THE ALG^E 183 



fact it seemed to be most abundant and to reach its best development 

 in quiet waters at the mouths of brooks where the percent of salt 

 must be perceptibly reduced. 



Pylaiella littoralis varia (Kjellm.) Kuck. 



Common on rocks, and on Fucus and other algae in quiet water from 

 Puget Sound to Bering Sea. Victoria, Juneau, Yakutat and Shumagin 

 Islands. 



This form is i 10 cm. in length, a light faded brown in color, very 

 intricate, the ultimate branches short and standing at right angles to the 

 axis. 



Pylaiella littoralis densa Saunders. 



The plant forms rope-like masses 2-4 cm. or more long on Fucus 

 and other algae. Victoria, Sitka, Prince William Sound (294), Shuma- 

 gin Islands (386). 



Pylaiella littoralis macrocarpa (Foslie) Kjellm. 



On fruiting tips of Fucus evanescens macrocephalus, Victoria. 



The plant is 1-3 mm. or more long, the branches and the upper 

 part of the main filament, except for a few-celled stalk at the base and 

 one of the cells at the tip, form plurilocular sporangia. No unilocular 

 sporangia were observed. 



Family SPHACELARIACE^E. 

 Sphacelaria cirrosa (Roth) Ag. 



Forming small light olive tufts on Fucus evanescens, Annette 

 Island. 



Sphacelaria racemosa arctica (Harv.) Reinke. 



Wrangell (70) ; Yakutat Bay (195) ; Prince William Sound (283). 



Forming dark olive-brown, densely tufted mats sometimes several 

 cm. wide and I cm. high ; unilocular sporangia abundant on all ma- 

 terial collected at the various stations. 



Family ENCOELIACE^ft. 



Homeostroma undulatum J. Ag. (Plate XLVI, fig. 3.) 



On Zoostera marina in a quiet cove near Seldovia, Cook Inlet 



(412). 



Fruiting plants 3 cm. long, 1-3 mm. wide. 



The plurilocular sporangia project little if at all above the surface of 

 the plant and are massed together more than is indicated in Reinke's 

 figures. The single hairs are very scarce on all the Pacific coast 

 material. 



