Fresh Water Algae in Vicinity of Montreal 413 



Cosmarium Botrytis, Menegh. 



Cells nearly twice as long as broad, sinus nar- 

 rowly linear, semi-eells with nearly straight 

 base inclining to reniform, sides converging 

 from inferior rounded angles to truncate end. 

 Cell-wall granular. Diam. 35-36 micr. 



Verdun, Amherst Park. 



Micrasterias americana, (Ehrenb.) Ralfs. 



Semicells three-lobed, lateral lobes broad margins, 

 incised serrate, subdivisions narrow and dentate 

 at extremities. Diam. 100-115 microns. Length 

 one-third greater. 



Verdun, Amherst Park. 



Family 2. Zygnemacege. 

 Zygnema Vaucherii, Ag. 

 Cella 10-22 micr. 2y 2 or 3 to 5 times as long as 



broad. 

 Zygospores subglobose or broadly elliptical. 

 Verdun. 



*Zygnema insigne, Kutz. 

 No fruiting material. Vegetative cells 26-30 micr. 



diam. Length equal or up to 2 diam. 

 Verdun. 



*Spirogyra fluviatilis, Hilse. 



Filaments 36 micr. diam. cells 5-6 diam. long. 



Chromatophores, slender, very pale green, making 

 l 1 /2-2Mi turns in the cells. No fruiting material ; 

 found sterile attached to stones; formed rhi- 

 zoids when cultivated in water, in laboratory. 



Amherst Park, Back River. 



*Spirogyra setiformis, Kutz, of Collins or 

 Spirogyra orbicularis of Cooke. 

 Cells 110-140 micr. diam. about as long as broad, 4 



