EXPLANATION OF PLATE II. 



Fig. 1. LormoDON oregonensis : 



Two upper molar teeth, much worn and seen on their triturating surfaces. Specimen from 

 Bridgo Creek, Oregon. Natural size. 



Fig. 2. Megacerops coloradensis : 



Side view of the same specimen as that of figures 2, 3, of Plate I. One-half the natural size. 



Figs. 3, 4. Elotherium superbum : 



Fig. 3. Portion of a lower canine tooth, natural size. From Bridge Creek, Oregon. 

 Fig. 4. Crown of an anterior premolar, natural size. From John Day's River, Oregon. 



Fig. 5. Anchitherium Condoni : 



A mutilated upper molar tooth, natural size. From Oregon. 



Figs. 6, 7. Rhinoceros pacificus : 



Fig. 6. An upper molar seen on the triturating surface, natural size. From Alkali Flats, 



Oregon. 

 Fig. 7. An upper last premolar, seen on the triturating surface, natural size. From Alkali 

 Flats, Oregon. 



Figs. 8, 9. Rhinoceros hesperius (?) : 



Fig. 8. An upper last molar, seen on the triturating surface, natural size. From the Condon 



collection of Oregon. 

 Fig. 9. An inferior molar, seen on the triturating surface. 



Fig. 10. Patriofelis ulta: 



Portion of the right ramus of the lower jaw, half the natural size. It contains the remains 

 of five teeth hehind the position of the canine. From near Fort Bridger, Wyoming. See 

 page 114. 



Figs. 11, 12. Hyrachyus agrarids : 



Fig. 11. Left ramus of the lower jaw, one-half the natural size. Specimen obtained by 

 Professor Hayden on Smith's Fork of Green River, Wyoming. 



Fig. 12. Portion of the left ramus of the lower jaw of a young animal, natural size. It con- 

 tains the temporary series of teeth hehind which the first of the true molars is inclosed 

 within the jaw. From Black's Fork of Green River. Hayden's collection. 



Fig. 13. Hyrachyus modestus: 



A first or second upper molar of the left side, slightly larger than natural. From Smith's 

 Fork of Green River. Hayden's collection. 



Fig. 14. Hyrachyus nanus : 



Portion of left ramus of the lower jaw, with two premolars and the three molars, natural 

 size. Obtained by Dr. Joseph K. Corson from Grizzly Buttes. 



Fig. 15. Diseased calcaneum (hyperostosis) of Merycochcerus uusticus. From Sweetwater River. 

 Hayden's collection of 1870. 



Fig. 16. Oreodon superbus : 



Portion of right ramus of lower jaw, with the three premolars and first molar; natural size. 

 Condon collection of Oregon fossils. 



