vol. i] Setchell— Gardner. — Algce of Northwestern America. 195 



Scytonema varium Kuetzing. 



On rocks moistened by spray from a waterfall. Juneau, 

 Alaska. Saunders, No. 76! (1901, p. 398.) 



Scytonema Hofmanni Agardh. 



On dripping rocks. Iliuliuk, Unalaska, Alaska, W.^.S. and 

 A.A.L.. No. 4031! 



Scytonema mirabile (Dillwyn) Bornet. 



On moist ground or iu fresh water streams. Kukak Bay 

 and Glacier Bay, Alaska, Saunders (1901, p. 398). 



This species has not occurred to us, but Sannders has men- 

 tioned it under the synonyms, S. figuratum and S. mirabile. 

 We do not know whether he intended to indicate different species 

 or the same species, but Bornet has demonstrated that the S. 

 figuratum Agardh is the same as the Conferva mirabilis Dillwyn 

 (cf. Bornet, 1889, p. 12). 



Scytonema Myochrous (Dillwyn) Agardh. 



Forming small tufts on rocks in a brook. Glacier Bay, 

 Alaska. Saunders (1901, p. 398). 



Hassallia byssoidea f. saxicola Grnnow. 



Among mosses on dripping rocks. Amaknak Island, Bay of 

 Unalaska, Alaska, W.A.S. and A.A.L., No. 4005! 



Tolypothrix distorta (Fl. Dan.) Kuetzing. 



Floating or attached to plants or stones iu quiet, fresh waters. 

 Cape Nome, Alaska, W.A.SA; Fidalgo Island, Wash., N.L.G., 

 No. 604!; Lake Washington, Seattle, Wash., N.L.G., Nos. 

 352!, 570! 



Tolypothrix lanata (Desv.) Wartmann. 



Forming dark brown, felt-like layers on rocks or on the bot- 

 tom of shallow fresh waters or dried streams. Iliuliuk, Alaska, 

 W.A.S. and A.A.L.. No. 4050!, and in Collins, Holden and 

 Setchell, P. B.-A., No. 956!; near Seattle, Wash., Professor 

 T. C. D. Kincaid, No. 766! 



All the specimens noted, represent the older stages with deep 

 brown sheaths. 



