OEDOGONIUM 65 
1. Oc. laeve Wittrock. 
(Pl. XI, fig. 100.) 
1874, p. 8; De Toni 1889, p. 35; Hirn 1900, p. 75. 
Monoecious; oogonium single,* depressed-globose, pore median; 
oospore depressed-globose, filling oogonium, spore wall smooth; anther- 
idium in groups of 1—2,* subepigynous, sperm 1; vegetative cell 10-14 
20-70u; oogonium 32-38 X 24-30; oospore 30-35 X 23-26u; antheridium 
9-10 X9-13y. 
United States: Illinois, Michigan; France. 
Originally distributed from France, the species was found 
subsequently in Illinois and Michigan (Transeau), and the 
above description is made from the American material. The 
large oogonium in relation to the diameter of the vegetative 
cell and the depressed-globose oospores are chief characteristics. 
t is clearly separated from Oe. curvum, in addition, by the 
absence of any marked tendency toward irregularly curved 
filaments. 
2. Oe. curvum Pringsheim. 
(Pl. XI, figs. 103 and 104.) 
1858, p. 69, Pl. 5, fig. 3; Hirn 1900, p.'74, Pl. I, fig. 3; Tiffany 1926, p. 99, Pl. III, 
figs. 25-27. 
Monoecious; oogonium 1—6, depressed globose, pore median; oospore 
depressed-globose, filling or not filling oogonium, spore wall smooth; 
antheridium 1-7, sperm 1; basal cell elongate; filament usually irregularly 
curved; vegetative cells 5-10X10-40u; oogonium 21-25 18-24y; 
oospore 19-23 X 14-19; antheridium 6-9 X6—9un. 
United States: Iowa, Alabama; Germany, Spain, Sweden. 
This species is to be compared with Oe. cryptoporum below. 
The irregularly curved filaments, particularly in the region of 
the antheridia, are usually characteristic. The pore is some- 
times a little above the median position. : 
3. Oe. cryptoporum Wittrock. 
(Pl. XI, fig. 101.) 
1870, p. 119; Hirn 1900, p. 72, Pl. I, fig. 1; P. B. A. No. 1525. 
Monoecious; oogonium 1, subdepressed-obovoid-globose or sub- 
depressed-globose, pore median; oospore subdepressed-globose, quite 
filling oogonium, spore wall smooth; antheridium 1-7, scattered or 
subhypogynous or subepigynous; sperm 1; vegetative cell 7--10x* 
28-60u; oogonium 23-28 X 26-314; oospore 22-27 X 19-21u; antheridium 
6-3 7-l 1p. 
United States: Utah; Austria, Denmark, Norway, Sweden. 
*Hereafter a numeral (or numerals) only will indicate the number of oogonia 
and antheridia; thus l=a single oogonium or antheridium and 2-7 means that 
oogonia (or antheridia) may occur in groups of from two to seven seriate individ- 
uals. The same applies to androsporangia. 
