Oedogonium oelandicum var. contortum Prescott 1944, p. 355 



PI. 42, Figs. 1-3 



A variety differing from the typical by its contorted filaments 

 which sometimes form short spirals, several of which may occur in 

 one filament. Vegetative cells 11-12^ in diameter, distinctly capi- 

 tellate. Oogonia much shorter than wide; depressed-globose; 29-30/x 

 in diameter, 20-21. 5/x long. Oospores depressed-globose; the wall 

 smooth; 25-27/a in diameter, 18-20/x long. Dwarf male plants 

 unicellular; on the oogonia. 



Attached to grass in small lakes. Wis. 



Oedogonium rugulosum Nordstedt 1877, p. 28 

 PI. 44, Figs. 14, 15 



Nannandrous; gynandrosporous. Vegetative cells cylindric, (4)- 

 8-9.5fi in diameter, (10)-11.7-19.5-(35)/i, long. Oogonia solitary 

 (rarely 2 together); ellipsoid or globose-ellipsoid; operculate; di- 

 vision superior; (16)-20/x in diameter, (22)-25.4-29/i, long. Oospores 

 globose or subglobose; wall smooth; 15-17.5- ( 18 ))ut in diameter, 

 17.5-19.7- ( 25 )jLi long. Dwarf male plants short; on the oogonia. 

 Antheridia exterior, 5fi in diameter, 6/a long. Basal cell of female 

 filament 7.8/i, in diameter, 1 1-13.6- ( 14) /a long. 



In a roadside fosse. Mich., Wis. 



Oedogonium rugulosum fa. rotundatum ( Him ) Tiffany 



1936, p. 169 

 PL 39, Figs. 9, 11, 12 

 Vegetative cells cylindric or slightly capitellate, 5-6.8-(8))U, in 

 diameter, 27-30-(31 )^ long. Oogonia 1-3; ovate or globose-ellipsoid; 

 division superior; ( 19 ) -20-23- ( 30 );« in diameter, (20)-29^0/aong. 

 Oospores globose or ellipsoid-globose; nearly filling the oogonia; 

 wall smooth; 18-20- (22) /a in diameter, 22-25^ long. 



Our plants are in agreement with this variety except that the 

 cells have a tendency to be capitellate. 

 With the typical plant. Wis. 



Section 10 

 Nannandrous — Idioandrosporous or Gynandrosporous — Operculate 



Oedogonium acrosporum DeBary 1854, p. 47 



PI. 41, Fig. 7 



Nannandrous; gynandrosporous or idioandrosporous. Vegetative 



cells cylindric, (.12)-15-19.5-(21)/. in diameter, (34) -40-68- (125)^ 



long. Oogonia solitary; ellipsoid; terminal; wall ridged internally 



[ 207 ] 



