OEEODON. 51 



MEASUREMENTS. 



Inches. Lines. 



Breadth of face at infra-orbitar foramina ....... 1 8 



Distance from infra-orbitar foramina to frontal angular processes ... 1 4 



Length of series of upper molars 3 1 



Length of series of lower molars 3 



Length of series of upper true molars 1 8 



Length of series of lower true molars 1 10 



16. The skull of a young animal, accompanied by the greater portion of the left 

 side of the lower jaw. The end of the nose and superficial portion of the right 

 side of the face are broken away. The upper jaw, on the right side, contains all the 

 molars perfect; consisting of the first permanent premolar and the succeeding three 

 temporary and two true molars protruded, and the last true molar just on the 

 point of protrusion. The portion of lower jaw also contains all the molars nearly 

 perfect; consisting of three temporary molars and three permanent true molars, the 

 last of which is only partially protruded. 



Independently of the specimen not being adult, it evidently indicates a smaller 

 individual of Oreodon Culhertsonii than any of the others previously designated. 

 (Plate V. Figs. 1, 2.) 



From the collection of Dr. Owen. 



MEASUREMENTS. 



Inches. Lines. 

 Length from occipital condyle to canine alveolus ...... 6 



Length of series of upper molars ........ 3 1 



Length of series of lower molars . . . . . . . .,3 



Length of series of upper permanent true molars 1 8 



Length of series of lower permanent true molars ..... 1 10 



Antero-posterior diameter of last upper molar ...... 7f 



Antero-posterior diameter of last lower molar ...... 9 



17. Fragment of the left side of the lower jaw of an old individual, containing 

 the true molars and the two premolars in advance, with the characteristic enamelled 

 triturating surfaces nearly obliterated. (Plate VI. Figs. 8, 9.) 



From the collection of Dr. Owen. 



MEASUREMENTS. 



Inches. Lines. 



Length of series of true molars . . . .... . .1 9 



Antero-posterior diameter of last molar 10 



18. Seven fragments of upper and lower jaws, containing true molars, appa- 

 rently from six different individuals. 



From the collection of Dr. Owen. ^ 



19. A skull, without the lower jaw, and with the end of the nose and posterior 

 part of the cranium broken away. It is particularly valuable from its preserving 

 the post-orbital arch entire on both sides. The teeth are all broken. (Plate IV. 

 Fig. 3.) 



From the collection of Dr. Hiram A. Prout, of St. Louis. 



