Notes on the canidJ: of The White river oligocene. 387 



The third metacarpal, though short and slender, is somewhat the longest and heav- 

 iest of the series. The proximal articular surface for the magnum is shaped very much 

 as in Canis, but is slightly broader in proportion and rather more concave transversely ; 

 on the radial side of the head is a large facet for mc ii, which has a more oblique 

 position than in the modern genus. On the ulnar side is a small projection which 

 abuts against the unciform and is relatively larger than in Canis. The shaft, and 

 indeed the whole metacarpal, has a viverrine rather than a canine appearance ; it has not 

 acquired the prismatic, quadrate shape which is so characteristic of the modern dogs, 

 but is of oval section and is of almost uniform width throughout, but broadens slightly 

 at the distal end. The distal trochlea, though much lower in the vertical diameter, is 

 yet of decidedly more canine character than is that of Daphcenus, being broad and hemi- 

 cylindrical in shape instead of subspherical. The pit above the trochlea, which is absent 

 in Daphcenus, is distinctly marked and the lateral processes for ligamentous attachment 

 are much less prominent, All of these conditions are approximations to the conditions 

 seen in Canis. 



The fourth metacarpal is not completely preserved in any of the specimens, but it 

 appears to have been of about the same length as mc iii and to have formed with it a 

 symmetrical pair, although the two metacarpals are not so closely appressed as in Canis, 

 but diverge slightly toward the distal end. The head has a simply convex facet for the 

 unciform and is somewhat narrower proportionately than in the existing members of the 

 Canidce, owing to the overlapping of the head by mc iii, in order to reach the unciform. 

 So far as it is preserved, the shaft is rather more slender than that of mc iii and of a 

 more cylindrical, less compressed shape. 



The 'fifth metacarpal is remarkably short, much more so in proportion to the length 

 of mc iii than is that of Canis. The head is less broadened and thickened than in the 

 latter genus, and carries a simple, convex facet for the unciform. In the modern genus 

 there is likewise a large facet for the pyramidal, which extends down over the unciform 

 and comes into contact with mc v. In Cynodictis there appears to be a facet of a simi- 

 lar kind, but if so, it is very small and obscurely marked and maybe regarded as in only 

 an incipient stage of development. The shaft is slender proximally and broadens dis- 

 tally, the reverse of the proportions which obtain in Canis, and the distal trochlea is 

 small and is of somewhat more spherical, less cylindrical, shape than in the existing 

 members of the family. 



The phalanrjes. It is unfortunate that in all of the specimens in the collection the 

 phalanges are in such a fragmentary state that only an incomplete account of them can 

 be given, and some important questions must be left unanswered for the jjtresent. The 

 proximal phalanx of one of the median digits is short, slender and straight, and is rela- 



