J o .0 8 Algae of the Susquehanna River Basin In New York George J. Schumacher ! BULLETIN NUMBER 412 NEW YORK STATE MUSEUM AND SCIENCE SERVICE The University of the State of New York ALBANY, NEW YORK The State Education Department NOVEMBER 1969 LIBRARY SEP 1 6 1970 r HJEW YORK BOTANICAL 3Af*DE?N Algae of the Susquehanna River Basin In New York George J. Schumacher The University of the State of New York ALBANY, NEW YORK The State Education Department NOVEMBER 1969 THE UNIVERSITY OF THE STATE OF NEW YORK Regents of the University (with years when terms expire ) 1984 Joseph W. McGovern, A.B., LL.B., L.H.D., LL.D., D.C.L., Chancellor New York 1970 Everett J. Penny, B.C.S., D.C.S., Vice Chancellor White Plains 1978 Alexander J. Allan., Jr., LL.D., Litt.D. . . .Troy 1973 Charles W. Millard, Jr., A.B., LL.D., L.H.D. Buffalo 1972 Carl H. Pforzheimer, Jr., A.B., M.B.A., D.C.S., H.H.D Purchase 1975 Edward M. M. Warburg., B.S., L.H.D. . . . New York 1977 Joseph T. King, LL.B Queens 1974 Joseph C. Indelicato, M.D Brooklyn 1976 Mrs. Helen B. Power, A.B., Litt.D., L.H.D. . Rochester 1979 Francis W. McGinley., B.S., LL.B., LL.D. . . Glens Falls 1980 Max J. Rubin, LL.B., L.H.D New York 1971 Kenneth B. Clark, A.B., M.S., Ph D., Litt.D. . Hastings on Hudson 1982 Stephen K. Bailey, A.B., B.A., M.A., Ph.D., LL.D Syracuse 1983 Harold E. Newcomb, B.A Owego 1981 Theodore M. Black, A.B Sands Point President of the University and Commissioner of Education (Acting) Ewald B. Nyquist Associate Commissioner for Cultural Education Hugh M. Flick Assistant Commissioner for State Museum and Science Service John G. Broughton Principal Scientist — Biological Survey Donald L. Collins State Botanist Eugene C. Ogden TABLE OF CONTENTS Page Introduction 1 Collecting Stations 6 Annotated List 9 References 41 Illustrations 44 Index to Families and Genera 56 Digitized by the Internet Archive in 2017 with funding from IMLS LG-70-15-0138-15 https://archive.org/details/bulletinnewyorks4121 newy Algae of the Susquehanna River Basin In New York1 2 3 By George J. Schumacher 2 3 INTRODUCTION The algae of the Susquehanna River Basin in New York are not well known. The earliest work of any consequence was a bio- logical survey of the watershed, conducted by the New York State Conservation Department in 1935. This was restricted to lakes, however, and identifications were made only to genera. Since that time, only the work of Hohn (1951) is significant. This investiga- tion was concerned with the diatom distribution in western New York and included 57 taxa from the Susquehanna basin. More recently, two unpublished theses have dealt with this area. Patricia Lane (1966) studied the plankton algae of two small ponds near Binghamton, while Wager (1968) investigated the seasonal varia- tions in the net phyto-plankton of the Susquehanna in the vicinity of Binghamton. Other rivers and river basins in this State have been studied in somewhat the same manner as described in this report; e.g., Schumacher (1961), but the present effort is more complete and comprehensive than any of the others, particularly in respect to the desmids and other planktonic forms. A general review of limno- logical investigations in New York and the other Middle Atlantic States can be found in Berg (1963). 1 A survey sponsored by the New York State Museum and Science Service. 2 Professor of Biology, State University of New York at Binghamton, Bing- hamton, New York; under temporary appointment as Senior Scientist (Bot- any) in the New York State Museum and Science Service Biological Survey for this project. 3 Manuscript submitted for publication March 18, 1969 2 The Susquehanna River drains 6,080 square miles of New York State (Hoyt and Anderson, 1905); this equals 13 percent of the entire State (Fig. 1) . It drains all or sizeable parts of the follow- ing counties: Broome, Chemung, Chenango, Cortland, Delaware, Madison, Otsego, Schuyler, Steuben, Tioga, and Tompkins. It has its origin in Otsego Lake, near Cooperstown, in Otsego County and flows southwesterly until it reaches Broome County. Here it dips to the south and enters Susquehanna County, Pennsylvania. It quickly returns to New York and continues west until it reaches the southwest corner of Tioga County where it turns south and again enters Pennsylvania. It continues through Pennsylvania in a southeasterly direction, crossing Maryland and finally emptying into Chesapeake Bay. The Susquehanna basin in New York is part of the Allegany Plateau and consists generally of rolling, somewhat broken country. The plateau separates those waters flowing north and west into the St. Lawrence, Great Lakes, or the Mississippi from those draining south and east into the Atlantic. According to the New York State Department of Health (1954) “the main use of the land is for farming and raising cattle; second-growth timber covers the ridges and slopes; residential areas, industrial areas and the major por- tions of recreation areas are located primarily in unincorporated communities. ” The primary objective of this study has been to collect and identify the desmids of the Susquehanna River Basin in New York. The desmids are green algae assigned to the families Mesotaeniaceae and Desimidiaceae. In general, waters that are shallow, rich in organic acids, and with a pH of 5.0 to 6.8 are ideal habitats. Permanent pools, shallow ponds, edges of bogs, and lakes with little or no current present excellent conditions for desmid populations. Several terms can properly be used in describing the precise location of a desmid habitat and they appear throughout the annotated list. They are as follows: euplankton (true floating or drifting), peri- phyton (attached to aquatic plants near the surface), and tycho- plankton (entangled with various plants near the shore in shallow water) . One common method of sampling the euplankton is to pull or tow an extremely fine plankton net through the open water and place the material trapped in the net into a vial. The words “ tow ” or “ straining ” are often used to designate this type of sampling. In this survey, tows and strainings yielded many diatoms as well SHOWING COLLECTING STATIONS 4 as desmids and other planktonic green algae. To collect tycho- plankton samples, the various aquatic plants are usually gently pulled from the water and the entangled algae flushed into the collecting container by squeezing the plants over a jar. This type of collection is commonly known as a “ squeezing.” Most collections were made in situations favoring a desmid flora; however, sampling was not restricted to these particular loca- tions. Wherever the conditions warranted, other samples were taken at these stations and it was not uncommon to collect algae attached to rocks, twigs, and dams, or those forming mats on the muddy bottom as well as algae from other ecological niches. This accounts for many of the blue-green and filamentous green algae recorded in this study. However, certain aquatic habitats that ordinarily do not support desmid growth were not visited. This explains the absence of certain major groups of algae in this report, notably the reds (Rhodophyta) and the stone worts (Charophyceae) . All taxa identified during this survey have been arranged in an annotated list. Following each name is a word or phrase describ- ing the particular type of sample in which it was found. This is usually followed by the sampling station and the county in which that station is located. In many instances, information such as rela- tive abundance and seasonal distribution is given if it is considered important. In addition, some taxonomic characteristics are frequently included when they can be readily seen or measured and can be useful in the identification of that taxon. A summary of the taxa is as follows: Chlorophyta 258 Volvocales 4 Tetrasporales 9 Ulotrichales 21 Oedogoniales 3 Cladophorales 5 Chlorococcales 81 Pediastrum 17 Scenedesmus 21 Others 43 Zygnematales 135 Closterium 21 Cosmarium 33 Staurastrum 30 Other 51 5 Euglenophyta 7 Chrysophyta 78 Xanthophyceae 3 Chrysophyceae 10 Bacillariophyceae 65 Centrales 4 Pennales 61 Pyrrophyta 4 Cyanophyta 56 Chroococcales 21 Chamaesiphonales 1 Oscillatoriales 34 Total 403 The desmids represent the largest single group of algae with 132 taxa within the order Zygnematales. The desmids are all illustrated. The second largest group is the diatoms with 65 repre- sentatives within the Bacillariophyceae. All illustrations were made directly from living material with the aid of the camera lucida or from photographs of the living material. 6 COLLECTING STATIONS4 OTSEGO CO. 1. Otsego Lake, Cooperstown. The Susquehanna River heads in Otsego Lake at an altitude of 1193 feet. The lake is approximately 7.5 miles long by 1.5 miles wide. Most collections were taken at the south end of the lake near the beginning of the Susquehanna River. 2. Cherry Valley Creek, 5 miles east of Milford. Altitude approxi- mately 1167 feet. The origin of this creek is in the vicinity of Cherry Valley. The creek flows in a southwest direction, reaching the Susquehanna at Milford, 8 miles south of Otselic Lake. 3. Oak Creek, Oaksville. A small stream flowing southeast from Schuyler Lake and joining the Susquehanna 3 miles south of Otsego Lake. 4. Otego Creek, Hartwick. Otego Creek has its beginnings a few miles west of Oaksville and flowing southward joins the Susque- hanna 3 miles west of Oneonta. 5. Susquehanna River, Unadilla. This station is 40 miles from the source and the elevation is 1000 feet — a drop of 167 feet. CHENANGO CO. 6. Unadilla River, South New Berlin. The river’s origin is in the town of Bridgewater. It flows southward until it joins with the Susquehanna near Sidney. 7. Chenango River, Norwich. Rising in Madison County, the Chenango River flows south and west, joining the Susquehanna at Binghamton. 8. Genegantslet Creek, Smithville Flats. Originating near East Pharsalia, Genegantslet Creek flows south through Chenango County until it meets the Chenango River 3 miles south of Greene. 9. Cincinnatus Lake. A large lake used commercially for swim- ming and fishing, situated on the border of Cortland and Chenango Counties. Samples were taken at the southeastern end, near the outlet. 10. Mud Creek, Linklaen. Mud Creek has its origin in the north- west corner of Chenango County. After flowing south it joins the Otselic River near Pitcher. CORTLAND CO. 11. Stump Lake, just north of Cincinnatus Lake on N.Y. Route 41. A shallow lake with a rich muck bottom and numerous submerged stumps. 4 See Fig. 1. 7 12. Otselic River, Willet. This is the main tributary of the Tiough- nioga River. It rises in Madison County, joining the Tioughnioga at Whitney Point to the southwest. 