﻿BOYSEN RESERVOIR VERTEBRATE FOSSILS — WHITE 



191 



The dentition of this specimen is distinctly more advanced than 

 that of D. ahsarokae of the Gray Bull. Unfortunately the upper 

 dentition of this genus is unknown from the Alkalai Creek exposures. 

 Consequently it is impossible to evaluate the stratigraphic significance 

 of this specimen. 



Family MIXODECTIDAE 



Genus CYNODONTOMYS Cope 



CYNODONTOMYS SCOTTIANUS COPE 



U.S.N.M. No. 18436, fragment of left mandible with posterior 

 half of P, and Mi_3 (loc. No. 48FI176) ; U.S.N.M. No. 18434, frag- 

 ment of right mandible wnth M^-s (loc. No. 48FR80) . 



The limited material pertaining to this species does not permit any 

 additions to Matthew's (1915c, pp. 470^77) discussion of the genus. 



CYNODONTOMYS LUNDELIUSI, new species 



FiGUiiB 77 

 Holotype.—VS.'^M. No. 18371 (fig. 77), fragment of a right 

 mandible with posterior half of Mi, Mo, posterior half of Ms, and the 

 roots of P3-4 (loc. No. 48FR65). 



Figure 77. — Cynodoniomys lundeliusi, new species, type, U.S.N.M. No. 18371; occlusal 

 view of teeth and lateral view of right mandible, X 2. 



Horizon and locality. — Lower Eocene, Lost Cabin. NWi4SWi/4, 

 sec. 5, T. 4 N., R. 6 E. of Wind River meridian, south side of Cotton- 

 wood (Dry Muddy) Creek, 11 miles (air line) north-northwest of 

 Shoshoni, Fremont County, Wyo. 



Diagnosis. — Size large, 33 percent larger than the average for 

 C. scottianus (Matthew, 1915c, p. 471) ; M3 relatively shorter than 

 in that species; heel of M3 narrower than on M2; paraconid on Mg 

 distinct; external and posterior cingula as in G. scottianus. 



