COPE.] PALEONTOLOGY^MIOCENE PERIOD. 509 



Should it be ascertained that this cat develoiaes a tubercular molar, 

 (of which I can now find no trace,) it will be necessary to estimate it as 

 a second species of Dinictis. Besides the large basal lobes of the second 

 premolar, the inferior canine has an apparently larger size and more 

 posterior extent of the fang; certainly much greater than in the Hoplo- 

 pJi07ieus oreodontis, which resembles the Dinictis felina in this region ex- 

 teriorly. In accordance with the continuation of the canine alveolus, 

 the inferior border of the jaw is rounded, and though flared on the outer 

 margin for the large superior canine, it is not truncate as in the saber- 

 toothed tigers generally. ^ Coincidentally the superior canine is reduced 

 in size, being relatively shorter than in D. felina, 



HOPLOPHONEUS, Cope. 



Bulletiu U. S. Geological Survey Terrs., No. 1, p. 23, 1874. 



Cliar. gen. — Dental formula of mandible, I., 3; C, 1; P. m., 2 ; M. 2. 

 Superior canine greatly developed ; end of mandible exi^anded and thick- 

 ened to protect it. 



This is simply Machcerodus with a tubercular molar, a's' in Dinictis. The 

 dental formula is the same as that of Buncelurus, but the latter proba- 

 bly has the character of Felis in its anterior dentition. 



HoPLOPHONEUS OREODONTIS, Cope; 21aclicerodus oreodontis^ Cope, Sy- 

 nop. New Vert. Col., 1873, p. 9. 



Cliar. specif. — The species was 'established on a young individual with 

 part of the temporary dentition remaining. A jaw of an adult furnishes 

 additional characters. The first premolar (the third) has two roots and 

 is as large as the second, instead of being smaller, as iu Drepanodon 

 primcevus. The second (fourth) has a prominent anterior basal tubercle, 

 as in the last-named species, but which is, according to Leidy, wanting 

 or very small in Dinictis felina. The anterior angle of the mandible is 

 not produced downward so much as in the Drepandon, but is more as 

 in Dinictis felina, with which the present species agrees nearly in size. 

 The diastema is very short and rises to the base of the large inferior 

 canine. There is a mental foramen below the anterior root of the first 

 premolar, and two vascular foramina on the front face of the ramus, one 

 above the other. In the form of the second premolar, this species re- 

 sembles Drepanodon occidentalism Leidy ; but that species is supposed not 

 to possess the tubercular molars, and is nearly twice the size of the pres- 

 ent animal. 



Measurements. 



M. 



Length of ramus to end of molar series 0.065 



Length of molar series 048 



Length of base of first premolar 014 



Length of base of sectorial 017 



Depth of ramus at sectorial 017 



Depth of ramus at diastema 024 



Dejjth of ramus at symi^hysis 024 



The second specimen is immature, and presents the following charac- 

 ters. It is represented by an incomplete raanibular ramus of the right 

 side, containing two incisors, and the deciduous sectorial, with j)ortions 

 of other teeth. The incisors are very stout, and exhibit slightly-curved 

 conic crowns, with a serrulate cutting-edge on the inner face. The sec- 

 torial tooth has the elevated acuteanterior lobe, which forms with the me- 

 dian lobe the usual sectorial shear. PostQriG«;ly to the median, there are 



