with 23-30 longitudinal ribs; operculate; division superior; (30')- 

 35-48/A in diameter, 50-63/x long. Oospores filling the oogonia, with 

 as many ridges on the membrane as the ribs on the wall of the 

 oogonia, and fitting in between them. Dwarf male plants 2 to 4 

 cells long, the stipe elongate; 2- or 3-celled; attached to the sufi^ultory 

 cell. Antheridia exterior, 7/i, in diameter, ll;u, long. 



This species is separated from its varieties mostly by the stout 

 suffultory cell and by the somewhat longer oogonia, with more 

 ridges. 



Common in several lakes and Sphagnum bogs. Wis. 



Oedogonium acrosporum var. boreale Wolle 1887, p. 84 



Vegetative cells 7.8-12/>t in diameter, 54.6-140/x long. Oogonia 

 elliptical, with 11-15 longitudinal ribs; 30-31yu, in diameter, 44-46/* 

 long. Dwarf male plants 2-celled. Antheridia exterior, 9;u, in diameter, 

 11/A long. Suffultory cell 15.6/x in diameter, 39/* long. 



In acid and soft water lakes. Wis. 



Oedogonium acrosporum, var. bathmidosporum ( Nordst. ) Him 



1900, p. 246 

 PI. 41, Figs. 5, 6 



Vegetative cells (8)-12-17]ix in diameter, 46-54-(125)/x long. 

 Oogonia with few ridges (about 18 in our specimens); thick and 

 sometimes interrupted; 27.3-30- ( 40 )/x in diameter, (37)-39-59/x long. 

 Dwarf male plants 2-celled; on the suffultory cell, which is enlarged 

 to 22;a. Antheridia exterior, 5-8-(10)/x in diameter, 9-12-(13)/x long. 



Specimens collected in Wisconsin have the characteristics of this 

 variety except that the ribs are not crenulate as originally described 

 for it. 



Common in several lakes and Sphagnum bogs. Mich., Wis. 



Oedogonium acrosporum var. majusculum Nordstedt 1878, p. 21 



PI. 41, Fig. 10 



Vegetative cells relatively longer; (14) -16-20- (21)^ in diameter, 

 50-125- ( 165 )/x long. Oogonia 45-58/* in diameter, 50-65.5- (70)/* 

 long. Oospores 46-55/* in diameter. 



Attached to grass in a ditch through a Sphagnum bog. Mich., Wis. 



Oedogonium macrospermum West & West 1897a, p. 472 



PL 41, Fig. 12 

 Nannandrous; gynandrosporous or idioandrosporous. Vegetative 

 cells cylindric, (10) -16-18.5/* in diameter, (30) -55-57- (80)/* long. 

 Oogonia solitary; subglobose; operculate; division median; (39)- 



[208 1 



