OEDOGONIUM 149 
(or rarely globose-ellipsoid, not filling oogonium) spore wall sometimes 
crenulate; dwarf male on or near oogonium; antheridium exterior, 
1—?, curved; vegetative cell 4-8X10-35u; oogonium 16-20 X 22-29n; 
oospore 15-18X19-23u; antheridium 4-5X5-6u; dwarf male 5-7X 
11—-14u. 
United States: Iowa, Michigan, New York; Denmark, 
France, Sweden; Australia. 
179a. Form minutum (Hansgirg) Hirn. 
(Pl. LVIII, fig. 561.) 
1900, p. 242, Pl. XL, fig. 251; Oe. crispulum Wittr. and Nordst. var. minutum 
Hansg. 1886, p. 44. 
Smaller; median spore wall distinctly crenulate (Transeau); vege- 
tative cell 3-7X12—-40u; oogonium 14-18X18—-24y; oospore 13-17 
15-20u. 
United States: Illinois; Austria. 
179b. Form rotundatum Hirn. 
(Pl. LVII, fig. 562.) 
1900, p. 242, Pl. XL, fig. 252. 
Oogonium a little larger and shorter; oospore globose-ellipsoid; 
vegetative cell 5-8 X 15-31y; oogonium 19-23 K 20-26; oospore 18-22 
18—23u; dwarf male stipe 5-6 11—l5yu; antheridium 4-6 X4—6uy. 
Germany. 
This species is near Oe. longatum (No. 178) and is separable 
largely on the basis of the form of the oogonium and relative 
length of the oospore. Sometimes the oospore wall of Oe. 
rugulosum is crenulate. The latter is characteristic of f. 
minutum, which is smaller and has more obovoid oogonia. 
F. rotundatum has globose-ellipsoid oospores and slightly larger 
oogonia. 3 
180. Oe. hians Nordstedt and Hirn. 
(Pl. LVIII, figs. 570 and 571.) 
In Hirn 1900, p. 227, Pl. XX XVIII, fig. 238. 
Dioecious, nannandrous, gynandrosporous; oogonium 1-2, subovoid 
or globose, operculate, division superior, wide; oospore globose,_ quite 
filling oogonium, spore wall smooth, thick, and often lamellose; suffultory 
cell tumid; androsporangium 1—2, subepigynous; basal cell elongate; 
terminal cell apically obtuse; dwarf male curved, on suffultory cell, 
antheridium exterior, unicellular; vegetative cell 9-15 X37—145u; sufful- 
tory cell 26-3340-80u; oogonium 37-43 45-60u; oospore 33-40 
33-40u; androsporangium 11-12X15-18u; dwarf male stipe 7-9X 
32-35u; antheridium 6-8 X 5-6u. 
United States: Iowa; Brazil. 
Characterized by its swollen suffultory cells, wide operculum, 
and tendency toward capitellate vegetative cells. 
