186 University of California Publications. [ botany 



Phormidium favosum (Bory) Gomont. 



Floating or attached to wood in streams or on the ground. 

 Glacier Valley, Unalaska, Alaska, A.A.L., No. 5020c!; Juneau, 

 Alaska, W.A.8. and A.A.L., Nos. 5188x!, 5190x! 



No. 5020c represents an unusually slender form, No. 5190x 

 represents a typical form of what Gomont calls var. a, and 

 No. 5188x a typical form of what the same writer calls var. b. 



Phormidium Treleasei Gomont. 



Mixed with other Cyanophycese in a scum on sluggish small 

 streams. Glacier Valley, Unalaska, Alaska, A. A. L,, No. 5022c! 



This very slender species (0.6-0.8 /*) with elongated cells, 

 has been found hitherto only in thermal waters (Arkansas Hot 

 Springs and Yellowstone National Park), but this specimen 

 seems to belong under it, though of cold waters. 



Phormidium uncinatum (Agardh) Gomont. 



Forming more or less extended blue-black layers, either sub- 

 merged or on the surface of the ground. St. Michael, Alaska, 

 W.A.S., No. 5236x!; near Iliuliuk, Unalaska, W.A.S. and 

 A.A.L.. No. 5034!; Orca, Alaska, W.A.S. and A.A.L., No. 

 5172!; LaConner, Skagit County, Wash., N.L.G., No. 331!; 

 Seattle, Wash., N.L.G., Nos. 397!, 400! 



This is a very wide-spread species and is frequently so close 

 to the following that it is distinguished with difficulty. 



Phormidium autumnale (Agardh) Gomont. 



Similar to the last in appearance and habit. Iliuliuk, Unalaska, 

 W.A.S and A.A.L., No. 5034!; Kukak Bay, Alaska, Saunders 

 (1901, p. 398); Sitka, Alaska, W.A.S. and A.A.L., No. 5205!; 

 Coupeville, Whidbey Island, Wash., N.L.G., Nos. 450!, 609!; 

 La Conner, Skagit County, Wash., N.L.G., No. 336!; Seattle, 

 Wash., N.L.G., Nos. 394!, 401!, 499! 



Lyngbya aestuarii f. limicola Gomont. 



On mud in salt marshes. Whidbey Island, Wash., N.L.G., 

 Nos. 451!, 599!, and in Collins, Holden and Setchell, P. B.-A.. 

 No. 903! 



