PLATE IV. 



Page. 



Gryph^a vesicularis Lamarck -• ' ^ 



Fi"-. 1. Exterior view of a specimen whicli somewhat n]>pronclies Tr. Pitcheri m form. 

 2. View of the upper side of tlie same. 



:^>. View of the upper side jf a large dat 'form having a deep lateral channel. See 

 PL V, Fig. 2, for profde. 



Dii'LOSCHiZA CRETACEA Courad - 



Figs. 4 and 5. Views of a broad specimen doubtfully of the species. 

 G-8. Copies of Mr. Conrad's figures of the tyix- of the species. 



Anomia argentaria Morton 



Fig. 9. View of a large specimen referred to this species. 



10. View of a valve having the specilic mirrkings described by Dr. Morton. 



11. An enlargement of the surface of the same. 



AXOMIA TELLINOIDES Morton 



Fig. 1-2. View of a group of lower valves of this si^^cies. 



13. Upper surface of a cast (^f I'otb. valves, showing the form of the perforation and 

 indistinct wrinkles near the border of the valve. 



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