PLATE LX. 



Ostrha (continued). 

 Figs. 

 1—15. 0. Boucheroni, Coq. Upper Chalk. (P. 301.) 



1. Zone of Actinocamax quadratus, Wield. Mr. Brydone's Collection. Left 

 valve. lb, posterior view. 

 2 — 4. Zone of Marsiqntes testudinarius, Brighton. 2, 3, Brighton Museum. 

 4, British Museum, No. L 11795. Left valves. 36, posterior view of 3a. 



5. Uintacrinu8 band, Thanet coast. Dr. Rowe's Collection, a, left valve; 6, 



right valve ; c, anterior view. 



6. Zone of Marsupites testudinarius, Brighton. Brighton Museum, a, left 



valve; 6, posterior view; c, right valve. 



7. Zone of Micraster cor-anguinum, Loam Pit Hill, Lewisham. Sedgwick 



Museum. Left valve. 

 8, 9. Zone of Micraster cor-anguinum, Gravesend. 8, Museum of Practical 

 Geology, No. 25977. 9, Ssdgwick Museum. Left valves ; Sb, posterior 

 view of 8a. 

 10 — 13. Uintacrirms band, Thanet coast. Dr. Rowe's Collection. 10a, right valve 

 and margin of left valve ; 10b, posterior view of 10a. 11, left valve with 

 large surface of attachment ; 6, posterior view. 12, left valve. 13a, right 

 valve; 13b, anterior view of both valves showing large surface of attach- 

 ment. 



14. Zone of Micraster cor-anguinum, Loam Pit Hill, Lewisham. Sedgwick 



Museum. Left valve. 



15. Uintacrinus band, Devizes Road, Salisbury. Dr. Blackmore's Collection. 



Left valve, b, posterior view. 



16 — 19. 0. lunata, Nilss. Zone of 0. lunata, Trimingham. Mr. R. M. Brydone's 

 Collection. Left valves. (P. 393.) 



