Oedogonium pisanum Wittrock 1876, p. 50 

 PI. 36, Figs. 8,9 



Macrandrous; dioecious. Vegetative cells cylindric, (5)-6-7.5-(12)/x 

 in diameter, (12)-14.8-18-(72)ja long. Oogonia solitary; ellipsoid- 

 ovate; operculate; division superior; 20-29-(32)//, in diameter, 34-45/^. 

 long. Oospores globose; nearly filling the oogonia; wall smooth; 

 18-21-(25)/x in diameter, 18-26-(37)/a long. Antheridia 8/x in 

 diameter, 6-8/x long. 



In a small lake among sand hills. Wis. 



Oedogonium poecilosporum Nordstedt & Him in Hirn 1900, p. 298 



Macrandrous; dioecious or monoecious (?). Vegetative cells cy- 

 lindric, 6-8ja in diameter, 20-47/a long. Oogonia 1 or 2; ellipsoid to 

 depressed-globose; operculate; division median and wide; 24-28/x 

 in diameter, 25-28/x long. Oospores ellipsoid to depressed-globose; 

 nearly filling the oogonia; wall smooth; 23-26/a in diameter, 21-28/x 

 long. 



Mich. 



Oedogonium porrectum Nordstedt & Hirn i^i Hirn 1900, p. 186 



PL 36, Figs. 6,7 



Macrandrous; dioecious. Vegetative cells cylindric, 5.8-8-(10)/a in 

 diameter, 23-29- (55) /a long. Oogonia solitary; ellipsoid or oblong- 

 ellipsoid; operculate; division superior; 19.5-22- ( 27 )/x, in diameter, 

 ( 27.3) -39-44- ( 53 )ju, long. Oospores ellipsoid; not filling the oogonia; 

 wall smooth; (17.5)-18-24jii in diameter, 25-27.3- ( 28 )iu long. 

 Antheridia 6-7 fx in diameter, 6-8/x long. 



Our specimens are slightly smaller in the diametric dimensions 

 of the oogonia and of the oospores but otherwise seem to agree 

 with this species. 



In shallow water of swamp. Wis. 



Oedogonium pratense Transeau 1914, p. 297 

 PL 36, Figs. 4, 5 

 Macrandrous; dioecious. Vegetative cells cylindric, 9.2-1 1.7-(17)/a 

 in diameter, 24-35- (95) /a long. Oogonia solitary; globose or 

 subpyriform-globose; operculate; division median; (33)-42-44/^ in 

 diameter, (35)-42-44-(50)/i, long. Oospore globose; filling the 

 oogonium (not quite filling it in our specimens); wall smooth; 

 32-38- ( 40 )/x in diameter, (28)-36-42/x long. Antheridia lO-Ufx in 

 diameter, 13-18ju, long. 



[ 186 1 



