84 POTTSVILLE FAUNA OF OHIO 



Feet Inches 



Sandstone, coarse, thin-bedded, cross-bedded 15 



Ore, nodular, 



Limestone, hard, blue, sparingly 



fossiliferous ____________________ } Lower Mercer ____ * 



Limestone, very fossiliferous 



Shale, extremely fossiliferous _______ J 



Collections were made from both the hard, limestone and the ex- 

 tremely fossiliferous black shale which underlies it: 



FOSSILS FROM THE LOWER MERCER LIMESTONE 



Crinoid segments 



Derby a crassa (Meek and Hayden) 



Chonetes mesolobus Norwood and Pratten 



Productus cora d'Orbigny 



Productus semireticulatus (Martin) 



Pustula nebraskensis (Owen) 



Marginifera muricata var. missouriensis Girty 



Marginifera wabashensis (Norwood and Pratten) 



Spirifer opimus Hall 



Squamularia perplexa (McChesney) 



Composita subtilita (Hall) 



Acanthopecten carboniferous (Stevens) 



s 



FOSSILS FROM THE BLACK SHALE BELOW THE LIMESTONE 



Crinoid segments 



Derbya crassa (Meek and Hayden) 



Chonetes mesolobus Norwood and Pratten 



Productus cora d'Orbigny 



Productus semireticulatus (Martin) 



Pustula nebraskensis (Owen) 



Marginifera muricata var. missouriensis Girty 



Marginifera wabashensis (Norwood and Pratten) 



Spirifer opimus Hall 



Squamularia perplexa (McChesney) 



Composita subtilita (Hall) 



Aviculopecten herzeri Meek 

 Aviculopecten coxanus Meek and Worthen 

 Deltopecten occidentalis (Shumard) 

 Deltopecten scalaris (Herrick) 

 Acanthopecten carboniferous (Stevens) 

 Entolium attenuatum Herrick 

 Entolium aviculatus (Swallow) 



Naticopsis altonensis (McChesney)? 



In the extreme eastern part of Mahoning County near the Ohio- 

 Pennsylvania line, Lower Mercer fossils were collected from exposures 



