globose; operculate; division median; (28)-33-39jU in diameter 

 33-40- (43) /A long. Oospores depressed-globose; nearly filling the 

 oogonia; wall smooth; 27-31/x in diameter, 23-27ja long. Antheridia 

 9-12/A in diameter, 6-1 0-( 11.7 )/x long. 



Our plants seem to belong here, although the vegetative cells 

 are slightly larger than described for this species and the oospores 

 sometimes do not completely fill the oogonia. 



In a ditch through a Sphagnum bog. Wis. 



Oedogonia pusillum Kirchner 1878, p. 59 

 PI. 37, Figs. 11, 12 



Macrandrous; monoecious or dioecious. Vegetative cells cyhndric, 

 6/A in diameter, (10)-25-50-(60)/i, long; basal cell hemispheric. 

 Oogonia solitary; subbiconic-elhpsoid to subbiconic-globose, with 

 a shght median constriction when mature; operculate; division 

 median; 14-16/>i in diameter, (15)-20-25jti long. Oospores broadly 

 ellipsoid, but deeply constricted in the median portion; wall smooth; 

 11-13/x in diameter, (13)-14-15-(16);u long. Antheridia S-4fx in 

 diameter, 5-6/a long. 



On aquatic vegetation in swamps and ditches. Mich., Wis. 



Oedogonium pyriforme Wittrock 1875, p. 39 

 PI. 34, Figs. 5, 6 



Macrandrous; monoecious. Vegetative cells cylindric, 13.6-15- 

 (16)/x in diameter, (48)-74-80-(90)ja long. Oogonia solitary; 

 pyriform; operculate; division superior; 40-44.8-(46)/>t in diameter, 

 (44)-52.6-(60)/x long. Oospores usually filling the oogonia and of 

 the same shape; wall smooth; (36)-40-42/x in diameter, (36)-40-44/x 

 long. 



On grass and Eleocharis in soft water lakes. Wis. 



Oedogonium Reinschii Roy in Cooke 1883, p. 160 

 PI. 34, Figs. 1-3 



Macrandrous; monoecious. Vegetative cells subellipsoid to hexa- 

 gonal or fusiform, especially the latter shape in the lower portions 

 of the filament; (5)-7.5-8-(ll)/* in diameter, 8.5-19.2- ( 24 )/a long. 

 Oogonia 1-2; pyriform-globose; operculate; division median; (17)- 

 19-20/A in diameter, 15-21-(22.8)/a long. Oospores depressed-globose; 

 not filling the oogonia longitudinally; wall smooth; (13)-15-18ha in 

 diameter, 14-15-(17)jli long. Antheridia 4-9.5/x in diameter, 9-11.4/x 

 long. 



This species was found to be in a reproductive state in several 

 places during August. It is one of the few species of the genus 



[193] 



