26 A Canadian Arctic Expedition, 1913 — 1918 



areas form two groups — a polar group of 12-14 areas and a band next to the 

 sinus of 18-22 areas, 7-11 seen on one side. Each elevated area, from smus 

 to pole, bears 4-5 pairs of scrobiculations and often an unpaired terminal one. 

 This is a peculiar type of desmid without any close relation to other species. 

 In possessing canal-like depression with scrobiculate elevated areas it is distinct 

 from other species of this genus. Only a few plants were seen in the material 

 collected from the creek at Bernard harbour, August 16, 1915. 



at. 



Fig. 3. Cosmarium Stefanssonii nov. sp. X 840; a, face view, b, end view. 



Cosmarium subcostatum Nordst. 



This is a small desmid. It occurred in the plankton of the lake at Bernard 

 harbour, and in the swamp at Herschel island. It closely resembles C. subcren- 

 atum which is also found at Bernard harbour. The crenulations were almost 

 wanting at the apex and they were generally bi-granulate in other places. 

 Central granules 14-16. 



Cosmarium subcrenatum Hantzsch 



This is a species of world-wide distribution. It was found in small quantities 

 in two localities, from the bottom of a tundra pond at Collinson point, and with 

 other desmids in the river bed at Bernard harbour. 



Cosmarium Subcucumis Schmidle (Plate IV, fig. 2) 



This species is interesting on account of its limited distribution, for hither- 

 to it has been recorded only from Great Britain, Germany, and Austrian Galicia. 

 It was found in the collection from the Hippuris swamp at Herschel island. 



Cosmarium subexcavatutn W. and G. S. West 



This desmid has been recorded from Nova Zembla and Greenland, so it is 

 not surprising that it should turn up in the Canadian arctic. In the pond in 

 a swamp in the second bay east of Bernard harbour. It was not very plentiful. 



C. subexcavatutn var. ordinatum W. and G. S. West (Plate III, fig. 10) 



Amongst the individuals of the last-mentioned species was one which was 

 less granulate and longer than the typical form and identical with West's figure 

 of the var. ordinatum, so that I have no hesitation in recording this variety, 

 although it has only been recorded previously from Switzerland and England. 



Cosmarium subtumidum Nordst. var. Klebsii (Gut.) W. and G. S. West. 



(Plate IV, fig. 5) 

 There is little difference between the species and its variety, but the 

 specimens from the north were identical with some specimens I collected in 

 Lake Winnipeg, Manitoba, and which the late Professor G. S. West immediately 

 identified as the variety Klebsii. It was fairly common at Bernard harbour in 

 plankton and bottom deposits and in a drying tundra pond at Demarcation 

 point. 



