Plate IV. 



Page 



Figs. 1, 2, 3. Marginifera muricata var. missouriensis Girty 54 



Lower Mercer limestone: White Cottage, Muskingum 



County. 



Fig. 1. Dorsal valve. 

 Fig. 2. Ventral valve. 

 Fig. 3. Side view of ventral valve. 



Figs. 4, 5. Marginifera wabashensis (Norwood and Pratten) .... 54 

 Lower Mercer limestone: White Cottage, Muskingum 



County. 



Fig. 4. Ventral valve. 

 Fig. 5. Side view of ventral valve. 



Fig. 6. Solenomorpha lamborni n.sp 61 



Sharon ore: Lick Run, Scioto County. 

 Right valve of a cotype. x2 



Figs. 7, 8, 9. Nucula lunulata Girty mss 64 



Morrow formation: Arkansas. 



Fig. 7. Right valve of a cotype. x3 



Fig. 8. Posterior end of the same cotype showing 



the well defined lunule. x3 

 Fig. 9. Anterior end of the same cotype. x3 



Figs. 10, 11, 12. Nucula elongata n.sp 63 



Sharon ore: Lick Run, Scioto County. 

 Fig. 10. Left valve of a cotype. x2 

 Fig. 11. Right valve of another cotype. x2 

 Fig. 12. Side view. x2 



Figs. 13, 14, 15. Nucula subrotundata Girty mss 63 



Morrow formation : Arkansas. 

 Fig. 13. r Left valve of a cotype. x3 

 Fig. 14. Right valve of the same cotype. x3 

 Fig. 15. Posterior view of the same cotype in out- 

 line. x3 



Fig. 16. Solenomya ?? sharonensis n.sp 61 



Sharon ore: Lick Run, Scioto County. 

 Right valve of the holotype. x2 



Figs. 17, 18, 19. Leda inflata Girty mss 67 



Morrow formation: Arkansas. 



Fig. 17. Right valve of a cotype. x2 



Fig. 18. Left valve of the same cotype. x2 



Fig. 19. Cardinal view of the same cotype. x2 



90 



