20 



that the species is not a Hyracodon. The molar teeth are unfortunately broken away. 

 The other ramus supports the second premolar, the last deciduous molar, with the first 

 two permanent true molars. 



The anterior (? fourth) premolar has a single large root, with a deep groove on the exter- 

 nal side. In the true molars the V-shaped crests are fully developed, and there is a low 

 cross-crest at the anterior border of the crown. There is no complete cingulum, but short 

 sections opposite the valleys on both the internal and external bases of the crown, on the 

 external side near the front, and at the posterior base. The measurements show how much 

 smaller this species is than the C. mitis, and that it does not exceed the Hyracodon nebras- 

 censis. 



Measurements. 



No. 1. 



M. 



Width between bases of P. m. i 033 



Length of base of anterior three premolars 042 



Depth of ramus at diastema 036 



" third premolar 042 



No. 2. 



Length of molars i and ii 039 



( Anteroposterior 020 



Diameter M. ii. ■! 



(.Transverse 012 



Depth of ramus at front of M. ii 033 



ANCHITHERIUM, Kaup. 

 Anchithekium westonii, Cope. 



American Naturalist, 1889, p. 153. 



This species is represented by a single superior molar and two inferior molars, the 

 latter in place in a part of the mandible. The teeth are smaller than those of the A. 

 bairdii, from which they also differ in their greater transverse as compared with their 

 anteroposterior diameters. The intermediate tubercle of the posterior cross-crest is more 

 distinct than that of the anterior, and the posterior intermediate cingular cusp, so promin- 

 ent in the A. bairdii, is here wanting. The posterior cingulum continues round the inter- 

 nal base of the posterior internal cusp. Diameters of superior molar : Transverse, 13.5 

 mm. ; anteroposterior, 10 mm. Diameters of inferior molar : Transverse, 8 mm. ; antero- 

 posterior, 10.5 mm. This species, interesting for its primitive character in the absence of 

 the posterior cingular cusp, is dedicated to Mr. T. C. "Weston, the most successful col- 

 lector in the region from which these fossils were obtained. 



ARTIODACTYLA. 

 ELOTHERIUM, Pomel. 



Entelodon, Aymard. 

 Elothekitjm arctatum, Cope. 



American Naturalist, 1SS9, p. 62 Hum morlonii, Leidy, Cope, Report G. & N. H. Surw, Canada, 1885, 



p. 154. 



Established on a left mandibular ramus which supports all the molar teeth, but 



