Freshwater Algae 31 a 



Staurastrum polymorphutn Ralfs 



This species is a common one in all parts of the earth, and in the collections 

 made by the expedition was, in its genus, only second in abundance to S. punctu- 

 latum. It was found at Teller, in the big lake and in the river at Bernard 

 harbour, and in the swamp at Herschel island. Three- and four-sided forms 

 were about evenly distributed. 



Staurastrum polytrichutn Pert. 



This very spiny desmid was found in small quantity in the material 

 collected from the Hippuris swamp at Herschel island. It has not been 

 previously recorded from the arctic regions of America. 



Staurastrum punctulatum Br^b. 



This was found in larger numbers and in more localities than any other 

 species of its genus. At Teller it occurred in the lagoon lake, the brackish pond, 

 and in the pond between the lake and sea. It was also found at Demarcation 

 point and Collinson point, at Bernard harbour, and on Herschel island. 



Staurastrum Reinschii Roy ' (Plate IV, fig. 8) 



This species is one of those found only at Herschel island. It is common 

 in Europe generally but not in arctic waters. It was not very plentiful. A 

 number of empty semi-cells were found, but very few complete plants. 



Staurastrum setigerum Cleve 



Like the last species, this also was found only at Herschel island, and it 

 was moderately frequent. It is common in the United States of America and 

 occurs also in Manitoba. 



Staurastrum vestitum Ralfs 



This is another species collected only from the Hippuris swamp at Herschel 

 island. It was a little below average size and about as common as the last 

 species. It is well known in Europe and the United States but is not previously 

 known from arctic America. 



Sphaerozosma Corda. 



Sphaerozosma excavatum Ralfs 



This filamentous desmid appeared only from Herschel island and was not 

 abundant. It has been previously found in Alaska and is not uncommon in 

 the arctic. Cells slightly below average size. 



Spondylosium Br 6b. 

 Spondylosium planum W. & G. S. West 



This is a desmid fairly abundant in the United States and in some parts 

 of Canada but is not frequent in arctic regions. It appeared only in bottom 

 deposits from the lake at Teller, in short filaments of usually not more than 

 eight cells. Not common. Size: 11^ wide, 9/i long. 



Hyalotheca Ehr. 

 Hyalotheca dissiliens (Smith) Br 6b. 



This species was found only at Herschel island, in the Hippuris swamp. 

 It is well known from some arctic regions but not from those of the American 

 continent. The cells of the filaments were of the average size. 



