36 A Canadian Arctic Expedition, 191S-1918 



Melosira Ag. 

 Melosira granulata (Ehr.) Ralfs 



This is a typical plankton diatom in the lakes of the Dominion. It was 

 found in the plankton of the lagoon lake at Teller, July and September, 1913, 

 and in a tUndra pond at CoUinson point, June, 1914. 



Melosira undulata Ehr. 



This species was found in a collection of bottom deposits and plankton 

 from the lagoon lake at Teller, August, 1913, and in a plankton sample taken 

 from the big lake at Bernard harbour, September, 1915, and in a mud sample 

 from the same place, February, 1915. 



Melosira varians Ag. 



A few short filaments of this species were found attached to other plants 

 in a collection -from a tundra pond at Teller, August and September, 1913. 



Cyclotella Kutz. 

 Cyclotella antiqua W. Sm. 



This pretty little diatom was not very numerous in any one locality but 

 was present in many collections. It occxured in the brackish pond at Teller, 

 August, 1913, and in the plankton from the big lake at Bernard harbour in the 

 months of July and August, 1915, and February, June and July, 1916. It was 

 also attached to the Ophrydium mass taken from the same lake, August, 1915. 



Stephanodiscus Ehr. 

 Stephanodiscus niagarae Ehr. 



This common American diatom was found only in the mud sample from 

 under the ice taken in February, 1916, at the big lake at Bernard harbour. 

 Only a small number were present. 



Tabellarieae. 



Grammatophora Ehr. 



Grammatophora angulosa Ehr. 



This is another marine species found in the big lake at Bernard harbour in 

 the mud sample taken February, 1916. Its presence here is probably.accidental. 



Tabellaria Kiitz. 



Tabellaria fenestrata (Lyng.) Kiitz. 



This is a common plankton diatom. It was found in collections of plankton 

 from the lagoon lake. Teller, July and August, 1913. At Bernard harbour it 

 was in the lake plankton in June, 1916, August and September, 1915. It was 

 taken at the creek mouth, July, 1915, in the same locality, and at Herschel 

 island in the Hippuris swamp, August, 1914. 



Tabellaria flocculosa (Roth) Kutz. 



This species was about as frequent as the preceding one. It was found at 

 Teller, July, 1913, in the lagoon lake, and August of the same year in a tundra 

 pond, also at Martin point in a tundra pond, in the plankton of the lake at 

 Bernard harbour, August, 1915, and in the stomach of a fish taken October 4, 

 1915. 



