REFERENCES TO THE PLATES. 467 



Fig. 34. Rhinoceros occidentalis. See page 224. 



Anterior extremity of the lower jaw, containing the incisors, viewed in front. 



PLATE XXII. 



Rhinoceros occidentalis. See page 220. 



Figures one-half the size of nature. Repetition of plate XII, of the " Ancient Fauna of Nebraska." 



Fig. 1. Inferior view of the skull. 



Fig. 2. View of the left side of the same specimen. 



PLATE XXIII. 



All the figures of the natural size, except 11, 12. 

 Figs. 1-.3. Rhinoceros occidentalis? See page 22.5. 



Portion of a sixth upper molar, apparently of a large individual of the species. 

 Figs. 2, 3. Crowns of two lower lateral incisors, apparently from large individuals of the species. 

 Figs. 4-9. Rhinoceros crassus. See page 228. 



Fig. 4. A right upper molar of the deciduous series, the third or fourth, outer view. 

 Fig. 5. View of the triturating surface of the same tooth. 

 Fig. 6. An upper left lateral incisor tooth, viewed externally. 

 Fig. 7. The same tooth, viewed on its triturating surface. 



Fig. 8. Portion of a last upper molar of the right side, viewed on the triturating surface. 

 Fig. 9. Fragment ofa lower jaw of a young animal, containing the first large temporary molar. 

 Fig. 10. Rhinoceros meridianus. See page 229. 



Portion of the upper penultimate molar of the right side, viewed on its triturating surface. 

 Figs. 11, 12. Rhinoceros hesperius. Seepage 230. One-half the diameter. 

 Fig. 11. Greater portion of the right ramus of the lower jaw, containing the lateral incisor and the 

 true molars. 



Fig. 12. Triturating surfaces of the latter teeth. 



PLATE XXIV. 



Titanotherium Prouti. See page 206. 



All the figures three-fourths the diameter of nature, except 7, which is two-thirds the diameter, and 

 8 to 12, which are of the natural size. 



Fig. 1. A complete series of molars of the upper left side, together with the corresponding fore part 

 of the jaw, viewed from beneath. 



Fig. 2. The same viewed externally. 



Figs. 3, 4. Two isolated third or fourth upper premolars of the left side, viewed on their triturating 

 surfaces. 



Figs. 5, 6. The second and third upper left true molars, belonging to the same individual, viewed on 

 their triturating surfaces. 



Fig. 7. An upper last true molar of the left side, less worn than in Fig. 1. Tlie specimen farther 

 differs from that of Fig. 1 in the less proportionate degree of development of the back portion of its 

 crown. It was carelessly drawn by the artist on a different scale from the preceding, being represented 

 two-thirds the diameter of nature. 



Fig. 8. A supposed second upper temporary premolar of the right side, of the natural size. 



