INDEX. 
233 
Classes of molluscous animals, 3. 
Clausilia genus, 165 ; geological distribution and synoptical 
list of species of, 166. 
- bidens, 167. 
- biplicata, 166. 
- dubia, 169. 
- laminata, 167. 
- Mortilleti, 170. 
- nigricans, 168. 
- perversa, 168. 
- Bolphii, 169. 
- rugosa, 168. 
Clausium , nature of, 165. 
Coelenteratous animals, 2. 
Coil snails (Planorbis), characters of, 210 ; red fluid of, ib. ; 
geological distribution of, 211 ; synoptical table of 
species of, ib. ; collecting small species of, 218. 
Cold, effects of, on Paludina vivipara and Anodon cygneus, 
56 ; on land snails, 97. 
Collecting bivalves, 19 ; small water snails, 218 ; small land 
snails, 223. 
Colour, secretion of, in shells, 46. 
Colourless blood of molluscous animals, 15. 
Columella of shells, 44. 
Composition of shell in bivalves, 11 ; in univalves, 46. 
Concentric operculum, 46. 
Conchiferous animals, 3. 
Conovulus bidentatus, 179. 
- denticulatus, 178. 
- myosotis, 179. 
- pyramidalis, 179. 
Corbicula consobrina, geographical distribution of, 43. 
Crystalline style in stomach of bivalves, 14. 
Cycladid^: (family), 32; genera of, 33. 
Cyclas (genus), 33. 
- calyculata, 36. 
