84 Tr EOE DOE ON PACES 
4lb. Var. columbianum G. S. West. 
(Pl. XXV, fig. 219.) . 
1914, p. 1048, text fig. 3D. 
Vegetative cell more slender; oogonium a little longer and more 
tumid; oospore more ellipsoid than the type; vegetative cell 56-70 
248-425; oogonium 98-100 X 163-1744; oospore 81-84 X 124-128. 
Columbia. 
4ic. Var. punctatum Lemmermann. 
1910, p. 313. 
Oogonium not tumid; oospore globose, not filling oogonium in length, 
spore wall yellow-brown, densely punctate; vegetative cell 64-75 
210—-245u; oogonium 64-75 101-1184; oospore 63-71 X63-71p. 
Paraguay. 
Oe. fabulosum with its three varieties represents the largest 
size attained by any species of the genus so far recorded. The 
variety punctatum is easily separable by its punctate oospore, 
although unfortunately Lemmermann left no figure; colum- 
bianum is the most slender; maximum is slightly larger than the 
species. 
42. Oe. rivulare (Le Clerc) Al. Braun. 
: (Pl. XXIV, figs. 209 and 210.) é 
(2?) Prolifera rivularis Le Cl. 1817, p. 472, Pl. 23, fig. 1; Oe. rivulare Al. Br. 1855, 
p23, Blanes. IO Sica 1900s plo Bileexchi es O0. 
Dioecious, macrandrous; oogonium 1-7, obovoid, pore superior; 
oospore obovoid, ellipsoid, or subglobose, not filling oogonium longi- 
tudinally, spore wall smooth; antheridium to 13-seriate; sperms. 2, 
division horizontal; basal cell elongate; female vegetative cell 35-45 xX 
110-350pu, male 30-36 X 120-280u; oogonium 70-85 X 130-1604; oospore 
55-70 X 65-100; antheridium 21-28 X 14—26n. 
United States: Iowa, Florida, Massachusetts; Denmark, 
England, Austria, France, Scotland, Germany, Sweden. 
Very readily recognized by its large size and particularly by 
its oospore which is much smaller than the oogonium. 
43. Oe. pachyandrium Wittrock. 
(Pl. XX, figs. 179 and 180.) 
In Wittr. and Nordst. Alg. Exs. No. 5, 1877; Hirn 1900, p. 142, Pl. XX, fig. 104. 
Dioecious, macrandrous; oogonium 1-3, subobovoid or obovoid- 
ellipsoid, pore superior; oospore ellipsoid, not filling oogonium (rarely 
inflating it), spore wall smooth; antheridium 1-4; sperms 2, division 
vertical; female vegetative cell 30-36 X 80-220u, male 32-45 x 60-160; 
oogonium 53-57 X 84—-108u; oospore 51-54 69-85y, antheridium 30-43 
X 11-20. 
United States: Pennsylvania, New Jersey, Massachusetts; 
Sweden. 
