66 TUFTS COLLEGE STUDIES, VOL. IV, No. 7 



division median or slightly superior, narrow ; oospore globose 

 or depressed-globose, filling the oogonium ; membrane smooth ; 

 vegetative cells more or less distinctly clavate ; basal cell 

 depressed-globose ; filaments often united in dense stellate 

 clusters. 



veg. cell, 6-12 M ( -20 n) diani., 1-4 diain. long, 



oog., 28 M diani., 26-28 M long, 



oos., 26/1 " 24-26 M " 



Bermuda, A. B. Hervey. 



79. OE. PRATENSE Transeau, 1914, p. 297, PI. XXIX, 

 figs. 9-12. Dioecious, macrandrous, oogonium single, very rarely 

 2, subdepressed-globose or broadly pyriform-globose, opercu- 

 late, division median, narrow but distinct ; oospore depressed- 

 globose or subglobose, filling or nearly filling the oogonium, 

 membrane smooth ; male filaments more slender than female ; 

 antheridia i-2-celled, usually alternating with vegetative cells ; 

 spermatozoid single ; basal cell of filament commonly elongate. 



veg. cell, female, 10-17 M diatn., 3-5-5-5 diam. long, 



veg. cell, male, 8-15 M " 4-5-5 " " 



oog., 33-40 M " 33-50 M long. 



008., 32-38 M " 28-35 M " 



anth. cell, 10-14 M " 13-18 M " 



Charleston, 111., Transeau. 



Somewhat resembling Of. acmandrium Elfv. and Of. psacg- 

 matosporum Nordst., but both these are monoecious, and of 

 smaller dimensions. 



80. OE. PAUCO-COSTATUM Transeau, 1914, p. 300, PI. 

 XXVIII, fig. 5. Dioecious, macrandrous; oogonium singlf. 

 ellipsoid, operculate, division superior ; oospore ellipsoid, nearly 

 filling the oogonium ; outer membrane smooth, median longi- 

 tudinally ribbed, ribs 15-19, inner membrane smooth ; anthe- 

 ridium 2-8-celled ; spertnatozoids binate, division hori/ontal ; 

 terminal cell obtuse, basal cell usually elongate. 



veg. cell, female, (15- ) 20-27 M diam., 3.5-5.5 diam. long, 



veg. cell, male, (15- ) 10-25 M " 3.2-5.5 " " 



oog., 54-60 M " 70-104 M long. 



oo., 50-56 M " 66-90 M " 



anth. cell, 18-23 M " 8-12 M " 



Casey, 111,, Transeau. 



Resembling Of. australicum Him, but larger, spores more 

 distinctly ellipsoid, and with fewer ribs. 



81. OB. OBLONGUM Wittrock ex Him, 1900, p. 185, PI. 



