DESCRIPTION OF THE PLATES. 



Fig. 6. Cerithium spiratum, completely calcedonic. 



7. Terebra plicatula. 



8. A fossil shell from Courtagnon, of the genus Cancellana. 



9. Mdania marginata. 



10. Calyptr&a sinensis from Essex. 



1 1 . A silicious rostellarite from Devonshire, imbedded in sandstone. 



12. Turrit ellites perforatus. 



13. A volute from Essex. 



14. Marginella eburnea from Grignon. 



15. Murex tubiferfroui Grignon. 



16. Murex rugosus from Essex. 



17. A fossil shell partaking of Cassis and Buccinum. 



18. A fossil shell approaching to the genus Delphinula. 



19. The opposite side of the fossil shell, No. 17. 



20. Buccinum stromboides from Grignon. 



21. A fossil patella from Gloucestershire. 



22. A fossil shell resembling Murex Erinaceus. 



23. A fossil shell possessing some of the characters of Harpa, Cassis, and Buccmum, 



24. A cast of a large species of sulcated Cypraa from Verona. 



25. Eburna glabrata. 



26.' A species of Pleurotoma from Grignon. 



N. B. The shells in this plate are, by mistake, reversed. 



PLATE VI. 



fig. 1. A fossil shell of an unknown genus somewhat resembling Delphinula. 



2. Natica Canrena, completely silicious, from Devonshire. 



3. 'The opposite side of the fossil, Fig. 1. 



4. A calcedonic cast of Nerita Conoidea with the containing shell. 



5. The under side of Fig. 4. 



6. Murex contrarius from Essex. 



7. ) The upper and under sides of a fossil of the same genus with that figured Fig. 1. 



8. j and 3. 



9. A magnified representation of a fossil shell of the genus Sigarctus. 



10. The same shell of its natural size. 



11. A spirulite in red marble from Oeland. 



12 % 



I Vermiculita in the fissile stone of Pappenheim. 



13. ) 



