l66 SAUNDERS [4^*2] 



Very abundant in freshwater pond near Seldovia, Cook Inlet (424). 

 Diameter 8-1 2 /z, length 100 fi. 



Tetmemorus brebissonii (Menegh.) Ralfs. 



In freshwater near Prince William Sound : frequent. 

 Diameter 23//, length 78/z. 



Tetmemorus laevis ( Kuetz.) Ralfs. 



In a freshwater stream, Virgin Bay (300) ; Yakutat Bay. 



Diameter 21-24//, length 91-100//. The plant is slightly constricted 

 and not at all punctate. 

 Pleurotaenium nodosum (Bail.) Lund. 



Common in a freshwater pond, Popof Island. 



Diameter 40-45//, length 290-325//. 



Pleurotaenium truncatum (Breb.) Naeg. 



In a freshwater pond near Seldovia, Cook Inlet. 

 Diameter 45/1, length 216/1. 



Disphinctium cucurbita (Br^b.) Reinsch. 



In a freshwater pond near Prince William Sound (302). 

 Diameter 27//, length 67//. 



Disphinctium connatum (Br^b.) DeBary. (Plate xliii, fig. 30.) 



In a freshwater pond near Seldovia, Cook Inlet. Only one speci- 

 men was seen. 



Diameter 24 //, length 38 /z. 



Docidium baculum Br^b. 



In a freshwater pond, Popof Island. 



Diameter 27//, length 228//. The plant is slightly wider than the 

 description given, but is not at all narrowed as are the other species. 



Docidium coronulatum Grun. 



In a freshwater pool near Kukak Bay. 

 Diameter 40//, length 432//. 



Docidium dilatatum (Cleve.) Lund. 



In a freshwater pond, Popof Island. 



Diameter 13//, length 165//. The plant has five pearly granules 

 at each end. 



Docidium gracile Wittr. 



Triploceras gracile Bail. Micr. 

 Common in fresh water near Prince William Sound. 

 Diameter 27//. The plant has two rows of rather long spines. 



