640 Wisconsin Academy of Sciences, Arts, and Letters. 
Genus COELASTRUM Nageli 1849. 
CoELASTRUM MiCROPORUM Nageli. 
In Braun, Alg. Unicell. 70. 1855; Senn. Bot. Ztg. 57: 53. pL 2, -jigs. 11-17. 
1899. 
II. Browns (rr), Center (rr), Elizabeth (rr), Mary (rr), Mill (rrr), Silver 
(rr). 
III. Bear (rr), Chetac (rr), Granite (rr), Island (rr), Prairie (rrr). 
Shell (rrr), Vermilion (rr). 
CoELASTRUM CAMBRicuM Archer. 
Quart. Jour. Mier. Sci. N. S. 8: 65. 1868; W. West, Jour, of Bot. 31: 99. 
pi. 333, /. 14. 1893. 
II. Silver (rr). 
III. Beaver dam (rr), Owen (rrr), Prairie (rrr). 
CoELASTRUM RETicuLATUM (Dang.) Senn. 
Bot. Ztg. 57: 66. pi. 2, -figs. 1-10. 1899. 
II. Browns (sss). Camp (r). Eagle (rr), Mary (rr). 
III. Bear (rr), Beaverdam (rr), Birch (rrr), Lac Court Oreilles (rr), 
Eeserve (rr), Eice (rr). 
Genus SORASTRUM Kiitzing. 
SoRASTRUM AMERiCANUM (Bohl.) Schmidle. / 
Engl. Jahrb. 27: 230. Lemmermann, Arch. f. Hydrobiol. u. Planktonkde. 
5: 310. /. 5. 1910. 
Little is known concerning the manner of reproduction of this 
alga, the general assumption being that it forms autospores in 
the same manner as Coelastrum, Many of the cells of the 
colonies from Devils Lake had lost their contents through a 
silt-like opening, while the very young colonies of the variety 
undulatum were enclosed in a hyaline gelatinous envelope 
(%. 6 ). 
This suggests a formation of zoospores as in Pediastrum but 
the genus is left in the conventional place until these have been 
observed. (Plate 13, figs. 6, 8). 
III. Devils (rr). 
var. undulatum var. nov. 
Sides of base of stipe forming central sphere undulate instead 
of straight. (Plate 13, fig. 7). 
III. Beaverdam (rrr). 