13. East Branch of the Tioughnioga, 2 miles south of Cuyler. The East Branch flows southwest from its origin in Madison County to the town of Cortland where it unites with the West Branch. 14. West Branch of the Tioughnioga, southern city limits of Homer. Beginning near Tully, the West Branch joins the East Branch at Cortland. 15. Tioughnioga River, 4.5 miles north of Marathon. The Tiough- nioga is the main tributary of the Chenango and joins it at Chenango Forks. BROOME CO. 16. Junction of Tioughnioga and Otselic Rivers, Whitney Point. The Tioughnioga continues from Whitney Point south and east to meet the Chenango. 17. Lily Lake, Chenango State Park, 9 miles north of Bingham- ton. 18. Pickerel Pond, 1.5 miles southeast of Nineveh. Altitude approxi- mately 1527 feet. The presence of submerged aquatic plants and warm, shallow, slightly acidic water make this pond ecologically ideal for desmids. 19. Camp Tuscarora, Gulf Summit. A lake located in a Boy Scout camp near the Pennsylvania border. 20. Big Snake Creek, Corbettsville. The Big Snake actually has its beginning in Pennsylvania, but it flows northward and into the Susquehanna River at Corbettsville. 21. Big Snake Creek, .75 miles southwest of Corbettsville, just north of Pennsylvania border. 22. Little Snake Creek, Conklin Corners. 23. Boland Pond, on Thomas Brook. A beaver pond north of Chenango River bridge, Route 11, north side of Binghamton. 24. Little Choconut Creek, Stella Ireland Road, Binghamton. 25. Small swamp between Erie-Lackawanna railroad and Watson Boulevard, west of I.B.M. Golf Course, Endicott. 26. Small stream, 1 mile north of Glendale Road and Route 11 junction. 27. Nanticoke Creek, Maine. This creek flows from the northern section of the county southward and empties into the Susquehanna at Endicott. 28. Pond 1, Hawleytown Road, 2 miles south of Binghamton, See No. 29. 8 29. Pond 2, Hawleytown Road, 2 miles south of Binghamton. This pond and the one listed in No. 28 are two very small private ponds along the Hawleytown Road. Both are shallow with clay bot- toms. 30. Susquehanna River, bridge between Conklin and Binghamton. 31. Susquehanna River, below the confluence with the Chenango. 32. Susquehanna River, .5 miles below Binghamton-Johnson City sewage treatment plant. 33. Susquehanna River, Route 26 bridge, Endicott. 34. Chenango River, Main Street bridge, Binghamton, .5 miles upstream from its junction with the Susquehanna. 35. Harpur Pond, S.U.N.Y. campus, Binghamton. Shallow, soft- bottomed pond at south end of campus. Fed by runoff from sur- rounding hills; water circum-neutral. TIOGA CO. 36. Owego Creek, 1.6 miles north of junction of Routes 38 and 96. 37. Owego Creek, at junction of Routes 38 and 96. 38. Owego Creek, 1.6 miles north of Catatonk. 39. Pipe Creek, Tioga Center. A small creek emptying into the Susquehanna River at Tioga Center. 40. Susquehanna River, Route 96 bridge, Owego. 41. Susquehanna River, Smithboro. CHEMUNG CO. 42. Chemung River, 2 miles west of Waverly. The Chemung River is formed by the union of the Canisteo, Cohoc- ton, and Tioga Rivers near Painted Post. From there it flows south- east, enters Pennsylvania, and joins with the Susquehanna near Athens. STEUBEN CO. 43. Meade Creek, 2.5 miles west of Painted Post on U.S. Route 15. Arising in Schuyler County, Meade Creek fol- lows a course southwest and meets the Cohocton River near Cooper’s Plains. 44. Cohocton River, Curtis. Originating in Livingston County, the Cohocton flows southeast and joins the Canisteo River at Painted Post forming the Chemung River. 45. Canisteo River, 2.5 miles east of Addison. The headwaters of the Canisteo are in Allegany County. The river joins with the Cohoc- ton to form the Chemung. 46. Tioga River, Presho. The Tioga flows north from Pennsyl- vania into New York and merges with the Canisteo near Erwins. 9 ANNOTATED LIST DIVISION — CHLOROPHYTA CLASS — CHLOROPHYCEAE ORDER — VOLVOCALES FAMILY — VOLVOCACEAE Gonium pectorale Mueller. In plankton and squeezings of aquatic plants, summer. Tioughnioga River, Little Snake Creek, and Pickerel Pond, Broome Co.; Otselic River, Cortland Co. Pandorina morum (Muell.) Bory. Rare or infrequent in plankton and plant squeezings but rather widespread in creeks, rivers, and ponds of Broome, Chemung, Chenango, Cortland, and Otsego Cos. Eudorina elegans Ehren. Apparently widespread throughout the Susquehanna and its tributaries, becoming abundant in plankton of warm summer months. Volvox tertius Meyen. In plankton of Pond 1, Hawleytown Road, Broome Co., particularly common in winter months. Should be present in waters of other ponds in area. TETRASPORALES PALMELLACEAE Sphaerocystis Schroeteri Chodat. In tows and squeezings of aquatics of Pickerel Pond and Susquehanna River, Broome Co.; Che- mung River, Chemung Co.; Stump Lake and West Branch Tioughnioga River, Cortland Co. Gloeocystis ampla (Kuetz.) Lager. In tows and squeezings. Pick- erel Pond and Susquehanna River, Broome Co.; Genegantslet Creek, Chenango Co.; West Branch Tioughnioga River, Cort- land Co. G. gigas (Kuetz.) Lager. Infrequent in plankton of Tioughnioga River, Broome Co.; Cincinnatus Lake and Genegantslet Creek, Chenango Co.; Otselic River and Stump Lake, Cortland Co. Asterococcus limneticus G. M. Smith. Rare in strainings from Pick- erel Pond and Big Snake Creek, Broome Co. TETRASPORACEAE Tetraspora gelatinosa (Vauch.) Desv. Entangled near shore about Sparganium stems. Owego Creek, Tioga Co. 10 T. lubrica (Roth) C. A. Agardh. Along shoreline of Harpur Pond, Broome Co. Frequent in fall months when water temperature is near freezing and pH is about 6.6. Schizochlamys gelatinosa A. Braun. Frequent to abundant in quiet water along margins of Harpur Pond, Broome Co. Similar loca- tion to Tetraspora lubrica. Fig. 140. CHLORANGIA CEAE Stylosphaeridium stipitatum (Bachm.) Geitler & Gimesi. A frequent epiphyte on colonies of Coelosphaerium Naegelianum, a blue- green alga, during summer plankton of Susquehanna River, Broome Co. Fig. 137. COCCOMYXA CEAE Elakatothrix gelatinosa Wille. Occasional colonies seen in spring plankton of Pond 1, Hawleytown Road, Broome Co. ULOTRICHALES ULOTRICHACEAE Ulothrix sp. Rather widespread along shores and in plankton of streams in area. U. zonata (Weber & Mohr) Kuetz. Frequent in spring plankton of Susquehanna River, Broome Co.; on submerged rocks in Tioughnioga River, Cortland Co. Stichococcus subtilis (Kuetz.) Klercker. In squeezings of plants from Genegantslet Creek, Chenango Co. Geminella interrupta (Turp.) Lager. Filaments found in floating debris of Lily Lake, Broome Co.; Otsego Lake, Otsego Co. Radiofilum conjunctivum Schmidle. Entangled among Sparganium stems. Stump Lake, Broome Co. R. flavescens G. S. West. Several filaments collected in debris along shore during September, Little Choconut Creek, Broome Co. Fig. 143. MICROSPORA CEAE Microspora crassior (Hansg.) Hazen. This thick-walled species was infrequent and scattered in September with debris along shore of Little Choconut Creek, Broome Co. 11 M. stagnorum (Kuetz.) Lager. In plankton of Tioughnioga River and Harpur Pond, Broome Co. M. tumidula Hazen. Frequent in summer tychoplankton of Stump Lake, Broome Co. CYLINDROCAPSACEAE Cylindrocapsa conferta W. West. Rare to infrequent in spring plankton of Chenango and Susquehanna Rivers, Broome Co. Probably washed in from nearby ponds or bogs. CHAE TOPHORA CEAE Stigeoclonium sp. Scattered fragments on rocks of Tioughnioga River, Marathon, Cortland Co. Chaetophora incrassata (Huds.) Hazen. Forming green gelatinous strands in summer on pebbles near shore of Otsego Lake, Otsego Co. Drapamaldia acuta (C. A. Agardh) Kuetz. Attached to Sparganium stems, common in Camp Tuscarora Lake, Broome Co. D. glomerata (Vauch.) C. A. Agardh. Branched green filaments attached to rocks and twigs in 6-8 inches of water, Tioughnioga River, Whitney Point, Broome Co. D. plumosa (Vauch.) C. A. Agardh. Frequent in spring in Har- pur Pond, Broome Co. Aphanochaete repens A. Braun. Epiphytic upon filaments of Cla- dophora and Oedogonium in Pickerel Pond, Broome Co.; Cin- cinnatus Lake and Otselic River, Cortland Co. Fig. 139. PROTOCOCCA CEAE Protococcus viridis C. A. Agardh. Widespread throughout entire study area wherever suitable surfaces are found. COLEOCHAE TA CEAE Coleochaete orbicularis Pringsheim. Found in squeezings of Ana- charis from West Branch of Tioughnioga River, Cortland Co. C. pulvinata A. Braun. From scrapings of submerged stump, Stump Lake, Cortland Co. Chaetosphaeridium Pringsheimii Klebahn. Frequent on stems of Pontederia throughout Pickerel Pond, Broome Co. Fig. 134. 12 TRENTOPOHLIA CEAE Gongrosira lacustris Brand. Frequent in scrapings of rocks and bridge foundations, Owego Creek, Tioga Co. OEDOGONIALES OEDOGONIA CEAE Oedogonium sp. Found in most habitats throughout study area. O. Reinschii Roy. Because of the hexagonal shaped vegetative cells, this is one of the few species of Oedogonium that can be identi- fied without fruiting material. Along border and mixed with Sphagnum of Pickerel Pond, Broome Co. Bulbochaete sp. Not as widespread as Oedogonium. Restricted to Pickerel Pond, Broome Co.; Cincinnatus Lake, Chenango Co.; Stump Lake, Cortland Co. CLADOPHORALES CLADOPHORA CEAE Cladophora crispata (Roth) Kuetz. Floating filaments in the West Branch of Tioughnioga River, Cortland Co. C. glomerata (L.) Kuetz. Attached to rocks and sticks, often with the epiphyte Aphanocapsa repens. Chenango and Tioughnioga Rivers, Broome Co.; Cherry Valley Creek, Otsego Co.; Meade Creek and Canisteo River, Steuben Co. Rhizoclonium hieroglyphicum (C. A. Agardh) Kuetz. Thicker walls than typical, up to 7^ in some. Common floating green, August, Tioga River, Steuben Co. Basicladia Chelonum (Collins) Hoffman & Tilden. Long green filaments collected from shells of several speciea of turtles, spring and summer, Broome Co. Pithophora Oedogonia (Mont.) Wittr. In autumn collections from quiet waters around edge of Harpur Pond, Broome Co. CHLOROCOCCALES CHLOROCOCCA CEAE Chlorococcum humicola (Naeg.) Raben. Cells solitary and in clusters, Stump Lake, Broome Co. 13 MICRA C TIN I A CEAE Micractinium pusillum var. elegans G. M. Smith. Excellent colonies with each cell bearing many long setae, spring, Susquehanna River, Broome Co. DIC TY OSPHAERIA CEAE Dictyosphaerium Ehrenbergianum Naegeli. Frequent in squeezings of aquatics from Pickerel Pond and Camp Tuscarora Lake, Sep- tember, Broome Co. D. pulchellum Wood. More common than previous species. Tiough- nioga River and Pickerel Pond, Broome Co.; Stump Lake, Cort- land Co.; quite common in summer plankton of Susquehanna River, Broome Co. Dimorphococcus lunatus A. Braun. Autumn and winter plankton of Harpur Pond, Broome Co. CHARACIACEAE Characium ambiguum Hermann. Epiphytic on Cladophora during summer collections. Chenango River, Broome Co.; Canisteo River, Steuben Co. Fig. 129. C. ensiforme Hermann. As above, epiphytic on Cladophora, Chenango River, Broome Co. Fig. 130. C. limneticum Lemmermann. With blue-greens on submerged log, Genegantslet Creek, Chenango Co. Fig. 131. HYDRODICTYA CEAE Pediastrum araneosum var. rugulosum (G. S. West) G. M. Smith. Easily recognized because of the undulate cell walls. Only seen in tychoplankton of Camp Tuscarora Lake, Broome Co. P. biradiatum G. M. Smith. In summer plankton, Susquehanna River, Broome Co. P. biradiatum var. heteracanthum G. M. Smith. A rare variety, identified by the unequal incisions in the apices of the marginal cells, and the interstices of the interior cells. Summer plankton in Susquehanna River, Broome Co. Fig. 149. P. Boryanum (Turp.) Meneghini. One of the most widespread and common planktonic green algae. Found in every collecting station, often frequent to common in summer and autumn. 