Oedogonium sinuatum (Trans.) TiflFany 1934, p. 325 



Nannandrous; idioandrosporous. Vegetative cells undulate (with 

 4 undulate constrictions), (13)-19-26/i, in diameter, 48-1 10/x long. 

 Oogonia 1-2, subglobose or ellipsoid-globose; operculate; division 

 inferior; 56-68/a in diameter, 45-80/a long. Oospores globose; not 

 filling the oogonia; wall smooth; 42-60/* in diameter, 42-56/i long. 

 Dwarf male plants elongate-obconic, on the suflFultory cell. (Typical 

 plant not found in our collections. ) 



Oedogonium sinuatum fa. seriatum Prescott 1944, p. 354 



PI. 40, Fig. 2 



Vegetative cells undulate and capitellate, with 4 median undula- 

 tions; 22-25/t in diameter, 48-59.2-(140)/t long. Oogonia in series 

 of 4 or 5; operculate; division inferior; 62-67/a in diameter, 62-12fx 

 long. Oospores globose; not filling the oogonia; wall smooth; 55.5/*. 

 in diameter. Dwarf male plants usually crowded on the suffultory 

 cell. Antheridia exterior (?), 10.9/u, in diameter. 



This form has some features resembling Oe. undulatum, with 

 which it should be compared. The principal difference is the seriate 

 arrangement of the oogonia in our specimens. 



Attached to overhanging grass in a Sphagnum bog ditch. Wis. 



Section 9 

 Nannandrous — Gynandrosporous — Operculate 



Oedogonium ambiceps ( Jao ) Tiffany 1937, p. 79 

 PI. 37, Figs. 7-9 



Nannandrous; gynandrosporous. Vegetative cells distinctly capi- 

 tellate, (9)-12-13/x in diameter, 22-42/1 long. Oogonia solitary, 

 depressed-globose, with 8-10 median longitudinal bulges separated 

 by narrow creases, or sometimes by broad depressions; operculate; 

 division inframedian; 32— 37— (38) /i in diameter, ( 19 ) — 29.6— 33/i 

 long. Oospores depressed-globose; nearly filling the oogonia; wall 

 thick, smooth; (19)-26-33/t in diameter, (19)-25.9-27/x long. 

 Dwarf male plants not observed. Androsporangia 11— 13/i, in diam- 

 eter, 4/1 long. 



The absence of dwarf male plants from our specimens and the 

 small proportions of the androsporangia make it possible to confuse 

 this with some other monoecious species, but the distinctive form 

 of the oogonium and its markings, together with the gynandrous 

 condition, are helpful in identification. 



Attached to logs. Wis. 



[203 ] 



