35 



sist of most ot" the upper teeth, with small attached jaw-fragments, obtained 

 l)y Dr. Carter on Henry's Fork of Green River. Of these specimens a com- 

 ])lctc series of nearly perfect molar teeth is represented in Figs. 5, G, Plate 

 IV. The teeth in their abraded condition ilidicate an older animal than that 

 to which the facial specimen above described belonged. The summits of the 

 constituent lobes of the teeth are nearly all worn to such a degree as to 

 exhibit tracts of dentine, and the enamel is everywhere smooth, except on 

 the external faces of the outer lobes near the basal ridge. 



The molars are almost identical in character with those above described 

 ill the facial specimen. Trifling differences consist in the less production of 

 the median fold on the outer face of the external lobes, and perhaps the less 

 degree of prominence of the tubercle in the interval anteriorly of the anterior 

 pair of lobes. The last premolar is likewise identical with those above 

 described, except that its crown is rather more square, or is not quite so 

 wide. The anterior three premolars depart considerably from their character 

 in the facial specimen, and their differences may probably indicate a different 

 species. The third premolar is a diminished representative of the one behind 

 it, the three lobes of the crown holding nearly the same proportionate devel- 

 opment; whereas in the corresponding tooth of the facial specimen the pos- 

 tero-external lobe is considerably reduced in its proportions. In the second 

 ])remolar the crown still retains a postero-external lobe reduced in proportion 

 to the others, but in the corresponding tooth alaove described it is obsolete. 

 The retention of this lobe gives the crown a greater fore and aft breadth than 

 that contained in the facial specimen. The first premolar has the same form 

 as that of the latter, but it is much lai'ger. 



The mutilated canine, accompanying the molars first described, is repre- 

 sented iu Fig. 1, Plate IV, and is but little more than half the size of those 

 contained in the facial specimen. 



An isolated incisor, represented in Fig. 8, accompanying the molars and 

 canine just described, is regarded as an upper one. Tiie crown is mutilated, 

 l)ut when complete appears to have had a short, conical crown, bounded 

 behind by a strong basal ridge. The fang is laterally compressed, and is 

 about an inch in length. 



Comparative measurements of the series of teeth of the two individuals of 

 Palseosyops. indicated by the facial specimen, with teeth, from Grizzly Buttes, 



