UNIVALVES. 65 



Xerophila itala Helix ericetorum, 270. 

 Xerophila pisana Helix pisana, 278. 

 Xerophila virgata Helix virgata, 287. 



One more list, in conclusion. The following genera are non- 

 marine that is, are either land or fresh-water. In our list of 

 illustrations their names are set a quarter of an inch in, so as to 

 distinguish them at a glance from the sea-shells : 



Pelecypoda 



Anodonta, 58, 59. 

 Dreissensia, 60. 

 Pisidium, 85 to 89. 

 Sphaerium, 81 to 84. 

 Unio, 55 to 57. 



Gastropoda. 



Achatina, 312. 

 Acicula, 398. 

 Amalia, 232, 233. 

 Ancylus, 205, 206. 

 Arion, 241 to 245. 

 Balea, 303. 

 Bithynia, 430, 431. 

 Bulimus, 259 to 262. 

 Carychium, 201. 

 Clausilia, 304 to 309. 

 Cochlicopa, 310, 311. 

 Cyclostoma, 397. 

 Geomalacus, 246. 

 Helix, 263 to 287. 

 Hydrobia 



as regards Hydrobia similis, 427, 



and Hydrobia ventrosa, 428. 

 Limax, 234 to 240. 

 Limnaea, 207 to 214. 

 Neritina, 356. 

 Physa, 227 to 229. 

 Planorbis, 215 to 226. 

 Pupa, 288 to 291. 

 Succinea, 313 to 317. 

 Testacella, 230, 231. 

 Valvata, 441, 442. 

 Vertigo, 292 to 302. 

 Vitrina, 247. 

 Viviparus, 439, 440. 

 Zonites, 248 to 258. 



