Freshwater Diatoms 41 a 



Cymbella gastroides Kiitz. var. minor H. V. H. 



This variety was rare when compared with the species; it was found in the 

 brackish pond and lagoon la;ke at Teller, and in the plankton sample, September, 

 1915, at Bernard harbour. 



Cymbella ventricosa Ag. 



This species was found only in one locality but was very plentiful. It was 

 obtained from the bed of the warm creek near the Sadlerochit river. 



Cocconema Ehr. 



Coccpnema lanceolatum Ehr. 



This diatom was by no means common, occurring only in small numbers 

 at Teller, August, 1913. Most specimens were below average size. 



Naviculoideae. 



Stauroneis Ehr. 

 Stauroneis Gregorii Ralfs 



This species is typically a brackish one and was found in the brackish pond 

 and a tundra pond at Teller, August, 1915. 



Stauroneis Phoenicenteron Ehr. 



This species was found only in the big lake at Bernard harbour, where it 

 appeared in one mud sample and one plankton collection. 



Stauroneis Smithii Grun. 



This species occmred in small numbers in the lagoon lake at Teller. 



Navicula Bory. 

 Navicula aspera Ehr. 



This is a marine species which was found in a mud sample taken from under 

 the ice of the big lake at Bernard harbour, February, 1916. Only a few specimens 

 were observed. 



Navicula Bombus Ehr. 



Although a marine species this diatom was not uncommon in three samples 

 obtained from the lagoon lake at Teller, July and August, 1913. 



Navicula borealis Ehr. 



This species occurred in two July collections from the lagoon lake at Teller. 

 It is a freshwater diatom. 



Navicula Braunii Grun. 



This species occurred in the same collections as the last mentioned one. 

 Both species were very infrequent. 



Navicula Crabo Ehr. 



This is a marine species which was found only in the brackish pond at 

 Teller. Not common. 



Navicula didyma Ehr. 



This is another marine species found only in collections from Teller. 



