82 THE PERMO-CARBONIFEROUS RED BEDS OP 



Ohio. West Virginia. 



Harlem coal Harlem coal. 



Roundknob horizon Pittsburgh red shale. 



Barton coal Bakerstown (?) coal. 



Ewing limestone. 



Cowrun sandstone (?) 



Portersville fossiliferous horizon: 



Anderson coal Bakerstown (?) coal. 



Cambridge limestone Cambridge limestone. 



Wilgus coal. 



Buffalo sandstone Buffalo sandstone. 



Brush Creek fossiliferous horizon . . Brush Creek limestone. 



Mason coal Brush Creek (Mason) coal. 



Mahoning sandstone horizon: 



Upper Upper Mahoning sandstone. 



Mahoning coal Mahoning coal. 



Lower Lower Mahoning sandstone. 



Of these formations only the Birmingham shale, the Round Knob Forma- 

 tion, and the Ewing limestone have yielded remains of reptiles or amphibians. 



The Birmingham shale was named by Stevenson from its position near 

 Birmingham, a suburb of Pittsburgh, Pennsylvania. It lies here 30 feet above 

 the Ames limestone and is from 35 to 50 feet thick. A thin coal-seam at the 

 base has been named by Raymond the Duquesne coal. Just above this coal 

 are found plants, Estheria and fish teeth (Diplodus). 



' ' This shale* is also present in Ohio and, as at Allegheny, has a thin coal (Duquesne 

 of Raymond) marking the lower limit. The Elklick coal of Pennsylvania and West 

 Virginia sections is wanting in Ohio, hence the upper limit of the Birmingham is not 

 definite. Immediately over the Duquesne coal is a persistent fossiliferous limestone, 

 which is named the Skelly, from exposures at Skelly Station on the Pennsylvania 

 Railroad, in Jefferson County, about 10 miles west of Mingo Junction. This bed is 

 25 to 40 feet above the Ames limestone and occurs nearly everywhere in eastern 

 Ohio, excepting where replaced by massive sandstone * * * . 



"In addition to the marine fauna, the shales have also insect and reptilian re- 

 mains. The cockroach fauna from near Richmond, Ohio, collected by Samuel 

 Huston, of Steubenville, and described by S. H. Scudder in Bulletin 124 of the 

 United States Geological Survey, is accounted for as coming from shales a little 

 above the 'crinoidal limestone.' It is probable that this material is from the 

 Birmingham horizon. Professor Scudder lists 2 2 species from this locality, belong- 

 ing to the genera Etoblattina, Gerahlattina, and Poroblattina, 1 7 of which are of the 

 genus Etoblattina. A long list is also given from Cassville, West Virginia, collected 

 from the base of the Dunkard formation, and Professor Scudder '' remarks that, 

 although this locality has no species in common with the Richmond, Ohio, locality, 

 there is a remarkably close relation in the material from the two places. 



"The replacement of the shale by the Morgantown sandstone has already been 

 commented upon in the description of that bed. This has taken place over much 

 of the eastern part of the State, and the fossiltferous shale is rendered very irregular 

 by numerous patches of coarse sandstone. The relation of these beds would indicate 

 that the shale and sandstone are of contemporaneous origin. The sandstone is 

 probably an estuarine or delta deposit, laid down at the same time that sedimenta- 

 tion of clays and silts was taking place in the neighboring salt-water lagoons. 



"Toward the southern part of the State there is an increasing amount of red clay 

 and shale above the Ames limestone, and in many localities these beds, together with 

 the thin-bedded sandstone, constitute almost the entire Ames-Pittsburgh interval. 



• Condit, Bull. 17, Geol. Sur. Ohio, p. 27. 



'' Scudder, Bull. U. S. Geological Survey No. 124, p. 12. 



