1881.1 l^-*- ICope. 



Pelycodus angulatus Cope. 



The species of this genus are, in the present state of our knowledge, best 

 distinguished by their size. 



Length of true molars on base M. .024 ; P. pelvidens* 



" " " " M. .019 ; P. jarrovii. 



.M. .017; P. tutus. 



" " " " M. .015 ; P. frugworus. 



" " " " M. .012 ; P. angulatus. 



Remains of species of this genus are very common in the Wind River 

 bad lands ; they were originally found in the "Wasatch beds of New 

 Mexico, and have not yet been announced from the Bridger formation. 



The P. angulatus, heretofore only known from New Mexico, is rep- 

 resented in the Big-Horn collection by five mandibular rami, and a por- 

 tion of a maxillary bone with teeth. 



Peltcodus frugivorus Cope. 



Two mandibles and seven separate rami represent this Mesodont. 



Peltcodus tutus Cope. 



Four rami display the typical length of the true molars, M. .017. Three 

 are smaller, having the molars .016 in length, while one gives .018 for the 

 same teeth. Other portions of the skeleton will be necessary to deter- 

 mine exactly the specific position of these specimens. 



Pkosimi^e. 



Cynodontomys latidens, gen. et sp. nov. 



Char. gen. Derived from mandibular rami. Dental formula I. ? ; C. 

 1 ; P-m. 2 ; M. 3. The premolars are counted as two, on the supposition 

 that the anterior one is two-rooted ; should it prove to be one -rooted, then 

 the number will be three. The canines are very large and close to the 

 symphysis, so that there do not appear to have been any incisors. The 

 true molars have the frequently occuring three tubercles in front and a 

 heel behind ; but the arrangement is peculiar in that the three tubercles 

 are but little more elevated than the borders of the heel, and occupy a 

 small part of the crown. The last molar is lost from both jaws, but the 

 space for it is about as large as that occupied by the penultimate. The 

 fourth premolar has but two anterior cusps, and these are more elevated 

 than those of the true molars, and the heel is narrower. The mandibular 

 rami are not coossified. 



The dental characters of this genus resemble considerably those of 

 Anaptomorphus and Necrolernur, but the large size of the inferior canine 

 tooth distinguishes it from both. The double anterior cusps of the fourth 

 premolar equally distinguish it from them. 



Char. Specif. The inferior true molars are subquadrate in horizontal 

 outline, somewhat narrowed anteriorly. The concave heel is the larger 

 part of the crown.; it is only elevated into a low cusp at the posterior 

 external angle. The anterior cusps are conic, and are in contact at the 



* Lipodectes pelvidens Cope, Amer. Naturalist, Dec, 1881, p. 1019. 