14 P. Boryanum var. longicome Raciborski. Rather rare in spring and summer collections from Chenango and Susquehanna Rivers, Broome Co. P. Boryanum var. undulatum Wille. In plankton and floating debris of Tioughnioga River, Broome Co.; Tioga River, Steuben Co.; Owego Creek, Tioga Co. P. duplex Meyen. Frequent planktonic form in Susquehanna River, Broome Co. P. duplex var. clathratum (A. Braun) Lager. In squeezings of A..utharis from Owego Creek, Tioga Co. P. duplex var. coharens Bohlin. Almost as widespread as P. Bory- anum. Certainly a widely distributed taxon throughout the area. P. duplex var. gracillimum West & West. Often reaching high numbers during summer plankton in Chenango and Susquehanna Rivers, Broome Co. P. duplex var. reticulatum Lager. Infrequent in plankton samples of Chenango and Susquehanna Rivers, Broome Co. P. integrum Naegeli. Occasionally seen in samples from Cohocton River, Steuben Co.; Owego Creek, Tioga Co. Fig. 150. P. obtusum Lucks. Found only in squeezings of Sphagnum from border of Pickerel Pond, Broome Co. P. simplex (Meyen) Lemmermann. Seen in September plankton collections from Susquehanna River, Broome Co. P. simplex var. duodenarium (Bailey) Raben. Infrequent in July plankton samples. Several coenobia with cells bearing hyaline setae on terminal projections, Susquehanna River, Broome Co. Fig. 147. P. tetras (Ehren.) Ralfs. Quite common throughout entire region. P. tetras var. tetraodon (Corda) Hansgirg. This variety, with 8- celled coenobia and more pronounced and deeper incisions found in Geneganslet Creek, Chenango Co. Sorastrum americanum var. undulatum G. M. Smith. A beautiful planktonic taxon with undulate walls along interior margins. Camp Tuscarora and Pickerel Pond, Broome Co. S. spinulosum Naegeli. Scattered in area’s plankton. Susquehanna River, Broome Co.; Cincinnatus Lake, Chenango Co.; Stump Lake and West Branch Tioughnioga River, Cortland Co.; Meade Creek and Cohocton River, Steuben Co.; Catatonk Creek, Tioga Co. Hydrodictyon reticulatum (L.) Lagerheim. Common in all rivers and larger creeks in area. Often forming abundant, large, green 15 mats along margins during hot weather of late summer when water level is low. Mats turning orange as cells decay. COELASTRACEAE Coelastrum cambricum Archer. In squeezings of aquatics from Camp Tuscarora Lake and Pickerel Pond, Broome Co. C. microporum Naegeli. Widespread in squeezings and plankton samples from most stations. C. sphaericum Naegeli. Quite rare, found only in Susquehanna River, Broome Co. BO TR YOCOCCA CEAE Botryococcus Braunii Kuetz. Entangled on aquatic stems, Pickerel Pond, Broome Co.; Cincinnatus Lake, Chenango Co. B. sudeticus Lemmermann. Rare in plankton of West Branch of Tioughnioga River, Cortland Co. OOCYSTACEAE Treubaria setigerum (Archer) G. M. Smith. Rare in Susquehanna River plankton, Broome Co. Oocystis Borgei Snow. Observed in August collections from Susque- hanna River, Broome Co. O. Naegelii A. Braun. A single chromatophore distinguishes this from the previous species. Found only in plankton of Stump Lake, Cortland Co. Should be found elsewhere. O. parva West & West. Also found in Stump Lake, Cortland Co., but cells have pointed ends, not rounded as in previous taxa. Nephrocytium Agardhianum Naegeli. In squeezings from Stump Lake, Cortland Co. N. lunatum W. West. Infrequent in plankton of Susquehanna River, Broome Co. Chodatella subsalsa Lemmermann. Rare in Susquehanna River plankton, Broome Co. Ankistrodesmus falcatus (Corda) Ralfs. Quite common and widely distributed in many situations. A. falcatus var. mirabilis (West & West) G. S. West. The long solitary cells of this variety were seen only in Genegantslet Creek, Chenango Co. A. falcatus var. stipitatus (Chod.) Lemmermann. This variety has been seen but records are not clear and exact location cannot be established. Fig. 132. 16 Selenastrum Bibraianum Reinsch. In tow of water from Genegants- let Creek, Chenango Co. S. Westii G. M. Smith. Tioughnioga River, Broome Co.; Genegantslet Creek, Chenango Co. Kirchneriella contorta (Schmidle) Bohlin. Plankton of Tioughnioga River, Broome Co. K. lunaris (Kirch.) Moebius. Cells strongly curved. Little Snake Creek, Broome Co. K. lunaris var. irregularis G. M. Smith. Lunate cells with the apices prating in different directions are peculiar to this variety. Camp Tuscarora Lake and Little Snake Creek, Broome Co.; Oak Creek, Otsego Co.; Owego Creek, Tioga Co. K. obesa (W. West) Schmidle. Plump cells with bluntly pointed ends, Camp Tuscarora Lake, Broome Co. Quadrigula closteroides (Bohlin) Printz. In squeezings of Spar- ganium stems, Camp Tuscarora Lake, Broome Co. Tetraedron enorme (Ralfs) Hansgirg. Squeezings of Sphagnum along border of Pickerel Pond, Broome Co. T. minimum (A. Braun) Hansgirg. Plankton of Tioughnioga River, Broome Co.; frequent in squeezings of Owego Creek, Tioga Co. T. pentaedricum West & West. Squeezings of Sphagum along border of Pickerel Pond, Broome Co. Cerasterias staurastroides West & West. Like those reported by Prescott from the Great Lakes region, my cells have processes tipped with 3 short, sharp teeth. Cincinnatus Lake, Chenango Co. SCENEDESMA CEA E Scenedesmus abundans (Kirch.) Chodat. Plankton of Tioughnioga River, Broome Co.; tychoplankton of East Branch Tioughnioga, Cortland Co.; Oak Creek, Otsego Co.; common in scrapings of rocks and bridge foundations, Owego Creek, Tioga Co. S. abundans var. longicauda G. M. Smith. Cells with spines up to 1(V long. In Susquehanna River, Broome Co.; Owego Creek, Tioga Co. S. acuminatus var. tetradesmoides G. M. Smith. Cells of this alga are not all in one plane when coenobe is seen in apical view. Genegantslet Creek, Chenango Co. 5. acutiformis Schroeder. Genegantslet Creek, Chenango Co.; Stump Lake, Cortland Co.; Owego Creek, Tioga Co.; Tioga River, Steu- ben Co. 17 S. arcuatus Lemmermann. Cells arranged in curved arc like S. acuminatus var. tetradesmoides but its cells have rounded apices, not pointed, Tioughnioga River, Cortland Co. S. arcuatus var. platydisca G. M. Smith. Generally distributed in lake and stream plankton. S. armatus (Chod.) G. M. Smith. In squeezings from Tioughnioga River, Broome Co.; Cincinnatus Lake and Unadilla River, Che- nango Co.; East Branch Tioughnioga, Cortland Co.; Oak Creek, Otsego Co. 5. armatus var. Chodatii G. M. Smith. In tows and squeezings from Tioughnioga River, Broome Co.; Cincinnatus Lake and Gene- gantslet Creek, Chenango Co.; West Branch Tioughnioga, Cort- land Co.; Owego Creek, Tioga Co. S. bijuga (Turp.) Lager. Common in squeezings of Sphagnum from Pickerel Pond, Broome Co. and common in scrapings of rocks in Owego Creek, Tioga Co. S. bijuga var. altemans (Reinsch) Hansgirg. Tioughnioga and Susquehanna Rivers, Little Snake Creek, Broome Co.; Susque- hanna River, Chenango Co. S. brasiliensis Bohlin. Widespread throughout area. Collected in plankton, squeezings, in floating debris, on dams and with fila- ments of blue-greens from mud bottoms. S. denticulatus Lager. In plankton of Tioughnioga River, Broome Co.; squeezings from Cincinnatus Lake, Chenango Co.; on mud bottom of West Branch Tioughnioga, Cortland Co. S. denticulatus var. linearis Hansgirg. In squeezings from Genegants- let Creek, Chenango Co. S. dimorphus (Turp.) Kuetz. Quite common in region and in varied habitats. S. hystrix Lager. In squeezings of aquatics from West Branch of Tioughnioga River, Cortland Co. S. obliquus (Turp.) Kuetz. In squeezings of plants and scrapings of rocks. Genegantslet Creek, Chenango Co.; Chemung River, Chemung Co.; Oak Creek, Otsego Co.; Owego Creek, Tioga Co. S. quadricauda (Turp.) Breb. In tows and squeezings from Susque- hanna River, Broome Co.; Chemung River, Chemung Co.; Tioga River, Steuben Co.; Owego Creek, Tioga Co. S. quadricauda var. longispina (Chod.) G. M. Smith. Tychoplankton of Boland Pond, Broome Co.; Genegantslet Creek, Chenango Co. 18 S. quadricauda var. maximus West & West. In plankton samples from Susquehanna River, Broome Co. S. quadricauda var. parvus G. M. Smith. In plankton of Chenango River, Broome Co.; with blue-greens on mud, Genegantslet Creek, Chenango Co. S. serratus (Corda) Bohlin. Squeezings from Genegantslet Creek, Chenango Co. Crucigenia apiculata (Lemm.) Schmidle. A very short tooth found on the free apex of each cell. Owego Creek, Tioga Co. C. quadrata Morren. Squeezings of Anacharis from West Branch of Tioughnioga River, Cortland Co. C. rectangularis (A. Braun) Gay. In plankton of Harpur Pond, Broome Co.; squeezings from Genegantslet Creek, Chenango Co. Actinastrum gracillimum G. M. Smith. Summer plankton of Susque- hanna River, Broome Co. A. Hantzschii Lager. Frequent in summer plankton of Susquehanna River, Broome Co. A. Hantzschii var .fluviatile Schroeder. Occasionally seen in plankton of Susquehanna River, Broome Co. ZYGNEMATALES Z YGNEMA TA CEAE Mougeotia sp. Sterile material collected in Big and Little Snake Creeks, Pickerel Pond, Broome Co.; Genegantslet Creek, Chen- ango Co. Zygnema sp. Only vegetative filaments seen in samples from Pick- erel Pond and Camp Tuscarora Lake, Broome Co.; Stump Lake, Cortland Co.; Otsego Lake, Otsego Co. Spirogyra sp. Truly cosmopolitan throughout the area. Non-fruiting material only. MESO TAENIA CEAE Gonatozygon aculeatum Hastings. Found only in squeezings of Pontederia stems and With blue-greens on mud near shore of Pickerel Pond, Broome Co. Fig. 7. G. pilosum Wolle. Squeezings of Sphagnum from Pickerel Pond, Broome Co.; squeezings of Anacharis and Sparganium stems, Stump Lake, Cortland Co. Fig. 8. 19 Netrium digitus (Ehren.) Itz. and Rothe. In squeezings and strainings from Little Choconut Creek, Pickerel Pond, and Camp Tuscarora Lake, Broome Co. Fig. 1. Spirotaenia condensata Breb. Rare in Sphagnum squeezings. Pickerel Pond, Broome Co. Fig. 14. 