Raymond : Fauna of the Allegheny Series. 145 



Enoiiiih is at hand, Iiowever, to indicali' that the fauna of the Vanport is 

 much more Hkc that of the Pottsville tliaii it is like the fauna found in the 

 various marine dejwsits of the Conemau^h. 



CONEMAUGH SERIES, BrITSII CrEEK LIMESTONE. 



Marine fossils are found at a number of horizons in the Conemaugh. 

 In West Virginia there is a shale with a marine fauna at the base of the 

 series, but so far as the writer knows this shale does not occur in Pennsyl- 

 vania. In this State the oldest marine fauna is found in the Brush Creek, 

 about 100 feet above the base of the series and 350 feet above the Vanport. 

 The Brush Creek consists of both limestone and shale, the limestone 

 usually thin and impure, the shale fine grained and black. Fossils are 

 abundant, and, in the shale, well preserved. This formation has an even 

 greater extent than the Vanport, as it is found from the Allegheny Front 

 to the western border of the State, and has been recognized in Maryland, 

 West V^irginla, and Ohio. 



Fossils have been collected from the Brush Creek at Bens Creek, 

 Donohoe, Blackburn, West Apollo, Wittmer, and Allegheny, and the 

 commoner species so far as identified are listed in the table. The locality 

 at Bens Creek is of some historical interest, as the type locality of the first 

 fossils described from the Coal Measures is only a few hundred yards 

 east from that station. These first fossils, described by Conrad in 1835, 

 are Turbo tabulata {Worthenia tahulata), Stylifer primngenia (Sphcerodoma 

 primogenia) , and Turho insedus, a shell similar to, if not the same as 

 Pleurotomaria carbonaria. The locality was described by Edward Miller 

 in the Transactions of the Geological Society of Pennsylvania, Vol. I, 

 1835, page 251. He wrote; "The most interesting specimens found in this 

 quarter are in a deep cutting at the head of inclined plane No. 3 [of the old 

 Portage Railroad]. A stratum of good coal [Gallitzin] two feet thick is 

 found at this place, having a roof of black shale four feet thick, upon which 

 is an unstratified bed of argillaceous rock containing a great variety of 

 shells and other marine remains." 



The fossiliferous layer is not at present exposed, as the soft shales above 

 it have crumbled down and covered it, but several loose fragments mingled 

 with the talus show that fossils may still be obtained there. The type of 

 Petalodus alleghaniensis (P. ohioensis Safford), described by Leidy in 

 1856, was also obtained at this locality. 



In the fauna of the Brush Creek the mollusca predominate, the gastro- 

 poda being especially abundant. Only one common species, Worthenia 



L 



