472 EEFERENCES TO THE PLATES. 



Fig. 4G. Outer view of the same tooth. 



Fig. 6. Megalonyx validus. See page 412 for descrijition. 

 Triturating surface of a molar tooth. 

 Figs. 7-9. DELrHiNODON mento. See page 424. 

 Figs. 7, 8. Inner and outer views of a tooth. 

 View of another tooth. 



Figs. 10-12. Delphinodon Wymani. See page 425. 

 Fig. 10. View of a tooth. From Charles Co., Md. 

 Fig. 11. View of another tooth, found with the former. 

 Fig. 12. A tooth similar to that of Fig. 10. From Virginia. 

 Figs. 13-15. HorLOCETUs obesus. See page 438. 

 Fig. 13. Lateral view of a tooth. From Ashley River, South Carolina. 

 Figs. 14, 15. Two views of a tooth. From the miocene, in the vicinity of Richmond, Va. 

 Figs. 16, 17. Orycteeocetus quadratidens. See page 436. 

 Fig. 16. View of a straight tooth. Fig. 17. A curved tooth. 

 Fig. 18. Squaeodon atlantious.. See page 416. 



Portion of the right side of a jaw, containing three teeth. The anterior tooth of the series of four is 

 introduced from the oj:)posite side. 



