No. 2.] THE RELATIONS OF PROTOCERAS. 34 1 



down upon the hook. The distal end is occupied by the wide 

 and shallow (fore and aft) facet for the unciform. 



The pisiform is neither traguline nor cervine in character, 

 but differs from that of the musk-deer much as the latter does 

 from the larger species of Cervtis. 



As compared with the pisiform of Moschus, it is somewhat 

 longer and more slender and is but slightly incurved at the tip. 

 On the other hand, it differs much more radically from the 

 straight, slender, and elongate pisiform of the oreodonts, and 

 tends distinctly toward the shape taken in the Pecora. It is 

 short, deep, and compressed, rugose and somewhat incurved 

 distally. The facets for the ulna and cuneiform are continuous ; 

 the former is small, triangular, and plane, the latter is larger, 

 of irregular outline, and saddle-shaped. 



The trapezium is not preserved in any of the specimens in 

 the Princeton collection, but, fortunately, Osborn and Wort- 

 man are able to assure us of its presence. 



A significant feature in the carpus of Protoceras, pointed out 

 by the authors just mentioned, is the complete separation of the 

 magnum and trapezoid, as in P cebrothermni and the Tylopoda 

 generally. The trapezoid is quite high and deep in the dorso- 

 palmar direction, but very narrow ; it is somewhat wedge- 

 shaped, broad behind and thinning to an edge antero-externally. 

 Its proximal surface forms a rounded, convex head for the 

 scaphoid, the articular surface of which is continued down 

 upon the palmar side, doubtless for the trapezium. The con- 

 tact with the magnum is by means of two facets which meet in 

 the middle of the ulnar side. Distally the trapezoid bears a 

 triangular, nearly plane surface for the second metacarpal, but 

 has no contact with the third. 



The magnum is relatively high and narrow, as compared 

 with that of the recent Pecora. The dorsal face is subquad- 

 rate in outline, the palmar very much narrower, and the 

 posterior hook, though stout and rugose, is very short. The 

 proximal surface is unequally divided between the facets for 

 the scaphoid and lunar. Anteriorly the scaphoid facet takes 

 up quite two-thirds of the width of the magnum and is here 

 slightly concave. Upon the " head " the surface is convex, and, 



