[407] THE ALG^ 171 



Staurastnim furcigerum Breb. 



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

 Diameter 45 fi^ length 50 ix. 



Staurastrum arctiscon (Ehrenb.) Lund. 



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

 Common. 



Diameter 1 16 /i. 



Staurastrum polymorphum Br^b. (Plate xliii, figs. 23, 24.) 

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

 Diameter 40 /x, length 45 [i. 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 81 yu, length 88 [i. 



Euastrum gemmatum Breb. 



In a freshwater pond near Seldovia, Cook Inlet. 



Diameter 40 fi^ length 67 ft. The plant agrees exactly with Br^b- 

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



Euastrum pokomyanum Grun. 



In a freshwater pond near Kukak Bay. 



Diameter 21 /x, length 43 [x. 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 /i, length 130 //. 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 /x, length 148 [i. 



Euastrum didelta (Turp.) Ralfs. (Plate xliv. Fig. 24.) 



In freshwater near Kukak Bay. 



Diameter 46-60 /x, length 86-120 jm, sinus 16 ij. deep, bridge 11 /t 

 wide. 



Euastrum ansatum Ralfs. 



In a freshwater pond near Yakutat Bay. 



