156 BULLETIN OF THE 



Metatarsal IV., length 068 



" V. " 055 



Proximal phalanx, digit IV., length 025 



" " " IV., width proximal end 013 



« « " v., length 022 



" " " v., width proximal end Oil 



Entelodon (Elbtherium) Mortoni, Leidy. Eepresented by several skulls 

 in good preservation, one of which is particularly interesting as showing the 

 milk dentition. This wiU be fully described in our final paper. 



HYOPOTAMID^. 



HyopotamuB americanus, Leidy. Represented by fragments of lower 

 jaws with molar teeth. 



CAMELID^. 



Poebrotherium Wilsoni, Leidy. Two skulls, one of which exhibits the 

 milk dentition, represents this species. 



TRAGULID^. 



Leptomeryx Evansi, Leidy. Riitimeyer* has recently questioned the 

 propriety of referring this genus to the chevrotains, and considers it more 

 allied to the Camelidce. In consequence of this opinion from such a distin- 

 tinguished source, we have carefully examined the dentition and skeleton of the 

 genus, and are now in position to give a nearly complete account of it, which 

 will be done in the final paper. Here we need only record the conclusion 

 reached, that Leptomeryx, though exhibiting several points of divergence from 

 the modern genera of the family, is nevertheless a true traguline. We thus 

 reach a different conclusion from Riitimeyer on this subject, and agree with 

 Schlosser.t 



GENUS INCERT^ SEDIS. 



Hypisodus minimus, Cope. This minute ruminant is the earliest known 

 hypsodont form found in America. Professor Cope gives the dental formula 

 as I. ^, C. ^, Pni. ^, M. f ; and states that "in the mandibular series the six 

 incisors, two canines, and two first premolars form an uninterrupted series of 

 ten subequal teeth, and are followed by a long diastema." X The genus has 

 hitherto been known only from the dentition, but there is fortunately in this 



Abh. d. schweiz. pal. Gesell., Bd. X. p. 98. 

 t Morph. Jahrb., Bd. XH. p. 75. 

 t U. S. Geol. and Geogr. Surv. Terr., 1873, p. 501. 



