[401] THE ALG^E 165 



smaller in all its parts than the measurements given by various au- 

 thorities. 



Closterium juncidum Ralfs. 



In quiet water near Seldovia, Cook Inlet (422). 



Diameter io,u, length 240/1. The plant is slightly bent, but little 

 contracted toward the ends, which are obtusely rounded ; membranes 

 smooth, light brown ; vacuoles not apparent. 



Closterium angustatum reticulatum Wolle. 



Occasional in a freshwater pond near Cook Inlet. 



Diameter 16-19/1, length 340 /*. The plant is dark brown, marked 

 with delicate longitudinally and spirally arranged striae. 



Closterium acerosum (Schrank) Ehrenb. (Plate XLIII, fig. 27.) 

 In a freshwater pond near Seldovia, Cook Inlet. 

 Diameter 18-29/1, length 200-300/1. 

 Virgin Bay, Prince William Sound. 

 Diameter 29/1, length 265-300/1. 



Closterium striolatum Ehrenb. 



In quiet water in Kukak Bay (283). 

 Diameter 25-30/1, length 275-300/1. 



Closterium brebissonii Delp. 



In a freshwater pond near Cook Inlet (224). 

 Diameter 18/1, length 650/1. 



Closterium lunula (Muell.) Nitzsch. 



Occasional in quiet water near Kukak Bay. 

 Diameter 70/1, length 450/1. 



Closterium acutum (Lyngb.) Bre"b. 



In a freshwater pool near Prince William Sound (300) . 



Diameter 8-9/1, length 85-100/1. The plant is small and slightly 

 bent, ten times as long as broad, tapering from the middle to the 

 rounded ends ; cytoderm smooth and colorless. 



Closterium dianae Ehrenb. 



Freshwater pool, Prince William Sound (302) . Only one specimen 

 seen. 



Diameter 16/1, length i8o/t. 



Closterium venus Kuetz. (Plate XLIII, fig. 15.) 

 In a pond near Seldovia, Cook Inlet (422). 

 Diameter 9/1, length 85/1. 



Closterium parvulum Naeg. (Plate XLIII, fig. 14.) 



