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



Dioecious, nannandrous, gynandrosporous ; oogonia single, de- 

 pressed-globose or subglobose, pore median or slightly higher; 

 oospore subglobose, nearly filling the oogonium, epispore cov- 

 ered with subuliform spines ; suffultory cell similar to other 

 veg. cells; androsporangia hypogynous, i- (or more-?) celled; 

 dwarf males slightly curved, on the suffultory cells, antheridium 

 external, i-2-celled. 



This species was collected by Ravenel, but the specimen re- 

 mained unnoticed until Hirn found it and published it in his 

 Monograph in 1900. It is quite similar in character to Oe. 

 aster, a Swedish plant, also of a single station, which has a 

 similar spinous oospore, but is smaller in all its dimensions, 

 with longer cells ; Oe. cchinospcrmum has similar spines on the 

 oospore, but has stouter vegetative cells, so that the oogonia do 

 not appear so swollen ; they are moreover ellipsoid instead of 

 depressed. 



46. OE. ECHINOSPERMUM A. Braun in Kiitzing, 1849, p. 

 366; Wolle, 1887, p. 86, PI. LXXXIV, fig. 7; Hirn, 1900, p. 

 199, PI. XXXIII, fig. 204; Wittr. and Nordst., Alg. Exsicc., 

 Nos. 12, 506. Dioecious, nannandrous, gynandro- or idioandro- 

 sporous ; oogonia single, ellipsoid-globose or subglobose, pore 

 median ; oospore globose, almost filling the oogonium, epispore 

 with subulate spines ; suffultory cell not swollen ; androspor- 

 angia i-5-celled, dwarf males slightly curved, on the suffultory 

 cell, antheridium external, i-2-celled. 



veg. cell, 18-30 M diam., 2%-$ l / 2 diam. long. 



oog., 39-50 M " 41-57 Mlong. 



COS., 38-47 M " 38-49 M " 



andr. cell, 21-25 M " 9 -I 5 M " 



nan. stipe, 10-15 M " 26-35 M " 



anth. cell, 6-12 fj. " 6-15 /a " 



Mass., N. Y., N. J., Pa. Europe. 



Var. HORRIDUM Hirn, 1900, p. 201, PI. XXXIII, fig. 205; 

 Oe. echinospermum var. ? Wolle, 1887, p. 86, PL L,XXXV, 



