418 M. R. Thorpe — Leptauchenla Lekly and 



basicranial area is not known to me to occur so distinctly 

 in any species of Cyclopidius where the skull characters 

 have been described. The palatonarial border is opposite 

 the posterior lobe of M^. In Cyclopidius emydimis it is 

 nearly halfway between the glenoid articular surface and 

 M^. The palate is slightly concave. 



The transverse diameter of the posterior lobe of M^ is 

 but a trifle greater than that of P^. The tooth rows are 

 not parallel, as in Oreodon and most of the genera of this 

 family, but converge anteriorly. The canine is situated 

 inwardly of the line of the tooth row and is nearly circular 

 in section, being of somewhat greater diameter at the 

 internal face. As stated above, the incisor border is 

 missing, but the amount of space available for incisors 

 was not more than would accommodate two unless they 

 were extremely small. However, I am inclined to believe 

 that it had but two of these teeth. 



The infra-orbital foramen is single and above the inter- 

 val between P^ and P^. The external auditory meatus 

 is directed more posteriorly than outwardly, and situated 

 posterior to a line above the paramastoid process. 



Measurements of Holotype. 



mm. 



Skull, length, occip. condyles to canine inc., approx 93 



Bizygomatic diam 82 



Diam. of postorbital constriction 17 



Max. width of brain-case 39.5 



Width above P^ 26 



Width between middle of orbits 33 



Depth of malar below middle of orbits 14.7 



Ant.-post. diam. of bull-a 22 



Transverse diam. of bulla 19.5 



Dental series, with canine, length 53 



Molar series, length 28.5 



Premolar series, length 20 



Beferences. 



Cope, E. D. 1878A. New artiodactyles of the upper Tertiary. Amer. 

 Nat., 12, 58. 



— 1878B. Descriptions of new Vertebrata from the upper Tertiary forma- 



tions of the West. Proc. Amer. Philos. Soc, 17, 219-231. 

 1884. Synopsis of the species of Oreodontidae. Ibid., 21, 503-572. 

 Leidy, J. 1856A. Notices of remains of extinct Mammalia, discovered 

 by Dr. F. V. Hay den in Nebraska Territory. Proc. Acad. Nat. 

 Sci. Phila., 8, 88-90. 



— 1856B. Notice of some remains of extinct vertebrated animals. Ibid., 



8, 163-165. ' 



