278 



PLATE VII 



Page 



Figs. 1 to 3. Lingula carbonaria Shumard 166 



Fig. 1. Anthony coal horizon: Scioto County, near 



Scioto Furnace, Locality 7. x2 



Figs. 2, 3. Upper Mercer member: Vinton County, Elk 

 Township, Locality 60. x2 



Fig. 4. Glossina waverlyensis (Herrick) 169 



Lower Mercer limestone: Muskingum County, southeast 



of Frazeysburg, Locality 43. 

 "Squeeze" of external mold. 



Figs. 5 to 8. Orbiculoidea stoutella n. sp 173 



Harrison ore: Jackson County, Hamilton Township, 



Locality 1. 

 Fig. 5. Internal cast of dorsal valve of a cotype showing 



internal markings. x2 

 Fig. 6. Internal cast of another cotype. 

 Fig. 7. Another cotype on which portions of the shell are 



preserved. 



Fig. 8. Lateral view of a cotype showing the normal con- 

 vexity of the species. 



Figs. 9, 10. Derbya crassa (Meek and Hayden) 176 



Fig. 9. Ventral valve showing average size of specimens 

 from the Lowellville member. 



Lowellville member: Muskingum County, Poverty 



Run, Locality 19. 



Fig. 10. Dorsal valve showing average size of specimens 

 from the Lower Mercer limestone. 



Lower Mercer limestone: Licking County, Bald 

 Knob, Locality 46. 



Fig. 11. Derbya robusta (Hall) 177 



Internal cast of dorsal valve. 



Lower Mercer member: Scioto County, Vernon Township, 

 Locality 31. 



Fig. 12. Aulacorhynchus millepunctatus Meek and Worthen 180 



Internal mold. 



Lower Mercer member: Scioto County, Vernon Township, 

 Locality 31. 



Fig. 13. Rhipidomella pecosi (Marcou) 175 



After Mark. Conemaugh formation: Ames limestone, 



Deersville, Ohio. x2 

 Ventral valve. 



Figs. 14, 15. Chonetes mesolobus Norwood and Pratten 179 



Lower Mercer limestone: Muskingum County, southeast 



of Frazeysburg, Locality 43. 

 Fig. 14. Ventral valve. 

 Fig. 15. Dorsal valve. 



Figs. 16 to 18. Chonetes choteauensis Mather 178 



Lowellville member: Muskingum County, Poverty Run, 



Locality 19. 

 Figs. 16, 17. Ventral valves of two specimens with shell 



partly preserved showing punctate structure. x2 

 Fig. 18. Ventral valve, showing character of spines on the 

 hinge line. x2 



