208 MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 
The bone, as a whole, tapers rather more upwards than in the higher forms, and 
would appear to do so more plainly but for the tibiad production of the anterior 
superior tibial angle, or summit of the surface for the hallux. 
The postero-peroneal face of the entocuneiforme is, in the Orang, almost entirely 
occupied by surfaces which articulate with the naviculare, the mesocuneiforme, and the 
second metatarsal. These articular facets are well defined by sharp margins (Pl. XLIII. 
figs. 22-26 6, d, e), but are nevertheless continuous, and form an oblique band of 
articular surface extending from the posterior inferior angle of the bone to its anterior 
superior one, 
Mesocuneiforme. (Plate XLIII. figs. 27-31.) 
This bone in the Orang is less vertically and more antero-posteriorly extended than 
are its homologues in Man and the Gorilla. Its dorsum (Pl. XLIII. fig. 27) also is 
larger antero-posteriorly (as compared with its transverse dimensions) than in Troglodytes, 
in which it more resembles that of man. As in the Gorilla and Chimpanzee, its posterior 
surface (Pl. XLII. fig. 31) is more concave than in the human mesocuneiforme. Its 
anterior surface (as also in the Gorilla) has its upper tibial part more bevelled off than 
in Man (PI, XLIII. fig. 30), and the rest of that surface is more concave than in him 
or in the Gorilla. The tibial surface of the bone (Pl. XLIII. fig. 28) presents one 
large articular surface (for the entocuneiforme) which is mainly extended from behind 
forwards, instead of the two distinct facets which exist in Man. 
The peroneal surface has, at its posterior plantar angle, a rather convex articular facet 
(Pl. XLII. fig. 29 d) which articulates with the ectocuneiforme ; and there is also a more 
or less marked articular surface extending antero-posteriorly along the top of this 
peroneal face, 
Ectocuneiforme. (Plate XLIII. figs. 32-36.) 
In the Orang the ectocuneiforme has its proximal articular surface (Pl. XILIII. 
figs. 32 & 366) much more oblique and much more convex than in either Man or 
Troglodytes. As in the latter genus, the posterior extension of the bone, below the 
hinder articular surface, is greater than in Man; and the posterior inferior angle is 
produced into a rounded head (Pl. XLIII. fig. 34¢), The distal articular surface is 
somewhat T-shaped (Pl XLIII. fig. 35) and more concave than in the higher forms. 
The tibial surface presents a strong convexity above, and near its posterior plantar angle 
is a small concave facet (Pl. XLIII. fig. 33 ¢) for articulation with the mesocuneiforme. 
The peroneal surface either presents two distinct facets for the cuboid, or these may 
coalesce and form one continuous articular surface for that bone (Pl. XLIII. fig. 34 d). 
Cuboides. (Plate XLII. figs. 17-21.) 
This bone is shorter antero-posteriorly, as compared with its transverse extent, than is 
AP «ss 
