium) 91, 95 rubrum Mont. (Scytonema) 212, 228 rubrum (Menegh.) De Toni (Symplo- castrum) 144, 145 rufescens (Breb.) Naeg. (Chroococ- cus) 248 rufescens Crouan (Lyngbya) 119, 125 rupestre Kuetz. (Nostoc) 176 rupestre Borzi (Sacconema) 281 rupestris Kuetz. (Gloeocapsa) 14, 19 rupestris (Lyngbye) Born. (Gloeo- thece) 25, 26 var. tepidar'iorum (A. Br.) Hansg. 26 rupestris Wolle (Tolypothrix) 229, 234 rupicola Collins (Dichothrix) 274, 279 rupicola Tilden (Schizothrix) 153 Index 317 saccata (WoUe) Born, and Flah. (Wollea) 181 saccata Wolle (Sphaerozyga) 182 Sacconema Borzi 252, 281 salinarum Collins (Oscillatoria) 60, 17 sancta Kuetz. (Oscillatoria) 58, 64 var. aequinoctialis Gom. 65 var. caldariorum (Hauck) Lag. 65 sandvicense Nordst. (Lophopodium) 266 sandvicensis (Nordst.) Schmidle (Calothrix) 255, 266 sanguinea (Ag.) Kuetz. (Gloeocapsa) 15, 23 sargassi Crouan (Mastichonema) 279 saxicola Naeg. (Aphanothece) 29, 30 saxicola Naeg. (Sirosiphon) 249 schauinslandii Lemm. (Aulosira) 202 schauinslandii Lemm. (Chondrocys- tis) 24 schizodermaticus West (Chroococ- cus) 4, 6 Schizophyceae i Sch'izothrix Kuetzing 58, 150 schousboei (Dermocarpa) 50 schousboei Thur. (Xenococcus) 49, SO schowiana Crouan (Leibleinia) 123 schowiana Kuetz. (Lyngbya) 118 scopulorum (Weber and Mohr) Ag. (Calothrix) 254, 258, 280 scutata cladophorae Tilden (Pring- sheimia) 46 Scytonema Agardh 206, 211 Scytonemaceae 56, 205 scytonematoides Wood (Sirosiphon) 233 scytonemicola n. sp. (Calothrix) 255, 26s sejunctum Wood (Mastigonema) 256, 27Z semiplena (C. Ag.) J. Ag. (Lyngbya) no, 118 setchellianum Gom. (Phormidium) 93, 108 setchellii Collins (Tolypothrix) 229, 234 simmonsiae (Collins) De Toni (Inac- tis) 147, 149 simmonsiae Collins (Schizothrix) 149 simplex Wood (Scytonema) 212, 229 simplice Wood (Scytonema) 229 smaragdina (Reinsch) nob, (Dermo- carpa) 52, 54 ^ smaragdinum Crouan (Phormidium) 132 smaragdinus Reinsch (Sphaenosi- phon) 54 smithii (Thw.) Wolle (Sphaerozyga) 191 solutum Born, and Grun. (Hormo- thamnion) 205 sordida Crouan (Lyngbya) no, 118 sordida (Zanard.) Gom. (Lyngbyal , 118 forma bostrychicola (Crouan) Gom. 118 spadiceum Crouan (Phormidium) 132 sparsa Wood (Gloeocapsa) 14, 19 sphaerica Born, and Flah. (Anabae- na) 186, 188 var. macrosperma Born, and Flah. 188 sphaericum Vauch. (Nostoc) 163, 173 sphaerocarpa Born, and Flah. (Nodu- laria) 182, 183 sphaero'ides Kuetz. (Nostoc) 163, 176 Sphaerozyga Agardh 183 spiralis Lemm. (Catagnymene) 70, 159 var. capitata (W. West JunJ Wille 160 Spirulina Turpin 57, 86 spirulinoides Gom. (Lyngbya) no, 126 splendida Grev. (Oscillatoria) 60, 76 var. uncinata Setch. and Gard. 76 spongiaeforme Ag. (Nostoc) 162, 168 spumigena Mert. (Nodularia) 182, 184 var. genuina Born, and Flah. 185 var. litorea (Kuetz.) Born, and Flah. 185 var. major (Kuetz.) Born, and Flah. 185 stagnale (Kuetz.) B'orn. and Flah. (Cylindrospermum) 197, 198 stagnalis Kuetz. (Anabaena) 198 stagnalis Gom. (Calothrix) 255, 265 stagnina (Spreng.) A. Br. (Aphano- thece) 30, 32 Stigonema Agardh 237, 244 Stigonemaceae 56, 236 stragulum Crouan (Phormidium) 114 stuposum (Kuetz.) Born. (Scytone- ma) 212, 221 subbrevis Schmidle (Oscillatoria) 79 subfuscum Kuetz. (Phormidium) 93, 105 var. joannianum (Kiietz.) Gom. 106 submarina Crouan (Calothrix) 276 submarinum Crouan (Scytonema) 263 submembranaceum (Ard. and Straff.) Gom. (Phormidium) 92, 104 subrigida (Wood) De Toni (Anabae- na) 187, 196 subrigidum Wood (Dolichospermum) 196 subsalsa Ag. (Oscillatoria) 61, 82 var. dulcis Crouan 67 subsalsa Oerst. (Spirulina) 87 3i8 Minnesota Algae subsalsa Oerst. (Spirulina) 87, 89, 90 forma oceanica (Crouan) Gom. 90 subtilis Holden (Lyngbya) 109, 115 subtilis W. West (Lyngbya) 112 subtilissima Kuetz. (Oscillatoria) 59, 74 subtilissima Kuetz. (Spirulina) 86, 88 subtorulosa (Breb.) Farlow (Oscilla- toria) 61, 83 subtorulosum Breb. (Phormidium) 158 subtorulosus (Kuetz.) Gom. (Micro- coleus) 95, 158 subuliforme Gom. (Phormidium) 92, 99 subuliformis Kuetz. (Oscillatoria) 60, 71 sutherlandi Dickie (Nostoc) 181 Symploca Kuetzing 57, 128 symplocarioides Crouan (Oscillaria) 129 Symplocastrum Gomont 57 Synechococcus Naegeli 2, 11 Synechocystis Sauvageau 2, 10 tenax Wolle (Hypheothrix) 139, 141 tenax Wolle (Leptothrix) 141 tenera Thur. (Microchaete) 202, 203 tenerrima Thur. (Lyngbya) 114 tenerrima Kuetz. (Oscillaria) Tz tenerrima Kuetz. (Spirulina) 86, 88 tenerrimus Gom. (Microcoleus) iSS tenue (Menegh.) Gom. (Phormidium) 92, 98 tenue Thur. (Plectonema) 206, 207 tenuis Kuetz. (Oscillaria) var. sordida Kuetz. 106 tenuis Ag. (Oscillatoria) S9, 7i, 72 var. natans (Kuetz.) Rab. 73 var. tergestina (Kuetz.) Rab. 73 tenuis Kuetz. (Tolypothrix) 229 forma bryophila Rab. 230 tenuissima W. and G. S. West (Mi- crochaete) 202, 203 tenuissima Kuetz. (Spirulina) 8g tenuissimum Lemm. (Mensmopedi- um) 42, 45 tenuissimus Grun. (Hapalosiphon) 240 terebrans Born, and Flah. (Plectone- ma) 52, 206, 209 terebriformis Ag. (Oscillatoria) 61, 83 terrestris Desmaz. (Microcoleus) 157 testarum Lagerh. (Mastigocoleus) 213, 237 Tetrapedium Reinsch 3, 41 thelephoroides (Mont.) Gom. (Schi- zothrix) 151 thermale Schwabe (Mastigonema) 268, 278 thermale Borzi (Scytonema) 243 tliermale Kuetz. (Scytonema) 223 thermale (Schabe) Borzi (Stigonema) 243 thermalis (Schwabe) Hansg. (Calo- thrix) 255, 268, 270, 275 thermalis Schwabe (Fischera) var. Americana Farl. 243 thermalis (Schabe) Gom. (Fischerel- la) 242, 243 var. mucosa Lemm. 243 thermalis Lemm. (Gloeocapsa) 15, 22 thermalis Crouan (Lyngbya) 125 thermalis Crouan (Oscillaria) 79 thermalis (Kuetz.) Gom. (Symploca) 129, 130 thermophilus Wood (Chroococcus) 4,7 thiebautii Gom. (Trichodesmium) 84 tinctoria Rab. (Hypheothrix) 149 tinctoria (Ag.) Thur. (Inactis) 147, 149 tinctoria Kuetz. (Leptothrix) 149 tinctoria Kuetz. (Lyngbya) 94 tinctoria Gom. (Schizothrix) 149 tinctorium A. Br. (Hydrocoleum) 149 tinctorium Kuetz. (Phormidium) 91, 94 Tolypothrix Kuetzing 206, 215, 229, 265 tolypotrichoides Kuetz. (Scytonema) 212, 222 tomasinianum (Kuetz.) Born. (Plec- tonema) 206, 207 tomentosum (Kuetz.) Hier. (Stigone- ma) 244, 246 torridum Ag. (Scytonema) 2ig torta Crouan (Leibleinia) 125 torta Crouan (Lyngbya) 125 torulosa (Carm.) Lagerh. (Anabaena) 186, 192 trapezoidea Tilden (Oscillatoria) 82 treleasei Gom. (Phormidium) 92, 96 Trichodesmium Ehrenberg 57, 84 trigonum W. and G. S. West (Tetra- pedium) 41 truncicola (Rab.) Wolle (Tolypo- thrix) 233 tuberculosa (Hansg.) Wille (Chloro- gloea) 46 turfaceum (Berk.) Cooke (Stigone- ma) 244, 249 var. parvum Wood 249 turfosum Kuetz. (Scytonema) 224 turgida Wolle (Mastigothrix) 256, 273 turgidus CKuetz.) Naeg. (Chroococ- cus) 4, 5, 32 var. fuscescens (Kuetz.) De Toni 6 turicensis (Naeg.) Hansg. (Chroococ- cus) 3, 5 turicensis Naeg. (Hypheothrix) 139, 141 LliST OF ILLUSTRATIONS (Magnification: 500-700 diameters) PLATE I. . Fig. I. Chroococcu's macrococcus (Kuet^.) Rab. (After Hassall) Fig. 2. Chi-Qococcus turicensis (Naeg.) Hahsg. (After Hinsgirg) Fig. 3. Chroococcus turg.idus '(Kiietz.) Naeg. (After West) Fig. 4. Chroococcus schizodermaticus West. (After W. and G. S. West) Fig. 5. Chroococcus multicoloratus Wood. (After, Wood) Fig. 6. Chroococcus refractus Wood. (After Wood) Fig. 7. Chroococcus minor (Kuetz.) Naeg. (After W. and G. S. West) Fig. 8. Chroococcus limneticus Lettim. (After Leirimermann) Fig. 9. Chroococcus purpureus Snow. (After Snow) Fig. 