PAL.5<]0SY0PS LEIDY, AND ITS ALLIES. 811 
facet is more sharply separated from the navicular than in P. paludosiis. The 
cuboid facet ot the astragalus is large and takes up nearly one-third of the 
anterior lace ot the bone. Strange to say, in Diplacodon, where we should expect 
to find tliis facet still larger, such is not the case, the astragalus of this genus 
figured Scott and Osborn in their Uinta Mammalia being really not as large com- 
pared with the breadth of the whole face of the bone as in P. paludosus. 
Whole face. 
Cuboid facet. 
M. 
M. 
Diplacodon- 
.060 
.015- 
P. paludosus— 
.050 
.015- 
Navtailar . — The navicidar in P. pahidosus resembles very closely that of the 
Tapir. It is a flat and very low bone and rather deep; its proximal surface is 
bordered externally by a prominent raised process as in Tapiriis. The distal artic- 
ular face of the navicular is subdivided differently from that of the Tapir. Owing 
to the small size of the ectocuneiform, the facet for this bone upon the navicular 
is not much larger than that for the mesocuneiform, although the facet for the 
latter is not as deep as that for the ectocuneiform. 
Ectocimeiform. — The ectocuneiform in this species is a much narrower and 
higher bone than that of the Tapir. In Plyrachyus we see the breadth in compari- 
son to the height still more reduced than in P. paludosus. The narrowness and 
great depth are the most important characters of this bone in P. pahidosus. * Both 
articular foces are nearly plane, the upper one being slightly concave. On the 
external side the ectocuneiform shows a single large facet for the cuboid and, inter- 
nally, two separated facets for metatarsal II. The articulation of metatarsal II 
aud the ectocuneiform is quite different from that in Tapirus. In P. pahidosus this 
metapodial oveiliangs, as it were, the upper surface of metatarsal III, aud thus the 
ectocuneiform does not pass beyond the articulating surface of this metatarsal as it 
does ill the tarsus of the Tapir. 
Mesocuneiform . — This cuneiform is much larger in P. paludosus than in the 
Tapir, and consequently there is not as great a difference in size between the two 
internal cuneiforms as in the tarsus of the Tapir. This bone is triangular in outline, 
being broad in front and narrow behind ; its external side presents an oblique sur- 
face oiitAvard, and internally there is apparently no facet for the entocuneiform, 
although this facet is displayed by the navicular. 
Cuboid, No. 10,288. — The cuboid is compressed and very deep ; its external 
surfiice is concave, being bordered anteriorly and posteriorly by the prominent raised 
edges of the bone. The inferior surface of the cuboid is provided with a deep, 
narroAv and very prominent tuberosity which is median in position. The form of 
the cuboid is quite unlike that of P. minor. In the latter species this bone 
has nearly a square form with very much less depth than in P. paludosus. The 
in the articular surfaces of the cuboid in the smaller species are also much flatter than 
latter. The tuberosity of the cuboid in P. minor is not so narrow and elongated 
