i to 



CRETACEOUS LAMELLTBRANCHTA. 



Remarks. — Internal casts of Cyprina are found commonly in the Hytlie Beds 

 of Hytlie, etc. Those from the " rag " have their original form well preserved, but 

 the specimens found in the softer greensand beds are more or less crushed. One 

 example of the same species with the shell preserved has been obtained from the 

 Lower Greensand between Atherfield and Blackgang. The form of the shell 



i %i 



,,.,;,., -,,;,... 





■>i'-.yt*. 



■yi 





SiilW 



■ -I.- 



' 



Fig. 22 — Cyprina Sowerbyi, d'Orb. Lower Greensand, Parham Park. British Museum, No. 5933. 

 Internal cast. Left valve, and dorsal view of both valves, x i. 



resembles that of C. lineolata (see below), but the anterior curvature of the 

 umboncs is considerably less, and the postero-dorsal margin of the shell is less 

 convex. It is difficult to determine satisfactorily the affinities of this species until 

 more specimens with the shell have been obtained. It may be identical with the 

 form from the Upper Aptian of Ste. Croix and the Perte-du-Rh6ne referred by 



