No. 2.] THE RELATIONS OF PROTOCERAS. 345 



vexity in the middle, is plane ; it rises steeply toward the ulnar 

 side, so as to present internally almost as much as proximally. 



The Phalanges (PI. XXII, Figs. 17 and 19) are short, both 

 in proportion to the size of the animal and the length of the 

 metacarpus, but are for the most part of typically ruminant 

 pattern, nevertheless. The proximal phalanx is slender and 

 relatively longer than in Dorcatlierium, though shorter than in 

 MoscJius. It is nearly straight, and of quite a different shape 

 from the curved, depressed phalanges of Oreodon. At the 

 proximal end the dorso-palmar and transverse diameters are 

 nearly equal ; the metacarpal facet is not concave and only 

 the palmar border is notched for the metacarpal carina. The 

 distal end is depressed, wider than deep, and its trochlea is 

 obscurely divided by a shallow notch into two condyles. 



The second phalanx is notably short and rather broad and 

 depressed, the transverse diameter exceeding the dorso-palmar. 

 This phalanx is thus of quite a different shape from that which 

 characterizes the recent chevrotains and Pecora. The distal 

 trochlea is neither deeply grooved nor reflected far upon the 

 dorsal side of the bone. 



The ungual phalanx is altogether ruminant in character, its 

 shape being trihedral, slender and pointed ; it is not so slender 

 and elongate as in Mosc/ms, nor so curved and depressed as in 

 the tragulines, and is less symmetrical than in Posbrotheiium, 

 indicating that the median digits were more closely approxi- 



mated than in that genus. 



Measurements. 



Protoceras Protoceras 



No. I. No. i}- MoscHus. 



Scapula, height 0.131 0.106 



Scapula, greatest breadth 069 .059 



Scapula, breadth of neck 015 .014 



Scapula, fore-and-aft diameter of glenoid cavity . .022 .018 



Scapula, transverse diameter of glenoid cavity . . .018 .015 



Humerus, length (fr. ext. tub.) -149 -^49 



Humerus, thickness of proximal end (ant.-post.) . .045 .032 



Humerus, breadth of distal trochlea .025 .019 



Radius, length I47 -UO -127 



1 This individual is part of the type specimen of P. celer Marsh; it was found 

 in 1894 by Mr. Hatcher. 



