EESEARCHES 
CCNECTED WITH GEOLOGY. 
145 
number of fossil species, and the succeeding columns, 
varying with the number of different formations in the 
district, to contain the estimate of distribution.) 
I. C. Dim j/ aria. 
1. Tubicolidse. 
2. Pholadidse. 
3. Solenidae. 
4. Myadss. 
5* Mactridse. 
6. Corbulidse. 
7. Lithophagidse. 
8. Nymphidae. 
9. Conchidse. 
10. Cardiidse. 
21. Tritonidse. 
22. PhylHdidee. 
23. Semiphyllididas. 
24. Calyptrteidse. 
28. Colimacidse. 
29. Limneeidse. 
30. Melanidse. 
31. Peristomidse. 
32. Neritidse. 
33. Janthinidss. 
34. Macrostomidse. 
35. PHcacidse. 
ClRRHlFEDA. 
CONCHIFERA, 
11. Arcid^e. 
12. Naiidese. 
13. Chamidap. 
II. C. Monomyaiia- 
14. Tridacnidse. 
15. Mytilidge. 
16. Malleidse. 
17. Pectinidse. 
18. Ostreidse. 
19. Eudistidse. 
20. Brachiopodidse. 
MOLLUSCA. 
I. Pferopoda. 
II. Gasteropoda. 
25. Bullidse. 
26. Laplyisidse. 
27. Limacidse. 
III. Trachelipoda. 
36. Scalaridse. 
37. Turbinidse. 
38. Canaliferidse. 
39. Pteridse. 
40. Purpuridse. 
41. Columellidse» 
42. Convolutidae, 
