256 Hind : Fossil Zones in the (Uirhonifcrons Rocks. 



most prolific in species, occurs about 40 feet below the Zone of 

 Anthracomya adatnsii or the Burnwood ironstone. A second 

 marine bed, known as the Florence marine bed, occurs some little 

 distance below this coal. The fifth marine bed occurs above the 

 moss coal or Zone of Carboiticola turgida^ and the sixth a short 

 distance below that seam. The seventh marine band is found 

 250 feet below the Zone of Anthracomya ivilliamsoni or the 

 Hard mine coal. The eighth bed, the horizon of which is 

 doubtful, need not detain us. Bed No. 9 is in the Cheadle Coal 

 Field, and for the present we will not discuss its equivalent in 

 the main coal field of North Staffordshire. Marine Bed No. 10 

 occurs between the Winpenny and four feet coals. Marine Bed 

 No. 1 1 consists of two or three bands with marine fossils, near 

 the Crabtree Coal, which we consider to be the equivalent of 

 the Bullion seam of Lancashire and the Hard bed of Yorkshire. 

 It is my hope that this brief table of Life Zones, which has 

 been established for one important coal field, may be a guide to 

 workers in other coal fields, and enable fossil charts to be drawn 

 up for each of them. There is no doubt that collectors have 

 studiously neglected the mollusca of the coal measures in the 

 past, but it is to be hoped that the future will tell a very 

 difi"erent tale. 



DESCRIPTION OF PLATE XXI. 



Figs. 



I, 2. Anthracomya modiolaris, Sow. Sp. 



3, 4. Naiaiites modiotaris, Sow. Sp. 



5. Carbonicola titrgida. Brown .Sp. 



6. Naiadites carinata, Sow. Sp. 



7. Anthracomya adamsii, van expansa, Hind. 

 8, 9. Naiadites quadrata, Sow. Sp. 



10, II. Anthracomya dolahrata, Sow. Sp, 



12. Naiadites triangularis, Sow. Sp. 



13. ,, carinata, Sow. Sp. 



14. ,, elongata. Hind. 

 15, 16. Anthracomya -auirdi, Etli. 



DESCRIPTION OF PLATE XXII. 

 Figs. 



1-3. Carbonicola acuta. Sow. 



4. ,, aquilina. Sow. Sp. 



5. Anthracomya senex, Sow. 

 6, 7. Carbonicola robusta, Sow. 



8. Anthracomya pulchra, Hind. 



9. Carbonicola cuneiformis. Hind. 



10. Anthracomya phillipsi, Williamson. 



11, 12. ,, ivilliamsoni Hrown Sp. 

 13, 14. Carbonicola gibhosa. Hind. 



15. ,, similis. Brown Sp. 



16, 16a. Anthracomya minima, Liidwit;', Sj). 

 17- .1 pulchra. Hint!. 



18. ,, adamsii, .Sow. Sp. 



19. ,, nuctilaris, Hind. 



Naturalist, 



