EXPLANATION OF PLATE LXV1I. 



CYPRIMERIA EXCAVATA (Morton) , p. 602 



1-2. Views of two left valves. 



3. View of the hinge of the right valve. 



4-6. Interior and exterior views of a left valve, and a plaster cast 

 taken from the interior of the same. 



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



CYPRIMERIA CRETACEA Conrad, p. 604 



7-8. The internal cast of a right valve, and a plaster cast taken 

 from the natural mould of the exterior of the same. 

 Woodbury clay; Lorillard, (102). 



-1016 



