344 Wisconsin Academy of Sciences, Arts, and Letters. 
var. apiculata forma spinosa (Bisset) W. & G. S. West 
Brush (rrr), Long (1) (rrr), Pennsylvania (rrr). 
Ml CRASTERIAS sol (Ehr.) Ktz. 
Big Dudley (rrr), Burned Rock (rrr), Otter (rrr), Rowley (rrr). 
var. ornata (Nords.) W. & G. S. West 
Corner (rrr), Otter (rrr). 
var. ornata forma elegantior G. S. West 
Echo (rrr), Muskoka (rrr). 
Micrasterias radi at a Hassall 
Clear (2) (rrr). Little Dudley (rrr). 
var. simplex (Wolle) comb. nov. PL IX, figs. 1-5. 
Micrasterias furcata var. simplex Wolle. Bull. Torrey Bot. Club. 12: 
128. PI. 51, figs. 6, 7. 1885. 
Big Dudley (rr), Black (1) (r), Brush (rrr), Hamer (rr), Long 
(1) (rr), Nelson (rrr), Otter (rrr), Round (2) (rr), White (rrr). 
The great variation in the subdivision of the lateral lobes of 
this species is well known to all students of the group. Johnson 
has studied these variations (Bot. Gaz. 19: 58-60, PI. 6, figs. 7-13 
1894) and reached the conclusion that it is impossible to recognize 
any of the varieties which have been based upon this reduction 
in the number of lateral lobes. The Wests in their Monograph 
of the British Desmidiacaeae (2:114—115) arrive at the same con¬ 
clusion. 
In the collections that I have made from Ontario lakes the re¬ 
duction in the branching of the lateral processes to a simple bifur¬ 
cation is the predominant type. Although there are variations 
from this in that some of the semicells approach the typical M. 
radiata. I feel that the variety with the reduced number of 
lateral branches is sufficiently distinct to warrant recognition and 
that Wolle was justified in establishing the variety simplex. 
var. gracillima var. nov. IX, figs. 6-11. 
Semicells with a single lateral process that is deeply incised to 
form two divergent branchlets. Unbranched portion of lateral 
lobes much narrower than in var. simplex and with sides sub- 