10. Synechdcystis aquatilis Sauv. (After Engler and PrantI) Fig. II. Synechococcus aeruginosus Naeg. (After Engler and Frantl) Fig. 12. Chroothece richteriana Hansg. (After Engler and PrantI) Fig. 13. Gloeocapsa granosa (Berkeley) Kuetz. (After Hassall) Fig. 14. Gloeocapsa polydermatica Kuetz. (After. West) Fig. 15. Gloeocapsa fenestralis Kuetz. , (After Kuetzing) Fig. 16. Gloeocapsa arenaria ,(Hass.) Rab. (After Saunders) Fig. 17. Gloeocapsa montana K^uetz. (After Kuetzing) Fig. 18. Gloeocapsa quaternata (Breb.) Kuetz. (Original) Fig. 19. Gloeocapsa aeruginosa (Carm.) Kuetz. (After Cooke) Fig. 20. Gloeocapsa gelatinpsa Kuetz. (After Kuetzing) Fig. 21. Gloeocapsa cpriglomerata Kuetz. (After Kuetzing) Fig. 22. Gloeocapsa -atrata, (Turp.) Kuetz. (After Cooke) Fig. 23. Gloeocapsa, muralis Kuetz. (After Kuetzing) Fig. 24. Gloeocapsa rupestris Kuetz. (After Cooke) Fig. 25. Gloeocapsa sparsa .Wood. (After Wood) Fig. 26, 27. Gloeocapsa gigas W. and G. S. West. (After W. and G. S. West):, Fig. 28. Gloeocapsa crepidinum (Rab.) Thur. (After Hornet and Thuret) Fig. 29. Gloeocapsa magma (Breb.) ICuetz. (After Lemmermann) Fig. 30. Gloeocapsa ralfsiana (Harv.) Kuetz. (After Cooke) Fig. 31. Gloeocapsa thermalis Lemm. (After Lemmermann) Fig. 32. Gloeocapsa viplacea (Corda) Rab. (Original) Fig. 33. Entophysalis granulosa Kuetz. (After Engler and PrantI) Fig. 34-36. Chondrocystis schauinslandii Lemm. (After Lemmermann) PLATE IL Fig. I, 2. Gloeothece linearis Naeg. (After W. and G. S. West) Fig. 3. Gloeothece confluens Naeg. (After West) Fig. 4. Gloeothece rupestris (Lyngb.) Born. . (After Cooke) Fig. 5. Gloeothece lunata W, and G. S. West. (After V/. and G. S. West) Fig 6. Aphanocapsa elachista W. and G. S. West. (After W. and G. S. West) Fig. 7. Aphanocapsa greviUei (Hass.) Rab. (After West) Fig. 8, 9. Aphanocapsa rivularis (Carm.) Rab. (After Cooke) Fig. 10, II. Aphanocapsa virescens (Hass.) Rab. (After Hansgirg) Fig. 12. Aphanothece microscopica Naeg. (After West) Fig. 13. Aphanothece castagnei (Breb.) Rab. (After Engler and PrantI) Fig. 14. Aphanothece naegelii Wartm. (Original) Fig. 15. Aphanothece stagnina (Spreng.) A. Br. (After Lemmermann) Fig. 16. Aphanothece prasina A. Br. (Original) Fig. 30. Fig. 31. Fig. 32. Fig. 33- Fig. 34. Fig. 35. fig. 36. Fig. 37- 322 Minnesota Algae Fig. 17. Microcystis marginata (Menegh.) Kuetz. (After West) Fig. 18. Microcystis fios-aquae (Witt.) Kirchn.' (After Eiijgler and Prantl) Fig. 19. Microcystis labens (Menegh.) Kuetz. (After Lemmermann) Fig. 20. Microcystis packardii (Farlow) Tilden. (Original) Fig. 21, 22. Clathrocystis aeruginosa (Kuetz.) Henfr. (After Engler and Prantl) Fig. 23-28. Gomphosphaeria aponina Kuetz. (After West) Fig. 29. Coelosphaerium kuetzingianum Naeg. (After West) Coelosphaeriopsis halophila Lemm. (After Lemmermann) Tetrapedium trigonum W. and G. S. West. (After W. and G. S. West) . Merismopedium aerugineum Breb. (After Kuetzing) Merismopedium elegans A. Br. (After West) Merismopedium novum Wood. (After Wood) Merismopedium glaucum (Ehr.) Naeg. (After West) Merismopedium convolutum Breb. (After Hansgirg) Merismopedium tenuissimum Lemm. (After Lemmermann) Fig. 38-40. Eucapsis alpina Clements and Shantz. (After Shantz) Fig. 41. Oncobyrsa cesatiana Rab. (After Lemmermann) Fig. 42. Chlorogloea tuberculosa (Hansg.) Wille. (After Wille) PLATE IIL Fig. I. Pleurocapsa caldaria (Tilden) Setchell. (Original) Fig. 2, 3. Pleurocapsa fuliginosa Hauck. (After Hauck) Fig. 4. Pleurocapsa amethystea Kolderup-Rosenvinge. (After Kolder- up-Rosenvinge) Fig. S, 6. Xenococcus laysanensis Lemm. (After Lemmermann) Fig. 7. Xenococcus schousboei Thur. (After Engler and Prantl) Fig. 