90 



phyta. Flora of Nebraska. 23. pi. i. f. 6. 1894. R^ .— a— — - —0 



Marines du Groenland. Ann. Sci. Nat. Bot. VIL 19: 163. 1894. Collins, 

 Holden and Setchell. Phyc. Bor.-Am. Fasc. 6. no. 252. 1897. Rosenvinge. 

 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: 43. 1900. Setchell and Gardner. Algae of 

 Northwestern America. Univ. Calif. Pub. Bot. l: 182. 1903. West. West 

 Indian Freshwater Algae. Journ. of Bot. 42: 293. 1904. Collins. Phyco- 

 logical Notes of the late Isaac Holden. — I. Rhodora. 7: 172. 1905. Borge- 

 sen and Jonsson. The distribution of the Marine Algae of the Arctic Sea 

 and of the northernmost part of the Atlantic. Botany of the Faeroes. Ap- 

 pendix. XXV. 1905. Clark. The Holophytic Plankton of Lakes Atitlan 

 and Amatitlan, Guatemala. Proc. Biol. Soc. Wash. 21: 96. 1908. 



Plate IV. fig. 49. 



Plant mass dark blue-green or greenish-yellow; trichomes often mixed 

 with other algae, 1-2 mic. in diameter, twisted into a somewhat irregular 

 dense (here and there loose), or rarely regular spiral, 3-5 mic. in diameter, 

 the turns being contiguous to each other or almost so. 



Greenland. Growing in cavities with brackish water among mouldering 

 aigae. Tessarmiut, Baffin Bay. (Wormskiold). West Greenland, south of 

 61° lat. N. (Rosenvinge). West Greenland and Atlantic North America. 

 (Borgesen and Jonsson). Maine. Mixed with other algae, forming dark 

 purple-colored patches on the wharves at low-water mark. Eastport. (Far- 

 low). On rocks on shore near Seal Harbor. (Collins). (West). New 

 Hampshire. (Collins). Massachusetts. Gloucester, Cambridge, Wood's 

 Hole. (Farlow). Everett and Medford; on wharves, Nantucket. (Collins). 

 Connecticut. In large jelly-like masses on stalks of R u p p i a in Fresh 

 Pond (brackish), Stratford. July 1892. ("Could take it up in jelly-like masses 

 half an inch thick, pure Spirulina"). (Holden). . New York. Frequent 

 in sulphur springs. Clifton. (WoUe). New Jersey. Mixed with O s c i 1- 

 latoria. Atlantic City. (Morse). Swimming River, Monmouth County. 

 (Britton). Staten Island. (Pike). Mixed with other minute forms. Atlantic 

 City. (Martindale). Florida. Glen Cove Spring. (Wolle). Nebraska. 

 Frequent in salt water. Lincoln. (Saunders). Central America. Growing 

 in very warm water. Guatemala. (Meek). West Indies. On the roots of 

 mangroves. Near Bridgetown; Graeme Hall Swamp, Barbados. (Howard). 



Forma oceanica (Crouan) Gomont. 1. c. 274. De Toni. 1. c. 215. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 20. no. 954. 1902. 



Trichomes i mic. in diameter, somewhat straight in outline, twisted 

 into a regular spiral. 



Washington. Floating in slightly brackish water. Crocket's Lake. June 

 1901; in mud of pools of brackish water on salt marshes, Whidbey Island. 

 (Gardner). 



183. Spirulina duplex Wolle. Fresh-Water Algae U. S. 323. pi. 210. f. 4, 5. 

 1887. De Tom. Syll. Algar. 5: 216. 1907. 



