bodies without a pyrenoid; pigment-spot sometimes evident; cells 

 8-10/A in diameter, 12-16/1, long. 



This species is more rarely seen than C. vesiculosum. When pre- 

 sent it produces dense green growths which are barely discernible 

 to the unaided eye on microzoa such as Crustacea. The colony 

 usually forms a plume on the head region. 



Wis. 



Colacium vesiculosum Ehrenberg 1832b, p. 115 



PL 89, Figs. 18, 19 



Cells fusiform to somewhat pyriform, solitary or 2-4 together, 



attached by short stalks to microfauna; cells 8-15|ii in diameter, 



18-25- (29)/* long; chloroplasts several to many ovoid discs without 



pyrenoids. 



Not widely distributed but common in habitats where it appears; 

 usually on Cladocera and Copepoda. Mich., Wis. 



[420] 