8. Xenococcus kerneri H&nsg. (After Hansgirg) Fig. 9-11. Hyella caespitosa Born, and Flah. (After Engler and Prantl) Fig. 12. Hyella fontana Buber and Jadin. (After Lemmermann) Fig. 13-15. Dermocarpa prasina (Reinsch) Born, and Thur. (After Bor- net and Thuret) Fig. 16-18. Dermocarpa (?) rosea (Reinsch) Batters. (After Reinsch) Fig. 19-21. Dermocarpa violacea Crouan. (After Crouan) Fig. 22, 23. Dermocarpa fucicola Saunders. (After Saunders) Fig. 24, 25. Dermocarpa smaragdina (Reinsch) Tilden. (After Reinsch) Fig. 26, 27. Dermocarpa olivacea (Reinsch) Tilden. (After Reinsch) Fig. 28. Dermocarpa leibleiniae (Reinsch) Born. var. pelagica Wille (After Wille) Fig. 29-30. Chamaesiphon incrustans Grun. (After West) Fig. 31. Chamaesiphon curvatus Nordst. (After Nordstedt) Fig. I PLATE IV, Oscillatoria prolifica (Grev.) Gom. (After Gomont) Fig. 2. Oscillatoria agardhii Gom. (After Lemmermann) Fig. 3. Oscillatoria princeps Vauch. (After Gomont) Fig. 4. Oscillatoria proboscidea Gom. (After Gomont) Fig. S. Oscillatoria sancta Kuetz. (After Gomont) Fig. 6. Oscillatoria limosa Ag. (After Gomont) Fig. 7. Oscillatoria curviceps Ag. (After Gomont) Fig. 8. Oscillatoria ornata Kuetz. (After Gomont) Fig. 9. Oscillatoria anguina Bory. (After Gomont) Fig. 10. Oscillatoria bonnemaisonii Crouan. (After Gomont) Fig. II. Oscillatoria margaritifera Kuetz. (After Gomont) Fig. 12. Oscillatoria nigro-viridis Thwaites. (After Gomont) Fig. 13-15. Oscillatoria capitata W. West Jun. (After West) Fig. 16. Oscillatoria corallinae Gom. (After Gomont) Fig. 17-18. Oscillatoria tenuis Ag. (After Gomont) Fig. 19, 20. Oscillatoria amphibia Ag. (After Gomont) Fig. 21. Oscillatoria minnesotensis Tilden. (Original) Fig. 22. Oscillatoria chlorina Kuetz. (After Wood) Illustrations 323 Fig. 23-25. Oscillatoria splendida Grev. (After Lemmermann, Setchell and Gardner) Fig. 26. Oscillatoria amoena (Kuetz.) Gom. (After Gomont) Fig. 27. Oscillatoria subuliformis Kuetz. (After Gomont) Fig. 28. Oscillatoria laetevirens Crouan. (After Gomont) Fig. 29. Oscillatoria acuminata Gom. (After Gomont) Fig. 30. Oscillatoria animalis Ag. (After Gomont) Fig. 31. Oscillatoria violacea (Wallr.) Hass. Fig. 32. Oscillatoria brevis Kuetz. (After Gomont) Fjg- 33- Oscillatoria formosa Bory. (After Gomont) Fig. 34. Oscillatoria cortiana Menegh. (After Gomont) Fig. 35- Oscillatoria okeni Ag. (After Gomont) Fig. 36. Oscillatoria chalybea Mert. (After Gomont) Fig. ZT, 38. Oscillatoria boryana Bory. (After Gomont) Fig. 39. Oscillatoria terebriformis Ag. (After Gomont) Fig. 40. Trichodesmium erythraeum Ehr. (After Gomont) Fig. 41, 42. Trichodesmium thiebautii Gom. (After Gomont) Fig. 43. Trichodesmium contortum Wille. (After Wille) Fig. 44. Arthrospira jenneri (Kuetz.) Stiz. (After Gomont) Fig. 45- Spirulina meneghiniana Zan. (After Gomont) Fig. 46. Spirulina major Kuetz. (After Gomont) Fig, 47. Spirulina subtilissima Kuetz. (After Gomont) Fig. 48. Spirulina caldaria Tilden. (Original) Fig. 49. Spirulina subsalsa Oerst. (After Gomont) Fig. 50, SI. Spirulina duplex Wolle. (After Wolle) Fig. 52, S3. Phormidium fragile (Menegh.) Gom. (After Gomont) Fig. 54. Phormidium' foveolarum (Mont.) Gom, (After Gomont) Fig. 55. Phormidium tinctorium Kuetz. (After Gomont) Fig. 56, 57. Phormidium luridum (Kuetz.) Gom. (After Gomont) Fig. 58. Phormidium rubrum Tilden. (Original) Fig. 59. Phormidium purpurascens (Kuetz.) Gom. (After Gomont) Fig. 60, 61. Phormidium crosbyanum Tilden. (Original) Fig. 62. Phormidium laminosum (Ag.) Gom. (After Gomont) Fig. 63-65. Phormidium tenue (Menegh.) Gom. (After Gomont) Fig. 66. Phormidium valderianum (Delp.) Gom. (After Gomont) Fig. 67. Phormidium subuliforme Gom. (After Gomont) Fig. 