Myxophyceae 'i-77 



Expedition. Proc. Wash. Acad. Sci. 3: 398. 1901. Setchell and Gardner. 

 Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. 



Colonies of medium size, spherical, green becoming bluish; trichomes 

 4-7 mic. in diameter, tapering at the apices; gonidia (>-^ mic. in diameter, 

 exactly spherical, angular from mutual pressure, orange becoming brown- 

 ish; wall of gonidium somewhat thick, rough. 



Alaska. Forming a soft, bluish green coating on rocks near Juneau. 

 (Saunders). Massachusetts. Cambridge. (Farlow). Fresh Pond, Cam- 



bridge. (Richards). Connecticut. Pools. Whitneyville and Beaver Mead- 

 ows. (Eaton). 



332. Nostoc depressum Wood. Contr. Hist. Fresh-Water Algae North 



America. 30: 1872. De Toni. Syll. Algar. 5: 415. 1907. 



Colonies irregularly suborbicular, gregarious and sometimes aggregated, 

 elastic, surrounded by a firm, translucent outer layer, about the size of a 

 mustard seed or smaller, adhering to submerged mosses, blackish in color; 

 filaments mostly loosely interwoven; sheaths not present; trichomes 3 

 mic. in diameter; cells spherical, generally rather closely connected, rarely 

 distant: heterocysts, 7 mic. in diameter, rather larger than the cells. 



New Jersey. Attached to a brook moss, growing in a rapid rivulet in 

 the northern part of the state. (Austin). 



333. Nostoc glomeratum Kuetzing. Tab. Phyc. 2: 2. pi. 3. f. 5. 1850. De 



Toni. Syll. Algar. 5: 415. 1907. 

 Wolle. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. 



Plate VIII. fig. 6, 7. 



Colonies spherical, usually aggregated in grape-like clusters, lead- 

 colored or becoming somewhat purplish, with inconspicuous outer layer; 

 trichomes 3.S-4 mic. in diameter, more or less densely entangled, somewhat 

 equal in thickness; cells spherical, crowded; heterocysts ^-^.^ mic. in 

 diameter. 



California. On filaments of old Cladophora. (Anderson). 



334. Nostoc caeruleum Lyngbye. Hydrophytologia danica. 201. pi. 68. 



f. B. 1819. Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. 



Bot. VII. 7: 213. 1888. De Toni. Syll. Algar. 5: 416. 1907. 

 Wood. Contr. Hist. Freshwater Algae. North America. 31. 1872 

 Wolle. Fresh-Water Algae U. S. 284. 1887. Wolle and Martindale. 



Algae. Britton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 

 2: 606. 1889. Tilden. American Algae. Cent. I. no. 84. 1894; List of Fresh- 

 Water Algae collected in Minnesota during 1894. Minn. Bot. Studies. 

 i: 236. 1895. Setchell and Gardner. Algae of Northwestern America. 

 Univ. Calif. Pub. Bot. i: 191. 1903. Collins, Holden and Setchell. Phyc. 

 Bor.-Am. Fasc. 24. no. 1166. 1904. Buchanan. Notes on the Algae of Iowa. 

 Proc. Iowa Acad. Sci. 14: 11. 1908. 



Plate VIII. fig. 8. 

 Colonies very small, up to S-6 mm. in diameter, spherical, solid. 



