EXPLANATION OF THE PLATES. 2 
Oo 
Fig. 18. Outer view of the condyle of the left side of the lower jaw. 
Fig. 19. Posterior view of the same specimen as the preceding. 
Fig. 20. View of the occipital region. 
Fig. 21. View of the base of a skull, The jaw yet contains on both sides the last two molars nearly 
perfect. 
Pla Av Bing oe Tee 
All the figures are of the natural size. 
Anchitherium Bairdit. ; 
Fig. 1. View of the left side of a skull, with the zygoma and fore-part of the face broken away. In the 
jaw may be observed the posterior two molars entire. 
Fig. 2. Upper view of the same specimen as the last. 
Fig. 3. Masticating surfaces of all the right superior molar teeth except the first, which is small, and in 
the specimen is broken away. 
Fig. 4. Outer view of the same specimen as the last. The surface of the teeth is much injured from the 
influence of the weather. 
Fig. 5. Portion of the right side of the lower jaw attached to a mass of matrix. It contains the posterior 
two molar teeth. é 
Fig. 6. Inner view of a portion of the right side of the lower jaw containing the posterior five molar teeth. 
From the same specimen as figure 14, Plate X. 
Fig. 7. View of the masticating surfaces of the latter-mentioned teeth. 
Fig. 8. View of the masticating surfaces of six inferior molars of the left side. 
PLAT Bi XL. 
Figures half the diameter of Nature. 
Rhinoceros occidentalis. 
Fig. 1. View of the base of theskull. The left zygoma is preserved nearly entire, and upon the same side 
of the jaw all the molars except the first, which is, however, whole upon the right side. <A portion of the 
left occipital condyle remains; and in advance of it may be observed the anterior condyloid foramen, the 
mastoid process, the post-glenoid process, and the glenoid articulation. 
Fig. 2. View of the left side of the skull. The face is much mutilated, but the form of the orbit is 
comparatively well preserved. The zygoma is almost entire, and posterior to its root is observed the meatus 
auditorius, formed between the post-glenoid and mastoid processes. By the restoration of the first tooth of 
the series, all the molars are exhibited quite perfect. 
PEATE, X EEE. 
Figs. 1-4. Half the diameter of nature; the remaining two of the natural size. 
Rhinoceros occidentalis. 
Fig. 1. View of the top of the skull, from the same specimen as Plate XII. 
Fig. 2. Fragment of the left side of the lower jaw containing the last two molars, viewed from without. 
Fig. 3. Fragment of the left side of the lower jaw, containing the three molars anterior to the last. 
Fig. 4. View of the triturating surfaces of the teeth, from the same specimen as the last. 
Figs. 5, 6. Outer view of two inferior, slightly worn, molars of the right side. 
