PLATE XV. 



PAGE. 



Fig. 1. ScHizoDUs Medinaensis 299 



la. A view of the left side of an internal cast. 



16. A right side view of the cast of another specimen, differing a little in form. 



Ic. An interior view of an internal cast. 



Fig. 2. Prothyris Meeki 305 



A right side view of a cast, natural size. 



Fig. 3. Pal^oneilo Bedfordensis 298 



3a. A cast, mainly of the exterior, but having portions of the hinge exposed so as to show the 



denticles. Natural size. 

 3b. Same, magnified. 

 3c. Right side view of another specimen in same condition. 



Fig. 4. Entolium SnuMARDiANtiM? 292 



4a. Apparently a left valve, external view. 



46. Internal view of apparently a right valve of the same species. 



Fig. 5. Aviculopecten WiNCHELLi 296 



5a. A cast of the exterior of the left valve of a large specimen. 

 56. A cast of right valve of a smaller individual. 



Fig. 6. CaRDIOMORPHA? SUBGLOBOSA 304 



6a. Right side view of a somewhat distorted specimen. 

 66. An anterior view of same. 



Fig. 7. Aviculopecten crenistriatus 295 



7a. Cast of the exterior of a left valve. 

 76. Cast of a riglit valve. 



