238 
INDEX. 
L im ngea (pond snails), characters of, 184; food of, 185 ; 
species of, 186 ; geological distribution of, ib . 
- auricularia, 190. 
- Bumetti, 188. 
-fossaria, 194. 
-glaber, 195. 
- glutinosa, 196. 
- involuta, 198. 
-lacustris, 187. 
- minuta, 194. 
- octona, 195. 
- ovata, 187. 
-- palustris, 193. 
-peregra, 186 ; varieties of, 187 ; dispersion of, 188. 
- stagnalis, 190 ; teeth of, 191 ; disappearance and re¬ 
appearance of, 192. 
- tmncatula, 194. 
Limn^id^e family (water snails), characters of, 181; habits 
and reproduction of, 182 ; peculiar sensation produced 
by, 183; decollation of spire of shells of, 185 ; dispersion 
of, 188 ; disappearance of, 192 ; synoptical list of genera 
of, 184. 
Limpets, fresh-water, 205. 
Lines of growth , 11. 
Lingual ribbon or tongue, described, 48 ; methods of pre¬ 
paration of, 49 ; mounting of, ib. ; different sets of teeth 
of, 50; numerical formula of, 51; value of in classifi¬ 
cation, ib. 
Lips of bivalves, 14. 
Littorinim: (family), 62. 
Longitudinal lines on shells, 45, 
Lunule of bivalve shells, 11. 
M. 
Mantle of bivalves, 13. 
Mantle-lobes , 13. 
