74 tae Om pio Ccon fA Cr we 
21. Oc. globosum Nordstedt. 
(Pl. XIV, fig. 139.) 
1878, p. 20, Pl. 2, fig. 16; Hirn 1900, p. 94, Pl. V, fig. 30. 
Monoecious; oogonium 1, globose or subglobose, pore superior; 
oospore globose, quite filling oogonium, spore wall smooth; antheridium 
1-7, subepigynous or subhypogynous or scattered; sperms 2, division 
horizontal; basal cell elongate; terminal cell setiform; vegetative cell 
10-14 40-954; oogonium 32-40382-46u; oospore 30-387 X28-37y; 
antheridium 9-12 4—8u. 
United States: Illinois, Massachusetts; Australia; Greece, 
Serbia. 
The relation of this species to Oe. hirnit (No. 20) and to 
Oe. intermedium (No. 19) is discussed under these latter forms. 
22. O68. zigzag Cleve. 
(Pl. XV, figs. 143 and 144.) 
In Wittr. 1870, p. 120; Hirn 1900, p. 101, Pl. VII, fig. 42. 
Monoecious; oogonium 1, globose or obovoid-globose, pore superior; 
oospore of same form as oogonium and quite filling it, spore wall smooth, 
thick; antheridium 1, subepigynous or subhypogynous, alternating with 
oogonium and vegetative cell; sperms 2, division horizontal; basal cell 
elongate; terminal cell apically obtuse; vegetative cell 15-20 30-80p; 
oogonium 45-63 52-63 (—67)u; oospore 43-60 (44—) 48-58 (-63)y; 
antheridium 15-19 8—15uy. 
Sweden. 
The short, few-celled filaments of Oe. zigzag are quite 
unmistakable. It bears some resemblance to the dioecious 
Oe: alternans (No. 139) and is perhaps closely related to Oe. 
curtum (No. 23). From the latter it is distinguished by its 
shorter filaments, by its single oogonium, and by its single 
antheridium alternating with a vegetative cell. 
23. Oe. curtum Wittrock and Lundell. 
(Pl. XV, fig. 149.) 
In Wittr. 1870, p. 121; Oe. curvum Pringsh. in Roumeguere Alg. Exs. No. 
793; Hirn 1900, p. 102, Pl. VI, fig. 41; Skuja 1927, p. 98, Pl. II, fig. 11. 
Monoecious; oogonium 1-4, obovoid-globose or subglobose, pore 
superior; oospore of same form as oogonium, which it nearly fills, spore 
wall smooth, often thick; suffultory cell occasionally larger than 
vegetative cell; antheridium 1-4, subepigynous, sometimes terminal; 
sperms 2, division horizontal; basal cell elongate; vegetative cell 12-22 
25-110; oogonium 38-55 X 37-54; oospore 36-52 X 35-51; antheridium 
10-17 X8-l3p. 
Finland, Germany, Sweden, Latvia. 
Similar to Oe. zigzag (No. 22). Skuja (1927) reports Oe. 
curtum with 10-12 cells (and often 20) in a filament. Oe. 
