OONSPBCTUS OP OOSPORES. 71 



V. Oospore terete, fusiform or ellipsoidal. Mem- 

 brane thin or thick ; flexible, semi-rigid or rigid ; 

 translucent, semi-opaque or opaque ; granulate . Chara. 



(1) Membrane translucent — 



(i) membrane strongly granulate. 



(a) granular density c. 5 per 10 ju C. hispida. 



(b) granular density c. 6 per 10 fi 



G. contraria. 



(c) granular density c. 7 per 10/^ C. vulgaris. 



(d) granular density c. 8 per 10 fx 



C. denudata. 

 (ii) membrane very faintly granulate. 



(a) dull brown . . . G. aculeolata. 



(b) chestnut brown . . . G. rudis. 

 (o) clear yellow . . . C. tomentosa. 

 (d) red-brown . . . . G. haltica. 



(2) Membrane semi-opaque or opaque — 



(i) membrane thick with many evident lamina. 



(a) granules very obscure. 



(i) dull brown and brittle G. aspera. 



(b) granules less obscure. 



(i) granular density c. 7 per 10 jj, 

 very dark dull brown 



G. connivens. 

 (ii) granula.r density c. 9 per 10 f.(, 



dark brown . G. fragifera. 



(iii) granular density c. 5 per 10 /y, 



very dark to black . G. frayilis. 

 (iv) granular density c. 5 per 10 ju, 



very dark to black G. delicatula. 

 (v) granular density c. 7 per 10 /j, 

 bright red-brown 



G. desmacantha. 

 (ii) membrane less thick without evident 

 lamina. 



(a) granular density c. 7 per 10 ju, dull 



brown to black . . G. Braunii. 



(b) granular density c. 6 per 10^, very 



dull brown . . .6'. canescens. 



