Peterson: Material Discovered in Uinta Basin. 83 



which are more or less doubtfully referred to the above species. Of 

 these may be mentioned No. 2917, a pair of lower jaws mutilated in 

 front, No. 2933, a left lower jaw, No. 3020, a portion of a skeleton 

 including nearly the complete tail, and No. 3038, also a portion of a 

 skeleton. C. M. Nos. 2987 and 3067 may possibly belong to a dif- 

 ferent (new) species on account of the rather small skull and large 

 teeth, but as the specimens pertain to young individuals, I i)refcr to 

 place them with P. medms. 



Specific Characters: If- Cy- P^' P- isolated by a diastema, upper 

 molars with reduced intermediate cusps. Pes relatively long. Animal 

 considerably larger than Protoreodon parvus, P. pumilus, P. paradoxicus, 

 or P. minor. 



The cranial region is long and the face short as in P. paradoxicus 

 Scott, but the infra-orbital foramen appears to be located further 

 back than in either P. paradoxicus or P. parvus. The premaxillary 

 is of well-proportioned size, and, as already stated, there are three 

 incisors present in the skull. The premolars have the same develop- 

 ment as in P. parvus, but the upper molars have advanced a step, 

 the anterior intermediate cusp being reduced. 



The present species is probably from a later horizon than those 

 heretofore described. In fact it appears that even the fragmentary 

 remains from this locality, referred to P. parvus and other known species 

 of the Uinta, are possibly further advanced, especially with regard 

 to the reduction of the anterior intermediate cusp of the molars, which 

 is a mere remnant in nearly all of the specimens, in which the upper 

 molars are preserved. 



The new species here proposed is by far the most abundantly 

 represented in this new fossil locality of the Duchesne Valley, the 

 smaller species being comparatively few in number. 



In general detail the skeleton answers very well to the descriptions 

 furnished by Professor Scott and need not here be repeated. However, 

 the illustrations herewith reproduced will serve as a correct guide to 

 proportions, as the type of P. medius is represented by practically 

 all the main parts of the skeleton, thus enabling us for the first time to 

 effect a restoration of an Oreodent from the Uinta with approximate 

 correctness. 



Unfortunately the carpus is not represented in the type. There 

 are, however, two metacarpals which give a fair idea of the proportions 

 of the fore and hind foot. A feature at once noticeable is the relatively 



