STRATIGRAPHY OP FOSSILIFEROUS MEMBERS 53 



The following fossils were obtained here: 



Crinoid segments 



Rhombopora lepidodendroidea Meek 



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) 



Spiriferina kentuckyensis (Shumard) 



Spirifer opimus Hall 



Composita subtilita (Hall) 



Vinton County. Excellent collecting is found in the dark, ex- 

 tremely fossiliferous shales which outcrop in Rock Hollow, western 

 part of Section 33, Elk Township, where the following geologic section 

 was measured (Locality 34): 



Feet Inches 



Limestone, gray __ 10 



Shale, gray 2 6 



Shale, dark, very fossiliferous__. \ T n/r / 6 



J > Lower Mercer 4 



Limestone, gray, very fossiliferous I I __ 6 



The following fossils were collected: 



Plantae 



Derbya crassa (Meek and Hayden) 

 Marginifera muricata var. missouriensis Girty 



Posidonia girtyi n. sp. (abundant) 

 Posidonia vintonensis n. sp. (very abundant) 

 Aviculopecten coxanus Meek and Worthen 

 Pleurophorella sesquiplicata Price 



Schizostoma catilloides (Conrad) 

 Pseudorthoceras knoxense (McChesney) 



Hocking County. The two benches of the Lower Mercer with its 

 normal thickness are well shown near the plant of the Union Furnace 

 Brick Co., Section 23, Starr Township, about three-fourths mile 

 south of Union Furnace. No collections of fossils were made, but the 

 geologic section below was measured: 



Feet Inches 



Limestone, blue, fossiliferous 1 1 5 



Shale ? Lower Mercer < _. 1 



Limestone, blue, fossiliferous- _ , 2 2 



