46 POTTSVILLE FAUNA OF OHIO 



Schizodus wheeleri Swallow 

 Aviculopecten coxanus Meek and Worthen 

 Deltopecten scalaris ( Herri ck) 

 Deltopecten occidentalis (Shumard) 

 Acanthopecten carboniferous (Stevens) 

 Crenipecten foerstii Herrick 

 Astartella concentrica (Conrad)? 



Euphemus carbonarius (Cox) 

 Pleurotomaria sp. 

 Schizostoma catilloides (Conrad) 

 Naticopsis altonensis (McChesney) 



Pseudorthoceras knoxense (McChesney) 

 Temnocheilus forbesianus (McChesney) 



Fish teeth and plates 



LOWER MERCER LIMESTONE 

 Historical Review 



The Lower Mercer limestone received its name from outcrops 2 

 feet in thickness in Mercer County, Pennsylvania, which were first 

 described by H. D. Rogers in 1858. 1 In 1878 I. C. White and other 

 workers of the Second Pennsylvania Geological Survey made constant 

 use of the term. The stratum was also early recognized by the first 

 geologists of Ohio, among whom was Professor E. B. Andrews, who re- 

 ferred to it simply as the Blue limestone. In 1878 Dr. Newberry gave 

 the name Zoar limestone to exposures of hard, blue, fossiliferous lime- 

 stone near the village of Zoar in the northern part of Tuscarawas County. 2 

 The term Zoar limestone was later employed by Dr. Edward Orton 

 who described it in the Hanging Rock District, 3 and it was so used in 

 some of the later reports of the Geological Survey of Ohio. However, 

 in 1884 Dr. Orton correlated it with the Lower Mercer limestone of 

 Pennsylvania, and at the present time the term Lower Mercer is uni- 

 versally accepted. 4 



Stratigraphy and Extent 



The Lower Mercer is the third member of the series of marine 

 limestones occurring in the Pennsylvanian system, and is the next fos- 

 siliferous horizon above the Boggs where the latter is present. It is 

 the most persistent stratum and has the most extensive outcrop of any 



Rogers, H. D., Geol. of Pennsylvania, Vol. II, Pt. 1., p. 476, 1858. 

 2 Newberry, J. S., Geol. Surv. Ohio, Vol. II, section opp. p. 81; pp. 81-180, 1874; 

 Vol. Ill, p. 60, 1878. 



KMon, Edward, Geol. Surv. Ohio, Vol. Ill, pp. 891, 892, 1878. 

 Orton, Edward, Geol. Surv. Ohio, Vol. V, pp. 13, 14, 1884. 



