PEDIA6TRTJM. 155 



Pediastrum Ski.kx/t.a. Kg. 



Coenobium orbicular; cells cresent-shaped, arranged in one 



or more circle- round one or two central cells. 



A form reported by Bailey from Rhode Island. 

 P. OON8TRICTUM, Ha--. 



Conobium nearly orbicular, continuous, composed of 1632 

 c.|l- ; cells of the periphery two lobed, or suddenly contracted 

 into two short cylindrical, obtuse process -. 



Bailey reports this species fr South Carolina, < reorgia 



ami Rhode Island. It i.- very nearly allied to Boryanum and 

 is probably a variety of that Bpec 



