104 POTTSVILLE FAUNA OF OHIO 



Pustula nebraskensis (Owen) 



Pustula punctatus (Martin) 



Marginifera wabashensis (Norwood and Pratten) 



Spirifer cameratus Morton 



Spirifer opimus Hall 



Collections were made from the Upper Mercer black flint which is 

 exposed in the bed of Symmes Creek, east of the crossroads; fossils 

 from the Boggs and Lower Mercer members were also obtained from 

 Symmes Creek (Locality 29). The fauna from the flint includes the 

 forms listed below: 



Fusulina secalica (Say) 



Girtyina ventricosa (Meek and Hayden) 



Crinoid segments 



Fenestella limbata Foerste 

 Prismopora sereata (Meek) 



Derbya crassa (Meek and Hayden) 



Chonetes mesolobus Norwood and Pratten 



Productus cora d'Orbigny 



Productus semireticulatus (Martin) var. 



Pustula nebraskensis (Owen) 



Marginifera wabashensis (Norwood and Pratten) 



Spiriferina kentuckyensis (Shumard) 



Spirifer cameratus Morton 



Spirifer opimus Hall 



Squamularia perplexa (McChesney) 



Probably the best locality for collecting fossils which was found 

 in the Upper Mercer member, is located along the small eastern tribu- 

 tary of the North Branch of Symmes Creek about one-fourth mile 

 north of the crossroads. Here the member reaches the exceptional 

 thickness of 5 feet 3 inches and is composed of two layers, the upper 

 of flint and the lower of hard, very fossiliferous limestone in which 

 large crinoid stems are abundant. This limestone resembles the Lower 

 Mercer very closely not only in appearance but also in character and 

 abundance of fossils. The stream forms a small waterfall over a pro- 

 jecting ledge of Upper Mercer limestone. Below the limestone there 

 occurs a layer of extremely fossiliferous black shale associated with 

 the Bedford coal, from which a collection of fossils was also made. 

 The geologic section here follows (Locality 68) i 1 



'Stout, W., Geol. Surv. Ohio, Fourth Ser., Bull. 21, p. 106, 1918. 