68. Phormidium incrustatum (Naeg.) Gom. (After Gomont) Fig. 69, 70. Phormidium inundatum Kuetz. (After Gomont) Fig. 71, 72. Phormidium corium (Ag.) Gom. (After Gomont) Fig. 73, 74. Phormidium papyraceum (Ag.) Gom. (After Gomont) Fig. 75, Phormidium interruptum Kuetz. (After Wolle) Fig. 76. Phormidium naveanum Grun. ('After Wolle) PLATE V. Fig. 1-4. Phormidium r^tzii (Ag.) Gom. (After Gomont) Fig. 5. Phormidium ambiguum Gom. (After Gomont) Fig. 6. Phormidium submembranaceum (Ar. and Strafif.) Gom. (After Gomont) Fig. 7, 8. Phormidium laysanense Lemm. (After Lemmermann) Fig. 9, 10. Phormidium favosum (Bory) Gom. (After Gomont) Fig. II. Phormidium calidum Gom. (After Gomont) Fig. 12-15. Phormidium subfuscum Kuetz. (After Engler and Prantl) Fig. 16, 17. Phormidium uncinatum (Ag.) Gom. (After Gomont) Fig. 18, 19. Phormidium autumnale (Ag.) Gom. (After Gomont) Fig. 20, 21. Phormidium setchellianum Gomont. (After Gomont) Fig. 22, 23. Lyngbya lagerheimii (Mob.) Gom. (After Gomont) Fig. 24! Lyngbya nana Tilden. (Original) Fig. 25, 26. Lyngbya ochracea (Kuetz.) Thur. (After Bornet) Fig. 27-29. Lyngbya ferruginea G. S. West. (After West) Fig. 30, 31. Lyngbya lutea (Ag.) Gom. (After Gomont) Fig. 32, 33. Lyngbya aerugineo-caerulea (Kuetz.) Gom. (After Gomont) Fig. 34. Lyngbya cladophorae Tilden. (Original) 324 Minnesota Algae Fig. 3S. Lyngbya versicolor (Wartm.) Gom. (After Gomont) Fig. 36. Lyngbya gracilis (Menegh.) Rab. (After Gomont) Fig. 37. Lyngbya sordida (Zan.) Gom. (After Gomont) Fig. 38. Lyngbya semiplena (C. Ag;.) J. Ag. (After Gomont) Fig. 39. Lyngbya confervoides C. Ag. (After Gomont) Fig. 40, 41. Lyngbya aestuarii (Mert.) Liebm. (After Gomont) Fig. 42. Lyngbya majusciila (Dillw.) Harv. (After Gomont) Fig. 43. Lyngbya martensiana Menegh. (After Gomont) Fig. 44. Lyngbya martensiana var. calcarea Tilden. (Original) Fig. 4S. Lyngbya putealis Mont. (After Gomont) Fig. 46. Lyngbya major Menegh. (After Gomont) Fig. 47. Lyngbya spirulinoides Gom. (After Gomont) Fig. 48. Symploca atlantica Gom. (After Gomont) Fig. 49. Symploca hydnoides Kuetz. (After Gomont) Fig. so. Symploca laete-viridis Gom. (After Gomont) Fig. 51. Symploca thermalis (Kuetz.) Gom. (After Gomont) Fig. 52. Symploca dubia (Naeg.) Gom. (After Kuetzing) Fig. 53. Symploca muralis Kuetz. (After Gomont) Fig. 54. Symploca muscorum (Ag.) Gom. (After Gomont) Fig. 55. Porphyrosiphon notarisii (Menegh.) Kuetz. (After Gomont) Fig. 56. Hydrocoleus comoides (Harv.) Gom. (After Gomont) Fig. 57. Hydrocoleus cantharidosmus (Mont.) (jom. (After Gomont) Fig. 58. Hydrocoleus lyngbyaceus Kuetz. (After Gomont) Fig. 59. Hydrocoleus glutinosus (Ag.) Gom. (After Kuetzing) Fig. 60, 61. Hydrocoleus holdenii Tilden. (After Holden) Fig. 62, 63. Hydrocoleus homoeotrichus Kuetz. (After Gomont) Fig. 64, 65. Hydrocoleus ravenelii Wolle. (After Wolle) Fig. 66. Hydrocoleus heterotrichus Kuetz. (After Gomont) PLATE VL Fig. I. Hypheothrix calcicola (Ag.) Rab. (After Gomont) Fig. 2. Hypheothrix coriacea Kuetz. (After Gomont) Fig. 3. Hypheothrix lardacea (Ces.) Hansg. (After Gomont) Fig. 4. Hypheothrix arenaria (Berk.) De Toni. (After Gomont) Fig. 5. Symplocastrum fragile (Kuetz.) De Toni. (After Gomont) Fig. 6. Symplocastrum rubrum (Menegh.) De Toni. (After Gomont) Fig. 7-9. Symplocastrum cuspidatum (West and West) De Toni. (After W. and G. S. West) Fig. 10. Symplocastrum friesii (Ag.) Kirchn. (After Gomont) Fig. 11-13. Inactis pulvinata Kuetz. (After Kuetzing) Fig. 14, 15. .Inactis fasciculata (Naeg.) Grun. (After Gomont) Fig. 16. Inactis lacustris (A. Br.) De Toni. (After Gomont) Fig. 17. Inactis tlnctoria (Ag.) Thur. (After Gomont) Fig. 18. Inactis hawaiensis (Lemm.) De Toni. (After