PLATE LIX. 



OSTREA (run tinned). 

 Figs. 



1 — 10. 0. incurva, Nilsson. Upper Chalk. Right valves, except 13c. (P. 388.) 



1. Zoue of Micraster cor-anguinum, Croydon. Sedgwick Museum. 

 2, 3. TTintacrinus band, Devizes Road, Salisbury. "lb, posterior view of 2a. 



Dr. Blackmore's Collection. 

 4, 5. Zone of Actinocamax quadratics, Whaddon. Dr. Blackmore's Collection. 

 6 — 11. Zone of Actinocamax quadratus, East Harnham. Dr. Blackmore's Col- 

 lection. 6b, posterior view of 6a. 

 12 — 16. Zone of Belemnitella miicronata, Norwich. 12, Museum of Practical 

 Geology, No. 25983 ; the left valve is entirely attached to a slightly convex 

 surface. 13, Dr. Rowe's Collection ; 135, interior of right valve 13a ; 13c, 

 area and hinge of left valve. 14, Norwich Museum. Type of 0. triangu- 

 laris, Woodward, pi. vi, fig. 7 ; 146, posterior view showing portion of 

 Inoceramus to which the left valve was entirely attached. 15, Norwich 

 Museum ; exterior and interior of a right valve. 16, Sedgwick Museum, 

 Cambridge. 



