EXPLANATION OF PLATE LXVIII. 



MERETRIX TIPPANA Conrad, p. 607 



1-2. Internal and external views of a perfect left valve. 



Ripley, Miss. Coll. U. S. Nat. Mus., No. 20,690. 

 3. A somewhat distorted cast of the interior of a left valve. 

 Merchantville clay-marl; Lenola, (163). 



MERETRIX CRETACEA (Conrad), p. 608 



4-5. Views of two right valves. 



6-7. Views of the hinges of the two valves. 



Marshalltown clay-marl; near Swedesboro, (/77). 



MERETRIX EUFAULENSIS (Conrad), p. 609 



8. View of a left valve. 

 9-10. Interior and exterior views of a left valve. 



Marshalltown clay-marl; near Swedesboro, (177). 



CARYATIS VETA Whitfield, p. 611 



n-12. Anterior and lateral views of an internal cast. 



Manasquan marl; near Nezv Egypt, (155). 



PETRICOLA NOVA-AEGYPTICA Whitfield, p. 614 



13. Lateral view cf the type specimen. 



Manasquan marl; near New Egypt. 



CYPRIMERIA DENSATA (Conrad), p. 601 



14. Lateral view of a large internal cast of a left valve. 



Navesink marl; Holmdel. 



1018 



