Freshwater Algae 23 A 



Gosmarium Botrytis Menegh. 



This is probably the most generally distributed species of this genus and 

 was the commonest desmid in the collection. It was usually a little below 

 average size, although there were a few as large as any I have found in other 

 parts of Canada or Great Britain. It occurred in collections from Teller, 

 Demarcation point, CoUinson ' point, and from Bernard harbour, Herschel 

 island, and Cape Bathurst. 



Cosmarium conspersutn Ralfs 



This species was also fairly plentiful wherever found. It occurred at Teller 

 and Demarcation point, and at Bernard harbour and Herschel island. 



Gosmarium contractum Kirchn. var. ellipsoideum (Elf.) W. and G. S. West 



(Plate III, fig. 17) 

 The type form of this species has been recorded from the United States. 

 It is. more tropical than northern. The variety recorded here from Herschel 

 island has not previously been recorded from the North American continent, 

 -but it is more northern than the type and has been found in arctic regions 

 outside America. 



Cosmarium costatumi Nordst. 



This is a rare and typically arctic and alpine desmid. It was found in the 

 plankton collection of Jiily 3, 1916, from the big lake at Bernard harbour. 



Gosmarium crenatum Ralfs 



This also is a desmid common in arctic and alpine collections. It was 

 fairly comipon in the lagoon lake at Teller, but was found in no other locality. 



Cosmarium Gucumis (Corda) Ralfs (Plate IV, fig. 1) 



This species is world-wide in its distribution, although not recorded from 

 North America. It has been found in Greenland. It was found by the expe- 

 dition in the lake at Teller. Rare. 



Gosmarium Cucurbita Br6b. var. attenuatum G. S. West (Plate III, fig. 8) 



This variety has a very limited distribution. The type form is fairly 

 universal, but this variety has only been recorded from England, Germany, 

 and the West Indies. It was found in the, plankton of the big lake at Bernard 

 harbour, where it was very abundant. All specimens were small and about 

 same size, length 26ju, breadth 15/x- 



Cosmarium cyclicum Lund. var. Nordstedtianum (Reinsch) W. and G. S. 

 West (Plate III, fig. 18) 



This is another variety with a vfery limited distribution, being recorded 

 previously only from England, Ireland, Austria and North Russia. The type 

 form is fairly common in the north and has been found in Greenland, Spitz- 

 bergen, and the United States of America. A few individuals of the variety 

 were found in the Hippuris swamp at Herschel island. 



Cosmarium globosum Bulnh. (Plate IV, fig. 7) 



This rather small desmid occurred in the lagoon lake at Teller, where it 

 ^as fairly plentiful. Most specimens were a little below average size. 