5. obscura Ralfs. A rather rare species, seen only in plankton of Harpur Pond, Broome Co. Fig. 13. DESMIDIA CEAE Closterium acutum (Lyngb.) Breb. Smooth cells, gradually attenu- ated towards apices; pyrenoids several in a median series. Squeezings, Pickerel Pond, Broome Co. Fig. 25. C. costatum Corda. Median girdle apparent, wall with seven to eight heavy striae. Sphagnum squeezings and with blue-greens on mud, Pickerel Pond, Broome Co. Fig. 10. C. Dianae Ehren. Cell wall smooth and reddish in color, tips slightly truncate. Squeezings from Pickerel Pond, Broome Co.; Cincinnatus Lake, Chenango Co.; Owego Creek, Tioga Co. Fig. 4. C. didymotocum Corda. Easily recognized in our material by the red-brown ring near each tip of the cell. With blue-greens on mud, Pickerel Pond, Broome Co. Fig. 27. C. Ehrenbergii Menegh. Extremely large cells, some over 700/x in length; smooth walls; many scattered pyrenoids. Squeezings, Har- pur Pond, Broome Co.; Genegantslet Creek, Chenango Co.; Owego Creek, Tioga Co. Fig. 9. C. gracile Breb. Smooth, colorless cells, very narrow (seldom over 5/x wide) . Squeezings from Pickerel Pond, common in Boland Pond, Broome Co. Fig. 6. C. incurvum Breb. Lunate cells with smooth colorless walls and median pyrenoids. Squeezings from Camp Tuscarora Lake, fre- quent in Pickerel Pond, Broome Co.; Cincinnatus Lake and Gene- gantslet Creek, Chenango Co. Fig. 6a. C. intermedium Ralfs. Walls golden-brown with 8 to 10 stria- tions; truncate ends. Tychoplankton, Harpur Pond, Broome Co.; Stump Lake, Cortland Co. Fig. 20. C. juncidium Ralfs. Pyrenoids median, striations evident, cells 235/j.-340/x long. Plankton, Pickerel Pond and Chenango River, Broome Co. Fig. 19. 20 C. Kuetzingii Breb. Cells with tumid centers; walls with very fine striations. Squeezings from Genegantslet Creek, Chenango Co. Fig. 24. C. Leibleinii Kuetz. Smooth and colorless, resembling C. Dianae but differing in its tumid middle. Wide distribution in follow- ing counties: Broome, Chenango, Otsego, Steuben, and Tioga. Fig. 2. C. moniliferum (Bory) Ehren. Similar to C. Ehrenbergii except for its pyrenoids arranged in a line. Often frequent to abundant in squeezings, Susquehanna River, Broome Co.; Genegantslet Creek, Chenango Co.; West Branch Tioughnioga, Cortland Co.; Owego Creek, Tioga Co. Fig. 5. C. Ralfsii Breb. Frequent in Harpur Pond and Susquehanna River, Broome Co. Fig. 12. C. Ralfsii var. hybridum Raben. Large cells, some over 500/u. long, with 15 or more striations. Squeezings and plankton from Pickerel Pond and Susquehanna River, Broome Co. Fig. 11. C. Ralfsii var. immane Cushman. Larger than preceding, some over 600^ long, and with 50-60 striations. Squeezings of stems, Stump Lake, Cortland Co. Fig. 21. C. rostratum Ehren. In winter plankton of Harpur Pond, Broome Co. Fig. 22. C. setaceum Ehren. Swollen median section quickly narrowing to long attenuated apices; tips narrow, up to 2.5^ in width. Sphagnum squeezings. Pickerel Pond, Broome Co. Fig. 23. C. striolatum Ehren. Robust cells with many striations and median pyrenoids. Plankton of Susquehanna River, Broome Co. Fig. 18. C. toxon W. West. Long narrow cells, specimens average 320^ in length and 9/x wide. Plankton of Susquehanna River, Broome Co. Fig. 26. C. turgidum Ehren. Light brown cells with many fine striations; apices recurved slightly. Huge cells possibly reaching 800 p- x 75/u.; chloroplast ridged. Squeezings, plankton tows, and with blue- greens on mud bottom of Pickerel Pond, Broome Co.; West Branch of the Tioughnioga River, Cortland Co. Fig. 17. C. Venus Kuetz. A delicate, lunate cell with only one or two pyrenoids per semicell. Plankton, Chenango River, Broome Co.; Stump Lake, Cortland Co. Fig. 3. Penium margaritaceum (Ehren.) Breb. Cells with girdles; granules many, in lines or scattered; older cells often colored. Broome, Cortland, and Otsego Cos. Fig. 16. 21 P. spinospermum Josh. A rare species in Sphagnum squeezings from Pickerel Pond, Broome Co. Fig. 16a. Pleurotaenium coronatum (Breb.) Raben. Walls punctate; poles with 10-12 tubercules. Plankton of Harpur Pond, Broome Co.; squeezings of Genegantslet Creek, Chenango Co. Fig. 30. P. Ehrenbergii (Breb.) DeBary. Entangled among aquatics, Pick- erel Pond, Broome Co.; Stump Lake, Cortland Co. Fig. 28. P. nodosum (Bailey) Lundell. Series of radially arranged swellings make this a distinctive taxon. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 33. P. nodulosum Breb. Undulations run entire length of cell wall. Camp Tuscarora Lake, Broome Co. Fig. 36. P. subcoronulatum var. detum West & West. Slight constriction near apex of each semicell can be seen on each specimen. Squeez- ings, occasionally frequent. Pickerel Pond, Broome Co.; Chemung River, Chemung Co. Fig. 29. P. trabecula (Ehren.) Naegeli. Cells with several basal swellings and no apical tubercules. Widespread in Broome, Chenango, Cort- land, Otsego, and Steuben Cos. Fig. 34. P. trabecula var. rectum (Delp.) W. West. Smaller than the above and only a single basal undulation in each semicell. Squeezings, Pickerel Pond, Broome Co. Fig. 35. Tetmemorus Brebissonii (Menegh.) Ralfs. Easily recognized by the apical notches. In Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 15. Euastrum abruptum Nordstedt. Camp Tuscarora Lake, Broome Co. Fig. 39. E. abruptum forma minus West & West. Terminal lobe with two small spines; cell wall with many granules. Squeezings from Pick- erel Pond, Broome Co.; Genegantslet Creek, Chenango Co. Fig. 31. E. binale forma hians West. A minute desmid, the largest reaching only 20/x in length. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 32. E. evolutum West & West. Tychoplankton, Pickerel Pond, Broome Co. Fig. 37. E. gemmatum Breb. Tychoplankton, Pickerel Pond, Broome Co. Fig. 40. E. obesum var. crassum Prescott & Scott. A large Euastrum, averag- ing lOOfj, in length, with punctate walls. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 41. 22 E. verrucosum var. alatum Wolle. Another large taxon. Squeezings from Cherry Valley Creek, Otsego Co. Fig. 38. Cosmarium amoenum Breb. Semicells with eight to 10 linear rows of granules on each face. In Sphagnum border of Pickerel Pond, Broome Co. Fig. 64. C. bipunctatum Borg. Cells with truncate apices; walls granular with two prominent central granules. Squeezings from Pickerel Pond, Broome Co. Fig. 42. C. Botrytis var. subtumidum Wittr. Striking ornamentation as the granulations become larger toward the center and apices. Squeez- ings from Stump Lake, Cortland Co. Fig. 43. C. contractum var. ellipsoideum West & West. Sphagnum squeez- ings from Pickerel Pond, Broome Co. Fig. 73. C. cucumis (Corda) Ralfs. Chromatophore in vertical parietal bands with numerous, scattered pyrenoids. Squeezings of Ponte- deria stems. Pickerel Pond, Broome Co. Fig. 44. C. curcurbita Breb. Small cells with punctate walls. In Sphagnum border of Pickerel Pond, Broome Co. Fig. 54. C. denticulatum forma Borgei Irenee-Marie. Very large, beautiful Cosmarium reaching almost 200 (J- in length. Approximately three rows of small spines or granules around lateral margins. Tycho- plankton, Pickerel Pond, Broome Co. Fig. 59. C. granatum Breb. Walls finely punctate; apex truncate; pyrenoid single. Scattered throughout area. Fig. 49. C. Hammeri var. protuberans West & West. Rare, collected only on squeezings from Otsego Lake, Otsego Co. Fig. 48. C. impressulum Elefv. Small cells with eight even undulations along margin. Tychoplankton, Genegantslet Creek, Chenango Co.; Stump Lake, Cortland Co. Fig. 52. C. margaritatum (Lund.) Roy & Biss. Walls with prominent gran- ules, each granule surrounded by six small punctations. Squeez- ings from Camp Tuscarora Lake, Broome Co.; Stump Lake, Cort- land Co. Fig. 57. C. margaritatum forma minor West & West. Same as species, except smaller, reaching up to 60 ^ in length. Plankton, Lily Lake, and Susquehanna River, Broome Co. See species. Fig. 57. C. obtusatum Schmidle. Lateral margins with eight to nine undu- lations and with one to two rows of undulations inside them. Squeezings from Unadilla River, Chenango Co.; Canisteo and Co- hocton Rivers, Steuben Co.; Pipe Creek, Tioga Co. Fig. 58. 23 C. omatum Ralfs. Slightly elevated, truncate apex. Granules on sides and apex. Squeezings of Anacharis and Sphagnum , Pick- erel Pond, Broome Co.; Cincinnatus Lake, Chenango Co.; Stump Lake, Cortland Co. Fig. 62. C. pachydemum var. aethiopicum West & West. Walls with fine scrobiculations and punctuations. Stump Lake, Cortland Co. Fig. 74. C. Portianum Archer. “ Dumbell ” shaped with prominent granula- tions. Camp Tuscarora Lake and Harpur Pond, Broome Co.; Stump Lake, Cortland Co. Fig. 68. C. protractum (Naeg.) DeBary. Strainings from Cincinnatus Lake, Chenango Co.; squeezings from Stump Lake, Cortland Co. Fig. 67. C. pseudoconnatum Nordst. Cell wall with fine punctations; chloroplast with four pyrenoids in each semicell. Squeezings of aquatic plants, Pickerel Pond and Camp Tuscarora Lake, Broome Co.; Stump Lake, Cortland Co. Fig. 70. C. pseudopyramidatum Lundell. Similar to C. pyramidatum except that it has a single pyrenoid and smaller dimensions. Squeezings from Otsego Lake, Otsego Co. Fig. 53. C. punctulatum Breb. Cell wall with about 24 granules around margin. In Big Snake Creek, Broome Co.; on dam at Gene- gantslet Creek, Chenango Co. Fig. 71. C. punctulatum var. subpunctulatum (Nordst.) Borg. In Spaghnum, Pickerel Pond, Broome Co. Fig. 61. C. pyramidatum Breb. Truncate-pyramidate in shape; two pyrenoids per semicell. Squeezings, Pickerel Pond, Broome Co.; West Branch of Tioughnioga River, Cortland Co. Fig. 60. C. quasillus Lundell. In plankton of both the Chenango and Sus- quehanna Rivers, Broome Co. Fig. 50. C. quinarium Lund. Winter plankton of Harpur Pond, Broome Co. Fig. 45. C. refringens Taylor. Squeezings, Pickerel Pond, Broome Co.; Otsego Lake, Otsego Co. Fig. 72. C. Regnellii Wille. Cells with small swelling on lateral margins. Fairly widespread throughout area. Fig. 47. C. reniforme (Ralfs) Archer. Granules over entire cell wall, about 25-30 around margin. Camp Tuscarora Lake, Broome Co.; Cin- cinnatus Lake, Chenango Co. Fig. 56. C. sexangulare var. minimum Nordst. A very small cell, ours not over 1 7ju in length. Cincinnatus Lake, Chenango Co. Fig. 46. 