Cope.] 5b4 [Jan. 18> 



edge terminates in a rough band which curves upwards and backwards to 

 a point above the line of the occipital condyle. It is separated by a shal- 

 low groove from the corresponding posttympanic ridge. The tympanic 

 bone is not so long as in the species of Oreodontinse, and presents a tube- 

 rosity externally. Like the paroccipital its base unites with the otic bulla. 

 The bulla is small. Its base is extended towards the postglenoid process, 

 but it is we'll separated from it, and does not reach the line of its anterior 

 border. It presents a face anteriorly, and one inwards. The postglenoid 

 process is narrow transversely, the depth and width being equal, and is 

 elongate downwards. 



The coronoid process of the mandible is short, but has a base extended 

 anteroposteriorly. The articular face of the condyle is convex anteropos- 

 teriorly, and is extended downwards on the inner side behind. The hori- 

 zontal ramus is slender, and has a straight inferior border. (The angle is 

 broken away from this specimen.) The symphysis is oblique and nearly 

 straight in profile. It is moderately elongate, and has the suture persist- 

 ent. There is a tuberosity looking downwards from its posterior extremity, 

 where it is rounded-compressed. 



The facial part of the lachrymal bone is longer than deep, and the lateral 

 anterior part of the frontal is wide and obtuse, and extends anterior to the 

 lachrymal. The nasals extend posteriorly to terminate in an acute angle 

 which is above the anterior edge of the orbit. The frontoparietal suture 

 extends across the space between the anterior temporal ridges at a point 

 half way between the anterior border of the orbit and the anterior glenoid 

 margin. The malomaxillary suture has no anteroinferior process. The 

 mastoid forms a distinct mass between the exoccipital and squamosal. The 

 sutures are largely coossified. 



The infraorbital foramen is above the contact of the third and fourth 

 premolars. The space between the frontal foramina is about one-sixth the 

 interorbital width. There is a large postparietal foramen on the parieto- 

 squamosal suture, and there are two small postsquamosal foramina, in line 

 above the posttympanic tuberosity. The mastoid foramen is small, and is 

 not situated in a fossa of any extent, as is the case with the species of the 

 Oreodontinse. There is a large foramen intermediate in position between 

 that of the anterior condyloid and the jugular. Anterior and a little ex- 

 ternal to it and slightly elevated between the confluent base of the paroc- 

 cipital process and the otic bulla is another foramen, perhaps the jugular. 

 Between the posterior base of the bulla and the basisphenoid, is a smaller 

 foramen, probably the carotid. The other foramina are yet concealed by 

 the matrix. 



The teeth do not differ in their form from those of other species of the 

 genus. The second and third premolars have triangular bases, the second 

 the narrower. The first has two roots. It is accidentally lost from one 

 side, which circumstance led me to suppose at one time that this species 

 has but three premolars above. The fourth premolar has its posterior ex- 

 ternal V well developed, though a little smaller than the anterior. In the 



