464 Annals of the Carnegie Museum. 



the long axis of the calcaneum than in the camel, and is more nearly 

 like that of the llama. The facet for the cuboid is somewhat longer 

 antero-posteriorly than in the llama but the inferior projecting articu- 

 lar lip, which embraces the distal end of the astragalus in the camel 

 and the llama is entirely absent in Oxydactyhis lofigipes. There 

 are no important differences from that of living genera in the susten- 

 tacular facet. Below the latter facet and above that of the cuboid is 

 an opening, but not nearly so distinct as is seen in living forms. The 

 groove on the posterior face immediately above the cuboid facet is 

 deeper than that in the llama and resembles that of the camel. 



The Astragalus. — The astragalus is comparatively much longer and 

 narrower than that of the camel and llama. Anteriorly there is more 

 of a constriction and a greater separation between the proximal and 

 distal trochlea than in the recent genera. The internal condyle is 

 not nearly so heavy as that of the llama, except at the posterior apex, 

 where it has a slightly recurved shoulder not observed in the camel or 

 the llama. The articulation is continuous without the interruption 

 observed on the lateral side of the condyle of the camel. In the 

 llama this articulation is also uninterrupted. The external condyle is 

 comparatively lower in O. lougipes than in the camel giving the bone 

 a more symmetrical appearance than in the latter genus. The distal 

 trochlea is similar to that of the camel and the llama, with the postero- 

 internal portion of the navicular facet somewhat more extended in- 

 wardly than in the latter genus. 



The Cuboid. — (PI. IX, Fig. 5.) The cuboid is comparatively 

 larger in the antero-posterior direction and somewhat higher than that 

 of the camel and the llama. The calcaneal facet is long and narrow. 

 The astragalar facet is narrow, especially posteriorly, where the cal- 

 caneum takes up the entire width of the bone, forcing the conical 

 apex of the astragalar facet far inward, unlike that of the recent forms. 

 The facets on the tibial side are as distinct as in the living represen- 

 tatives. There is a deep narrow groove immediately below the cal- 

 caneal facet on the posterior face extending clear across the bone, and 

 differing in this respect from the llama. The posterior hook is com- 

 paratively heavy and extends outwards and downwards, fitting against 

 the palmar process of the fourth metatarsal. The smaller portion of 

 this bifid hook is superiorly located and is a conical projection on the 

 tibial side with a small facet for articulation with the navicular, the 

 distal facet supporting the fourth metatarsal is irregularly triangular in 



