PLATE LXXXVII 



PAGE 



Figs. 1, 2. DIAPHOROSTOMA vENTRicosvM (Conrad) 482 



Dorsal and ventral views of a large individual. Oriskany formation, 

 Ridgely member, Cumberland. 



Figs. 3, 4. PLATYSTOMA NIAGARENSE Hall 483 



Ventral and dorsal views. Helderberg formation, Keyser member, 

 Keyser, W. Va. 



Fig. 5. TENTACULITES ? ACUS Clarke 484 



Partially exfoliated specimen. Oriskany formation, New York. 



Figs. 6, 7. TENTACULITES ACULUS Hall 485 



6. Specimen from the Helderberg formation. New York. 



7. Same. X 5. 



Figs. 8-10. TENTACULITES ELONGATUS Hall 485 



8. An individual of medium size. 



9. An exfoliated individual. 



10. A portion of the same enlarged, showing the appearance of the annu- 

 lations. X 4. 

 New Scotland formation, New York. 



Fig. 11. TENTACULITES GYRACANTHUS (Eaton) 486 



A shell. X 5. Helderberg formation, Keyser member, Keyser, W. Va. 



78 



