208 M. R. Thorpe — New Species of 



can, therefore, be taken in the majority of specimens. 

 These terms, some of which are foreign to paleontology, 

 may be made clearer, as follows: 



Prosthion: The most prominent part on the alveolar 

 border between the two upper median incisors. 



Basion: The mid-point on the anterior margin of the 

 foramen magnum. 



Nasion: The highest point on the internasal suture. 



Bregma: The point at which the sagittal and coronal 

 sutures meet. 



Palatal length: Prosthion to posterior surfaces of the 

 maxillary parapets, in axial projection, including the 

 pterygoid processes of the maxillae, if present. 



Anterior palatal breadth: Between the roots of the 

 canines (minimum). 



Posterior palatal breadth: Between the innermost 

 roots of the carnassials. 



Length of the temporal fossa: Maximum measure- 

 ment in an antero-posterior plane between the maxilla 

 and the anterior margin of the glenoid fossa. 



Anterior zygomatic pedicle: Situated between the 

 inferior orbital margin and the alveolar margin beneath, 

 and between the infra-orbital foramen and the posterior 

 margin of the zygomatic process of the maxilla. 



The measurements of the anterior zygomatic pedicle 

 have proved of considerable value, both as absolute 

 measurements and as ratios, in specific determinations. 



The writer wishes to express his thanks to Professors 

 Schuchert and Lull and Doctor Eaton for their kindly 

 interest in, and friendly criticism of, this work through- 

 out its course. The drawings of the various specimens 

 have been made by Mr. Rudolf "Weber. 



Description of Species. 

 The Genus Hoplophoneus Cope. 



In 1851, Leidy 5 described a Machserodont from the 

 White River badlands, under the name of Machcerodus 

 primcBVUS. The description is very brief and is based 

 on a mutilated cranium, very much fractured and fissured. 

 Of this skull, the summit of the inion, the zygomata, 

 the anterior extremities of the ossa nasi, the superior 

 incisors, the greater portion of the corresponding canines, 



5 J. Leidy, Proc. Acad. Nat. Sci. Phila., 5, 329. 



