L88J.] 



565 



[Cope. 



specimen now described, the posterior internal rudimental cusp is quite 

 well developed ; in the two other specimens now before me it is not so 

 large. The superior canine is elongate, and not very robust, and its con- 

 vex anterior border is directed partly posteriorly at the apex. The 

 enameled portion of the crown is quite short. The premaxillary bones 

 are narrow and weak, and are separated so as not to be in contact on the 

 middle line. Its border displays two minute alveoli, from which teeth 

 have been shed. I do not suppose that their presence is constant in the 

 species. The external alveolus is twice the diameter of the internal. The 

 inferior incisors are of normal number, but are very narrow, and much 

 crowded. The canines are very narrow, but are longer than the incisors. 

 The first inferior premolar is more caniniform than in any other species of 

 Oreodontidse known to me. The crown is a compressed oval in section, 

 and is not expanded at its base. It is enameled to within 5 mm. of the 

 alveolar border. A considerable diastema separates it from the second 

 premolar. The description of the remaining teeth I take from a separate 

 ramus of similar dimensions, as they are concealed in the type by their po- 

 sition in juxtaposition with the cranium. The cusps of the true molars are 

 pyramidal and acute, and entirely separate from each other. The external 

 faces of the external are convex, their internal faces flat. The external 

 faces of the internal are convex, the internal faces concave at the base, and 

 convex near the apex. The anterointernal angle of the posteroexternal 

 cusp extends to the base of the anterointernal cusp. The only difference 

 between the first true molar and the fourth premolar, is that the anterior 

 crest of the anteroexternal cusp is continued round to the front of the an- 

 terointernal cusp, and to the internal side of the crown ; and the apices of 

 the two anterior crests are separated by a shallow notch. The second in- 

 ferior premolar has two roots. The heel of the third true molar is well de- 

 veloped, and is convex posteriorly. 



Measurements. M. 



Length from occipital condyles to postglenoid process . . .038 

 " " preglenoid border .. . .058 

 " " postfrontal process . .104 



" " canine, inclusive 226 



" " orbit to canine inclusive 085 



of mandibular ramus from condyle 176 



"symphysis mandibuli below 049 



Width of occipital condyles inclusive 046 



" " occiput above 045 



" " between otic bullae 016 



" " at postglenoid processes inclusive 079 



" "of skull above glenoid surfaces 100 



" " below orbits 099 



" " " between orbits 068 



" " " at fundus of canine alveoli 040 



