134 Annals of the Carnegie Museum. 



The length of the tibia is very little, if any, greater than the radius. 

 The bone is quite symmetrically formed with a prominent cnemial 

 keel well confined to the proximal end, unlike what occurs in Hyracodon, 

 in which it extends somewhat further down. The shaft has a slightly 

 backward curve, while the distal trochlea is deeply excavated and is 

 very oblique, in this respect closely suggesting the Hyracotheres. 



The astragalus of No. 3199 has received slight lateral crushing, 

 which makes it appear narrow in comparison with the specimen illus- 

 trated by Professor Osborn (/. c, PI. XI, Fig. 9). The pes as a whole is 

 in reality slightly smaller than in the type, which is, no doubt, due to^ 

 the incomplete maturity of the specimen at hand. The different 

 bones of the tarsus agree quite well with the description of the material 

 in Princeton University furnished us by Osborn (/. c, p. 549), and 

 needs no further description, except to say that the entocuneiform, 

 though quite large, and with the plantar process somewhat like that 

 of Hyracodon described and figured by Professor Scott, ^-^ has not 

 formed an articulating facet with the plantar process of Mt. Ill, and 

 the process itself has not attained the prominence seen on the ento- 

 cuneiform of the Oligocene genus (See Plate XLVI, Figs. 7-8). 

 41. Prothyracodon uintense sp. nov. (Plate XXXVI, Fig. i; Plate 

 XLV; Plate XLVI, Figs. 10-16). 



Type: Skull and lower jaws of young individual C. M. No. 30076!.^-^ 



Horizon: Uinta Eocene, horizon C. 



Locality: Six miles east of My ton, Utah. 



With the type specimen are provisionally associated three other 

 specimens in the Carnegie Museum as probably pertaining to the 

 same species. Of these No. 2990 consists of fragments of the lower 

 jaws, limbs, and foot-bones; No. 3097, portion of vertebral column, 

 scapulae, and humerus, and No. 3399, fragments of vertebrae. Of 

 these specimens No. 3007 was found together with the type, but is of 

 an adult individual, the others were found in the same general locality 

 and in the same horizon. 



Specific Character: Protoloph of molars with a ivell-markcd aut:crochet. 

 M- with smooth posterior face, no spur of the ectoloph-at all indicated. 

 Teeth proportionally large, zvhen compared with P. obliqiiidcns. Animals 

 larger than P. obliqnidcns. 



'-■•"Osteology von Hyracodon Lcidy," Festschrift fiir Carl rioii;cnl)aur, Leipzig, 

 1887, p. 377. PI- I. Fig- 7- 



'25 The type specimen was found together with the remains of other individuals 

 of different genera. 



