232 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



3-8 diam. long. 

 3-9 " 

 2 9-4i /x long. 



24-30 il " 



5-7 /x " 



So. America. 



Resembling Oe. cardiacum, but a more slender plant, and with 

 pore higher up on the oogonium. 



9. OE. VARIANS Wittrock and L,und in Wittrock, 1874, p. 

 ii ; Hirn, 1900, p. 89, PL IV, fig. 23; Oe. polymorphum Wolle, 

 1887, p. 73, PI. L/XXIV, figs. 16-19. Monoecious; oogonia 

 single, very rarely 2, depressed- or subdepressed-pyriform- 

 globose, pore nearly superior ; oospore globose, not filling the 

 oogonium, membrane smooth ; antheridia to g-celled, scattered ; 

 spermatozoids binate, division horizontal ; basal cell elongate, 

 terminal cell obtuse. 



veg. cell, 12-16 /u diam., 3-9 diam. long. 



oog., 35-50 /x " 34-55 M long. 



oos., 31-41 M " 3-4i M " 



anth. cell, 11-15 M " 5-7 M " 



N. J. Europe. 



Characterized specially by the high position of the pore, and 

 by the antheridia, in series of several, irregularly placed among 

 the vegetative cells. 



10. OE. FRAGILE Wittrock, 1870, p. 120; Wolle, 1887, p. 71, 

 PI. LXXIV, figs. 4-6 ; Him, 1900, p. 96, PI. V, fig. 33 ; P. B.-A., 

 No. 1477. Monoecious; oogonia single, globose or subobovi- 

 form-globose, pore superior ; oospore globose, filling the oogo- 

 nium, membrane smooth ; antheridia i-3-celled, hypogynous or 

 subepigynous ; spermatozoids binate, division horizontal ; basal 

 cell elongate. Fig. 81. 



veg. cell, 12-17 M diam., 4-7 diam. long. 



oog., 42-50 /x " 44-55 M long. 



oos., 39-46 /x " 39-46 /x " 



anth. cell, 12-15 M " 10-12 M " 



Mass., Pa. Europe. 



Beside the type, Hirn notes and figures, PI. VI, fig. 34, a 

 form, not named, from Massachusetts, with dimensions of cells, 

 oogonia and oospores about 3 ^ more than the type ; the an- 

 theridia may be up to 6 in a series, occurring irregularly in the 

 filament. 



11. OE. VAUCHERII (L,eCl.) A. Braun, 18553, p. 40, PL II, 

 fig. 13; Hirn, 1900, p. 97, PL VI, fig. 36; Wittr. and Nordst., 



