46 Annals of the Carnegie Museum. 



shaft, though relatively longer, is of a similar cylindroid character. 

 The facet for Mc. IV is located more laterally than in the Oligocene 

 genus and the dorsal and ulnar faces are less deeply grooved for 

 muscular attachments. Near the distal end is a flange on the postero- 

 ulnar angle, which is similar to that already described on Mc. II and 

 is not generally present in the Oligocene Titanotheres. 



There is apparently more inequality in size between Mc. II and 

 Mc. V than represented in the figure of the manus of Diplacodon by 

 Scott & Osborn. This is very probably due, to some extent, to the 

 crushing of Mc. II of the specimen in the Carnegie Museum. In the 

 specimen at Princeton the complete length of Mc. V is apparently 

 represented. Its measurements appear to be only about 13 mm. 

 longer, though nearly one-third broader, than that of the specimen 

 before us. 



The phalanges are short, broad, and in every respect titanotheroid. 



Measurements. 



No. 2860, 

 Mm. 



Scaphoid. Vertical diameter 35 



Scaphoid. Transverse diameter 33 



Scaphoid. Antero-posterior diameter 53 



Pisiform. Total length 60 



Trapezoid. Vertical diameter 20 



Trapezoid. Transverse diameter 26 



Trapezoid. Antero-posterior diameter 36 



Mc. II. Greatest length 153 



Mc. II. Transverse diameter of head, approximate 37 



Mc. II. Transverse diameter of middle of shaft, approximate 30 



Mc. II. Transverse diameter of near distal end, approximate 42 



Mc. V. Greatest length 125 



Mc. V. Greatest transverse diameter of head 36 



Mc. V. Greatest transverse diameter of middle of shaft 20 



Mc. V. Greatest transverse diameter of near distal end 33 



Proximal phalanx, length 31 



Proximal phalanx, transverse diameter of proximal end 29 



Proximal phalanx, transverse diameter of distal end 26 



Hind Limb. 



The pelvis of No. 2859 is represented by the greater portion of the 



ilium. It is quite broad across the gluteal surface, but the point of 



the ilium probably did not project laterally as much as in T. vaJidum. 



The constricted portion of the neck is actually longer than in the 



