UO TEE OF DIOeO NEN CB AGE: 
142a. Var. arechavalete (Wittrock) Hirn. 
(Pl. L, fig. 478.) 
1900, p. 216, Pl. XXXVI, fig. 222; Oe. arechavalete Wittr. in Wittr. and Nordst. 
Exs. 1886 and in De Toni 1889, p. 55. 
(?) Idioandrosporous; vegetative cell 21-29382-110u; oogonium 
39-54 X42-65u; oospore 37—5240-574; dwarf male 14-16X40-57n; 
antheridium 9-14 10—16ux. 
Uruguay. 
142b. Var. idioandrosporum Nordstedt and Wittrock. 
(Pl. XLIX, figs. 475 and 476.) 
In Wittr. & Nordst. Exs. 1879; Oe. huntit Wood in Tilden Amer. Algae 1894; 
Oe. crassiusculum Wittr. in P. B. A. 1895; Oe. crasstpellitum West 1899, p. 55, P1. 394, 
figs. 3-5; Hirn 1900, p. 215, Pi. XX XV, fig. 220; Collins 1909, p. 255; Heering 1914, 
p. 178, fig. 242; Tiffany 1926, p. 103, Pi. VIII, fig. 89; P. B. A. Nos. 72 and 716. 
Idioandrosporous; oogonium 1-8, globose-obovoid to globose, pore 
superior; oospore ellipsoid-globose, ovoid, angular-globose (rarely 
globose), nearly filling the oogonium, spore wall smooth, thick; andro- 
sporangium 1—4; dwarf male straight or slightly curved, on or near the 
suffultory cell; antheridium exterior, 1-2; vegetative cell 25-36 X 65—200y; 
oogonium 48-59X57—-90u; oospore 42-57 50-664; androsporangium 
30-34 X 12-214; dwarf male stipe 14-16X60-70u; antheridium 
8-10 X 10-18. 
United States: Massachusetts, Maine, Michigan, Penn- 
sylvania, New Jersey, Minnesota, Connecticut, South Dakota, 
Iowa, Ohio, New York, Illinois, Mississippi; England, Denmark, 
France, Germany, Sweden. 
This variety is one of the commonest of the nannandrous 
species of the genus. In fact, in comparison to it, the type 
seems rare. Characterized by the thick-walled oospore, globose- 
obovoid oogonia, and relatively long and straight vegetative 
cells. It differs from the species largely in its idioandrosporous 
habit. 
142c. Var. cataractum (Wolle) Tiffany nov. comb. 
(Pl. XLIX, fig. 477.) 
Oe. cataractum Wolle 1887, p. 77, Pl. 85, figs. 10-12; zbid., Hirn 1900, p. 308, 
Pil. XLII, fig. 264; zhid., Collins 1909, p. 266. 
Oogonium 1-2, often terminal, obovoid-globose or subglobose or 
broadly ovate, pore superior; oospore globose or obovoid-globose, 
nearly filling oogonium; androsporangium 2-6; dwarf male curved, on 
suffultory cell or below; vegetative cell 28-38 X42-112u; oogonium 
55-60 X60-75u; oospore 50-5550-60u; androsporangium 26-30X 
10-15; dwarf male 10 65uy. 
United States: Pennsylvania, Ohio. 
From Wolle’s description this plant is certainly very close 
to Oe. crassiusculum, as suggested by Hirn (1900). Wolle’s 
