Vol. 6] Merriam: Virgin Valley and Thousand ('reck. 



297 



The inner portion of the trochlea extends downward over this 

 process instead of turning slightly forward beneath the astragalus 

 as in Antilocapra. 



In the lunar of the fossil form the hook which extends down- 

 ward over the posterior side of the unciform is longer than in 

 Antilocapra. Corresponding to this modification of the lunar 

 there is a deep pit on the posterior side of the unciform immedi- 

 ately behind the face for contact with the lunar (figs. 76 and 

 77). The posterior hook of the lunar is received in this pit. In 

 the unciform of Antilocapra there is only a shallow depression 

 where the pit is situated in the fossil form, and the posterior 

 portion of the articular face for the lunar is not continued 

 downward as sharply as in the fossil form. The unciform also 

 differs from that of Antilocapra in the development of a down- 

 wardly projecting process extending from the posterior side, im- 

 mediately below the pit for the reception of the posterior hook 

 of the lunar. In Antilocapra the posterior border is almost per- 

 fectly even in this region. There is shown here a tendency to 

 develop a mere specialized interlocking joint in the wrist of the 

 fossil form than is shown in Antilocapra. 



The metatarsals (tig. 74) are not essentially different from 

 those of Antilocapra. They vary considerably in size in different 

 individuals. This bone in no. 11892 is relatively a little narrower 

 than in Antilocapra. 



The terminal phalanges of the fossil forms differ from those 

 of Antilocapra in that they are a little sharper, or more distinctly 

 pointed anteriorly, and the inferior foramen on the inner side of 

 the posterior end is on the average of approximately the same 

 size as the postero-superior foramen on the inner side, instead 

 of being much smaller as in Antilocapra. 



In the proximal end of a scapula (figs. 75a and 756) avail- 

 able there is a slight difference from Antilocapra in the form of 

 the coracoid process. In Antilocapra the process is wider trans- 

 versely and is not separated from the external border of the 

 glenoid cavity by a shallow notch as in the fossil form. 



The proximal end of the radius is a little more extended on 

 the outer side just outside of the proximal articular surface in 

 Antilocapra than in the fossil form. 



