OEDOGONIUM 109 
oogonia and oospores. Oe. undulatum (No. 119), anannandrous 
species, has vegetative cells four times undulate-constricted 
while Oe. nodulosum has two undulate constrictions. 
97. Oe. porrectum Nordstedt and Hirn. 
(Pl. XXXVIII, figs. 361 and 362.) 
In Hirn 1900, p. 186, Pl. X XIX, fig. 183. 
Dioecious, macrandrous; oogonium 1, oblong, operculate, division 
superior; oospore ellipsoid or globose-ellipsoid, not filling oogonium 
longitudinally, spore wall smooth; antheridium to 4-seriate; sperms 2, 
division horizontal; female vegetative cell 7-1025-55y, male 6-9 
25-62u; oogonium 24-27 X 44-53; oospore 23-24 X 25-28u; antheridium 
6-7 X6-8u. 
Brazil. 
98. Oe. nanum Wittrock; Tiffany. 
(Pl. XXXVI, figs. 342 and 343.) 
7 poe 1874, p. 37; Hirn 1900, p. 305, Pl. X XIX, fig. 174; Tiffany 1926, Pl. VI, 
gs. —Do. 
Dioecious, macrandrous; oogonium 1-8, ovoid to broadly ellipsoid, 
operculate, division superior; oospore ovoid to globose-ellipsoid, usually 
filling the oogonium, spore wall smooth; antheridium 1-3, sperm 1; 
basal cell subhemispherical; terminal cell, often an oogonium, apically 
obtuse; vegetative cell, often irregularly swollen, 6-1015—-33u; 
oogonium 24-28 x 30-364; oospore 21-27 X 23-380y; antheridium 7—-10X 
8-llyu; basal cell 14-17 X 12-16u. 
United States: Iowa; India. 
Originally found in India, this species was only completely 
described from the Iowan material. It bears some resemblance 
to Oe. pisanum below. It is found almost entirely epiphytic 
on submerged leaves, on Pithophora, on Cladophora, and on 
other species of Oedogonium. 
99. Oe. pisanum Wittrock. 
(Pl. XXXVIII, figs. 363 and 364.) 
1876, p. 50, Pl. 13, fig. 28; Oe. subpisanum Lewin 1888, p. 17, Pl. 3, figs. 49-52; 
ae 1900, p. 181, Pl. XXIX, fig. 175; Heering 1914, p. 203, fig. 291; Tiffany 1926, 
p. 97. 
Dioecious, macrandrous; oogonium 1 (rarely 2-3), ellipsoid-ovoid to 
ovoid, operculate, division superior; oospore ovoid to ellipsoid, nearly 
filling oogonium, spore wall smooth; antheridium 1-4; sperms 2, division 
horizontal; basal cell elongate; terminal cell piliferous; vegetative cell 
5-12 12-72; oogonium 23-29 (-32) «34-43 (-45)u; oospore 21-25 X 
27-37; antheridium 4-9 X 5-9u. 
United States: Iowa, Illinois, Ohio, Mississippi; Austria, 
Italy, Spain; Africa. 
