OEDOGONIUM 97 
only those specimens that conform to the above description. 
If it develops that these forms with a middle scrobiculate wall 
may also have the outer wall scrobiculate, the description will 
have to be emended accordingly. The former had best be 
considered a form: 
66a. Form michiganese Tiffany nov. f. 
Oe. argenteum Hirn (in part) in Ackley 1929, p. 302, Pl. XX XV, fig. 3-6. 
Middle wall of oospore scrobiculate; pore of oogonium supramedian; 
otherwise as in the type. 
United States: Michigan. 
67. Oc. wyliei Tiffany. 
(Pl. XXX, figs. 264-267.) 
1926, p. 90, Pl. I, figs. 1-4. 
Dioecious, macrandrous; oogonium 1-4, globose to ovoid, pore 
superior; oospore globose to ovoid, filling or not filling oogonium, 
outer spore wall irregularly scrobiculate; antheridium 1-4; sperms 2, 
division horizontal; basal cell elongate; terminal cell, often an oogonium, 
apically obtuse or broadly apiculate; vegetative cell 16-2480-170u; 
oogonium 52-64 68-112u; oospore 48-60 X 52-64; antheridium 16-19 
xX 8-18. 
United States: Iowa, Michigan. 
See Oe. punctatum (No. 65). 
68. Oe. americanum Transeau. 
(Pl. XXXI, figs. 275 and 276.) 
1917, p. 231. 
Dioecious, macrandrous; oogonium 1, globose to depressed-globose, 
pore superior; oospore globose, ellipsoid. globose, or depressed- slobose, 
filling oogonium or not, spore wall of three | layers: median layer scrobicu- 
late; antheridium. 1-5, frequently alternating with vegetative cell; 
sperms 2, division horizontal: basal cell elongate; terminal cell obtuse: 
female vegetative cell 28-48 x 40- 100u, male vegetative cell 24— 30% 
40-100y; oogonium 40-76 X 48-70; oospore 38— 74X46- —o6u; antheridium 
20-28 X4-12y. 
United States: Michigan, Illinois. 
See Oe. punctatum (No. 65). 
69. Oc. taphrosporum Nordstedt and Hirn. 
(Pl. XXXI, figs. 270 and 271.) 
In Hirn 1900, p. 133, Pl. XVI, fig. 91; Collins 1909, p. 239; P. B. A. No. 813. 
Dioecious, macrandrous; oogonium 1-6, obovoid or obovoid- ellipsoid, 
pore superior; oospore globose or ellipsoid globose, not filling oogonium, 
outer layer of spore wall scrobiculate, inner layer smooth; antheridium 
-2-?; terminal cell, sometimes an oogonium, obtuse; basal cell elongate; 
