EXPLANATION OF THE PLATES. 125 



Figs. 6, 7. Fragment of a superior true molar. Fig. 6. Inner view. Fig. 7. Triturating surface of the 

 same specimen, presenting a large conical lobe, with portion of an enamelled pit at the outer side of its 

 base. 



Figs. 8-12. The size of nature. 



Figs. 8-10. A second? inferior molar of the left side. Fig. 8. The triturating surface. Fig. 9. The 

 outer view. Fig. 10. The inner view, whieh is a vertical plane. 



Figs. 11, 12. An inferior canine tooth, the size of nature. Fig. 11. Outer view. Fig. 12. Inner view. 



PLATE XVII. 



All the figures of the natural size, except 8-10, which are two-thirds the diameter. 



Figs. 1—10. Titanothermm Proutii. 



Figs. 1-3. A superior premolar. Fig. 1. Inner view. Fig. 2. Outer view. Fig. 3. View of the tritu- 

 rating surface. 



Fig. 4. View of the triturating surface of another superior premolar. 



Figs. 5, 6. Fragment of a superior premolar. Fig. 5. View of the triturating surface. Fig. 6. Inner 

 view. 



Fig. 7. View of the triturating surface of a fragment of a superior premolar. 



Figs. 8-10. A last posterior inferior molar of the left side. Fig. 8. Outer view. Fig. 9. View of the 

 triturating surface. Fig. 10. Inner view. 



Figs. 11-18. Palaeotherium giganieum. Views of three fragments of as many superior molar teeth; 

 being single external lobes seen upon their outer face. 



PLATE XVIII. 



Figures of the natural size. 



Macliairodus primacvus. 



Fig. 1. View of the right side of a skull, with the lower jaw. The symphysis of the latter, upper inci- 

 sors, and zygoma are broken away. The upper jaw presents a portion of the canine, and the second to the 

 last molar inclusive; and in the lower jaw the first and a portion of the second molars are visible. 



Fig. 2. Superior view of the right half of the same specimen as the preceding. 



Fig. 3. View of the left side of the lower jaw, containing the three molars and a portion of the upper 

 jaw, exhibiting the second molar, from the same specimen as the preceding. 



Fig. 4. Outer view of the right inferior canine, which was attached to the mass of matrix adhering to the 

 preceding specimen. 



Fig. 5. Front or anterior view of the same tooth. 



PLATE XIX. 



Figures two-thirds the diameter of nature. 

 Testiido Nehrascensis. 

 Fig. 1. Dorsal view of the carapace. 

 Fig. 2. Lateral view of the carapace. 

 Fig. 3. Inferior view of the sternum. 



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