522 THE MAMMALIA OF THE UINTA FORMATION. 



trcqjezoid is small, subquadrate, with convex scaphoid and metacarpal facets and sub- 

 equal trapezium and magnum facets. The magnum has a pentagonal face with sub- 

 equal scaphoid and trapezoid facets; the remaining three sides articulate— o, with the 

 lunar ; this facet, although narrow in front, extends back to the full depth of the 

 lunar; also presenting a narrow unciform facet posteriorly ; 5, with the extension of 

 mc. Ill ; c, with the horizontal face of mc. iii and the extension of mc. ii. The 

 unciform has a broad cuneiform facet, and oblique lunar facet ; the inferior face pre- 

 sents subequal facets for the extension of mc. iii and the upper flxce of mc. iv. 

 The facet for the fifth metacarpal is narrow upon the anterior face and is presented 

 obliquely outwards and backwards. The full extent of this impoitant facet cannot 

 be ascertained, owing to a partial fracture and the immaturity of tlie individual. 



The second and third metacarpcds have subequal shafts with a rather flattened 

 and slender section, indicating that they were not long and that the digits were 

 rather short and spreading. The second metacarpal has a lateral trapezium facet, a 

 concave upper face for the trapezoid and an extension for the magnum and mc. in ar- 

 ticulations. The third metaeai'pal besides the above and the deeply concave magnum 

 facet has a lofty extension and abutment against the unciform. The fourth and fifth 

 metacarpals are missing ; the latter was borne upon the oblique unciform facet ; the 

 rearward extension of the unciform which foi-ms the principal support of the toe in 

 the tapir appears to be undeveloped. The proximal phalanges probably belonging 

 to these metacarpals are preserved ; they are elongated and rather slender. 



The only portion of the tarsus represented is the cuboid, which, however, 

 pi-esents important diagnostic charactei-s. It is very short and cylindroidal. The 

 superior face is subcirculai-, with a large hooked calcaneal facet and a compara- 

 tively extended facet for the astragalus. The outer surface is grooved for the flexor 

 tendons. The lower facet apparently supported mt. ii and a portion of mt. iii. The 

 vertical compression of the cuboid indicates that the navicular and cuneiforms were 

 much flattened. The distal portion of mt. in is broad with a prominent posterior 

 keel, while mt. ii is considerably narrower with an oblique face. 



The distal portion of the tibia shows a prominent malleolus and posterior spine. 

 The astragalar grooves are slightly oblique, and decidedly shallower than in Epi- 

 htp]?us. 



Special Measurements, Skeleton. 



licclohphus, No. 10,401. M. 



Cuboid, vcrlical diiiiiu'ter Oil 



" Uansvt'ise " 0095 



Distal face oft il)ia, transvtrsc 014 



" " " antcro-poskrior 020 



Carpus, viTliciil iliaiiiolcr, iiiuxiTiium -019 



" transvuisc ■• •' 02b 



