354 NOTES ON THE CAXTIMB OF THE WHITE EIVER OLIGOCENE. 



more widely separated from the external astragalar facet than in Canis. In the latter 

 genus occurs a third astragalar facet, which is distal to the sustentaculum, and which is 

 found in neither Dinictis nor Dapluenus. The distal end of the calcaneum is occupied 

 by the large cuboidal facet, which is more regularly oval in outline and much more deeply 

 concave than in the existing forms of Canidce. In these forms we find a facet for the 

 navicular, which adjoins and forms a right angle with the accessory astragalar surface 

 already mentioned, but is not present in either of the White River genera. On the 

 external side of the calcaneum, near the distal end, is a prominent projection for liga- 

 mentous attachment. This process is not present in Canis, but it recurs in Dinictis, less 

 markedly in Hoplophoneus, and is found in many of the recent viverrines, mustelines 

 and raccoons. 



The cuboid is not peculiar in any noteworthy way ; it is longer proxirno-distally 

 .than in Dinictis and is proportionately narrower and thinner (i. e., in the dorso-plantar 

 diameter). The long, thick and rugose ridge which on the fibular side of the bone over- 

 hangs the sulcus for the peroneal tendons is more prominent, especially on the plantar 

 face, than in the Machairodont, but lacks the great, rugose plantar protuberance, which 

 occurs in the recent Canido3. The facet for the calcaneum is more convex than in 

 Dinictis, very much more so than in Canis, in which this surface is almost plane. On 

 the tibial face of the cuboid are three facets, a narrow proximal one for the navicular, 

 and a median and minute distal facet for the ectocuneiform. The facet for the head of 

 the fourth metatarsal is very much more concave than in the modern dogs, while that 

 for mt. v is smaller than in the recent forms, and lateral rather than distal in position. 



The navicular, as compared with that of Canis, is short proximo-distally, but broad 

 transversely, not having undergone the reduction hi width which Schlosser mentions as 

 characteristic of the recent members of the family. The astragalar facet is not more 

 concave than in the latter, and there is no such stout tubercle on the plantar side of the 

 bone as occurs in them. Two very small facets articulate with the cuboid, one near the 

 dorsal and the other near the plantar border of the fibular side. The distal facets for the 

 three cuneiforms have nearly the same shape and proportionate size as in Canis, but they 

 are more in the same transverse line, the surface for the entocuneiform being less dis- 

 placed toward the plantar side. 



The entocuneiform is of similar shape, but relatively better developed than in Canis, 

 as would naturally be expected from the presence of a complete hallux in Daphcenics. 

 The hone is long proximo-distally, thick antero-posteriorly, and narrow, though broader 

 than in Canis, and it< proximal and distal facets, for the navicular and first metatarsal 

 respectively, are relatively larger and more concave. The only other facet is an obscurely 

 marked one on the tibial side for the mesocuneiform. 



