OEDOGONIUM 85 
This plant is very near Oe. grande (No. 45), but is dis- 
tinguished by having male filaments larger than the female. 
44, Oe. mexicanum Wittrock. 
(Pl. XXI, figs. 188 and 189.) 
1878, p. 138; Hirn 1900, p. 147, Pl. XXII, fig. 111. 
Dioecious, macrandrous; oogonium 1, cylindric-obovoid, pore 
superior; oospore cylindric-obovoid, quite or nearly filling oogonium; 
spore wall smooth; antheridium to 8-seriate; sperms 2, division vertical; 
female vegetative cell 34—41 x 60-140, male 30-38 X 60-1144; oogonium 
53-63 X 76— 110u; oospore 51-60 X 63-80yu; antheridium 28-35 X 7-17». 
United States: South Dakota, Massachusetts; Mexico. 
This species is close to Oe. grande below, being usually 
distinguished by its larger and considerably shorter vegetative 
cells and by its more cylindric oogonia. 
45. Oe. grande Kuetzing; Wittrock. 
(Pl. XXII, figs. 195 and 196.) 
In Wittr. and Nordst. Alg. Exs. No. 502, 1883; Kuetz. 1845, p. 200, 1853, p. 12, 
Pl. 37, fig. 1; Hirn 1900, p. 148, Pl. X XI, figs. 105-106; Collins 1909, p. 242; Heering 
1914, p. 202, fig. 288; Tiffany 1926, p. 98, Pl. II, figs. 14-16; P. B. A. No. 811. 
Dioecious, macrandrous; oogonium 1—5, subobovoid, pore superior; 
oospore of the same form as oogonium, which it completely fills or 
not, spore wall smooth; antheridium 1—10; sperms 2, division vertical; 
basal cell elongated; female vegetative cell 28-3770-210u, male 
28-33 X 70-1754; oogonium 49-60 86-1104; oospore 47-58 x 60—94y; 
antheridium 25-33 & 11-18u. 
United States: Iowa, Maine, Massachusetts, Pennsylvania, 
California, Michigan, Illinois, Ohio, Minnesota, Mississippi, 
Connecticut; Ontario; Australia; Austria, Sweden, Switzerland. 
45a. Form gemelliparum (Pringsheim) Hirn. 
(Pl. XXII, fig. 200.) 
1900, p. 145, Pl. XXI, fig. 107; Oe. gemelliparum Pringsh. 1858, p. 71, Pl. 5, 
ae At Oe. landsboroughi (Hass.) Wittr. var. gemelliparum (Pringsh.) Wittr. 1874, 
p. 36. 
Oogonium ellipsoid-ovoid, antheridium seriate; vegetative cell 
20-27 * 60-200u; oogonium 55-57 & 75—-80p; oospore 49-51 X 65-69. 
Germany. 
45b. Var. aequatoriale Wittrock. 
(Pl. XXII, fig. 201.) 
In Wittr. and Nordst. Alg. Exs. No. 1016, 1893; Hirn 1900, p. 145, Pl. X XT, fig. 
108; Oe. grande Kuetz.; Wittr. var. aequatoriale Wittr. f. hortense Wittr. in Hirn 
1900, p. 145, Pl. X XI, fig. 109. 
Vegetative cell 26-33 < 70-165; oogonium 44-51 X 75-100u; oospore 
42-49 X 50-8 1p. 
Ecuador; Greenland. 
