516 THE MAMMALIA OF THE UIN^TA FORMATION. 



Ulna and radius (Fig^. 18). These bones are complete, and taken together indi- 

 cate a rather long and slender forearm. Tlie proximal portion of the radins covers 

 the entire nlna, and the shaft crosses to the ental side. The relative diameters of the 

 distal fiicets are about as five to two. The ulna has a very stout rugose olecranon ; 

 the posterior border pi'esents a single concave curvature to the distal extremity ; the 

 midsection of the shaft is triangular with a deep groove upon the anterior face. The 

 radius in midsection of the shaft is suboval anteriorly and flattened posteriorly; 

 the facet for the ental condyle of the humerus has the same transverse, but much 

 deeper antero-posterior diameter than that for the ectal. 



The Manus. The carpus is entirely wanting. The metacarpus and a few of the 

 phalanges are preserved. They show a high stilted tetradactyl metapodium of the 

 "digitigrade" type, that is, with the jihalanges resting entirely upon the ground. 

 The distinctive feature of the foot is seen iu the subequal size of the second and fifth 

 digits, which brings the working median axis between the third and fourth digits 

 instead of through the middle of the third. The carpus was thus undoubtedly of the 

 tyi^e intermediate between Pala^osyojjs and Titaaothermm as restored in outline. The 

 second metacarpal has proximally (Fig. 13?;) a pear-shaped facet for the trapezoid, 

 a magnum facet extending to its full depth ; it also overlaps mc. iii. The third meta- 

 carpal has a subquadrate magnum facet and triangular unciform facet, overlapping 

 mc. IV by separate anterior and posterior facets. The Iburth metacarpal has a corre- 

 sponding mc. Ill facet ; the uncifoi-m facet is fractured j)osteriorly. The fractured 

 proximal portion of mc. v shows a narrow concave unciform facet and a lateral facet 

 for mc. IV. The keels are entirely confined to the posterior surface, as shown in a 

 distal view of mc. ii (Fig. Via). The measurements are as follows : Length, mc. 

 in — 18 cm., mc. v — 13 cm. Depth o f p r o x i m a 1 f ac e t s , mc. iii — 3.5 cm., mc. 

 Ill — 3.3 em. Breadth of distal facets, mc. in — 4 cm , mc. v — 3.4 era., mc. 

 II — 3.4 cm. 



T\\c2)elv!s (No. 10,393). The marked characteristics of the pelvis are the great 

 length of the ossa-innominata as compared with their breadth. The accompanying 

 restoration of the pelvis, as viewed from above, shows the parts which are preserved 

 in Di])laco<lon in comjiarison with the pelves of Titanotherium and Pakeo^i/ops. The 

 ilia do not expand immediately above the acetabula as in the Miocene genus, but 

 there is a long and rather slender neck as in Falaiosyops, beyond which they expand. 

 The acetabular border presents a short sharp curvature, and is relatively much shorter 

 than in Pahmsyops ; the ischial border {!h.) is much longer, with a gradual curva- 

 ture. It follows that the suprailiac border apiiarently presented outwards more than 

 directly upwards and forwards as in /'aht'osyops and Titanotherium— a result of the 



