OEDOGONIUM 103 
etative cell 10-18X16—-40u, male 14-20*16—-40u; oogonium 382-36 
32—40u; oospore 28-32 X 28-34; antheridium 14-18 X 12—20u; basal cell 
16-24 X 12-16. 
United States: Iowa, Mississippi, Alabama, Kentucky. 
The wide operculum, the capitellate vegetative cells, the 
single antheridium alternating with a vegetative cell, and the 
subhemispherical basal cell are characteristic of the species. 
82. Oe. acmandrium Elfving. 
(Pl. XXXIV, fig. 300.) 
In Hirn 1895, p. 13; Hirn 1900, p. 150, Pl. XXIII, fig. 120. 
Monoecious; oogonium 1-2, depressed-globose or subglobose, 
operculate, division median and narrow; oospore depressed-globose or 
subglobose, filling oogonium, wall smooth; antheridium 1-3, sub- 
epigynous, ‘epigynous, or hypogynous, often terminal; sperm single; 
basal cell elongate; vegetative cell 7-10X30-80u; oogonium 30-35 x 
28-38; oospore 28-33 & 25-29; antheridium 8-10 10-15y. 
United States: Illinois; Finland, Sweden; India. 
Cf. Oe. pratense (No. 80) and Oe. psaegmatosporum below. 
83. Oc. psaegmatosporum Nordstedt. 
(Pl. XXXIV, fig. 301.) 
1877, p. 24, Pl. 3, fig. 1-3; Hirn 1900, p. 150, Pl. XXIII, fig. 121. 
Monoccious; oogonium 1-5, broadly pyriform-globose, operculate, 
division median, narrow but distinct; oospore depressed-globose to 
globose, inflating the middle part of oogonium, spore wall (?) smooth; 
antheridium to 15-seriate, hypogynous, cell a little tumid; sperm single; 
vegetative cell 9-10X56-80u; oogonitum 28-33X33-40u; oospore 
27-31 X 24-27; antheridium 9-12 6-10up. 
- Denmark, Sweden. ; 
Near Oe. acmandrium above, differing in its . pyriform- 
globose and medianly inflated oogonia and many-seriate 
antheridia. ; 
84. Oe. minus Wittrock. 
(Pl. XXXIV, fig. 302.) 
1874, p. 9; Oe. punctato-striatum var. minor Wittr. 1870, p. 123; Oe. spirogranu- 
latum Schmidle 1894, p. 43, Pl. 7, fig. 1; Hirn 1900, p. 151, Pl. XXIII, fig. 122. 
Monoecious; oogonium 1, pyriform-globose or depressed-globose, 
operculate, division median, wide; oospore depressed-globose, not filling 
oogonium, spore wall smooth; antheridium to 10-seriate, subepigynous 
or subhypognous or rarely scattered, cells a little tumid; sperm 1; 
vegetative cell somewhat capitellate; wall of vegetative cell and of 
oogonium spirally punctate; basal cell depressed-globose or sub- 
hemispherical, wall vertically plicate; vegetative cell 9-13 30-78u; 
oogonium 34-46 xk 28—42u; oospore 30-42 < 26-36u; antheridium 9-13 x 
3—Om. 
