THE PALEONTOLOGY AND STRATIGRAPHY OF THE 
CORNIFEROUS ROCKS OF OHIO. 
INTRODUCTORY NOTE. 
In this paper the writer has followed Dana’s classification 
of the Devonian rooks. This drops the term Upper Helderberg 
and uses in its stead Corniferous. On this basis the strata of 
the Corniferous period compose two epochs, the Schoharie and 
the Corniferous. 
In classifying the faunas the writer has followed Eastman’s 
edition of Zittel’s Paleontology, as far as the uncompleted con- 
dition of the work would permit. 
TIME RANK OF THE STRATA INVESTIGATED. 
It is believed that the Schoharie epoch is absent in Ohio. 
The lithological characters which distinguish that epoch in New 
York are not present in Ohio, and the faunal characters in this 
state will not admit of division into two epochs. The Cornif- 
erous epoch only is recognized. 
GEOGRAPHICAL LOCATION. 
The territory in which this study was made embraces the 
three regions of Ohio in which Corniferous strata are found. 
The first of these is the central, extending from the southern 
part of Pickaway county north to the islands in Lake Erie. 
The second is the northwestern extending in a curve from the 
western part of Lucas county through Wood, Henry, Defiance, 
and Paulding counties into Indiana. The third is the western, 
and is a small outlier confined chiefly to Logan county. 
