201 



dage. They are rather sharply ribbed longitudinally, and are mostly of 

 glossy whiteness. 



So far as is at present known, the genus is peculiar to the Island of 

 Jamaica. 



1. affinis, C. B. Adams. 



2. Beardsleana, id. 



3. conica, id. 



4. costulosa, id. 



5. elegans, id. 



6. exilis, id. 



7. expansa, id. 



8. fort is, id. 



Species. 



9. gracilis, C. B. Adams. 17. pauperata, C. B. Adams. 



10. Hilliana, id. 18. procera, id. 



11. inornata, Cliitty. 19. pygmaea, id. 



12. Jamaicensis, Pfr. 20. pyramidata, id. 



13. magna, C. B. Adams. 21. sinuosa, Cliitty. 



14. media, id. 22. striosa, C. B. Adams. 



15. minor, id. 23. typica, id. 



16. parva, Cliitty. 24. vicina, irf. 



Geomelania Jamaicensis. PI. 18. Pig. 95. Shell of white, glassy 

 substance, showing its fine longitudinal ribs, and tongue-like pro- 

 duction of the aperture. 



Family 16. COLIMACEA. 



Shell ; multiform, not tubercled, nor spined, nor varicose, rarely 

 ribbed ; aperture occasionally toothed; lip sometimes simple, 

 mostly reflected. No operculum. 



In the great family of land shells included under this head, the animal 

 is more of the slug type, and has no operculum. The shell is mostly of 

 light structure, varying in substance and colour according to temperature 

 and to the nature of the vegetation on which its inhabitant feeds. As 

 there is no country without its snail, its geographical range is universal. 

 Some forms, such as Helix and Bulimus, have the widest possible distri- 

 bution, but others, such as Auostoma, Achatina, and Achatinella, are 

 extremely local. The species, numbering upwards of four thousand, are 

 divided into twelve genera, as follow : — 



Clausilia. Achatinella. Anostoma. 



Cylindrella. Partula. Proserpina. 



Pupa. Bulimus. Succinea. 



Achatina. Helix. Vitkina. 



