[407] THE ALG^E 1 7 1 



Staurastrum furcigerum Breb. 



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

 Diameter 45 //., length 50 //. 



Staurastrum arctiscon (Ehrenb.) Lund. 



In a freshwater pool, Virgin Bay, Prince William Sound (302). 

 Common. 



Diameter 116 /*. 



Staurastrum polymorphum Breb. (Plate XLIII, figs. 23, 24.) 

 In a freshwater pond near Seldovia, Cook Inlet (402). 

 Diameter 40 /*, length 45 //. The end view shows four arms 



rounded at the ends. 



Staurastrum echinatum (Perty) Rab. (Plate XLIII, fig. 16.) 

 In a freshwater pond near Seldovia, Cook Inlet. 



Euastrum verrucosum Ehrenb. (Plate XLIII, fig. 9.) 

 In freshwater, Popof Island. 

 Diameter Si //., length 88 //. 



Euastrum gemmatum Breb. 



In a freshwater pond near Seldovia, Cook Inlet. 



Diameter 40 /z, length 67 ,a. The plant agrees exactly with Breb- 

 isson's description except that the terminal lobe is not emarginate. 



Euastrum pokornyanum Grun. 



In a freshwater pond near Kukak Bay. 



Diameter 21 //, length 43 //. The basal lobe of the trilobe semicell is 

 crenate, the terminal lobe subcuneate, truncate and excised ; membrane 

 smooth. 



Euastrum oblongum (Grev.) Ralfs. (Plate XLIII, fig. 37.) 



In a freshwater pond near Prince William Sound. 



Diameter 67 //, length 130 fj.. The semicells are five lobed, all of 

 the lobes having the broad shallow marginal cavity. 



Euastrum crassum (Breb.) Kuetz. (Plate XLIII, fig. 4.) 

 In a freshwater pond near Seldovia, Cook Inlet. 

 Diameter 68 /./, length 148 /JL. 



Euastrum didelta (Turp.) Ralfs. (Plate XLIV, Fig. 24.) 



In freshwater near Kukak Bay. 



Diameter 46-60 /*, length 86-120 /*, sinus 16 /j. deep, bridge n /* 

 wide. 



Euastrum ansatum Ralfs. 



In a freshwater pond near Yakutat Bay. 



