division median (to supramedian in our specimens); 12.5-13- ( 18 )/x 

 in diameter, 1 1-12.5- ( 23 )/x long. Oospores depressed-globose; nearly 

 filling the oogonia; wall smooth; (12)-14-17/>i in diameter, (8)-ll- 

 12fx long. Antheridia ( ?) . 



This species is one of the smallest in the genus. It frequently is 

 found growing on filamentous algae, especially on other species of 

 Oedogonium, on Nitella, and on Chara. Our collections show a great 

 deal of variation in the plant in respect to form of vegetative cells, 

 the length of filaments, and the shape of oogonia. Some of the 

 smaller expressions of Oe. tapeinosporum are scarcely differentiated 

 from Oe. inconspicuum. Both of the species are imperfectly known. 



Common in many soft water lakes and bogs. Wis. 



Oedogonium iotvense Tiffany 1924, p. 181 



PL 35, Figs. 1-3 



Macrandrous; dioecious. Vegetative cells cylindric, 10-16- (18.5) /a 

 in diameter, ( 44 ) -74-99- ( 100 )/x long. Oogonia solitary (sometimes 

 2 together); ellipsoid; operculate; division superior; 52-60|a in 

 diameter, 60-80ju, long. Oospores ellipsoid; usually not filling the 

 oogonia; wall smooth; 45-52- (56)//. in diameter, 50-64- (68.4)//, long, 

 Antheridia 1-4, 10-12- ( 14.8 )/x in diameter, 8-10-(20)/t long; anther- 

 zoids 2; division horizontal. 



Attached to submerged vegetation. Wis. 



Oedogonium latiusculum (Tiff.) Tiffany 1924, p. 182 



PI. 44, Fig. 3 



Macrandrous; dioecious. Vegetative cells capitellate, (10)-12-16- 

 (18)/x in diameter, (16)-20-38-(40)/x long. Oogonia solitary (or 2 

 together); subglobose to pyriform-globose; 32-36/i, in diameter, 

 31.5-32- ( 40 )/i long; operculate; division median. Oospores globose; 

 not filling the oogonia; wall smooth; 28-30-(32)/u, in diameter, 

 (28)-30-34/x long. Antheridia (14)-16-18/i in diameter, 14-18/;i 

 long. 



In a ditch through a Sphagnum, bog. Wis. 



Oedogonium, microgonium, Prescott 1944, p. 353 



PI. 36, Figs. 11-14 



Macrandrous; dioecious (?). Vegetative cells distinctly capitellate, 



8-9.5/1 in diameter, 18-33/x long; basal cell elongate, 16-18.5/t long. 



Oogonia solitary (rarely 2 together); very little wider than the 



vegetative cells; globose or depressed-globose; operculate; division 



[184] 



