358 Wisconsin Academy of Sciences , Arts , and Letters. 
McGowan (rr), Mill (rrr), Mud (rr), Muldrew (s), Muskoka (s), Nel¬ 
son (rrr), Rosseau (rrr), Round (2) (r), Rowley (s), Silver (1) (r), 
Vernon (c), White (rrr). 
In view of Wolle’s rather diagrammatic figure of this variety, 
the determination rests upon the figure given by the Wests. The 
specimens that I have observed are not so long as the Wests state, 
and the breadth of the semicells with the processes may also be 
less. I have found the alga in quantity in several lakes without 
finding a single five-rayed individual and think, therefore, that it 
is a distinct variety. In some collections both four- and five- 
rayed individuals are present, but I consider this a mingling of 
the widespread type and variety and not a normal variation of 
the type. 
The twisting of the semicells 30 that the rays of one semicell 
are equidistant between the rays of the other semicell is a constant 
character and furnishes another distinction between this species 
and S. Ophmra. 
forma major forma nova. 
Processes much longer than in the -foregoing, body of semicells 
of the same size as in the variety. 
Breadth (with processes) 145-155 /x. 
Round (2) (r). 
Staurastrum ankyroides Wolle PL XIII, figs. 13-15. 
Bull. Torrey Bot. Club 11; 14. PI. U, fi9- 4- 1884; Desmids of the United 
States 137. PI. 51, fig. h. 1884. 
Length 60-68 /x; breadth (without processes) 20-24 /x, (with 
processes) 92-132 /x; breadth isthmus 11-13.5 /x. 
Brush (rr), (Burned Rock (r), Butterfly (ss), Echo (rrr), 'Gull (1) 
(rrr), Nelson (ss), Nine Mile (rr), Little Dudley (r), Marion (rrr). 
Silver (1) (rr). 
This species has not been noted since Wolle’s discovery of it in 
1884. I have found an alga in the plankton of Ontario which I 
believe is the organism that Wolle described. It is four-rayed, 
with the rays of the two semicells alternating with one another. The 
ornamentation of the rays is very similar to that of S. Oplniura, 
but the ornamentation of the apex is quite different, there being 
four heavy semicircular verrucae with four exterior lobes. The 
