25 



Fig. 15. Cyclotella bodanica , (4), cells 20-80u in diameter; 

 an isolated puncta occurs at the inner end of 

 several shortened marginal costae. X 1000. In 

 Great Lakes . 



Notes : 



Fig. 16. 



girdle view 



Cyclotella comta , (k) , cells 

 15-20u in diameter; similar to 

 C. bodanica but lacking punctae 

 at the end of shortened costae. 

 X 1000. In Great Lakes. 



valve view 



valve view 



Notes : 



Fig. 17. 



Cyclotella glomerata , ( 3) , cells 

 4-10u in diameter; forming 

 chains; often seen in girdle 

 view. X 1000. In Great Lakes. 



Notes : 





