[3971 THE ALG^E 161 



Schizothrix lacustris A. Braun. 



In a freshwater pool with Stigonema near Prince William Sound 

 (300). Identified by Setchell. 



Microcoleus vaginatus (Vaucher) Gomont. 



Forming, with Scytonema mirabilis, a thin coating on damp ground 

 recently covered by snow. Glacier Bay (104). 



Family NOSTOCACE^E. 



Nostoc commune Vaucher. 



Forming thin leathery thalli of indefinite size and shape on damp 

 ground near Glacier Bay (106) ; Hidden Glacier, Yakutat Bay (502). 



Cells spherical or oblong, 12-18 fi in diameter; often two to four 

 cells coalesced. Tegument colorless ; cytoplasm finely granulated. 



Aphanothece microspora Naegeli. 



Forming with Chroococcus turgidus a slimy coating on a perpendic- 

 ular cliff over which water was trickling. Juneau (75). 



Microcystis marginata Naegeli. 



Forming a slimy coating on a perpendicular cliff near Juneau (75). 



Dermocarpa prasina Born. & Thur. 



Abundant on Sphacclaria racemosa arctica and Sphacelaria cir- 

 rosa. From Puget Sound to the Shumagin Islands. 



Dermocarpa fucicola sp. nov. (Plate XLVI, figs. 4 and 5.) 

 Phycotheca Boreali-Americana, No. 80 1. 



Plant forming dark violet brown patches 212 mm. in extent; cells 

 40-60 tJ. high, 1825 f- broad, ovate, clavate or spatulate, much nar- 

 rowed below ; schizospores abundant. On Fucus evanescens mega- 

 cephala, Puget Sound (440) . Forming orbicular or irregular patches 

 which become confluent into irregular masses of indefinite extent. 



This plant is closely related to Savageau's D. biscayensis, but dif- 

 fers from it in the larger size of the patches and the shape and size of 

 the individual cells. In D. biscayensis the plant forms orbicular 

 patches i mm. broad and the cells are 25-30 fj. broad. 



Family OSCILLATORIACE^. 



Oscillatoria amoena (Kuetz.) Gomont. 



The plant formed a soft, felt like, dark bluish-green mass 3-10 mm. 

 thick, of indefinite extent, lining the bottom of the outlet of a hot 

 spring. The water in the outlet where the plant was abundant ranged 

 from 80 F. some distance from the spring to 120 F. near the spring. 

 Near Sitka (158). Identified by Gomont. 



