428 THE WASATCH EPOCH. 



Measurements. 



u. 



Leugth of posterior true molars 033 



Diameters of M.iii^»"t"°l"'«'«"'"" "|^ 



( transverse "'" 



Diauu-tersofM.Til ""'""?•'«'«"'"■ ] °!^ 



( trausverse "ii 



Depth of ramus at M. ii "30 



Tlie characters of the teeth of this species are something hke that of 

 some of the Paloeochceri of the Miocene, and resemble more those seen in 

 some of the bears. From the Big Horn River; J. L. Wortman. 



PHENACODUS Cope. 



Paleontological Bulletin, No. 17, p. 3, 1873. Report on Vertebrate Fossils of New Mexico, U. S. Geog. 

 Sur\s. W. of lOeth meridian, 1874, p. 10. Ibidem, p. l*i. Report U. S. Geol. Survs. W. of lOOtU 

 meridian, IV, Part II, p. 173. American Naturalist, 1881, p. 1017. Paleontological Bulletin, No. 

 34, p. 177, 1881. 



The characters of this genus are derived from the typical species, the 

 P. primoevus, and from the P. vortmani, both of which are represented by 

 almost perfect specimens. 



The skull is distinguished by the anterior abbreviation of the nasal 

 bones, and the consequent partly superior aspect of the anterior nostrils. 

 Posteriorly these bones are can-ied farther than usual, extending between 

 the orbits; in P. primoevus constituting a slightly nearer approach to the 

 living genus Tapirus than is usual in other Eocene genera now known. 

 The premaxillaries are slender, and do not unite in front. Posteriorly they 

 reach to the nasals, but not to the frontals. Theie are no postorliital pro- 

 cesses either of the frontal or malar bones. Sagittal crest present. The 

 palate is excavated beyond tiie posterior l)order of the last superior molar, 

 and the pyramidal processes of the palatine bone are not separated from 

 the maxillaries by a notch. Postglenoid processes prominent, no trace of 

 preglenoid ridge. Posttympanic process short, widely separated from the 

 postglenoid in front by the meatus auditorius, and from the paroccipital 

 behind by the robust bases of both processes. Petrous bones lost, but 

 probably small. 



Frontal bone deeply and widely excavated anteriorly to receive the 

 nasal bones. Parietals extending forwards lo their usual position poste- 

 rior to the orbits. Tho mastoid l)on(> well exposed botwocn the occii)ital 



