OEDOGONIUM wo 
wall smooth and thick; antheridium 1-4, subepigynous or hypogynous 
or rarely scattered, sperms 2, division horizontal; vegetative cell 15-18 x 
45-80yu; oogonium 31-37 X 34—45u,; oospore 30-36 X 33-41; antheridium 
14-16 X5-10x. 
United States: Illinois, Ohio, Mississippi; Austria, Finland, 
Sweden, Latvia, Germany; India; Siberia. 
19a. Var. fennicum Tiffany. 
(Pl. XIV, fig. 135.) 
1929, p. 74; Oe. intermedium Wittr. forma valida Hirn 1900, p. 95, Pl. V, fig. 32; 
Oe. intermedium Wittr. forma West 1909a, p. 239. 
Oogonium and oospore considerably larger; vegetative cell 17-19 
50-120u; oogonium 388-4642-60u; oospore 35-4035-40u; anth- 
eridium 13-18 X6-8u. 
United States: Michigan; Finland; Egypt. 
Oe. intermedium resembles Oe. fragile (No. 24) in general 
appearance, particularly those specimens that reach the upper 
limits of dimensions. It is rather intermediate between Oe. 
fragile and Oe. globosum (No. 21). Its size and location of 
antheridia are distinctive characters in this monoecious group 
with regularly supérior pore. The variety fennicum is larger 
and its oogonium is not filled by the oospore. 
20. Oe. hirnii Gutwinsk1. 
(Pl. XIV, figs. 136 and 137.) 
1896, p. 2, Pl. 5, fig. 1; Hirn 1900, p. 93, Pl. V, fig. 29; West and West 1902, 
p. 12, Pl. I, fig. 1-3. 
Monoecious; oogonium 1, subglobose or subobovoid, with superior 
pore; oospore globose, not filling oogonium, spore wall smooth; 
antheridium 1-2, subepigynous; sperms 2, division horizontal; vegetative 
cell (sometimes slightly capitellate) 8-13 28-80u; oogonium 32-37 xX 
32-39u; oospore 28-31 X 28-31u; antheridium 8-11 *4-9un. 
Austria, Ireland. 
20a. -Var. africanum G. S. West. 
(Pl. XIV, fig. 138.) 
1907, p. 98; Tiffany 1926, p. 100, Pl. ITI, fig. 24. 
Oogonium globose to subglobose; antheridium 1-3; vegetative cell, 
broadly capitellate, 13-15 33-60u; oogonium 39-40 38-40; oospore 
33-36 X 33-36u; antheridium 13-14 5-6u. 
United States: Iowa; Africa. 
The species is near Oe. globosum below in description, differing 
in its smaller size and its commonly subobovoid oogonia. 
The variety africanum is very distinct and is the only poriferous 
form in the monoecious group of the genus having broadly 
capitellate cells. 
