PLATE LIX. 



OSTREA {ronllnilPil). 

 Figs. 

 1 — IG. 0. inmrva, Nilsson. Upper Chalk. Right valves, e.Kcept 13f. (P. 388.) 



1. Zoue of Micraster cor-cnujuiiiiiiH, Crovdon. Sedgwick Museum. 

 2, 3. Uintacriiiiix baud, Devizes Road, Salisbury. •2/;, posterior view of '2a. 



Dr. Blaekmore's Collection. 

 4, 5. Zone of Adinocamax quadmtus, Whaddou. Dr. Blackniore's Collection. 

 6 — 11. Zone of Adinocamax qtiadratus, East Haruhani. Dr. Blackuiore's Col- 

 lection. 66, posterior view of Ga. 

 12 — 16. Zone of Belemn'ddla mucronata, Norwich. 12, Museum of Practical 

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

 surface. 13, Dr. Rowe's Collection ; 136, 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 

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

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

 Cambridge. 