24 C. subcostatum Nordst. Heavily ornamented with granules and punctations; two pyrenoids per semicell. Distributed throughout several counties of the area in squeezings. Fig. 66. C. subcostatum var. minor West & West. Smaller than var. sub- costatum, fewer lateral crenations and a single pyrenoid. Cohoc- ton River, Steuben Co. Fig. 63. C. subreniforme Nordst. Semicells with two pyrenoids each. Squeez- ings from Tioughnioga River, Broome Co.; West Branch Tiough- nioga River, Cortland Co. Fig. 55. C. subtumidum Nordst. Cell walls finely punctate. Lily Lake and Harpur Pond plankton, Broome Co. Fig. 51. C. Turpinii Breb. Two central protruberances on each face of semi- cell and two pyrenoids per semicell are obvious in this species. Squeezings, Susquehanna River, Broome Co.; Stump Lake, Cort- land Co.; Owego Creek, Tioga Co. Figs. 65, 69. Micrasterias americana (Ehren.) Ralfs. Polar lobes with secondary processes; cell walls with scattered granules, few in number; two rather prominent spines usually present at base of polar incision. Camp Tuscarora Lake, Broome Co. Fig. 75. M. apiculata var. fimbriata forma spinosa (Biss.) West & West. Rows of spines along polar, median and lateral incisions prominent. Strainings from Pickerel Pond, Broome Co. Fig. 76. M. laticeps Nordst. Polar lobe broad and rounded. Squeezings, Pickerel Pond, Broome Co.; Stump Lake, Cortland Co. Fig. 77. M. Nordstedtiana Wolle. Polar lobe with secondary processes; cell wall smooth. Tychoplankton of Pickerel Pond, Broome Co. Fig. 78. M. pinnatifida (Kuetz.) Ralfs. Squeezings of aquatics. Pickerel Pond, Broome Co. Fig. 81. M. radiata Hassall. Cells with deep lateral incisions; polar lobe concave; cell wall smooth. Infrequent in squeezings from Pick- erel Pond, Broome Co.; Cincinnatus Lake, Chenango Co.; Stump Lake and Tioughnioga River, Cortland Co. Fig. 79. M. radiata var. simplex (Wolle) G. M. Smith. Similar to preceding species except lateral lobes simple. Tychoplankton, Pickerel Pond, Broome Co. Fig. 80. M. radiosa Ralfs. Spines absent along margins. Camp Tuscarora Lake, Broome Co. Fig. 85. M. radiosa var. omata Nordst. Identical to species except spines present along some of incisions. Camp Tuscarora Lake and Pickerel Pond, Broome Co. Fig. 89. 25 M. rotata (Grev.) Ralfs. Cells practically circular. Squeezings from Pickerel Pond, Broome Co. Fig. 92. M. truncata var. semiradiata Bennett. Polar lobes broad and flat- tened, cells circular in outline. Variety with longer, finer teeth on lateral lobes. Squeezings, Camp Tuscarora Lake, Broome Co.; common in Stump Lake, Cortland Co.; common in Cohocton River, Steuben Co. Fig. 82. Xanthidium antilopaeum forma callosum Cushman. Constrictions pronounced; each semicell with a single central granule. Strain- ings of Pickerel Pond, Broome Co. Fig. 96. X. antilopaeum var. minneapoliense Wolle. Cells with a row of verrucae below each apex; small spine near each row. Irenee- Marie (1938) figures a cell bearing three lateral spines on one semicell and only two on the other. The specimens observed in this study had semicells bearing three lateral spines on one side and four on the other. Plankton of Harpur Pond and Camp Tuscarora Lake, Broome Co. Fig. 95. X. antilopaeum var. polymazum Nordst. Similar to preceding va- riety but lacking the spine below the row of subapical verrucae. Squeezings from Pickerel Pond and plankton of Harpur Pond, Broome Co. Fig. 98. X. cristatum var. uncinatum Breb. Lateral walls concave between spines; apex truncate; granules in central area. Tychoplankton, Pickerel Pond, Broome Co. Fig. 99. X. subhastiferum West & West. Typical cells have two spines on same vertical plane on lateral margins. Our specimens frequently with supplementary spines on the apices. Plankton, Harpur Pond, Broome Co. Fig. 93. Staurastrum altemans Breb. Small cell, triangular in apical view; arms of one semicell alternating with the arms of the other. Plankton of Tioughnioga River, Broome Co. Fig. 146. S. apiculatum Breb. Small cells tipped with short upright spines. Squeezings from Pickerel Pond, Broome Co.; Oak Creek, Otsego Co. Fig. 91. 5. Arctiscon (Ehren.) Lundell. Semicells with two whorls of pro- cesses, nine in median position and six in apical position. Squeez- ings, strainings, and in floating debris, Pickerel Pond, Broome Co.; Stump Lake, Cortland Co.; Otsego Lake, Otsego Co.; Owego Creek, Tioga Co. Fig. 120. S. Arctiscon var. glabrum West & West. Same as above except arms a little shorter and without granules. Squeezings of Sparganium 26 and Anacharis stems, Camp Tuscarora Lake, Broome Co.; com- mon in Stump Lake, Cortland Co. Fig. 117. S. brasiliense var. Lundellii West & West. A striking desmid! Ver- tical view usually five-sided; arms tipped with three long, stout spines measuring 30-40^ in length. Strainings and squeezings from Pickerel Pond, Broome Co. Fig. 111. S. Brebissonii var. brevispinum W. West. Spines on most of cell wall but absent from apices. Tychoplankton, Little Snake Creek, Broome Co.; Genegantslet Creek, Chenango Co. Fig. 101. S. crenulatum (Naeg.) Delponte. Two verrucae at the concave base of each arm in vertical view. Squeezings of aquatics from Pickerel Pond, Broome Co. Fig. 103. 5. cuspidatum Breb. Constriction deep and isthmus elongate; single, straight, sharp spine terminating each arm. Entangled with debris about aquatic stems, Pickerel Pond, Broome Co. Fig. 87. S. cuspidatum var. canadense G. M. Smith. Variety differs from species with its distinct notch at the isthmus and somewhat di- vergent spines. Sphagnum squeezings from Pickerel Pond, Broome Co. Fig. 115. S. Dickiei Ralfs. Similar to S. cuspidation but without elongate isthmus and with shorter spines. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 94. S. Dickiei var. circulare Turner. Variety has apical margin greatly rounded, almost semicircular. Tychoplankton, Pickerel Pond, Broome Co. Fig. 97. S. Dickiei var. rhomboideum West & West. This variety has straight lateral sides. Tychoplankton, Pickerel Pond, Broome Co. Fig. 88. S. dilatatum Ehren. Cells usually quadrangular in vertical view; wall with concentrically arranged granules. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 104. S. furcigerum Breb. Angles of semicells with two rows of pro- cesses tipped with spines and bearing granules. Plankton of Har- pur Pond, Broome Co. Fig. 114. S. furcigerum forma eustephana (Ehren.) Nordst. This form has six processes in an apical row, instead of three. Plankton of Pond 1, Broome Co. Fig. 112. S. grande var. parvum W. West. In squeezings of Anacharis stems, Stump Lake, Cortland Co. Fig. 83. S. illusum var. major Irenee-Marie. This taxon differs from S. altemans by its less rounded, nonalternating angles. Squeezings, 27 Little Snake Creek, Broome Co.; Cincinnatus Lake, Chenango Co.; Stump Lake, Cortland Co. Fig. 145. S. Johnsonii West & West. Cells with two rows of granules at basal inflation; one row of tubercles at apex. In Sphagnum border of Pickerel Pond, Broome Co. Fig. 116. 5. longiradiatum West & West. Semicells with basal inflation and terminal verrucae. Plankton of Susquehanna River, Broome Co. Fig. 110. S. muticum Breb. Small cells with broadly rounded angles; isthmus narrow. Squeezings of Genegantslet Creek, Chenango Co. Fig. 84. S. Ophiura Lundell. A large beautiful desmid especially in vertical view. Usually seven-rayed; each ray with short sharp spines near apical ends and verrucae near basal ends; rays tipped with three spines. Camp Tuscarora Lake, Broome Co. Fig. 102. S. pachyrhynchum Nordst. Lateral angles broadly rounded and walls quite thickened at the angles. Squeezings from Pickerel Pond, Broome Co. Fig. 86. S. polymorphum Breb. Small cells bearing three to seven arms on each semicell. Each arm terminated by three to four short spines and each arm with three to four series of granules. Squeez- ings from Cincinnatus Lake and Genegantslet Creek, Chenango Co. Fig. 106. S. pseudopelagicum West & West. Constriction deep and sinus acute; angles of semicells with long divergent processes, tipped with divergent spines. Squeezings, Cincinnatus Lake, Chenango Co. Fig. 107. S. pseudopelagicum var. minor G. M. Smith. The species has cells 40-60/x long, the variety is 30-3 8/x in length. In ours, some processes were terminated by three spines, others by two. Cin- cinnatus Lake, Chenango Co. Fig. 108. S. punctulatum Breb. Lateral angles somewhat pointed; cell wall granular. Plankton of Pond 1, Broome Co. Fig. 90. 5. rugosum Irenee-Marie. Short plump cells with very short angles; prominent granules arranged concentrically but lacking on the apex. Squeezings from Otsego Lake, Otsego Co. Fig. 109. 5. setigerum Cleve. Two sizes of spines are distinctive; three large vertically arranged spines on angles and more delicate, smaller spines on margins. Sphagnum squeezings, Pickerel Pond, Broome Co. Fig. 105. 28 S. tetracerum Ralfs. Very small biradiate cells, twisted at their isthmus. Tychoplankton of Pickerel Pond, Broome Co. Fig. 100. S. tetracerum var. evolutum West & West. This triradiate variety is much larger than the species and has long processes. Frequent in summer plankton of the Chenango and Susquehanna Rivers, Broome Co. Fig. 113. Onychonema laeve var. latum West & West. Apices of cells with short, truncate elevation; filaments often enclosed in gelatinous envelope. Squeezings of Sparganium stems, Camp Tuscarora Lake, Broome Co. Fig. 118. Sphaerozosma excavatum var. subquadratum West & West. Cells H-shaped with short, uniting, apical processes. Lateral lobes with minute granules on margins only, none on face. Camp Tuscarora Lake, Broome Co.; Cincinnatus Lake, Chenango Co. Fig. 125. S. granulatum Roy & Biss. Lateral lobes with granules on margin and face of semicell. Squeezings of Pickerel Pond, Broome Co.; Genegantslet Creek, Chenango Co. Fig. 127. Spondylosium planum (Wolle) West & West. Apical processes lack- ing in this genus, cell wall smooth. Squeezings of aquatics from Pickerel Pond, Broome Co.; Cincinnatus Lake, Chenango Co. Fig. 124. Hyalotheca dissiliens (J. E. Smith) Breb. Filaments with wide gel- atinous envelope; cell wall smooth, constriction weak and not too apparent. Squeezings from Harpur Pond, Camp Tuscarora Lake, and Pickerel Pond, Broome Co.; Otsego Lake, Otsego Co. Fig. 123. H. undulata Nordst. Cells longer than broad, appearing undulate along their margins; sheath weak or lacking. Sphagnum squeez- ings, Pickerel Pond, Broome Co. Fig. 126. Desmidium Baileyi (Ralfs) Nordst. Filaments in gelatinous sheath, twisted; cells concave at apices, mostly triangular in vertical view. Squeezings of Sphagnum and Pontederia, Pickerel Pond, Broome Co. Fig. 119. D. Grevillei (Kuetz.) DeBary. Apices not concave; vertical view elliptic. Camp Tuscarora Lake, Broome Co. Fig. 128. D. Swartzii C. A. Agardh. Apices not concave; vertical view tri- angular. Tychoplankton, Flarpur Pond, Pickerel Pond, and Camp Tuscarora Lake, Broome Co. Fig. 122. Gymnozyga moniliformis Ehren. Filaments composed of barrel- shaped cells, often in gelatinous sheath. Sphagnum and Ponte- deria squeezings. Pickerel Pond, Broome Co. Fig. 121. 