100 GEOLOGY OF OHIO. 



Until the commencement of the present survey it was supposed that 

 the Lower Carboniferous limestone did not extend into Ohio, but that, 

 rapidly thinning northward, in passing from central Kentucky to the 

 Ohio river, the whole mass wedged out. The investigations of Prof. 

 Andrews and his assistants in the south-eastern quarter of the State have 

 shown, however, that the Lower Carboniferous limestone does reach into 

 Ohio, and that it extends in a thin feather edge northward nearly to the 

 National Road. 



The best exposure of this limestone stratum — called by Prof. Andrews 

 the Maxville limestone — is in the vicinity of Newtonville, Muskingum 

 county, where it is from fifteen to twenty feet thick. It is also visible 

 in a layer of eight to ten feet in thickness in Scioto, Jackson, Vinton, 

 Hocking, and Perry counties. 



In lithological character it is generally a gray, compact, partially 

 crystalline rock, with few fossils, and these badly preserved. In certain 

 localities, however, it contains considerable ferruginous coloring matter, 

 by which it is striped and banded. In chemical composition it is a 

 dolomite. Mr. Meek has examined the collection of fossils made from 

 the Maxville limestone, and gives me the following memoranda upon 

 them : 



LIST OF FOSSILS FKOM THE MAXVILLE LIMESTONE. 



1. Zaphrentis. — A small, undetermined, curved, conical species. 



2. Scaphiocrinus decadactylus, Hall ? — Described from the Chester group. 



3. Productus pileiforrrm, McChesney. — Described from the Chester group. Thought 



by Mr. Davidson to be the same as P. Cora, D'Orbigny. 



4. Productus elegans, N. and P.— Described from the Chester group. Some of the 



specimens may be the form Prof. McChesney described from the same horizon 

 under the name of P. fasciculatus. 



5. Clionetes. — Undetermined species. 



6. Athyris subquadrata, Hall. — Described from the Chester (Kaskaskia) group. 



7. Athyris trinuclea, Hall, sp. — Described from the St. Louis (Warsaw) group. 



8. Spirifer (Martinia) contractus, M. and W. — Described from the Chester group. 



9. Spirifer. — Undetermined fragments of perhaps two species. 



10. Terebratula. — An undetermined, small, oval species, showing the fine punctures 



un^'sr a lens. 



11. Avic&i^kcten. — Undetermined species. 



-12. Allorisma.— Undetermined fragments, apparently like A. antiqua, Swallow. De- 

 scribed from the Chester group. 



13. Naticopsis. — A small, undetermined species. 



14. Straparollus perspectivus, Swallow, sp.— Probably a more elevated form of S. planir 



dorsatus, M. and W. Both were described from the Chester group. 



15. Bellerophon sublaevis, Hall.— Described from the St. Louis (Warsaw) limestone. 



16. Pleurotomaria. — A small, undetermined cast. 



