antheridium distinctly circinate, terminal on the branch; oogonia 

 usually 3 (2-4), ovoid, somewhat oblique on rather long stalks 

 (up to 1500/a) arising from just below the antheridium, 35-40;a in 

 diameter, 70-85/x long. 



In pooled streams and quiet water of lakes. Wis. 



Vaucheria Nichohii Brown 1937, p. 283 

 PL 67, Fig. 10 



Filaments very coarse, 112-120/a in diameter; monoecious; oogonia 

 globose, sessile, the opening vertical, 262-289|U, in diameter; oospore 

 the same shape as and filling the oogonium (except the beak), 

 yellow-brown; antheridia sessile, arising from all sides of the main 

 filament near the oogonium and recurved so as to lie parallel with 

 the filament and opening toward the oogonium, 39-50/x wide, 

 115-123/tlong. 



Shore of Douglas Lake, Michigan. 



Vaucheria orthocarpa Reinsch 1887, p. 191 

 PI. 67, Fig. 1 

 Filaments slender to moderately coarse, 77-1 10/x in diameter; 

 monoecious; oogonia sessile, ovoid, erect with the opening vertical; 

 oospore ovate, completely filling the oogonium, the wall thick, 

 50-65/x in diameter, 65-90ju long; antheridia sessile, arising near 

 the oogonia, distinctly coiled, with the opening directed toward 

 the oogonium. 

 Mich. 



Vaucheria pachyderma Walz 1866, p. 146 

 PI. 67, Fig. 2 

 Filaments variable, slender or stout, 40-123/^ in diameter; monoe- 

 cious; oogonia mostly solitary, globular or transversely ellipsoid, 

 the opening horizontal, or downwardly oblique, the wall thick, up 

 to 6^, with discolored spots, 69-l60iJ. high, 69-220/x long; oospore 

 filling the oogonium, 145/a in diameter, 180;a long, with a thick 

 wall; antheridium erect beside the oogonium, hooked at the apex. 

 Mich. 



Vaucheria pohjsperma Hassall 1843, PI. 6, Fig. 6 



PI. 67, Fig. 13 



Filaments very slender, 15-33/;, in diameter; monoecious; oogonia 



in a series of 3-5, each on a short pedicel, ovate, opening upwardly 



oblique, 60-65;Lt in diameter; oospores globose, filling the oogonium 



in width only, 44-60.5/x in diameter; antheridia cylindrical, sessile 



on a short pedicel, strongly reflexed and opening toward the oogonia. 



Mich. 



[293] 



