Cope.] 5t>2 [Jail . is, 



Measurements of Skull. M. 



Width "at rnalars below orbits 086 



" " zygomata at middle 092 



" " auricular meatus 070 



" of occipital condyles 0275 



" at middle of last molars inclusive 049 



" " " second premolars inclusive. . .030 



! anteroposterior. 023 

 transverse 018 

 vertical 019 



Diameters of nasal bones { ien ^ th of fra S ment of - 024 



*. width at base 0125 



Length of dental series 062 



" " premolar series 025 



" " true molar 033 



Diameters P-m. iii { anteroposterior 007 



*- transverse 0065 



Diameters m. i { anteroposterior , 0085 



<■ transverse 0085 



Diameters m . m . / anteroposterior 0146 



•- transverse (greatest) 011 



Depth of mandibular ramus at m. iii 031 



" "P-m.iv 019 



Length of symphysis , 0245 



" " premolar series 022 



" " true molar 035 



" " of total dental series 063 



Diameters P-m. iv \ anteroposterior 0085 



( transverse 006 



Diameters m. i \ anteroposterior 009 



( transverse 0068 



Diameters m. iii \ anteroposterior 016 



c transverse 0062 



The second specimen with permanent dentition is of smaller size than 

 the type, and the canine teeth are small. It may have been a female. The 

 dental series, including the canine, measures M. 0.59 ; the premolar series, 

 0.23 ; the true molars, 0.31. 



The number of specimens of this animal found in the restricted area of 

 the Ticholeptus bed of Deep river, Montana, shows the former abundance 

 of the species. It was probably gregarious, in the manner of the other 

 Oreodontidse. We can depict it as seeking the swamps of the shore for its 

 vegetable food, and spending much of its time in the water when not feed- 

 ing. It was doubtless a good swimmer, and the characters of its feet will 

 be sought for with interest for light on this point. The use of the huge 

 superior nasal vacuity of the skull of this genus and Leptauchenia can 



