120 KXl'LAiS^VTlON OP THE PLATES. 



PLATE III. 



Figures of the natural size. 



Oreodon Cidherlso-ii li. 



Fig. 1. View of the base of a skull contaiuing on both sides all the molars perfect, and on the left side 

 the canine in the same condition. From an adult male individual. The molar teeth are four premolars 

 and three true molars. 



Fig. 2. View of the left side of the same specimen as the last, exhibiting the canine and the succeeding 

 series of molars. 



Fig. 3. Inner view of a scries of inferior molars of the right side, restored from several different indi- 

 viduals. The teeth consist of three premolars and three true molars. 



Fig. 4. View of the masticating surface of the same series as the last. 



Fig. 5. External view of a right posterior inferior molar, removed from its socket. 



Fig. 6. View of the masticating surface of the same tooth as the last. 



PLATE IV. 



Figures of the natural size. 



Figs. 1—5. Oreodon CulbcrisoiiH. 



Fig. 1. Upper view of the skull, from the same specimen as figure 3, Plate II. 



Fig. 2. View of the inion or occipital region, from the same specimen as the preceding. 



Fig. 3. View of a specimen upon the left side of the face, exhibiting the orbit and lachrymal depression 

 entire. 



Fig. 4. Greater portion of the left side of the lower jaw of a young individual, containing the first pre- 

 molar, the succeeding two temporary molars, and the permanent true molar.s, of wiiich the last is only 

 partially protruded. 



Fig. 5. View of the triturating surfaces of the premolars and last temporary true molar, from the same 

 specimen as the last. 



Fig. 6. Oreodon major. View of the triturating surfaces of the superior true molars, of the right side, 

 considerably worn. 



PLATE V. 



All the figures arc of the natural size. 



Figs. 1, 2. Oreodon CidLerisonii. 



Fig. 1. View of the left side of the skull of a young individual. The zygoma, end of the nose, and 

 nearly all the teeth are broken away. In advance of the orbit is observable the large lachrymal depression. 



Fig. 2. View of the base of the same specimen as the last. Upon the right side of the jaw all the 

 molars are preserved, consisting of the temporary series and the permanent true molars. The foramina 

 visible at the base of the cranium, proceeding backward on each side, are the rotundum, ovale, lacerum, and 

 condyloideum. 



Figs. 3, 4. Oreodon gracilis. 



Fig. 3. View of the base of the skull of a young animal. The teeth visible on the left side, proceeding 

 backward, are, a fragment of the canine, the two fangs of the first premolar, three succeeding temporary 

 molars, and two permanent true molars. On the right side are preserved the last temporary true molar and 

 the succeeding two permanent true molars. The oblique lines indicate a portion of the matrix, in which 

 the specimen was originally imbedded. 



Fig. 4. Superior view of the same specimen as the last. It presents a remarkable degree of flatness of 

 the forehead. 



