82 TE AOE DOG ON TAGS Aue 
25-100u, male 24-3025-90u; oogonium 40-53X40-65u; oospore 
37-47 X 38-54; antheridium 22-30 5-10y. 
Uruguay. 
37c. Var. australe Wittrock. 
(Pl. XIX, figs. 176 and 177.) 
In Wittr. and Nordst. Exs. 1886; Oe. princeps (Hass.) Wittr. in Tilden Amer. 
Alg. 1894; Hirn 1900, p. 109, Pl. IX, fig. 52; Oe. capilliforme Kuetz.; Wittr. var. 
australe Wittr. f. uberosporum Hirn 1900, p. 110, Pl. 1X, fig. 538; Tiffany 1926, p. 92. 
Oogonium obovoid-globose to subglobose; female vegetative cell 
24-36 X 26-100u, male 22-33x40-100u; oogonium 37-53 X43-60y; 
oospore 35-50 X 36—55yu; antheridium 21-26 X4-9u. 
United States: Minnesota, Iowa, New York, South Dakota, 
Nebraska, California; Africa; Uruguay, Argentine, Brazil; 
Mexico; Vancouver. 
37d. Var. diversum (Hirn) Tiffany. 
(Pl. XIX, fig. 178.) 
1929, p. 75; Oe. capilliforme Kuetz.; Wittr. var. australe Wittr. f. diversum Hirn 
1900, p. 110, Pl. IX, fig. 54; Oe. stagnale Kuetz. in Tilden Amer. Alg. 1896. 
Dimensions larger throughout; female vegetative cell 34-46 
45-130u, male 33-4050-120u; oogonium 46-56X46-70u; oospore 
43-52 x 40-58; antheridium 30-37 X 6-I1y. 
United States: Iowa, Colorado, Montana, Minnesota. 
The “‘capilliforme’’ group is readily recognized by the 
smaller male vegetative filaments and shape of oogonia. The 
group is variable within itself, however, and the above varieties 
are recognized on the basis of differences in shape of oogonia 
and in dimensions. 
38. Oe. princeps (Hassall) Wittrock. 
(Pl. XVIII, figs. 167-169.) 
Vesiculifera princeps Hass. 1842, p. 388; V. cupillaris Hass. 1845, p. 195, Pl. 50, 
figs. 1 and 2; Oe. princeps Wittr. 1874, p. 42; Hirn 1900; p. 289, Pl. X, fig. 56. 
Dioecious, macrandrous; oogonium 1, little tumid, subobovoid, 
pore superior; oospore globose or subglobose, not filling oogonium, spore 
wall smooth; terminal cell apiculate; antheridium 1-7; vegetative cell 
33-42 X 40-1334; oogonium 54-63X67-80u; oospore 48-58 x 50-60y; 
antheridium 32-38  8—20u. 
United States: Minnesota, Mississippi; England. 
I have seen specimens of this alga from both Minnesota 
and Mississippi with immature antheridia which appear to 
belong with the oogonial filaments. I have therefore placed 
the species in the dioecious group. The cells of the antheridial 
filaments are somewhat longer than those of the male plants. 
It should be compared with the monoecius Oe. geniculatum 
(No. 31) and the dioecious Oe. capilliforme (No. 37). It is 
more robust than the latter. 