29 EUGLENOPHYTA EUGLENOPHYCEAE EUGLENALES EUGLENACEAE Euglena acus Ehren. Long thin cells tapering to an acute posterior tip, firm shape, 150/a long. Plankton, August, Harpur Pond, Broome Co. E. oxyuris Schmarda. Longitudinal striations of periplast, anterior groove and two annular, elongated paramylon bodies easily seen; cell 170/a long. Plankton, June, Susquehanna River, Broome Co. Phacus curvicauda Swirendo. Cells ovoid, twisted slightly posteri- orly; short, oblique caudus. August, with green algae on rocks, Chenango River, Broome Co. P. longicauda (Ehren.) Dujardin. Cells ovoid, tapering to an acute caudus as long as the main body of the cell; overall length 88/x. Plankton, Chenango River, Broome Co. P. pleuronectes (Mueller) Dujardin. Cells suborbicular with short, heavy caudus that is sharp and oblique; periplast longitudinally striated. Squeezings, from West Branch Tioughnioga River, Cortland Co. P. tortus (Lemm.) Skvortzow. Fusiform cells; spirally tapering and twisting to long, straight caudus; periplast longitudinally striated. Rare in mud, West Branch Tioughnioga River, Cortland Co. Trachelomonas euchlors (Ehren.) Lemmermann. Brown cyclindrical test with truncate ends. Squeezings, from Oak Creek, Otsego Co. CHRYSOPHYTA XANTHOPHYCEAE RHIZOCHLORIDALES S TIPITOCOCCA CEAE Stipitococcus apiculatus Prescott. Infrequent on Coelosphaerium, a blue-green and Asterionella, a diatom. This epiphyte and its long stipe is easily spotted. September, Susquehanna plankton; November, Chenango plankton, Broome Co. Fig. 138. 30 HETEROSIPHONALES BOTRYDIACEAE Botrydium granulatum (L.) Grev. Dark green beads up to several millimeters in diameter common on damp mud of shores, October, Susquehanna River, Broome Co. Fig. 148. VAUCHERIACEAE Vaucheria sp. Vegetative material collected on mud, in small pools, and attached to rocks in shallow water of streams in Broome and Cortland Cos. CHRYSOPHYCEAE CHR YSOMONADALES MALLOMONADA CEAE Mallomonas acaroides var. moskovensis (Wermel) Kreiger. Anterior needles pointing forward and curved outwards, median and other needles toward posterior. Plankton, Susquehanna River, Broome Co. M. caudata Iwanoff. Needles distributed all over cell and directed backward. Plankton, Chenango River, Broome Co. SYNURACEAE Synura uvella Ehren. This free-swimming, colonial alga is found frequently in the plankton and squeezings of streams and lakes throughout the area. In the Chenango and Susquehanna Rivers it can be collected at most times of the year; however, it is at its lowest during the warm summer months and at its greatest abundance in spring. OCHROMONADACEAE Dinobryon bavaricum Imhof. Loricas with undulate sides and long tapering base. Plankton and squeezings, Pickerel Pond, Camp Tuscarora Lake, and Chenango River, Broome Co. D. divergens Imhof. Only lower half of loricas undulate; mouth flaring; base short. Plankton, during late summer and autumn. Ponds 1 and 2, Susquehanna River, Broome Co. 31 D. sertularia Ehren. Loricas usually with an asymmetrical swelling near base. Frequent to common in winter and spring plankton, rare at other times, Ponds 1 and 2, Chenango and Susquehanna River, Broome Co. D. sociale var. americanum (Brunnthaler) Bachmann. Loricas short and stout, colonies loose and spreading. Spring plankton, Susque- hanna River, Broome Co. RHIZOCHR YSIDALES RHIZOCHR YSIDACEAE Chrysidiastrum catenation Lauterborn. Cells with four small taper- ing projections, each terminating with a long fine seta. Rare in plankton of Boland Pond, Broome Co. Lagynion ampullaceum (Stokes) Pascher. Ephiphytic on cells of Cladophora. Lorica flask shape, body of cell globose. Meade Creek, Steuben Co. Fig. 136. L. macrotrachelum (Stokes) Pascher. Lorica depressed and flattened against the cells of Tolypothrix tenuis, summer, Stump Lake, Cortland Co. Fig. 135. BA CILLARIOPH Y CEAE * CENTRALES COS CINODIS CA CEAE Melosira sp. Frequent bits and fragments found in spring plankton of Chenango and Susquehanna Rivers, Broome Co. Probably one of the following species. M. crenulata (Ehren.) Kuetz. In plankton of Chenango River, Broome Co., especially abundant in the fall. M. italica (Ehren.) Kuetz. Frequent in spring populations of Susque- hanna River, Broome Co. Stephanodiscus niagarae Ehren.* Common in plankton of Susque- hanna River, May and June, Broome Co. ♦Those diatoms marked with an asterisk were also reported by Hohn (1951) . 32 PENNALES TABEL l ARIA CEAE Tabellaria fenestrata (Lyngb.) Kuetz. Frequent in April and May plankton in Ponds 1 and 2, Broome Co. T. floccosa (Roth) Kuetz. In spring plankton of Chenango and Sus- quehanna Rivers, Broome Co. MERIDIONA CEAE Meridion circulare (Greville) C. A. Agardh. Frequent in net plank- ton of Chenango and Susquehanna Rivers during April and May, Broome Co. DIATOMACEAE Diatoma vulgare Bory. Frequent in April and May, common in June plankton, Chenango and Susquehanna Rivers, Broome Co. FRA GIL ARIA CEAE Fragilaria capucina Desmazieres. Infrequent in plankton of April collections from Chenango and Susquehanna Rivers, Broome Co. F. crotonensis Kitton. Common in spring and early summer, again in the fall plankton Susquehanna River, Broome Co. F. Harrissonii (W. Smith) Grun.* Susquehanna River, Tioga Co. F. virescens Ralfs. Infrequent in spring plankton, Susquehanna River, Broome Co. Synedra pulchella (Ralfs) Kuetz. Plankton, Chemung River, Che- mung Co. S. ulna (Nitzsch) Ehren. Present most of the year, most common in spring and early summer, Susquehanna River, Broome Co. S. ulna var. chaseana Thomas. Abundant in April counts, Susque- hanna River, Broome Co. Asterionella formosa Hassall. Infrequent, spring and fall plankton, Susquehanna River, Broome Co. A. gracillima (Hantzsch) Heiberg. Very common, especially during spring months, Susquehanna River; abundant in Pond 2 in winter, Broome Co. Those diatoms marked with an asterisk were also reported by Hohn (1951) . 33 A CHNANTHA CEAE Rhoicosphenia curvata (Kuetz.) Gron.* Rare, May plankton, Sus- quehanna River, Broome Co. Cocconeis pediculus Ehren.* Epiphytic on filamentous greens. May, Susquehanna River, Broome Co. C. placentula Ehren.* Susquehanna River, Tioga Co. NAVICULACEAE Navicula americana var. minor Perag & Haribaud.* Plankton, Sus- quehanna River, Tioga Co. N. bacillum Ehren.* Plankton, Susquehanna River, Broome Co. N. cuspidata Kuetz.* Plankton, Susquehanna River, Tioga Co. N. mutica Kuetz.* Plankton, Susquehanna River, Tioga Co. N. viridula Kuetz.* Plankton, Susquehanna River, Tioga Co. Pinnularia borealis Ehren.* Plankton, Susquehanna River, Tioga Co. P. divergens W. Smith.* Plankton, Susquehanna River, Tioga Co. P. gibba Ehren.* Plankton, Susquehanna River, Tioga Co. P. legumen Ehren. * Plankton, Susquehanna River, Tioga Co. P. nobilis Grun.* Plankton, Susquehanna River, Tioga Co. P. mesolepta Ehren.* Plankton, Susquehanna River, Tioga Co. P. subcapitata Greg.* Plankton, Susquehanna River, Tioga Co. P. viridis (Nitzsch) Ehren.* Plankton, Susquehanna River, Tioga Co. Caloneis amphisbaena (Bory) Cleve.* Plankton, Susquehanna River, Tioga Co. Neidium affine var. amphirhynchus (Ehren.) Clev.* Plankton, Sus- quehanna River, Tioga Co. N. productum (W. Smith) Cleve.* Plankton, Susquehanna River, Tioga Co. Stauroneis phoenicenteron Ehren.* Plankton, Susquehanna River, Tioga Co. Tropidoneis lepidoptera (Greg.) Cleve.* Plankton, Susquehanna River, Tioga Co. Frustulia rhomboides (Ehren.) DeToni.* Plankton, Susquehanna River, Tioga Co. *Those diatoms marked with an asterisk were also reported by Hohn (1951) . 34 Gyrosigma attenuatum (Kuetz.) Cleve. Infrequent in plankton, March and April; some infected with Chytrids. Plankton, Susque- hanna River, Broome Co. G. scalproides (Raben.) Cleve.* Plankton, Susquehanna River, Tioga Co. Amphiprora sp. Only a single cell seen in May collection, lost before species identification could be made. Susquehanna River, Broome Co. GOMPHONEMA TA CEAE Gomphonema Augur Ehren.* Susquehanna River, Tioga Co. G. sphaerophorum Ehren.* Susquehanna River, Tioga Co. G. ventricosum Greg.* Susquehanna River, Tioga Co. Gomphoneis herculeana (Ehren.) Cleve.* Susquehanna River, Tioga Co. G. herculeana var. robusta (Grunov) Cleve.* Excellent cells seen in plankton collections during May, Susquehanna River, Broome Co. CYMBELLACEAE Cymbella affinis Kuetz.* Plankton, Susquehanna River, Tioga Co. C. cuspidata Kuetz.* Plankton, Susquehanna River, Tioga Co. C. mexicana Ehren.* Plankton, Susquehanna River, Tioga Co. C. sinuata Greg.* Plankton, Susquehanna River, Tioga Co. C. tumida (Breb.) Van Heurck.* Infrequent in spring collections, Susquehanna River, Broome and Tioga Co. C. ventricosa Kuetz.* Plankton, Susquehanna River, Tioga Co. Amphora veneta Kuetz.* Plankton, Susquehanna River, Tioga Co. Epithemia zebra (Ehren.) Kuetz.* Plankton, Susquehanna River, Tioga Co. NITZSCHIACEAE Nitzschia sigmoidea (Nitzsch) W. Smith. Infrequent in winter and spring plankton; beautiful large cells during May collections. Sus- quehanna River, Broome and Tioga Counties. Hantzschia amphioxys (Ehren.) Grun.* Plankton, Susquehanna River, Tioga Co. Those diatoms marked with an asterisk were also reported by Hohn (1951) . 35 SURIRELLACEAE Cymatopleura elliptica (Breb.) W. Smith.* Plankton, Susquehanna River, Tioga Co. C. solea (Breb.) W. Smith.* Spring plankton, Susquehanna River, Broome and Tioga Counties. Surirella biseriata var. bifrons (Ehren.) Hurst.* Plankton, Susque- hanna River, Tioga Co. S. guatamalensis Ehren.* Plankton, Susquehanna River, Tioga Co. S. pinnata W. Smith.* Plankton, Susquehanna River, Tioga Co. S. spiralis Kuetz.* Spring plankton; Susquehanna River, Broome Co. S. tenera Greg. Winter collection, Susquehanna River, Broome Co. S. tenera var. nevosa A. Schmidt.* Plankton, Susquehanna River, Tioga Co. PYRROPHYTA DINOPHYCEAE PERIDINIALES PERIDINIA CEAE Peridinium gatunense Nygaard. A most important member of the plankton population in Ponds 1 and 2. Common to abundant, February through April. Broome Co. P. wisconsinense Eddy. Infrequent in summer collections, Sphagnum border, Pickerel Pond, Broome Co. CERATIACEAE Ceratium hirundinella (O. F. Muell.) Dujardin. Spring and summer plankton samples, Susquehanna River, Broome Co.; Cincinnatus Lake, Chenango Co.; Tioughnioga River, Cortland Co. DINOCOCCALES PHYTODINIA CEAE Stylodinium globosum Klebs. An extremely rare alga. Thompson (1949) reports this species from Maryland on Oedogonium during ♦Those diatoms marked with an asterisk were also reported by Hohn (1951) . 