THE OSTEOLOGY OF HYiENODON. 527 
the cuboid a highly characteristic appearance, which is not reproduced in Hyceno- 
don In the latter the tibial side of the bone displays proximally a large flat facet 
for the navicular, and distal to this two small, round projections for the ectocunei- 
form, which are separated from each other by a wide and deep sulcus. The plantar 
hook-shaped process is not long, but very broad and heavy and extends around both 
the external and plantar surfaces. The distal side has a large, triangular and con- 
cave articulai surlace, which is obscurely divided into facets for the fourth and 
filth metatarsals; in II. cruenlus the latter is very small and somewhat oblique in 
])osition ; in //. horridus it is larger and more entirely distal. 
1 he navicular is low and narrow, but with considerable dorso-plantar exten- 
sion. The astragalar surface is simply and deeply concave. On the fibular side is 
a large and nearly Hat surface for the cuboid, the proximal ends of the two bones 
lying in nearly the same plane. On the distal side are the usual three facets for the 
cuneiforms, the only noteworthy feature of which is the narrowness of that for the 
entocuneiform. The plantar hook is quite prominent; in H. sp. it is 'straight and 
knob-like, while in the larger species it is longer and more decurved. 
T'he entocuneiform is high and thick antero-posteriorly, but very narrow and 
compressed ; it is broadest on the plantar side, thinning to an edge on the dorsal, 
and the distal end e.xceeds the proximal in every dimension. The navicular facet 
is very small, while that for the first metatarsal is considerably larger and strongly 
concave in the dor.xo-plantar direction. On the fibular side is quite a large facet for 
tlie head of the second metatai’sal. 
The niesocuneiform is low, but exceeds the entocuneiform in the other two dimen- 
sions ; its distal surface stands at a higher level than that of the tarsals on each 
side of it, as is very generally the case in both the creodonts and carnivores. The 
bone is wedge-shaiied, but in the opposite sense from the entocuneiform, the dorsal 
surface being the wider. The lateral facets are small and obscurely indicated. 
T’he ectocuneiform is much the largest of the three, except in vertical height, 
which is less than tliat of the internal element, though much greater than in the 
median one. On the plantar surface is a heavy, prominent knob, shaped very much 
like that on the navicular. On the tibial face are two facets, a proximal one for 
the niesocuneiform and a distal one for the second metatarsal. The cuboid facets 
are both proximal; they are small, rounded and separated by a wide sulcus, but 
are not projecting and shelf-like, as are the corresponding facets on the cuboid. 
The distal facet for the third metatarsal is not much wider than that on the raeso- 
cuneiConn lor the second metataral; it is much extended from before backward 
and is (luite deeply concave in the same direction. 
The consists of nve fully developed members; thy are rather more 
slemlor than the metacarpals and exceed then, bnt little .u leyth. Th.ys 
usual ,„-o|K,rtio„ a.uong the lleshu,alera in which the hn.d- foot .. >^0^ 
ably IninrcM- lliail the Ihre-font. lioth are short, we.ak and slender m lelat on the 
siinf the animal, thongh in the larger specimens of HJ^ndus the feet are not 
^^uite so disproportionately weak. 