Lemmermann) Fig. 19. Schizothrix thelephoroides (Mont.) Gom. (After Gomont) Fig. 20, 21. Schizothrix purpurascens (Kuetz.) Gom. (After Gomont) Fig. 22. Schizothrix chalybea (Kuetz.) Gom. (After Gomont) Fig. 23. Schizothrix muelleri Naeg. (After Gomont) Fig. 24. Schizothrix braunii Gom. (After Gomont) Fig. 25. Schizothrix rupicola Tilden. (Original) Fig. 26. Dasygloea amorpha Berk. (After Gomont) Fig. 27. Microcoleus tenerrimus Gom. (After Gomont) Fig. 28. Microcoleus chthonoplastes (Fl. Dan.) Thur. (After Gomont) Fig. 29. Microcoleus vaginatus (Vauch.) Gom. (After Gomont) Fig. 30. Microcoleus paludosus (Kuetz.) Gom. (After Gomont) Fig. 31. Microcoleus pulvinatus Wolle (After Wolle) Fig. 32. Microcoleus subtorulosus (Kuetz.) Gom. (After Gomont) Fig. 33. Catagnymene pelagica Lemm. (After Wille) Fig. 34. Catagnymene spiralis Lemm. (After Wille) Fig. 3.';-37. Nostoc punctiforme (Kuetz.) Hariot (After Sauvageau) Fig. 38. Nostoc paludosum Kuetz. (After Janczewski) Illustrations 325 PLATE VII. Fig. I. Nostoc linckia (Roth) Born. (After Bornet and Thuret) Fig. 2. Nostoc piscinale Kuetz. (After Cooke) Fig. 3. Nostoc carneum Ag. (After Lemmermann) Fig. 4. 5- Nostoc spongiaeforme Ag. (After Cooke) Fig. 6-10. Nostoc ellipsosporum (Desm.) Rab. (After Bornet and Thuret) Fig. II. Nostoc gelatinosum Schousb. (Original) Fig. 12-14. Nostoc muscorum Ag. (After Bornet and Thuret) Fig. IS. Nostoc humifusum Carm. (After Cooke) Fig. 16. Nostoc foliaceum Moug. (Original) PLATE VIII. Fig. I. Nostoc commune Vauch. (After Hansgirg) Fig. 2. Nostoc sphaericum Vauch. (After Cooke) Fig. 3. Nostoc calidarium Wood. (After Wood) Fig. 4. Nostoc maerosporum Menegh. (After Cooke) Fig. s. Nostoc microscopicum Carm. (After Cooke) Fig. 6, 7. Nostoc glomeratum Kuetz. (After Kuetzing) Fig. 8. Nostoc caeruleum Lyngbye (Original) Fig. 9, 10. Nostoc pruniforme (Linn.) Ag. ((After Cooke) Fig. 11-16. Nostoc verrucosum (Linn.) Vauch. (After Thuret) Fig. 17-19. Nostoc amplissimum Setch. (After Setchell) Fig. 20. Nostoc parmelioides Kuetz. (After Gomont) Fig. 21, 22. Wollea saccata (WoUe) Born, and Flah. (After Engler and Prantl) PLATE IX. Fig. I, 2. Nodularia harveyana (Thwaites) Thur. (After Bornet and Thu- ret) Fig. 3. Nodularia sphaerocarpa Born, .and Flah. (After West) Fig. 4. Nodularia paludosa WoUe. (After Wolle) Fig. 5. Nodularia hawaiiensis Tilden. (Original) Fig. 6. Nodularia armorica Thur. (After Bornet and Thuret) Fig. 7, 8. Nodularia spumigena var. litorea (Kuetz.) Born, and Flah. (After Bornet and Thuret) Fig. 9. Anabaena variabilis Kuetz. (After Hansgirg) Fig. 10-13. Anabaena hallensis (Jancz.) Born, and Flah. (After Jan- czewski) Fig. 14. Anabaena flos-aquae (Lyngb.) Breb. (After Engler and Prantl) Fig. IS. Anabaena circinalis Rab. (After Hansgirg) Fig. 16. Anabaena inaequalis (Kuetz.) Born, and Flah. (After West) Fig. 17. Anabaena catenula (Kuetz.) Born, and Flah. (Original) Fig. 18. Anabaena laxa (Rab.) A. Br. (After Bornet and Flahault) Fig. 19. Anabaena torulosa (Carm.) Lag. (After Cooke) Fig. 20. Anabaena oscillarioides Bory. (After Hansgirg) Fig. 21. Anabaena confervoides Reinsch. (Original) Fig. 22. Anabaena cupressdphila Wolle. (After Wolle) PLATE X. Fig. I. Aphanizomenon flos-aquae (Linn.) Ralfs. (After Engler and Prantl) Fig 2 Cylindrospermum stagnate (Kuetz.) Born, and Flah. (After West) Cylindrospermum comatum Wood. (After Wood) Cylindrospermum majus Kuetz. (After Gomont) Cylindrospermum minutum Wood. (After Wolle) Cylindrospermum muscicola Kuetz. (After Kuetzing) Cylindrospermum catenatum Ralfs. (Original) Richelia intracellularis J. Schm. (After Lemmermann) Aulosira schauinslandii Lemm. (After Lemmermann) Fig. 3- Fig. 4- Fig. s. Fig. 