26 POTTSVILLE FAUNA OF OHIO 



and the coal may be interbedded with or replaced by shales and black 

 band ore. In Scioto County the coal is thin or is replaced entirely by 

 carbonaceous shales, while along Tattle Creek, south of Dever Valley, 

 the deposit gives way to sandstone. In Lick Township, Jackson 

 County, the coal is interbedded with dark fissile shales and black band 

 ore; in Muskingum County the member is thin and is usually represented 

 by dark, carbonaceous shales. Fossils are fairly abundant in number 

 of individuals, but with the exception of a single fish plate, all the 

 specimens discovered belong to a single species of the fresh or brackish 

 water pelecypod, Naiadites elongata Dawson. Collections were made 

 from various parts of Scioto and Jackson counties. 



Description of Geologic Sections and Collecting Localities 



Scioto County. In Section 3, Bloom Township, on the land of 

 H. H. Stevenson, Naiadites elongata Dawson occurs in the dark shales 

 overlying the Bear Run coal. The following section was measured 

 here (Locality 13) i 1 



Feet Inches 



Sandstone, massive 6 



Shale, blue, tough, lower part f ossilif erous 7 



Coal, Bear Run, upper part somewhat bony 2 4 



Jackson County. Along the Dever Valley in the southern part of 

 Hamilton Township, the shales above the coal are everywhere fossil- 

 iferous, and collections of Naiadites elongata were made at various 

 places along the valley. One of the best collecting localities was found 

 on the land of Edward Toffin, in the southern part of Section 25, where 

 the geologic section below was measured (Locality 14) : 2 



Rock succession on land of Edward Toffin, Section 25, Hamilton Township, 



Jackson County 



Feet Inches 



Coal blossom, Tionesta 1 



Covered 40 



Ore, Sand Block __ 4 



Covered 133 



Shale, blue 10 



Shale, blue, tough, lower part fossiliferous > 



Coal, good . 



Coal, bony f Bear Run - 



Shale, black, carbonaceous 



2 



1 7 



3 

 6 



'Stout, W., Geol. Surv. Ohio, Fourth Ser., Bull. 20, p. 556, 1916, 

 2 Idem., p. 116. 



