PLATE XIII. 



1. Helix unidentata, Chcmn. 



2. Cerithium gigas, l-4lh. 



3. Achatina fulica. Lam. 

 A. Argonauta. 



5. Aplysia. 



6. Dolabelfa. 



7. Interior mould of a Cerithium gigas, l-4lh. 



8. Clavalula scabra. 



9. Cyclostoma carinata, Oliv. 

 10. Melania marginata. 



41. Helix conaidea, Drap. 

 52. TV/ja flpena, Drap. 



13. Melania cochlearella . 



14. costellata. 



15. Bulimus terebraster. 



16. Buccinum Barbadense, Lister. 

 A. The head. 



.. lentacula- 

 /«. .. month . 

 trunk, 

 eyes. 



root. 



operculum . 



r. 



)7 Cerithium. (Buccinum Africanum, Lisler.) 

 The head. 



ff, . . tcntacula. 



»i. mouth. 



ee. .. eyes. 



T. .. trunk, 

 y. .. loot. 



o, ., operculum. 

 IS. Umax phospkorescetis, 1-2. 

 19. 20. Yetus, A dans. (Buccinum Persicum, Lister.) 



it. The head. 



it. ,. tcntacula. 



m. .. mouth. 



eyes, 

 trunk. 



extremity of the mantle, fanning a sort of pipe. 

 tin. ■■ membrane accompanying the mantle. 

 /. A part of its enormous foot. 

 21. Halyotis. 



h. The head. 



it. .. four tcntacula. 



ee. .. eyes. 



», .. membrane which attaches the lower tcntacula to the head. 

 /. .. two anterior extremities of the mantle, coming out of the se- 

 cond hole of the shell. 