6. Fig. 7. Fig. 8. Fig. 9- 326 Minnesota Algae Fig. 10. Microchaete tenuissima W. and G. S. West. (After W. and G. S. West) Fig. II. Microchaete tenera Thur. (After Bornet and Thuret) Fig. 12. Microchaete grisea Thur. (After Bornet and Thuret) Fig. 13. Hormothamnion enteromorphoides Grun. (After Engler and Prantl) PLATE XL Fig. I, 2. Plectonema tenue Thur. (After Gomont) Fig. 3. Plectonema tomasinianum (Kuetz.) Born. (After Bornet and Thuret) Fig. 4, 5. Plectonema wollei Fart. (After Gomont) Fig. 6. Plectonema terebrans Born, and Flah. (After Bornet and Fla- hault) Fig. 7. Plectonema nostocorum Born. (After Gomont) Fig. 8. Plectonema roseolum (Richter) Gom. (After Gomont) Fig. 9. Plectonema golenkinianum Gom. (After Gomont) Fig. 10. Plectonema calotrichoides Gom. (After Gomont) Fig. II, 12. Scytonema rivulare Borzi. (Original) Fig. 13, 14. Scytonema occidentale Setchell. (After Setchell) Fig. 15. Scytonema crispum (Ag.) Born. (Original) PLATE XII. Fig. I. Scytonema caldarium Setch. (After Setchell) Fig. 2, 3. Scytonema azureum Tilden. (Original) Fig. 4. Scytonema hofmanni Ag. (After Engler and Prantl) Fig. 5. Scytonema varium (Kuetz.) (After Kuetzing) Fig. 6. Scytonema javanicum (Kuetz.) Born. (After W. and G. S. West) Fig. 7. Scytonema javanicum var. hawaiiense Lemmermann (After Lem- mermann) Fig. 8. Scytonema ocellatum Lyngb. (After Wolle) Fig. 9. Scytonema intertextum (Kuetz.) Rab. (After Wolle) Fig. 10, II. Scytonema amplum W. and G. S. West. (After W. and G. S. West) Fig. 12. Scytonema wolleanum De Toni. (After Wolle) Fig. 13, 14. Scytonema stuposum (Kuetz.) Born. (After Kuetzing) PLATE XIII. Fig. I. Scytonema tolypotrichoides Kuetz. (After Wood) Fig. 2-S. Scytonema mirabile (Dillw.) Born. (After West) Fig. 6. Scytonema myochroum (Dillw.) Ag. (After Bornet and Thuret) Fig. 7, 8. Scytonema fuliginosum Tilden. (Original) Fig. 9. Scytonema alatum (Carm.) Borzi. (After Hone) Fig. 10-12. Scytonema crustaceum Ag. (After Kuetzing) Fig. 13. Scytonema densum (A. Br.) Born. (After Kuetzing) Fig. 14. Symphyosiphon'bornetianum Wolle. (After Wolle) Fig. 15. Scytonema hirtulum (Kuetz.) Rab. (After Wolle) PLATE XIV. Tolypothrix lanata (Desv.) Wartm. (After West) I. Tolypothrix distorta (Hofman-Bang) Kuetz. (Original) Tolypothrix penicillata (Ag.) Thur. (After Engler and Prantl) Tolypothrix byssoidea (Hass.) Kirchn. (After Cooke) Tolypothrix ravenelii Wolle. (After Wolle) Tolypothrix setchellii Collins. (After Collins) Tolypothrix rupestris Wolle. (After Wolle) Desmonema wrangellii (Ag.) Born, and Flah. (After Engler and Prantl) Diplocolon heppii Naeg. (After Engler and Prantl) Mastigocoleus testarum Lag. (After Engler and Prantl) Fig. I. Fig. 2- Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9- Fig. ID. Fig. II. Fig. 12. Illustrations 327 Fig. 13. Hapalosiphon fontinalis (Ag.) Born. (After Lemmermann) Fig. 14, 15. Hapalosiphon laminosus (Kuetz.) Hansh. (After Buscalioni) PLATE XV. Fig. 1-4. Hapalosiphon ma}or Tilden. (Original) Fig. 5. Hapalosiphon intricatus W. and G. S. West. (After W. and G. S. West) Fig. 6, 7. Hapalosiphon arboreus W. and G. S. West. (After W. and G. S. West) Fig. 8,9. Fischerella ambigua (Naeg.) Gom. (After W. and G. S. West) Fig. 10, II. Fischerella thermalis (Schabe) Gom. (After Lemmermann) Fig. 12. Fischerella thermalis var. mucosa Lemm. (After Lemmermann) Fig. 13. Stigonema hormoides (Kuetz.) Born, and Flah. (After W. and G. S. West) Fig. 14. Stigonema aefugineum Tilden. (Original) Fig. 1S-17. Stigonema ocellatum (Dillw.) Thur. (After West) Fig. 18, 19. Stigonema minutum (Ag.) Hass. (After West) Fig. 20. Stigonema turfaceum (Berk.) Cooke. (After Engler and Prantl) Fig. 21. Stigonema informe