DESCRIPTION OF THE PLATES. 
Fig. 6. Cerithium spiratum, completely calcedonic. 
7. Terebra plicatula. 
8. A fossil shell from Courtagnon, of the genus Cancellaria. 
9. Melania rnarginata. 
10. Calyptrcea sinensis from Essex. 
11. A silicious rostellarite from Devonshire, imbedded in sandstone. 
12. Turritellites perforatus. 
13. A volute from Essex. 
14'. Marginella eburnea from Grignon. 
15. Murex tubifer from Grignon. 
16. Murex rugosus from Essex. 
17. A fossil shell partaking of Cassis and Buccinum. 
18. A fossil shell approaching to the genus Belphinula. 
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 Buccinum. 
24>. A cast of a large species of sulcated Cyprcea from Verona. 
25. Eburna gldbrata. 
26. A species of Pleurotoma from Grignon. 
N. B. The shells in this plate are, by mistake, reversed. 
Fig. 1. 
2 . 
3. 
4. 
5. 
6 . 
7. 
8 . 
9. 
10 . 
11 . 
12 . 
13. 
PLATE VI. 
A fossil shell of an unknown genus somewhat resembling Belphinula. 
Natica Canrena, completely silicious, from Devonshire. 
The opposite side of the fossil, Fig. 1. 
A calcedonic cast of Nerita conoidea, with the containing shell. 
The under side of Fig. 4. 
IL urex contrarius from Essex. 
1 The upper and under sides of a fossil of the same genus with that figured Fig. 1 
J and 3. 
A magnified representation of a fossil shell of the genus Sigaretus. 
The same shell of its natural size. 
A spirulite in red marble from Oeland. 
j- Vermiculitce in the fissile stone of Pappenheim. 
