384 NOTES ON THE CANID.E OF THE WHITE RIVER OLIGOCENE. 



VI, The Manus (PI. XX, Fig. 23). 



By a fortunate discovery of Mr. Hatcher's, I am enabled to give an account of an 

 almost complete carpus belonging to Oynodictis, which has hitherto been entirely 

 unknown. 



A scapho-lunar is present, formed by the coalescence of the scaphoid, lunar and 

 centra], which distinguishes Oynodictis from the creodonts. This bone resembles that of 

 Caiiis in general character, but displays quite a number of differences in points of detail, 

 and these differences are, at the same time, approximations to the structure found in 

 Daphasnus. The scapho-lunar has a very small vertical (proximo-distal) diameter, 

 especially on the radial side, where it thins away to a mere edge, the facets for the radius 

 and the trapezium almost meeting. As compared with the corresponding carpal of Cards, 

 this bone has a somewhat greater transverse and smaller dorso-palmar diameter. The 

 radial facet is simply convex both transversely and antero-posteriorly, and has not the 

 saddle-shaped extension at the interno-palmar angle which is found in the recent dogs. 

 This facet descends quite low upon the dorsal side of the bone, as is also the case in 

 the modern plantigrade and semiplantigrade carnivores. The hook-like process which 

 arises from the postero-internal angle of the scapho-lunar is much shorter and less mas- 

 sive in every dimension than that of Cards. Another difference from the modern genus 

 consists in the absence of any distinct articular surface for the pyramidal, the facet for 

 the radius and that for the unciform almost coining into contact along the ulnar side of 

 the hone. 



On the distal side of the scapho-lunar are four facets, for all the carpal elements of 

 the distal row. That for the unciform is relatively smaller than in Cards, and is con- 

 fined to a narrow strip Dear the ulnar border; the magnum facet is much the same as in 

 the modern genus, hnt is somewhat more oblique in position. The surface for the tra- 

 pezoid is fairly large and keeps more marly parallel with that for the magnum than in 

 the recent dogs, while the trapezium facet is small and of almost circular shaj^e. 



The pyramidal is a very different-looking bone from that of the modern dogs, 

 being broad, depressed and scale-like in shape; its vertical (or proximo-distal) diameter is 

 very small and relatively much less than in Cards, and there is no such process from 

 the ulnar side of the bone as in the latter, in which the pyramidal articulates with the 

 head of the fifth metacarpal by a much more extensive facet than in Oynodictis. 

 The recent viverrines have the pyramidal shaped very much as in the White River 

 genus. The proximal surface is divided into two narrow and somewhat concave facets 

 for the ulna and pisiform respectively, of which the latter is slightly the larger. On 

 the distal side is a single large and concave facet for the unciform, and posterior to this 



