GUERNSEY COUNTY. 223 



5. Lopliophyllum. Sp. undetermined. 



6. Productus semi-reticulatus Martin, Sp. 



7. Productus Prattenanns Norwood. 



8. Productus Nebrascensis Owen. 



9. Productus punotatus. 



10. Productus longispiuus Sow. 



11. Productus. Sp. undetermined. 



12. Chonetes granulifera Owen. 



13. Chonetes Smithii N. and P. 



14. Ortbis carbonaria Swallow. 



15. Hemipronites crassus M. and H. 



16. Rhyncbonella Osagensis Swallow. 



17. Spirifer cameratus Morton. 



18. Spirifer planoeonvexus Sbumard. 



19. Spirifer lineatus Sowerby. 



20. Spiriferiua Kentuotensis Shum., Sp. 



21. Eetzia punctilifera Shum. 



22. Athyris subtilita Hallj Sp. 



23. Discina nitida ? 



24. Nucula Clike Nucula ventrlcosa, H.). 



25. Yoldia (like Yoldia carbonaria, Meek). 



26. Euomphalus rugosus Hall. 



27-28. Bellerophon. 2 sp. undetermined. 



29. Pleurotomaria. Sp. undetermined. 



30. Macroclieilus primogenius Conrad. 



31. Macrocheilus. Sp. undetermined. 



32. Cyrtoceraa. Sp. undetermined. 



33. Phillipsia. Sp. undetermined. 



34. Petalodus destructor Newberry. 



The shales immediately above the limestone frequently contain numer- 

 ous specimens of Spirifer cameratus, and it is more than probable that the 

 Nucula and Yoldia of the list are from the shales. In some portions of 

 the county a slaty coal or bituminous shale is found ten or twelve feet 

 above the limestone, but it is of no value at any point where seen. 



Coal No. 76 is worked at various localities in Madison, Jefferson, Cen- 

 ter, and Cambridge townships. It is variable in thickness — four feet in 

 Madison to ten inches in Knox — but is persistent, having been traced 

 from Carroll county, through Harrison and Guernsey, to within three 

 miles of the Muskingum River, in Muskingum county. It is seldom of 

 economical value, being usually a cannel coal of low grade. 



The interval between the Crinoidal limestone and Coal No. 7a seems 

 to increase southwardly, for in Adams township a peculiar buff limestone 

 is found seventy-five feet above the coal and from fifty to seventy fe^ 

 below the crinoidal. Above this limestone, which is fossiliferous, there is 



