1898.] Wortman, Extinct Camelidce of North A?neHca. 95 



of some of the material, and in part to other lines which resemble 

 them in certain points of skull and limb structure. These 

 resemblances are, no doubt, due to the close proximity to the 

 point at which the respective phyla began to diverge. 



For the purpose of bringing into stronger relief the characters 

 of the Cameloids of this horizon, it is necessary to compare them 

 accurately with the cotemporary Selenodonts, and, since several 

 of them apparently represent new genera, they are herewith 

 described. 



Leptoreodon marshi,' gen. et sp. nov. 



This genus and species is represented in the collection by an 

 almost perfect skull in good state of preservation, a number of 

 vertebrae, and a few fragments of the limbs (No. 2064), which I use 

 as the type. There are several other specimens of a more frag- 

 mentary character which are probably to be referred to the same 



Fig. I. Side view of skull oi Leptoreodon inarshi. 



genus and species, but they contribute little additional informa- 

 tion to the knowledge of the skeleton. The genus differs from 

 all the Oreodonts hitherto described in the possession of a short 

 diastema in front of, and a longer diastema behind, the first 

 superior premolar, together with a considerable diastema between 

 the first and second premolar in the lower jaw. The incisors are 



' This species is dedicated to Prof. O. C. Marsh, in recognition of his numerous contribu- 

 tions to American palaeontology. 



