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Fig. 20. Leda prolongata n.sp 66 



Lower Mercer limestone: Fairview School, Licking 



County. 

 Right valve of the holotype. 



Fig. 21. Anthraconeilo bownockeri n.sp 68 



Sharon ore: Lick Run, Scioto County. 

 Left valve of the holotype. x2 



Figs. 22, 23, 24. Naiadites elongata Dawson 73 



Figs. 22,23. Bear Run shale: Elk Township, Vinton 



County. 

 Crushed specimens showing the common mode of 



occurrence. x2 

 Fig. 24. Sharon ore: John Alexander mine, Scioto 



County. 

 Right valve of an uncrushed individual. x2 



Figs. 25, 26, 27. Naiadites ohioense n.sp 74 



Sharon ore: John Alexander mine, Scioto County. 

 Fig. 25. Right valve of a cotype. x2 

 Fig. 26. Left valve of another cotype. x2 

 Fig. 27. Cardinal view of a third cotype. x2 



Plate V. 



Page 



Figs. 1, 2. Posidonia girtyi n. sp 72 



Lower Mercer limestone: Rock Hollow, Vinton County. 



Fig. 1. Right valve of cotype. 



Fig. 2. Right valve of another cotype. 



Figs. 3, 4. Myalina pernaformis Cox . 71 



Boggs limestone: near Hopewell P.O. 



Right valves of two individuals of average size. 



Figs. 5, 6. Myalina pernaformis Cox var 72 



Sharon ore: Lick Run, Scioto County. 



Fig. 5. Right valve of internal cast. 



Fig. 6. Left valve of another internal cast. 



Figs. 7, 8. Deltopecten scalaris (Herrick) 78 



Boggs limestone: near Hopewell P.O., Muskingum 



County. 



Fig. 7. Right valve showing triangular delthyrium. 

 Fig. 8. "Squeeze" of right valve of another individual. 



Figs. 9, 10, 11, 12, 13. Pleurotomaria ornatiformis n.sp 84 



Harrison ore: Jackson County. 



"Squeezes" from external molds of several cotypes. 



92 



