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- 



