A NEW LIVING SPECIES OF HIPPOPOTAMUS. 239 



EXPLANATION OF THE PLATES. 



PLATE XXXII. 



Cranium of the younger of the two animals. The nasal region is pierced by two slugs, and the orbit, 

 zygomatic process and terminal portion of the occiput, are fractured and the fragments lost. 



PLATE XXXIII. 

 Parts of the same cranium. 



Fig. 1. Right half of the lower jaw with its nine teeth. 



Fig. 2. Right half of the upper jaw with its ten teeth ; the first proemolar, (fig. 5,) having been removed 

 for a separate drawing, was inadvertantly omitted in the present instance. The fourth and last premolar 

 is of the permanent series, but not fully elevated above the bone. I removed the shell of the corresponding 

 deciduous tooth in order to bring the permanent one into view. All the rest of the teeth in both jaws 

 belong to the permanent set. 



Fig. 3. Internal incisor of the upper jaw, natural size. 



Fig. 4. Incisor of the lower jaw, natural size. 



Fig. 5. First proemolar of the upper law, natural size. 



Fig. 6. First prsemolar of the lower jaw, natural size. 



Fig. 7. Third proemolar of the lower jaw, natural size. 



Fig. 8. Fourth prsemolar of the lower jaw, natural size. 



Fig. 9. Third or posterior molar of the lower jaw, natural size : the roots imperfectly developed. 



PLATE XXXIV. 



Fig. 1. Canine tooth of the lower jaw, natural size, with a transverse section. 

 Fig. 2. Canine tooth of the upper jaw, natural size, with a transverse section. 

 Fig. 3. Face and front view of the head and lower jaw. 



The three preceding figures were taken from the younger of the two animals ; the following figures are 

 derived from the older skull. 



Fig. 4. View of the occiput in its vertical position. 



Fig. 5. Cranium, viewed from above, the sutures being obsolete from age, as stated in the text. 



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