SO THE ORDO GCONTNCEE 
This species is quite easily recognized by its monoecious 
habit, large size, and subglobose to ellipsoid oospores not 
filling the oogonia. 
35. Oe. capillare (Linnaeus) Kuetzing. 
(Pl. XVIII, figs. 164 and 165.) 
Conferva capillare L. 1753, 1166; Oe. capillare Kuetz. 1843, p. 255, Pl. 12, 
fig. II, 1-10; Kuetz. 1853; p. 18, PDL. 40, fig. 3; Oe. capillare Kuetz. var. flavescens 
in Rabenh. Alg. Europe 1861; Oe. stagnale Kuetz. in Rabenh. ibid. 1883; Hirn 1900, 
p: 112)-Pl Oct fie. 58: Heering 1914, p. 197, fig. 278; Tiffany 1926, p. ‘Ol, PSE 
figs. 39 and 40. 
Dioecious, macrandrous; oogonium 1, not or scarcely exceeding the 
vegetative cell in diameter, ‘cylindrical to subcylindrical, pore superior; 
oospore globose to cylindric-globose to ovoid, not or completely filling 
oogonium, spore wall smooth; antheridium 1-4, often alternating with 
vegetative cell; sperms 2, division horizontal; basal cell elongate, 
terminal cell broadly apiculate to obtuse; female vegetative cell 35-56 x 
36-120u, male 35-50*35-90u; oogonium 40-6045-75u; oospore 
30-52 X 35-65u; antheridium 30-48 X 5-10z. 
United States: Iowa; Austria, Denmark, Finland, France, 
Germany, Spain, Italy, Russia, Sweden, Latvia; Africa (Vic- 
toria). 
35a. Form stagnale (Kuetzing; Wittrock) Hirn. 
(Pl. XVIII, fig. 166.) 
1900, p. 113, Pl. X, fig. 57; Oe. stagnale Kuetz. 1849, p. 368, and 1853. p. 13, 
Pl. 41, fig. 2; Wittrock 1874, p. 31. 
Oospore subcylindrical or cylindrical-globose, sometimes con- 
stricted at the middle, not filling oogonium; female vegetative cell 
38-50 40-100u, male 35-45x36-90u; oogonium 40-60X55-75y; 
oospore 36-57 X40-60u; antheridium 33-42 K 5—-9un. 
Germany, Latvia, Spain. 
This species and its variety are rather readily distinguished 
from others by having oogonia which scarcely exceed the 
vegetative cells in diameter. They are to be compared with 
Oe. suboctangulare (No. 32) and Oe. geniculatum (No. 31), 
both of which are monoecious. The variety stagnale 1s separable 
from the type on dimensions and shape of oogonium. 
36. Oc. plagiostomum Wittrock. 
(Pl. XIV, fig. 140.) 
Oe. sp. Wittr. 1872a, p. 24, Pl. 1, fig. 11; Wittr. 1874, p. 41; Hirn 1900, p. 100, 
Pl. VI, fig. 39; Collins 1918, p. 62; Heering 1914, p. 196, fig. 276; Tiffany 1926, p. 92. 
Dioecious, macrandrous; oogonium 1, obovoid-globose, with superior 
pore; oospore globose to subglobose, usually filling oogonium, spore 
wall smooth and thickened; antheridium 1-6, often alternating with 
vegetative cell; basal cell elongate; vegetative cell 22-27 65-120y; 
oogonium 42-49 x 50-60u; oospore 41-47 KX 42-49; antheridium 20-24 
8—10u. 
