416 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 10 



Genus actinastrum Lagerheim 



Actinastrum Hantzschii Lag. 



Wheeler's Pond, I; South Free Peoples Lake; North Washing- 

 ton Lake; Coe Lake; pond, southwest of Brush Lake; South 

 Washington Lake; Creel Bay, Devils Lake. 



Family Hydrodictyaceab 



Genus pediastrum Meyen 

 Pediastrum boryanum (Turp.) Menegh. 



Cut-off Pond, Stump Lake; Lake Metigosche; Jarves Lake; 

 Strawberry Lake; Carpenter Lake; Lake O; East Lake; Lake A; 

 Lamoreau Lake; Odessa, I; Eastgate's Pond; South Free Peoples 

 Lake; Willow Lake; mouth of Minnewaukon Bay and Creel 

 Bay, Devils Lake, below grade; Gordon Lake; Dion Lake; pond 

 south of Brush Lake; Juanita Lake; Crooked Lake; Spiritwood, I, 

 Bay; Brush Lake; Buffalo Lake; Florence Lake; Wood Lake 

 Long Lake, near Ruso; Clear Lake; Lake Isabelle; Lake X 

 Lake Etta; Tokio Lake; Lake Williams; Spiritwood Lake, II 

 pond southwest of Brush Lake ; South Washington Lake ; Ensigi 

 Lake; Lake Y or South Twin Lake, near Robinson; Lake C; Lake 

 P; Mission Lake. 



In many cases the two processes of each outer cell of the 

 coenobium, although distinctly side by side, did not lie in the 

 same plane, the one being in a much lower level than the other. 

 They were not arranged, however, vertically, one above the other 

 as in P. Kawraiskyi Schmidle. 



Var. longicorne Racib. 



Juanita Lake. 



P. duplex Meyen. 



Jarves Lake; Crow Lake; Carpenter Lake; Wheeler's Pond, I; 

 Spiritwood Lake, I; Buffalo Lake; North Twin Lake, near Wing; 

 Red Willow Lake; Long Lake, near Ruso; Coe Lake. 



Var. clathratum (A. Br.) Lagerh. 



Strawberry Lake; W T heeler's Pond, I; Juanita Lake; Brush 

 Lake. 



Var. gracillimum W. & G. S. West. 



Strawberry Lake; Carpenter Lake; Gordon Lake; Florence 

 Lake; Lake Williams. 



