COSMAEIUM. 129 



SECTION C. Semicells reniform, elliptical, subelliptical, or 

 oblong-elliptical in outline. 



Senaicells distinctly reniform in outline. 



t Apices of cells produced. 151. C. ornatum. 



152. C. commisurale. 

 ft Apices of cells not produced. 



153. C. dentiferum. 



154. C. reniforme. 

 Semicells elliptical in outline, sinus linear. 



f Cell-wall uniformly granulate, or nearly so. 

 J Margin of seinicells entire. 



155. C. Turneri. 



156. C. Brebissonii. 



157. C. Logiense. 



158. C. gramdatum. 



159. C. Portianum. 



160. C. orthosticJmm. 



161. C. solidum. 

 J{ Margin of semicells undulate. 



162. C. Etchachanense. 



163. C. Slewdrumense. 



tf Cell- wall not uniformly granulate ; granules in the 



*/ O 



centre of the semicells differentiated and sometimes 

 isolated. 



164. C. trachypleurum. 



165. C. isthmochondrum. 



166. C. jenisejense. 



167. C. splialerosticlium. 



168. C. geminatum. 



** Semicells elliptical or oblong-elliptical in outline, sinus 



open. 

 t Cells large. 



+ Cell- wall finely granulate. 



169. C. trachydermum. 

 ++ Cell-wall coarsely granulate. 



170. C. spliseroideum. 

 ft Cells small. 171. C. Wittrockii. 



172. C. synthUbomenum. 



SECTION D. Semicells pyraniidate or subpyraniidate in outline, 

 with the apex truncate. 



* Cells as Ions; as broad, or yerv slightly lono-er. 



/ v 



t Apex of semicells truncate and produced. 

 + Semicells with one central inflation. 



173. C. protractum. 



174. C. Corbula. 



175. C. Sportella. 



176. C. vexatvm. 



177. C. Quassilus. 

 VOL. III. 9 



