Vol.1] SetcJiell-Gardner. — Algce of Northwestern America. 179 



Family CHROOCOCCACE^. 



Chroococcus rufescens (Brebisson) Na^geli. 



Forming with Stig'onema a reddish coating on a rock five 

 hnndred feet above sea level. Prince William Sonnd, Alaska, 

 Saunders (1901, p. 396). 



Chroococcus turgidus (Knetzing) Napgeli. • 



Among other alga? in pools of fresh water or on dripping 

 rocks. Glacier Valley, Unalaska, Alaska, A.A.L., No. 5023a!; 

 Jnnean, Alaska, Saunders (1901, p, 39G) ; in brackish water, 

 Whidbey Island, Wash., N.L.G., No. -172! 



Gloeocapsa ambigua f. fuscolutea Nfegeli. 



Among other algtP, especially DicJiotlirix Baueriana (Grunow) 

 B. & F. and Schlzothrix Braunii Gomont, in a mountain stream. 

 Orca, Alaska, W. L. Jepson, No. 5175! 



The cell walls of this form are thick, opaque and reddish or 

 yellowish brown. 



Gloeocapsa ambigua f. violacea Neegeli. 



Intermingled with the last. 



The only difference between this form and the last is in the 

 color of the cell walls which are distinctly violet and somewhat 

 more opaque. 



Glceocapsa atrata Knetzing. 



Intermingled with the last two. 



The present species differs from the last two in having the 

 walls transparent and either colorless or else very light blue. 

 They all seem to be forms of one species which is variable in this 

 respect. 



Gloeocapsa polydermatica Knetzing. 



With other Cyanophyceae, forming a yellowish firm jelly on 

 dripping rocks. Near Ilinlink, Unalaska, Alaska 1ir.4.»S'. and 

 A.A.L., No. 4031! 



The specimens referred here have blue green cell contents 

 and colorless stratified walls. The families are one or two-celled. 

 The cells measure 21-22 /* in diameter. 



