PLATE LXXII 



PAGE 



Fig. 1. SPIRIFER ARENOSUS (Conrad) 415 



Internal cast of ventral valve. Oriskany formation, New York. 



Figs. 2, 3. SPIRIFER CONCINNUS Hall 417 



Dorsal and ventral views. Becraft formation, New York. 



Fig. 4. SPIRIFER COXCINNOIDEUS Schuchert n. sp 419 



Internal cast of dorsal valve. Oriskany formation, Ridgely member, 

 Pendleton County, W. Va. 



Figs. 5-7. SPIRIFER GORDONI Schuchert n. sp 420 



Dorsal, ventral, and side views of the type. Oriskany formation, 

 Ridgely member, Cumberland. 



Figs. 8-10. RETICULARIA BICOSTATA (Vanuxem) 420 



8, 9. Ventral and dorsal views. 



10. Dorsal view of a specimen showing stronger plications. 

 Niagara formation, New York. 



Figs. 11, 12. METAPLASIA PYXIDATA (Hall) 422 



Dorsal and ventral views. X 2. Oriskany formation, Ridgely mem- 

 ber, Cumberland. 



Figs. 13-15. RHYNCHOSPIRA RECTIROSTRIS (Hall) 424 



Dorsal, ventral, and side views of the type. Oriskany formation, 

 Ridgely member, Cumberland. (After Hall.) 



Figs. 16-25. RHYXCHOSPIRA GLOBOSA (Hall) 425 



16-18. Ventral, dorsal, and side views of an exfoliated specimen. 



Tonoloway. 



19. Side view of unusually large and gibbous specimen. Tonoloway. 

 20-22. Dorsal, ventral, and side views. Cumberland. 



Helderberg formation, Keyser member. 

 23. Side view of gibbous specimen. 

 24-25. Dorsal and ventral views. 



New Scotland formation, New York. 



Figs. 26-30. RHYNCHOSPIRA FORMOSA Hall 426 



26. Side view of doubtfully determined specimen having striae coarser 

 than usual, beak erect. Helderberg formation, Keyser member. 

 Cash Valley. 



27-29. Dorsal, ventral and side views. 

 30. Dorsal view of individual with finer plications. 

 New Scotland formation, New York. 



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