36 September. I found it on Oedogonium filaments during September. Excellent material, fitting Thompson’s description in every way. This immobile Dinophycean has a globular cell 30ja in diameter, a stipe 25,u long and a disc-like holdfast 10^ in diameter. On Oedogonium , in debris along edge of shore, Little Choconut Creek, Broome Co. Fig. 141. CYANOPHYTA MYXOPHYCEAE CHROOCOCCALES CHROOCOCCA CEAE Chroococcus dispersus (Keissl.) Lemmermann. Small cells, 3-5^ in diameter. In squeezings of aquatics, Tioughnioga River, Broome Co. C. minimus (Keissl.) Lemmermann. Large colonies of very small cells, 2-3 ju. wide. In floating debris, Tioughnioga River, Broome Co. C. minutus (Kuetz.) Naegeli. Cells 5-10^ wide. Tychoplankton, West Branch Tioughnioga River, Cortland Co.; Otsego Lake, Otsego Co. C. turgidus (Kuetz.) Naegeli. Very large cells with hyaline, lamel- lated sheaths. Squeezings, Pickerel Pond and Lily Lake, Broome Co. Aphanocapsa elachista West & West. Plankton colonies of pale, blue-green cells. Stump Lake, Cortland Co. A. Grevillei (Hass.) Raben. Cells 4-5.5^, close, blue-green and with pseudovacuoles. Entangled with aquatic plants. Pickerel Pond, Broome Co. A. rivularis (Carm.) Raben. Cells scattered, granular, 5-6/j- in diameter. On scrapings of dam boards, Genegantslet Creek, Che- nango Co. A. pulchra (Kuetz.) Raben. Cells finely-granular, not crowded. Tychoplankton, Pickerel Pond, Broome Co. Anacystis cyanea Drouet & Daily. ( Microcystis aeroginosa Kuetz.) Frequent young colonies seen during April and May, older larger colonies seen with frequency during summer, Susquehanna River, Broome Co.; Stump Lake, Cortland Co. 37 A. incerta (Lemm.) Drouet & Daily. (Microcrocystis incerta Lemm.) Squeezings, Pickerel Pond, Broome Co.; Stump Lake, Cortland Co. Aphanothece nidulans P. Richter. Entangled with attached filaments in water of Tioughnioga River, Broome Co. A. stagnina (Spreng.) A. Braun. In squeezings of Sphagnum , Pick- erel Pond, Broome Co. Merismopedia elegans. A. Braun. Cells bright blue-green, approxi- mately 6x8/i. Fairly widespread throughout the area, primarily in tychoplankton. M. glauca (Ehren.) Naegeli. Homogeneous cells, 4-7/* in diameter. Quite widespread in tychoplankton. M. punctata Meyen. In floating debris, Tioughnioga River, Broome Co. M. tenuissima Lemmermann. In squeezings, scrapings, and floating debris throughout the area. M. Trolleri Bachmann. Refraction of light on pseudovacuoles causes cells to appear orange, brown, purple, etc. A rare blue-green in squeezings of Anacharis, Cincinnatus Lake, Chemung Co. Coelosphaerium dubium Grunow. Spherical cells 5-7//. densely packed. Squeezings from Owego Creek, Tioga Co. C. Kuetzingianum Naegeli. Cells round, small, 4/jt or less. Squeez- ings and strainings from Cincinnatus Lake and Genegantslet Creek, Chenango Co.; West Branch Tioughnioga River, Cortland Co. C. Naegelianum Unger. Cells ovate — ellipsoid, granular. Quite common and widespread, becoming abundant in months of August and September in the Chenango and Susquehanna Rivers, Broome Co. Gomphosphaeria aponina Kuetz. Cells pyriform at ends of radiating strands within gelatinous envelope. Squeezings, Otsego Lake, Otsego Co. CHAMAESIPHONALES CHAMAESIPHONA CEAE Entophysalis lemaniae (Ag.) Drouet & Daily. ( Chamaesiphon in- crustans Grun.) . A small inconspicuous epiphyte on green fila- mentous algae, Susquehanna River, Otsego Co. Fig. 133. 38 OSCILLA T ORIALES O SC ILL A TORI A CEA E Spirulina princeps (West & West) G. West. Single celled, spiral trichome, 4-5/* wide. Plankton, Tioughnioga River, Broome Co. Oscillatoria Agardhii Gomont. Briefly tapered trichomes with gran- ular cell walls. Tychoplankton, Genegantslet Creek and Unadilla River, Chenango Co. O. amphibia C. A. Agardh. Forming small sheets on dam and aquatic plants. Cells with a single granule on either side of cross wall. Genegantslet Creek, Chenango Co. O. anguina (Bory) Gomont. Trichomes curved at apex, apical cell capitate. Forming mat on mud bottom, West Branch Tioughnioga River, Cortland Co. O. angustissima West & West. Extremely small trichomes, 1/* or less in diameter; cells only 1-3/* in length. Tychoplankton, Una- dilla River, Chenango Co.; Stump Lake, Corthnd Co. O. chlorina Kuetz. Protoplast yellowish-green, barely granular. On mud bottom, Pickerel Pond, Broome Co. O. curviceps C. A. Agardh. Trichomes twisted terminally; not con- stricted at cross walls. Tychoplankton, Camp Tuscarora Lake, Broome Co.; Oak Creek, Otsego Co. O. geminata Meneghini. Terminal cell rounded; cells constricted at cross walls and containing one or two large vacuoles. Strainings, Pickerel Pond, Broome Co. O. limnetica Lemmermann. Cross walls barely visible and not con- stricted. Plankton of Pickerel Pond and Tioughnioga River, Broome Co.; Canisteo River, Steuben Co. O. limosa (Roth) C. A. Agardh. Trichomes straight, not tapered; cross walls granulate and not constricted. Common and wide- spread throughout area. O. princeps Vaucher. Trichomes very large, 30-60/* in diameter; cells heavily granular. Widespread in most counties of area. O. proboscidea Gomont. Trichomes tapering, ending in a capitate, truncate cell; trichomes loosely spiraled. Rare on mud bottom West Branch Tioughnioga River, Cortland Co. O. sancta (Kuetz.) Gomont. Cells dark grey-green, turning violet if dried; cross walls granular. Widespread on aquatics, mud bot- toms, rocks, and dams. 39 O. splendida Greville. Trichomes gradually tapering over a long distance, solitary; cross walls with granules. Infrequent in squeez- ings, Oak Creek, Otsego Co. O. tenuis C. A. Agardh. Trichomes not tapering, cells 5-10/x wide, granular, blue-green; cross walls granular. The most widespread of all Oscillatoria, found everywhere. Lyngbya Nordgaardii Wille. A most peculiar Lyngbya, many of its cells attach to filamentous greens and follow its host for awhile, then its terminal cells break away curving upward; cells square, 1.5/x; sheath thin. Susquehanna River, Otsego Co. Fig. 142. L. putealis Montagne. Sheaths thin; filaments forming a mat almost black in color; cells 4-10/* and square. Pond 1, Broome Co. Microcoleus paludosus (Kuetz.) Gomont. Several twisted filaments with a common sheath; cells light blue-green, not constricted. On mud, Pickerel Pond, Broome Co. NOSTOCACEAE Anabaena affinis Lemmermann. Cells 5-7/x wide; heterocysts spher- ical, 7-10/x. Tychoplankton, Pickerel Pond, Broome Co.; Stump Lake, Cortland Co. A. Bornetiana Collins. Cells 11-12/q heterocysts 12-14/x; gonidia 12 fj. x 50-80 /x. Squeezings of Sphagnum, Pickerel Pond, Broome Co. A. sphaerica Bornet & Flahault. Cells 5-6/q heterocysts 6-7/*; gonidia 12-1 8/q spherical and contiguous to heterocysts. Canisteo River, Steuben Co. A. spiroides var. crassa Lemmermann. Trichomes spiral; cells 11- 15/x, heterocysts 10-15/x; gonidia 20-23 /x x 25-40/x. Common to very abundant, July through September, Chenango and Susque- hanna Rivers, Broome Co. A. variabilis Kuetz. Cells 4-6/x x 3-6/q heterocysts 6-8 /x; gonidia 6-10 /jl x 8-15/4, in series. Tychoplankton, Stump Lake, Cortland Co. Anabaenopsis Elenkinii Miller. Excellent filaments, all with terminal heterocysts. In Harpur Pond, Broome Co. Aphanizomenon flos-aquae (L.) Ralfs. Straight trichomes arranged laterally in bundles within a mucilaginous sheath; trichomes tap- ering towards both ends. Common in plankton of Susquehanna, April through July, Broome Co. 40 Cylindrospermum muscicola Kuetz. Trichomes with terminal hetero- cysts and gonidia adjacent to heterocysts; gonidia ellipsoidial. Tychoplankton, Canisteo River, Steuben Co. C. stagnate (Kuetz.) Bornet & Flahault. Similar to preceding species, but gonidia cylindrical, up to 40/* in length. On mud bot- tom, Little Choconut Creek, Broome Co. SCYTONEMA TA CEAE Tolypothrix distorta Kuetz. Filaments with false lateral branches; cells broader than long, 9-12/* x 6-8/*. Tychoplankton, Lily Lake and Pickerel Pond, Broome Co. T. tenuis Kuetz. Similar to the above but with cells square or slightly longer than broad, 5-8/* wide. Squeezings, Harpur Pond and Pickerel Pond, Broome Co.; Stump Lake, Cortland Co. 5 TIGONEMA TA CEAE Nostochopsis lobatus Wood. Trichomes freely branched within a macroscopic gelatinous matrix; cells usually barrel-shaped; hetero- cysts mostly terminal on lateral branches. Small gelatinous beads free-floating and attached on rocks, Susquehanna River, Che- nango Co. Fig. 144. RIVULARIACEAE Calothrix sp. Filaments attached to stones and boards, Pickerel Pond, Broome Co. C. fusca Bornet & Flahault. Filaments mostly solitary, tapering to fine long apices from a broad swollen base; strongly curved; heterocysts basal; sheaths thick and lamellose. In debris along shore, Little Choconut Creek, Broome Co. C. parietana (Naeg.) Thuret. Filaments single or in mats; tapering to attenuated apices; sheaths thick and lamellose, filaments not swollen at base. Stump Lake, Cortland Co. Gloeotrichia pisum (C. A. Agardh) Thuret. Trichomes radiating from center of macroscopic gelatinous ball, tapering to attenuated apices; heterocysts basal. Frequent on Sparganium stems, Stump Lake, Cortland Co. 41 REFERENCES Berg, C. C. 1963. Middle Atlantic States. In Frey, D. G., Ed. Limnology in North America. Univ. Wisconsin Press, Madison, pp. 91-237. Bourrelly, P. 1957. Recherches sur les Chrysophycees. Revue Algologique, Memoires hors-series No. 1, Paris. 412 pp. 1966. Les algues d’eau douce: les algues vertes. N. Boubee, Paris. 511 pp. Clovis, J. F. 1955. 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Memoir 308. 39 pp. 42 Lane, Patricia A. 1966. A study of the plankton algae of two ponds. Unpub. M.A. Thesis, State Univ. of N.Y. at Binghamton, N.Y. Muenscher, W. C. 1936. Aquatic vegetation of the Delaware and Susquehanna Areas. In A biological survey of the Delaware and Susque- hanna watersheds. Suppl. to Ann. Rept. N.Y.S. Conser- vation Dept., 25(1935): 205-221. New York State Department of Health. 1954. The Susquehanna River drainage basin. Recommended classifications and assignments of standards of quality and purity for designated waters of New York State. Water Pollution Control Board. 325 pp. Patrick, Ruth, & Reimer, C. W. 1966. The diatoms of the United States. Mono. Acad. Nat. Sci. Phila., No. 13. 688 pp. Schumacher, G. J. 1961. Biology of the Allegany Indian Reservation and vicinity. Part I: The algae. N.Y.S. Mus. & Sci. Serv. Bull., 383:5-18. Smith, G. M. 1920. Phytoplankton of the inland lakes of Wisconsin. Part I. Wise. Geol. & Nat. Hist. Surv. Bull., 57:243. 1924. Phytoplankton of the inland lakes of Wisconsin. Part II. Wise. Geol. & Nat. Hist. Surv. Bull., 57: 1-227. 1950. The fresh-water algae of the United States. 2nd Ed. Mc- Graw-Hill, N.Y. 719 pp. Thompson, R. H. 1949. Immobile Dinophyceae. I. New records and a new species. Amer. Jour. Bot., 36: 301-308. Tiffany, L.H., & Britton, M. E. 1952. The algae of Illinois. Univ. of Chicago Press, Chicago. 407 pp. Tressler, W. L., & Bere, R. 1936. A limnological study of some lakes in the Delaware and Susquehanna watersheds. In A biological survey of the 43 Delaware and Susquehanna watersheds. Suppl. to Ann. Rept. N.Y.S. Conservation Dept., 25 (1935): 222-236. Wager, D. B. 1968. Seasonal variations in net phytoplankton of the Susque- hanna River near Binghamton, New York. Unpub. M.A. Thesis, State Univ. of N.Y. at Binghamton, N.Y. West, W., & West, G. S. 1904/ 12. A monograph of the British Desmidiaceae. The Ray Society, London. Vol. I, 1904, 224 pp., 32 pi.; Vol. II, 1905, 204 pp., 32 pi.; Vol. Ill, 1908, 274 pp., 41 pi.; Vol. IV, 1912, 191 pp., 33 pi. & Carter, N. 1923. A monograph of the British Desmidiaceae. Vol. V. The Ray Society, London. 