^1^ Sew Sjivcies of Fossils from Ohio. 



Species from the Marcellus Sliales.^ 



Tlic following speeie8 occur in a highly bituminous brown 

 shale, of but a few feet in thickness, and having intercalated 

 beds of thin shaly limestone associated with it. The bed occurs 

 near the upper part of the limestones heretofore referred to the 

 Upper Helderberg group in Ohio, and below the layers known 

 as the Delaware stone, characterized by an abundance of remains 

 of Devonian fishes. Tliese black or brown shales, so far as yet 

 explored, contain only the following S2:)ecies. most of whicli are 

 known foi-ms, and some of them cliaracteristic species of the 

 Marcellus Shales of New York. The species Lliujida Maiini, 

 Hall, occurs in the upjier blue layers of the Delaware beds at 

 Delaware, and in a corres})onding j)osition at other localities, 

 but so far as yet known does ]iot occur in the lower i)ortious of 

 the grou]). At one of the localities where the fossils were ob- 

 tained from the brown shales, the layers immediately above 

 these beds are thickly covere<l with specimens of Teiitdculites 

 scalariformis. Hall, and Spirifer (jregaria, Clapp ; and although 

 both these si)ecies may be occasionally found at a lower horizon, 

 they are never abundant except in the uppei" part of the grou]), 

 and are unknoAvn in the lower part. Judging fi'om these cir- 

 cumstances, together with the lithological character of the shales 

 and the known position of the species occurring in them, it 

 would appear reasonable to consider these brown bituminous 

 shales and limestones as being the western representatives of the 

 Marcellus Shales of New York ; wliile the beds above them, 

 characterized by the presenc:^ of large numbers of Teidaculites 

 and Spirifer gvegaria, would ai)pear to represent the Hamilton 

 group of New York. In pursuance of this idea, several sections 

 have been critically examined in Central Ohio, and it is found 

 that the blue Delaware stone is followed by rapid repetitions of 

 brown shale, and thin bedded shaly limestones, and finally by 

 soft, blue, muddy shales, resembling the Moscow shales of New 

 York, which are followed by beds of thin fissile black shales, 

 representing the Genesee slates of the New York series. 



* In Vol. V, Pal. N. Y., on pp. 146 and 147, after speaking of the section of rocks at the 

 Falls of the Ohio, and the i)robability that the hydraulic cement bed and the layers above it, 

 up to the base of the Black Slates, are of the age of the Hamilton beds of New York, the au- 



