Tht .1 merica/n { rcolooist. 



April, IS!)'.' 



Iii the Oregon maxillary, tub posterior palatal foi'amen "issues 

 opposite the fourth premolar's internal root." In the Huerfano 

 specimen, it opens opposite the anterior part of the posterior root 

 of the first true molar, or opposite the middle of the molar. 



In comparing the Huerfano specimen with Leidy's type of A. 

 hesterna, it will be noticed that the fourth inferior premolar in the 

 former is. relatively to the adjacent first molar, larger than in the 

 latter, and that, in form, it more closely approximates a triangu- 

 lar prism or wedge; features which are apparently only in part 

 due to the somewhat more worn condition of the premolar of the 

 Huerfano specimen, by reason of which condition, however, the 

 lacuna of the grinding-surface is closed instead of being open 

 posteriorly as in hesterna. 



The strongly recurved posterior fifth lobe of the last upper 

 molar, in the Huerfano specimen, is but moderately developed.; 

 for, though the tooth has reached a more advanced stage of wear 

 than has the last lo wer molar of Leidy's type of hesterna, it does 

 not contribute to the area of the grinding-surface, but becomes 

 obsolete before reaching the plane of the latter. 



Whatever may be the final generic disposal of the Californian 

 hesterna, and of the Oregon desert maxillary, the present speci- 

 men is a true Auchenia. It lacks, however, the 1 ■compression - 

 folds' seen on the lower molars of recent llamas. Its size was 

 closely approximate to that of ('? Hohmieniscus) hesterna, from 

 which the available data indicate that it is probably distinct. The 

 species may be known as Auchenia huer/anensis. 



I append the following measurements: 



Inches. 



Mandible, from symphysis to posterior border (latter / j- 



taken at three inches below infra-condylar hook). . . . \ 



Elevation of summit of coronoid process above in- / *n 



ferior border of mandible ) 



Depth of mandible at postsymphyseal constriction 1.8 



Same at posterior edge of alveolus of first true molar. . 2.8 



Inferior post-canine diastema 3.8 



Antero posterior diameter of grinding surface of sec- / 



ond true molar ) 



Transverse diameter of same 1.125 



Antero-post. diam. griod'g surf, third true molar 1.5 



Transverse diameter of same 1.18 



Major diameter of acetabulum 2.75 



Minor diameter of acetabulum 2.5 



Breadth of cannon bone at distal extremity 3.6 



Length of first phalanx 4.4 



Breadth of same at proximal extremity 1.(52 



Breadth of same at distal extremity 1.25 