300 pp., 38 pi. 44 ILLUSTRATIONS PLATE I Figs. 1-21* 1. Netrium digitus . . . 130x35. 2. Closterium Leibleinii . . . 150x20. 3. Closterium Venus . . . 68x9. 4. Closterium Dianae . . . 172x17. 5. Closterium moniliferum . . . 290x61. 6. Closterium gracile . . . 150x4. 6a. Closterium incurvum . . . 60x13. 7. Gonatozygon aculeatum . . . 208x14. 8. Gonatozygon pilosum . . . 115x10. 9. Closterium Ehrenbergii . . . 350x65. 10. Closterium costatum . . . 228x38. 11. Closterium Ralfsii var. hybridum . . . 460x47. 12. Closterium Ralfsii . . . 520x54. 13. Spirotaenia obscura . . . 145x23. 14. Spirotaenia condensata . . . 155x18. 15. Tetmemorus Brebissonii . . . 185x23. 16. Penium margaritaceum . . . 137x20. 16a. Penium spinospermum . . . 33x14. 17. Closterium turgidum . . . 730x58. 18. Closterium striolatum . . . 248x32. 19. Closterium juncidium . . . 235x9. 20. Closterium intermedium . . . 200x26. 21. Closterium Ralfsii var. immane . . . 600x72. Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 46 PLATE II Figs. 22-56* 22. Closterium rostratum . . . 350x25. 23. Closterium setaceum . . . 263x8. 24. Closterium Kuetzingianum . . . 172x17. 25. Closterium acutum . . . 150x9. 26. Closterium toxon . . . 322x9. 27. Closterium didymotocum . . . 540x58. 28. Pleurotaenium Ehrenbergii . . . 596x24. 29. Pleurotaenium subcoronulatum var. detum . . . 405x23. 30. Pleurotaenium coronatum . . . 602x66. 31. Euastrum abruptum forma minor . . . 22x17. 32. Euastrum binale var. hians . . . 12x10. 33. Pleurotaenium nodosum . . . 960x65. 34. Pleurotaenium trabecula . . . 324x23. 35. Pleurotaenium trabecula var. rectum . . . 240x11. 36. Pleurotaenium nodulosum . . . 390x57. 37. Euastrum evolutum . . . 70x42. 38. Euastrum verrucosum var. alatum . . . 103x87. 39. Euastrum abruptum . . . 36x24. 40. Euastrum gemmatum . . . 50x37. 41. Euastrum obesum var. crassum . . . 119x66. 42. Cosmarium bipunctatum . . . 20x18. 43. Cosmarium Botrys var. subtumidum . . . 60x45. 44. Cosmarium cucumis . . . 75x45. 45. Cosmarium quinarium . . . 40x34. 46. Cosmarium sexangulare var. minimum . . . 16x13. 47. Cosmarium Regnellii . . . 17x17. 48. Cosmarium Hammeri var. protuberans . . . 32x25. 49. Cosmarium granatum . . . 35x27. 50. Cosmarium quasillus . . . 60x45. 51. Cosmarium subtumidum . . . 42x33. 52. Cosmarium impressulum . . . 28x20. 53. Cosmarium pseudopyramidatum . . . 42x27. 54. Cosmarium cucurbita . . . 29x18. 55. Cosmarium subreniforme . . . 39x38. 56. Cosmarium reniforme . . . 60x55. ♦Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 48 PLATE III Figs. 57-78* 57. Cosmarium margaritatum . . . 68x58. 58. Cosmarium obtusatum . . . 49x38. 59. Cosmarium denticulatum forma Borgei . . . 175x102. 60. Cosmarium pyramidatum . . . 75x47. 61. Cosmarium punctulatum var. subpunctulatum . . . 36x29. 62. Cosmarium omatum . . . 30x32. 63. Cosmarium subcostatum var. minor . . . 25x21. 64. Cosmarium amoenum . . . 40x21. 65. Cosmarium Turpinii . . . 59x52. 66. Cosmarium subcostatum . . . 35x31. 67. Cosmarium protractum . . . 33x33. 68. Cosmarium Portianum . . . 31x24. 69. Cosmarium Turpinii . . . 61x50. 70. Cosmarium pseudoconnatum . . . 54x42. 71. Cosmarium punctulatum . . . 34x28. 72. Cosmarium refringens . . . 35x29. 73. Cosmarium contractum var. ellipsoideum . . . 30x21. 74. Cosmarium pachydermum var. aethiopicum . . . 89x72. 75. Micrasterias americana . . . 129x70. 76. Micrasterias apiculata var .fimbriata forma spinosa . . . 206x200. 77. Micrasterias laticeps . . . 125x150. 78. Micrasterias Nordstedtiana . . . 136x126. Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 50 PLATE IV Figs. 79-100* 79. Micrasterias radiata . . . 166x155. 80. Micrasterias radiata var. simplex . . . 172x155. 81. Micrasterias pinnatifida . . . 70x75. 82. Micrasterias truncata var. semiradiata . . . 78x82. 83. Staurastrum grande var. parvum . . . 60x53. 84. Staurastrum muticum . . . 26x23. 85. Micrasterias radiosa . . . 164x160. 86. Staurastrum pachyrhynchum . . . 29x28. 87. Staurastrum cuspidatum . . . 21x28. 88. Staurastrum Dickiei var. rhomboideum . . . 33x64. 89. Micrasterias radiosa var. omata . . . 160x155. 90. Staurastrum punctulatum . . . 32x32. 91. Staurastrum apiculatum . . . 25x18. 92. Micrasterias rotata . . . 350x255. 93. Xanthidium subhastiferum . . . 50x80. 94. Staurastrum Dickiei . . . 45x46. 95. Xanthidium antilopaeum var. minneapoliense . . . 80x81. 96. Xanthidium antilopaeum var. callosum . . . 82x81. 97. Staurastrum Dickiei var. circulare . . . 39x35. 98. Xanthidium antilopaeum var. polymazum . . . 86x84. 99. Xanthidium cristatum var. uncinatum . . . 75x61. 100. Staurastrum tetracerum . . . (apical and face view) . . . 23x23. * Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 98 99 100 52 PLATE V Figs. 101-128* 101. Staurastrum Brebissonii var. brevispinum . . . 48x45. 102. Staurastrum Ophiura . . (apical view) . . . 80x145. 103. Staurastrum crenulatum . . (apical and face view) . . . 27x32. 104. Staurastrum dilatatum . . . 23x22. 105. Staurastrum setigerum . . . 45x47. 106. Staurastrum polymorphum . . . 25x32. 107. Staurastrum pseudopelagicum . . . 35x44. 108. Staurastrum pseudopelagicum var. minor . . . 35x44. 109. Staurastrum rugosum . . . 35x45. 110. Staurastrum longiradiatum . . . 85x63. 111. Staurastrum brasiliense var. Lundellii . . (apical and face view) . . . 126x120. 112. Staurastrum furcigerum forma eustephana . . . 51x49. 113. Staurastrum tetacerum var. evolutum . . . 58x50. 114. Staurastrum furcigerum . . . 65x50. 115. Staurastrum cuspidatum var. canadense . . . 30x22. 116. Staurastrum Johnsonii . . . 42x84. 117. Staurastrum Arctiscon var. glabrum . . . 130x120. 118. Onychonema laeve var. latum . . . 20x26. 119. Desmidium Baileyii . . . 20x24. 120. Staurastrum Arctiscon . . . 120x122. 121. Gymnozyga moniliformis . . . 25x17. 122. Desmidium Swartzii . . . 15x38. 123. Hyalotheca dissiliens . . . 14x18. 124. Spondylosium planum . . . 13x12. 125. Sphaerozosma excavatum var. subquadratum . . . 9x5. 126. Hyalotheca undulata . . . 13x7. 127. Sphaerozosma granulatum . . . 9x10. 128. Desmidium Grevillei . . . 21x43. Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 128 54 PLATE VI Figs. 129-150* 129. Characium ambiguum . . . 28x6. 130. Characium ensiforme . . . 50-60x6-12. 131. Characium limneticum . . . 70x9. 132. Ankistrodesmus falcatus var. stipitatus . . . 19x3. 133. Entophysalis lemaniae . . . 15x5. 134. Chaetosphaeridium Pringsheimii . . . 23x11. 135. Lagynion macrotrachelum . . . 17x11. 136. Lagynion ampullaceum . . . 19x12. 137. Stylosphaeridium stipitatum . . . 17x7. 138. Stipitococcus apiculatus . . . 16x4. 139. Aphanochaete repens . . . 15-30x8-10. 140. Schizochlamys gelatinosa . . . 12-15x12-15. 141. Stylodinium globosum . . . 70-80x35-40. (empty cell and vegetative cell) 142. Lyngbya Nordgaardii . . . 1-3x1. 5-2. 143. Radiofilum flavescens . . . 15x10. 144. Nostochopsis lobatus . . . 6-12x3-5. 145. Staurastrum illusum var. majus . . . 33x35. (apical and face view) 146. Staurastrum altemans . . . 32x30. (apical and face view) 147. Pediastrum simplex var. duodenarium . . . 11-13x26-28. 148. Botrydium granulatum ... up to 3mm. in diam. 149. Pediastrum biradiatum var. heteracanthum . . . 13-15x7-9. 150. Pediastrum integrum . . . 15-18x18-24. Numbers after each taxon indicate the actual overall length and width measurements in microns of the cell figured. 149 150 56 INDEX TO FAMILIES AND GENERA Achnanthaceae, 33 Coelosphaerium 37 Actinastrum 18 Coleochaetaceae 11 Amphiprora 34 Coleochaete 11 Amphora 34 Coscinodiscaceae 31 Anabaena 39 Cosmarium 22 Anabaenopsis 39 Crucigenia 18 Anacystis 36 Cylindrocapsa 11 Ankistrodesmus 15 Cylindrocapsaceae 11 Aphanizomenon 39 Cylindrospermum 40 Aphanocapsa 36 Cymatopleura 35 Aphanochaete 11 Cymbella 34 Aphanothece 37 Cymbellaceae 34 Asterionella 32 Asterococcus 9 Desmidiaceae 19 Desmidium 28 Basicladia 12 Botrydiaceae 30 Diatoma Diatomaceae 32 32 Botrydium 30 Botryococcaceae 15 Dictyosphaeriaceae 13 Botryococcus 15 Dictyosphaerium 13 Bulbochaete 12 Dimorphococcus 13 Dinobryon 30 Caloneis 33 Draparnaldia 11 Calothrix 40 Cerasterias 16 Elakatothrix 10 Ceratiaceae 35 Entophysalis 37 Ceratium 35 Epithemia 34 Chaetophora 11 Euastrum 21 Chaetophoraceae 11 Eudorina 9 Chaetosphaeridium 11 Euglena 29 Chamaesiphonaceae 37 Euglenaceae 29 Characiaceae 13 Characium 13 Fragilaria 32 Chlorangiaceae 10 Fragilariaceae 32 Chlorococcaceae 12 Frustulia 33 Chlorococcum 12 Chodatella 15 Geminella 10 Chroococcaceae 36 Gloeocystis 9 Chroococcus 36 Gloeotrichia 40 Chrysidiastrum . 1 Gomphoneis 34 Cladophora 1 ’ Gomphonema 34 Cladophoraceae 12 Gomphonemataceae 34 Closterium 19 Gomphosphaeria 37 Closterium 19 Gonatozygon 18 Coccomyxaceae 10 Gongrosira 12 Cocconeis 33 Gonium 9 Coelastraceae 15 Gymnozyga 28 Coelastrum 15 Gyrosigma 34 57 Hantzschia 34 Phacus 29 Hyalotheca 28 Phytodiniaceae 35 Hydrodictyaceae 13 Pinnularia 33 Hydrodictyon 14 Pithophora 12 Pleurotaenium 21 Kirchneriella 16 Protococcaceae 11 Protococcus 11 Lagynion 31 Lyngbya 39 Quadrigula 16 Mallomonadaceae 30 Radiofilum 10 Mallomonas 30 Rhizochrysidaceae 31 Melosira 31 Rhizoclonium 12 Meridion 32 Rhoicosphenia 33 Meridionaceae 32 Rivulariaceae 40 Merismopedia 37 Mesotaeniaceae 18 Scenedesmaceae 16 Micractiniaceae 13 Scenedesmus 16 Micractinium 13 Schizochlamys 10 Micrasterias 24 Scytonemataceae 40 Microcoleus 39 Selenastrum 16 Microspora 10 Sorastrum 14 Microsporaceae 10 Sphaerocystis 9 Mougeotia 18 Sphaerozosma 28 Spirogyra 18 Navicula 33 Spirotaenia 19 Naviculaceae 33 Spirulina 38 Neidium 33 Spondylosium 28 Nephrocytium 15 Staurastrum 25 Netrium 19 Stauroneis 33 Nitzschia 34 Stephanodiscus 31 Nitzschiaceae 34 Stichococcus 10 Nostocaceae 39 Stigeoclonium 11 Nostochopsis 40 Stigonemataceae 40 Stipitococcaceae 29 Ochromonadaceae 30 Stipitococcus 29 Oedogoniaceae 12 Stylodinium 35 Oedogonium 12 Stylosphaeridium 10 Onychonema 28 Surirella 35 Oocystaceae 15 Surirellaceae 35 Oocystsis 15 Synedra 32 Oscillatoriaceae 38 Synura 30 Oscillatoria 38 Synuraceae 30 Palmellaceae 9 Pandorina 9 Tabellaria 32 Pediastrum 13 Tabellariaceae 32 Penium 20 Tetmemorus 21 Peridiniaceae 35 Tetraedron 16 Peridinium 35 Tetraspora 9 58 Tetrasporaceae 9 Tolypothrix 40 Trachelomonas 29 Trentopohliaceae 12 Treubaria 15 Tropidoneis 33 Ulothrix 10 Ulotrichaceae 10 Vaucheria 30 Vaucheriaceae 30 Volvocaceae 9 Volvox 9 Xanthidium 25 Zygnema 18 Zygnemataceae 1 8 Printed by the University of the State of New York Press 6869/ 1/04212/2660