TABLE OF GENERA. 67 



* * Month longitudinal, dextral. 

 f Pillar-lip smooth, not folded. 



12. Succinea. Shell oval, amber-coloured; mouth large; front 



entire, rounded. 



13. Bulimus (acutus). Shell turreted, white, variegated ; mouth 



moderate ; front entire, rounded. 

 16. Achatina. Shell turreted, white ; mouth moderate ; front 

 truncated. 



f -j* Pillar with an oblique fold. 



24. LiMNiEUS. Shell ovate or subturreted, perforated ; inner lip 



not expanded. 



25. Amphipeplea. Shell ovate, very thin, imperforated ; inner lip 



rather expanded. 



# # # Mouth longitudinal, sinistral. 

 ■f Pillar-lip smooth ; shell very thin, imperforated. 



28. Physa. Shell ovate; inner lip rather expanded. 



29. Aplexus. Shell turreted ; inner lip not expanded. 



\ \ Pillar-lip with an oblique fold. 

 24. Limn^us pereger lineatus. A monstrosity. 



b. Shell moderately thick ; peristome not thickened, continued. 

 * Shell grooved, variegated, ovate ; mouth suborbicular. 

 32. Cyclostoma. 



* * Shell smooth, olive ; mouth ovate or orbicular. 



5. Valvata. Shell conical or depressed, umbilicated ; mouth 

 orbicular. 



3. Paludina. Shell ovate, conical, perforated, olive, banded ; 



mouth ovate. 



4. Bithinia. Shell ovate, conical, perforated, transparent ; 



mouth ovate. 

 2. Assiminia. Shell ovate, conical, solid, brown ; mouth ovate. 

 22. Acme. Shell subcylindrical, blunt, solid, brown; mouth 

 ovate. 



