THE GREEN ALGAE OF NORTH AMERICA 65 



fig. 31. Monoecious, oogonium single, oboviform to oboviform- 

 globose, pore superior; oospore globose or obovi form-globose 

 (more rarely globose-oboviform) quite or nearly filling the 

 oogonium ; membrane smooth, usually thick ; antheridium 1-4- 

 celled, subepigynous or hypogynous, or rarely scattered ; sper- 

 matozoids binate, division horizontal. 



veg. cell, 15-18 M diani., 3-4-5 diam. long, 



oog., 31-37 n " 34-45 u long, 



oos., 30-36 fj. " 33-41 M " 



auth. cell, 14-16 /x " 5-io/x " 



Charleston, 111. ; Utica, Ohio, Transeau. Europe. 



Stouter than Oe. fragile, more slender than Oe. Vaucherii, in 

 both of which species the oospores are more definitely globose 

 than in Oe. intermedium. 



76. OE. TYROLICUM Wittrock ex Him, 1900, p. 91, PI. IV, 

 fig. 25. Monoecious ; oogonium single, seldom 2, ellipsoid- 

 globose or sometimes obovoid, pore supramedian or nearly 

 superior ; oospore globose, rarely globose-ellipsoid, not quite 

 filling the oogonium ; membrane smooth ; antheridium 1-4- 

 celled, subepigynous or subhypogynous ; spermatozoids binate, 

 division horizontal. 



veg. fil., 15-24 fj. diam., 3-5 diam. long, 



oog., 45-53 M " 57-70 M long, 



oos., 40-48 M " 40-48 /x " 



anth. cell, 12-21 n " 9-1 IM " 



Middlesex Fells, Mass., F. D. Lambert. Halle in Tyrol. 



77. OE. ACMANDRIUM Elfving ex Him, 1900, p. 150, PI. 

 XXIII, fig. 120. Monoecious, oogonium single, rarely 2, 

 depressed-globose or subglobose, operculate, division median, 

 narrow ; oospore depressed-globose (or subglobose) filling or 

 nearly filling the oogonium, membrane smooth ; antheridium 

 i-3-celled, subepigynous, epigynous or hypogynous, often ter- 

 minal ; (?) spermatozoids single ; basal cell usually elongate. 



veg. cell, 7-10 M diam., 3.5-7 diam. long, 



oog., 30-35 M " 28-38 n long, 



oos., 28-33 M " 25-29 n " 



anth. cell, 8-10 M " 10-15*1 " 



111., Transeau. Northern Europe. 



78. OE. CONSOCIATUM Collins & Hervey, 1917, p. 36, PI. I. 

 figs. 1-4; P. B.-A., No. 2068. Dioecious ?, macrandrous ; 

 oogonium single, globose or depressed-globose, operculate, 