Kuetz. (After Kuetzing) Fig. 22. Stigonema mamillosum (Lyngb.) Ag. (After Gomont) PLATE XVL Capsosira brebissonii Kuetz. (After Engler and Prantl) Nostochopsis lobatus Wood. (After Engler and Prantl) Amphithrix janthina (Mont.) Born, and Flah. (After Engler and Prantl) Amphithrix violacea (Kuetz.) Born, and Flah. (After Kuetzing) Calothrix Juliana (Menegh.) Born, and Flah. (After Kuetzing) 6-8. Calothrix confervicola (Roth) Ag. (After Bornet and Thuret) Calothrix consociata (Kuetz.) Born, and Flah. (After Kuetzing) Calothrix fusco-violacea Crouan. (After Crouan) 12. Calothrix scopulorum (Web. and Mohr) Ag. (After Bornet and Thuret) Calothrix contarenii (Zan.) Born, and Flah. (After Kuetzing) Calothrix pulvinata (Mert.) Ag. (After Bornet and Thuret) 16. Calothrix parasitica (Chauv.) Thur. (After Bornet and Thuret) PLATE XVIL Fig. I. Calothrix aeruginea (Kuetz.) Thur. (After Bornet and Thuret) Fig. 2-6. Calothrix Crustacea Thur. (After Bornet and Thuret) Fig. 7. Calothrix scytonemicola Tilden. (Original) Fig. 8, 9. Calothrix stagnalis Gom. (After Lemmermann) Fig. 10, II. Calothrix fusca (Kuetz.) Born, and Flah. (After Teodoresco) Fig. 12. Calothrix sandvicensis (Nordst.) Schmid. (After Schmidle) Fig. 13, 14. Calothrix adscendens (Naeg.) Born, and Flah. (After Teodo- resco) PLATE XVIIL Fig. 1-5. Calothrix thermalis (Schwabe) Hansg. (Original) Fig. 6, 7. Calothrix calida P. Richter. (After Richter) Fig. 8-10. Calothrix kuntzei P. Richter. (After Richter) Fig. II. Calothrix braunii Born, and Flah. (After Lemmermann) Fig. 12. Calothrix parietina (Naeg.) Thur. (After West) Fig. 13. Calothrix lacucola Wolle. (After Wolle) Fig. 14. Schizosiphon obscurus Dickie. (After Dickie) Fig. 15. Mastigonema paradoxum Kuetz. (After Kuetzing) Fig. 16. Dichothrix orsiniana (Kuetz.) Born, and Flah. (After West) Fig. 17. Dichothrix calcarea Tilden. (Original) Fig. 18. Dichothrix baueriana (Grun.) Born, and Flah. (After Lemmer- mann) Fig. I. Fig. 2. Fig. 3- Fig. 4- Fig. 5- Fig. 6- Fig. 9- Fig. 10. Fig. II, Fig. 13- Fig. 14. Fig. IS, 328 Minnesota Algae PLATE XIX. Fig. I. Dichothrix meneghiniana (Kuetz.) De Toni. (After Wolle) Fig. 2. Dichothrix gypsophila (Kuetz.) Born, and Flah. (After Engler and Prantl) Fig. 3. Dichothrix hosfordii (Wolle) Bornet. (After Wplle) Fig. 4. Sacconema rupestre Borzi. (After Engler and Prantl) Fig. 5. Isactis plana (Harv.) Thur. (After Bornet and Tliuret) Fig. 6. Rivularia pisum Ag. (After Cooke) Fig. 7. Rivularia natans (Hedw.) Welw. (After Teodoresco) PLATE XX. Fig. 1-3, Rivularia natans (Hedw.) Welw. (Original) Fig. 4. Rivularia echinulata (Smith) Born, and Flah. (After Xemmer- mann) Fig. 5, 6. Rivularia polyotis (Ag.) Bornet and- Flah. (After Bornet and Thuret) Fig. 7-8. Rivularia borealis P. Richter. (After Richter) Fig. 9. Rivularia minutula (Kuetz.) Born, and Flah. (After West) Fig. ID. Rivularia atra Roth. (After Wille) Fig. 11-14. Rivularia haematites (DC) Ag. (Original) Fig. 15. Rivularia dura Roth. (After Cooke) Fig. 16, 17. Rivularia coadunata (Sommerf.) Foslie. (After West) Fig. 18. Brachytrichia quoyi (Ag.) Born, and Flah. (After Gomont) Fig. 19, 20. Asterothrix creginii Wolle. (After Wolle) Fig. 21. Asterocytis ramosa (Thwaites) Gobi. (After Wille) Fig. 22. Glaucocystis nostochinearum Itzig. '(After Lagerheim) Fig. 23. Forphyridium cruentum. (Ag.) Naeg. (After Cooke) ' Fig. 24, 25. Cryptoglena americana Davis, ' (After Davis) Pla 'o ''Sbo'■■ ri e) ?i3 ^■«t« oo.-.oo- o o o^' o^ 00^:00^ ^.O.--' .,..oo*''^ ^ Oo" jf ®eiooooooo. 3)0' ,CP' gO OocDOO' "^0000000° "^©oo©©®^ VII. Plate m. 9 Plate XIV. Plal XIII. Plate XL V. ^^^M XVIL Pla J KVIII. Plate XIX l< y.'" if ■ \. '^^tp "f — M l III .n~ PIat< KX.