COPE.] PALEONTOLOGY MIOCENE PERIOD. 505 



Measurements. 



Length of five molars 0.0260 



Length of three true molars 0175 



Length of last true molar 0080 



Width of last true molar 0070 



This species is smaller than the smallest of the genus yet described. 



Hypertragulus tricostatus, Cope, Bull. U. S. Geol.. Surv., No. 

 1, 1874, p. 27. 



A second species, about the size of the last, is represented by the 

 superior molars of one individual, and perhaps by numerous mandibles 

 which I cannot certainly associate with them. The last premolar has, 

 as in the preceding species, a strong posterior cingulum ; but there are 

 only three ribs on the outer side of the third molar, the characteristic 

 heel being absent. The latter also lacks the cingulum, which passes 

 round the inner side of the bases of the crowns in G. calcaratus, its rep- 

 resentative being the basal tubercle between the inner lobes of that and 

 the other molars. • 



LEPTOMEEYX, Leidy. 



Leptoimeryx evansii, Leidy, Ext. Fauna Dak. and Neb., p. 165 ; Tri- 



merodus cedrensis, Cope, Pal. Bull., No. 16, p. 8. 



The form of premolars characteristic of Trmerodus, as cited, pertains 

 also to this genus. The specific name represents the smaller forms, but 

 I find a considerable range in size in the numerous specimens obtained, 

 and do not at present regard them as belonging to more than one species. 



STIBAEUS, Cope. 



Paleontological Bulletin, No. 16, p. 3. 



This genus is known from a portion of a mandibular ramus which 

 supports two premolar teeth, one in an imperfect condition. These 

 teeth are of unusually large size as compared with the depth of the 

 ramus, especially in their antero-posterior diameter. The mental fora- 

 men issues opposite the anterior root of the first, which is also pre- 

 ceded by a diastema of uncertain length. The second premolar is sec- 

 torial in its form, and entirely symmetrical bilaterally, i. e., its cutting 

 edge is median, and there is no incurvature or ribbing of the inner or 

 outer side, but the sides slope symmetrically to the apices of the three 

 cusps of the crown. 



The character of this tooth is quite that of some carnivorous animals, 

 e. g., of some Canidce, but the elongate preceding premolar, diastema, 

 and absence of canine alveolus lead me to the opinion that it is an 

 artiodactyle, with the sectorial premolar teeth of the group just consid- 

 ered. The elongate form of these teeth resembles most that of Poehro- 

 tJierium, but it differs from this genus, as from the others, in the most 

 decided manner. But one species is known. 



Stebarus obtusilobus. Cope, loc. cit, p. 3. 



This species is rare in Colorado, as but one specimen has come under 

 my observation. It is represented by a portion of a mandibular ramus, 

 which supported the two anterior premolars. The teeth are elongated 

 and compressed, with low crowns and flattened roots ; the crown of the 



