EXPLANATION OF PLATES. 



PLATE XXX. 



Figs. 1-5. Detached beaks of Ziphioid Cetaceans, reduced to one-third the size of the specimens. 



1. Choneziphius liops. Upper view of a detached beak. 



2. Choneziphius trachops. Upper view of a detached beak. 



3. DioPLODON PROROPS. Upper view of a detached beak. 



4. Left lateral view of the same specimen. 



5. Eboroziphius ccelops. Upper view of a detached beak. 



6. RosMARUS OBESUS. Inner view of the left tusk. One-third the natural size. , 

 7-11. Teeth of Cetaceans, of the natural size. 



T. Tooth resembling those of the Sperm Whales, from the Ashley phosphate beds. 



8. Tooth of a similar character, from the same beds. 



9. Cetacean tooth, resembling that of a Grampus, from the same beds as the preceding. 



10. Cetacean tooth, from the Miocene marl of Nash Co., North Carolina. 



11. Cetacean tooth, found with the preceding. 



PLATE XXXL 



Fio-s. 1-3. Rio-ht lateral view of the detached beaks of the following Ziphoid Cetaceans, one-third 

 the natural size: — 



1. Choneziphius trachops. 



2. Choneziphius liops. 



3. Eboroziphius ccelops. 



All the remaining figures, consisting of the dental armature of Rays, are of the 



natural size. 

 4, 5. Myliobates jugosus. Tooth from Vincenttown, New Jerse3^ 



4. View of the triturating surface. 5. Anterior view of the tooth. 



6-10. Myliobates obesus. 6. View of the triturating surface of a median tooth. 



7. Posterior view of the same tooth. Specimen from MiiUica Hill, Gloucester Co., N. J. 



8. Plate consisting of two median teeth, seen on the triturating surface. 



9. Posterior view of the specimen. From Vincenttown, N. J. 



10. Dental plate, viewed on the triturating surface. From New Egypt, Ocean Co., N. J. 



11. Myliobates fastigiatus. 



Dental plate, viewed on the triturating surface. From Monmouth Co., N. J. 

 11a. Outline of a transverse section with the crown directed downward. 



12. Mesobatis eximius. 



Fragment of an inferior dental plate. From the sands of Ashley River, S. C. 



13. Jj^TOBATis PERSPicuus. Fragment of a tootli. From Monmouth Co., N. J. 

 14-18. J^Itobatis arcuatus. Cope. 



Fragments of teeth, from the miocene of Charles River, Maryland. 

 (258) 



