PLATE XVIII. 



Page. 

 GouLDiA CoNKAjji Whitfield , 125 



Fig. 1. Exterior of a left valve, enlarged three diameters. 



2. Inferior of same. 



3. Interior of a right valve, enlarged fo the same extent. 



GoULDiA DISCEMNAUIA Courad I"i4 



Fig. 4. View of the type specimen, greatly enlarged. 

 Vetocakdia crexulirata Courad 1".JS 



Fig. 5. Enlarged exterior view of one of the types. 



6. Interior view of same. 



7. Enlarged view of the hinge of a left valve. 



ScAMBULA PEHPLANA Conrad m 123 



Fig. rt. Exterior of one of the types. 



9. Enlarged view of a right valve (two diameters). 



10. Suuilar view of a left valve. 



GouLDiA BECLivis Courad 126 



Fig. 11. An enlarged copy of Mr. Conrad's figure of this shell. 



Goui-DIA PARALIS Conrad 126 



Fig. 12. Copy of Mr. Conrad's fignre cited under the description. 



13. View of a fragm(^nt of what is supposed to bo the shell, as obtained by a gutta- 

 percha impression from a mold in marl from Mr. Schanck'a pits near Marl- 

 borough, N. J. 



Crassatella subplana Conrad 121 



Fig. 14. Exterior of an imperfect specimen, which shows the general form and surface 

 markings. 



15. Interior of another .si)ccimen. 



16. An imperfect cast of the species. 



DosiNiA erecta Whitfield 162 



Fig. 17. Lateral view of a small specimen, preserving the shell. 



18. Lateral view of a cast which shows the depth of the inflected cardinal border. 



19. Profile view of same, showing the inflected border. 



20. Lateral view of a large specimen, imperfect at the beak, but retaining the shell in 



part. 



Lucixa Smockana Whitfield 130 



Fig. 21. Left view of an internal cast, showing the form and gibbosity of the valves. 

 22, Cardinal view of same. 



LuciNA CRETACBA Conrad 129 



Fig. 23. View of the interior of a right valve, enlarged. 



24. The hinge still farther enlarged. 



25. Exterior of a larger shell (two diameters). 



DiCERAS DACTYLOIDES Whitfield 131 



Fig. 26. View of the cast described. 



27. Lateral view of the same, showing the muscular scar. 



304 



