This dioecious plant seems to be assignable to Oe. pratense, 

 although the relatively smaller oospore (not filling the oogonium 

 completely in some specimens ) is unlike that species. 



On grass in a wooded swamp; found fruiting in both June and 

 August. Mich., Wis. 



Oedogonium Pringsheimii Cramer 1859, p. 17 

 PI. 36, Figs. 1-3 

 Macrandrous; dioecious. Vegetative cells cylindric, (14)-18-20|a 

 in diameter, 43-(100)jli long. Oogonia 1-6; globose or subovate- 

 globose; operculate; division superior; 35-39- ( 43 )/t in diameter, 

 (36)-39-42-(46)/i, long. Oospores globose; filling the oogonia; wall 

 smooth, thick; (30)-35-36-(37)/x in diameter, 35-36- ( 46 )/x long. 

 Antheridia ( 10 ) -1 5-1 6/a in diameter, (6)-8-9/>t long. 

 Common in many lakes and swamps. Mich., Wis. 



Oedogonium Pringsheimii var. Nordstedtii ( Wittr. ) Wittrock 

 in Wittrock & Nordstedt 1877, Algae Exsic. No. 8, p. 22 



PI. 38, Figs. 9, 10 

 A variety smaller than the typical plant. Vegetative cells 9.5-10)u 

 in diameter, 48-55/i, long. Oogonia Slfx. in diameter, 42.5/u, long 

 Oospores 33.3/x, in diameter, 33.3-35^ lo^g- 



On grass and on Isoetes in soft water lakes. Mich., Wis. 



Oedogonium punctatostriatum DeBary 1854, p. 47 

 PI. 38, Figs. 5, 6 



Macrandrous; dioecious. Vegetative cells cylindric, 18-2?.;u, in 

 diameter, 38-128/x long; wall with spiral punctations. Oogonia soli- 

 tary, depressed-globose; operculate, the opening narrow and median; 

 the wall spirally punctate; (48)-55-(66.5)/t in diameter, 38-48- 

 (55.5) fi long. Oospores depressed-globose; wall smooth; (40)-51-56/i, 

 in diameter, 35-42- ( 48 )/x long. Antheridia 19-20- (23) /a in diameter, 

 8-14-(19)/tlong. 



Our specimens are a little larger than the size described for Oe. 

 punctatostriatum but agree otherwise. 



Oedogonium pusillum Kirchner 1878, p. 59 



Macrandrous; dioecious or monoecious. Described in the next 

 section. 



Oedogonium Sancti-thomae Wittrock & Cleve in Wittrock 1874, p. 40 



Macrandrous; dioecious. Vegetative cells cylindric, 7-15/'. in 

 diameter, 16-88/a long. Oogonia 1-3; pyriform; operculate; division 



[187] 



