PLATE LIV 



PAGE 



Figs. 1, 2. BATOSTOMA JAMESI (Nicholson) 220 



1. Zoariuni natural size. 



2. Surface of same enlarged, showing rounded cells with thick wall and 



numerous acanthopores. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Pigs. 3, 4. RAFINESQUINA SQUAMULA (James) 264 



Two examples, each showing the pedicle valve. 

 Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 5, 6. DALMANELLA MULTISECTA (Meek) 244 



5. Pedicle valve. 



6. Interior of brachial valve. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 7-9. STOPHOMENA HALI.IE (Miller) 251 



7. Interior of pedicle valve. 



8. Brachial valve. 



9. Interior of brachial valve. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 10-14. STROPHOMENA SINUATA (James) 252 



10-11. Interior of the brachial and pedicle valves. 

 12-14. Anterior view and the two sides of a specimen. 



Ordovician (Cincinnatian) Maysville group, Cincinnati, Ohio. 



Figs. 15, 16. PLECTORTHIS PLICATELLA (Hall) 242 



Brachial valve and interior of the same valve of another example. 

 Ordovician (Cincinnatian) Maysville group, Cincinnati, Ohio. 



Figs. 17-19. CTENOOONTA OBLIQUA (Hall) 278 



Views of two shells and the cardinal side of one. X 10. 

 Ordovician (Cincinnatian) Maysville group, Cincinnati, Ohio. 



Figs. 20-22. ZYGOSPIRA MODESTA (Hall) 274 



Opposite sides and edge view of this small brachiopod. 

 Ordovician (Cincinnatian) Maysville group, Cincinnati, Ohio. 



Figs. 23, 24. PHOLIDOPS CINCINNATIENSIS (Hall) 236 



Brachial valve and profile of the same. X 3. 



Ordovician (Cincinnatian) Maysville group, Cincinnati, Ohio. 



Fig. 25. LEPTAENA GIBBOSA (James) 259 



Pedicle valve of a specimen identified by the author of the species. 

 Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 26-29. CTENODONTA FILISTRIATA (Ulrich) 279 



26. Left valve. 



27. Right side of cast of interior. 



28. Cardinal view of left valve. 



29. Portion of surface of shell, highly magnified. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Fig. 30. LYRODESMA CONRADI (Ulrich) 286 



Cast of the interior showing the muscular scars and the sinuate pallial 

 line. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 31-33. PLECTAMBONITES RUGOSUS (Meek) 255 



31, 32. Pedicle and brachial valves. 



33. Interior of the brachial valve. 



Ordovician (Cincinnatian) Eden shale, Cincinnati, Ohio. 



Figs. 34-36. BYSSONYCHIA VERA (Ulrich) 282 



34, 35. Left side and anterior view of a partial cast of the interior. 

 36. Well preserved cast of the interior snowing muscular impressions. 



Ordovician (Cincinnatian) Eden shale, Newport, Kentucky. 



Fig. 37. CLIDOPHORUS PLANCLATUS (Conrad) 280 



Shell of this species on slab with Plectambonites. 

 Ordovician (Cincinnatian) Pulaski shales of New York. 

 Figs. 1. 2 are after Nicholson ; 5, 6, 10-24 after Meek ; 7-9 after Miller ; 

 and 26-30, 34 after Ulrich. 



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