40 TiMEHRI. 



Natural History, to whom I desire to express my hearty 

 acknowledgment. 



Univalves (Gasteropoda,) 



1. Ampullaria glauca, Linne. 



2. „ cornu-arietes, Linne. 



3. „ peristomata, d'Orb. 



4. ,, sp. (papyracea ?) 



5. Melania atra. Rich. 



6. ,, circumsulcata, v.d. Busch. 



7. Streptaxis deformis, Fer. ( = S. glabra, Pfeiff.) 



8. Bulimus oblongus, Miill. 



9. ., fraterculus, Pfr. 



10. ,, bensoni, Reeve. 



11. ,, sp. 



12. Stenogyra o6lona, Chemnitz. 



13. ,, goodalli, Miill. 



14. ,, beckiana, Pfr. 



15. Leptinaria lamellata, Pot. et. Mich. 



16. Vaginula occidentalis, Guilding. 



17. Parmacella sp. (?) 



18. Physa sp. 



19. Hyalina sp. 



Bivalves (Lamellibranchiata.) 



20. hyria schomburgkiana , Sow. 



21. Prisodon latialata, Sow. 



22. Paxyodon latilobiata, Sow. 



23. Anodonta ensiformis , Spix. 



24. „ sp. 



Of the Univalves, the Black-shells (Melania) and the 

 Apple-snails (Ampullaria) are aquatic, and breathe by 

 means of plume-like or pe6^inated gills, which are 



