130 BRITISH DESMIDIACE^. 



J+ Semicells with two inflations near the centre. 



178. C. Turpinii. 

 ft Apex of semicells truncate and not produced. 



+ Semicells with two inflations near the centre. 



179. C. didymoprotupsum. 

 %% Semicells somewhat widely truncate, without a 



central inflation. 



Granules unequal in size and uneven in 

 disposition. 



180. C. entoclwndrum. 



181. C. Oligogongrus. 



182. C. Ungerianum. 



183. C. prfemorsvni. 



Granules approximately equal in size, and 

 more or less evenly distributed. 



.' 



184. C. margaritiferum. 



185. C. quaternarium. 



186. C. Amelia. 



187. C. furcatospermum. 

 Semicells with differentiated central granules and 



a slight indication of a central inflation. 



188. C. punctulatum. 



189. C. anisocliondrum. 



190. C. bipun datum. 



191. C. bipapillatum. 



192. C. distichum. 



193. C. quinarium. 



194. C. svbtrinodnlmn. 

 Semicells with a distinct central inflation. 



Margin not crenate. 



195. C.fastidiosum. 



196. C. Kjellmani. 



Margin either slightly or markedly crenate. 



a Central protuberance small and somewhat 

 papilliforni. 



197. C. hiimile. 



198. C. Blytu. 



/3 Central protuberance broader and granu- 

 late. 



199. C. sexnotatum. 



200. C. subcrenatum. 



201. C. subprotumidum . 



202. C. Boeckii. 



203. C. calcareum. 



204. C. subcostatum. 



205. C. costatum. 



206. C. formosulum. 



207. C. subreniforme. 



208. C. pycnoclwndrum. 



