&6 Hort OEDO'GCONTACE AE 
45c. Var. angustum Hirn. 
(Pl. XXII, figs. 198 and 199.) 
1900, p. 146, Pl. X XI, fig. 110; P. B. A. No. 410. 
Vegetative cell and oogonium elongated; antheridium to 36-seriate; 
oogonia sometimes 4; vegetative cell, female 19-3070-330u, male 
19-25 X 80-225; oogonium 42-5262-110u; oospore 40-50 60-89y; 
antheridium 18-22  7—-15u. 
United States: Massachusetts, Mississippi, Michigan, IIli- 
nois; Brazil. 
45d. Var. majus Hansgirg. 
(Pl. XXII, fig. 197.) 
1886, p. 45; Oe. grande forma robusta Hirn 1900, p. 144; Collins 1918, p. 68; 
Oe. grande Kuetz.; Wittr. var. robustum (Hirn) Tiffany 1924, p. 186, Pl. III, fig. 7, 
and 1926, p. 94, Pl. I1, fig. 19. 
Larger than the type; female vegetative cell 36-46 x 80-200, male 
32-42 X 80-2004; oogonium 52-68X75-90u; oospore 50-64 68-88u; 
antheridium 30-36 X 10—16u. 
United States: Illinois, Iowa, Michigan, Ohio, Massa- 
chusetts; Austria, Czecko Slovakia, Latvia. 
Oe. grande is one of our commonest species. The sub- 
obovoid oogonia often in series, with superior pore, the accom- 
panying smaller male filaments with vertical division of the 
antheridium are distinctive characters. The varieties are 
distinguished on the basis of size and differences in shape of 
oogonia. 
The common occurence of the distinct, robust variety of 
Oe. grande led to the varietal name robustum (Tiffany 1924). 
Hansgirg’s description of the variety majus is so near that: 
given above that the prior name must be used, in spite of its 
relegation by Hirn (1900) to be synonymous with the robust 
form of the type. Skuja (1927) records a robust form of 
Oe. grande with slightly smaller dimensions, which I have 
included under the variety majus. The dimensions of this 
variety are from the American material. 
46. Oc. oboviforme Wittrock. 
(Pl. XX, figs. 184 and 185.) 
1878, p. 140; De Toni 1889, p. 74; Hirn 1900, p. 141, Pl. XX, fig. 103; Collins 
1909, p. 241. 
Dioecious, macrandrous; oogonium 1, obovoid, pore superior; 
oospore obovoid (rarely ellipsoid-obovoid), about filling oogonium, 
spore wall smooth; antheridium to 19-seriate, sperms 2, division vertical ; 
basal cell elongate; female vegetative cell 21-33 X 72-280; male 21-31 X 
72-270u; oogonium 55-65 X80-1074; oospore 54-61X70-85y; anth- 
eridium 21-28 x 5-13u. 
Brazil; Mexico. 
