Freshwater Algae 15 a 



CHLOROPHYCEAE. 



ISOKONTAE. 



VOLVOCACEAE. 



Gonium Miill. 

 Gonium pectorale Miill. 



This alga was found only in the big lake at Bernard harbour and in small 

 numbers. Very few of these were perfect 16-celled colonies, most of them having 

 had one or two of the cells injured and killed by some means before reaching 

 maturity. It is fairly plentiful in some parts of Canada, but it is not common 

 in these arctic collections and does not appear to be generally found in arctic 

 regions. 



Eudorina Ehrenb. 

 Eudorina elegans Ehrenb. 



This was the only member of the Volvo caceae which was common in algal 

 collections. It occurred in the plankton and other collections frorxi the lake at 

 Teller and from Bernard harbour. It was also present in the brackish pond at 

 Teller, and in collections from the Hippuris swamp at Herschel island, from 

 Chantry island, and from Cape Bathurst. 



Volvox (L.) Ehrenb. 

 Volvox aureus Ehrenb. 



Only one specimen of this beautiful alga was observed. It was in the 

 material from the Hippuris swamp at Herschel island. Diameter of coenobium 

 300m; daughter cells, antheridia, and oogonia absent. It is not common in 

 arctic regions. 



PALMELLACEAE. 



Gloeocystis Nag. 



Gloeocystis infusionum (Schrank) W. & G. S. West (Plate III, fig. 5) 



This alga was by no means common, only a few cells being found in any 

 one collection. It occurred in the big lake at Bernard harbour, at Chantry 

 island, and at Cape Bathurst. I cannot find any previous record for the North 

 American continent or arctic regions for this species. Size, with integument, 60^ 

 in diameter; cell 21m- 



AUTOSPORACEAE. 



Oocystis Nag. 

 Oocystis solitaria Wittr. 



This was the only species of this genus and occurred in plankton and bottom 

 deposits of the lake at Teller. It was also present in much less quantity at 

 Bernard harbour. 



Nephrocytium Nag. 



Nephrocytium obesum W. West (Plate IV, fig. 17) 



This was only once observed, three plants being found in the plankton at 

 Bernard harbour, July 3, 1916. It is the first record for the American continent 

 and for the arctic. 



Tetraedron Kiitz. 



TetraSdron enorme (Ralfs) Hansg. 



This species appeared in small numbers in the material from the Hippuris 

 swamp at Herschel island and was not observed elsewhere. It has not been 

 previously recorded from the arctic regions of America. 



