EXPLANATION OP PLATES. 259 



14. Left half of an inferior tooth. 15. Median portion of an inferior tooth. 



16. Liferior tooth with the left extremity lost. 



l";. The right portion of a superior tooth. 



18. Portion of the left side of a superior tooth. 



19, 20. Ji]T0BATis PROFUNDUS, Cope. Teeth found mingled with the preceding. 



19. An anterior tooth of the lower dental series. 



20. The left portion of a similar tooth. 



21-3Y. Zygobates dubius. Isolated teeth, from the sands of Ashley River, S. 0. 



21. A median unworn tooth, seen on the triturating surface. 



22. Anterior view of the same; the root lost. 



23. 7\.nterior view of a median unworn tooth. 



24. Triturating surface of a worn median tooth. 



25. Anterior view of the same tooth. 



26. Triturating surface of a worn median tooth. 

 21. Posterior view of the same tooth. 



28. Triturating surface of a first lateral tooth. 



29. Posterior view of the same tooth. 



30. Triturating surface of a first lateral tooth. 



31. Posterior view of the same tooth.. 



32. Triturating surface of a first lateral tooth. 



33. Posterior view of the same tooth. 



34. Triturating surface of a second lateral tooth. 



35. Posterior view of the same tooth; the root lost, 



36. Triturating surface of an external lateral tooth. 

 31. Posterior view of the same tooth; the root lost. 



PLATE XXXIL 



Figs. 1-4 Represent detached beaks of Ziphioid Cetaceans, from the Ashley phosphate beds, one- 

 third the diameter of the originals. 

 1, 2. Proroziphius macrops. 



1. Upper view of a detached beak or rostrum. 2. Left lateral view of the same. 

 3, 4. Proroziphius chonops. 



3. Upper view of a detached beak. 4. Right lateral view of the same. 

 5-1 Represent the dental armature of Rays, of tlie natural size. 



5. Myliobates serratus. Inferior dental plate. 



5a. Transverse section of the same. Specimen from Pemberton, Burlington Co., N. J. 



6. Myliobates pachyodon. Cope. Fragment of an inferior dental plate. ^ 

 6a. Transverse section of the same, with the crown reversed or directed downward. From 



the miocene tertiary of Charles Co., Md. 

 1. Myliobates. Portion of an inferior dental plate. 

 la. Transverse section of the same. From the same locality as the preceding. 



