MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 211 
This proximal surface resembles that of the homotypal metacarpal one more in the 
Orang than in the other and superior forms; but it may be readily distinguished by 
the less inclination distad of its upper part, and by the large articular facet for the 
entocuneiform (Pl. XLIII. fig. 37 m. a). 
On the peroneal side of the bone there are two articular facets for the third meta- 
tarsal (Pl. XLII. fig. 43 4, b'), which are sometimes connected at their proximal ends 
by a very small vertical articular surface for the ectocuneiforme. 
As in Troglodytes, the tibial articular surface (for the entocuneiforme) in the Orang 
is relatively larger than it is in Man (Pl. XLIIL. fig. 42). 
There is a more or less marked tubercle at the proximal end of the plantar surface of 
the bone, between the articular surface for the entocuneiforme and that for the meso- 
cuneiforme. 
Third Metatarsal. (Plate XLIII. figs. 44-47). 
The proximal surface of the third metatarsal of the Orang is less concave than that of 
man, and is, indeed, partially convex, as also in the Gorilla. It is more notched on its 
tibial side (Pl. XLIII. fig. 37 m1.) than in the just-mentioned forms, by a deep groove, 
which divides the two articular facets for the second metatarsal. In the Gorilla the 
lower facet appears to be wanting. ; 
On the peroneal side of the bone (Pl. XLIII. fig. 47) there are two distinct facets, 
instead of one as in Man and the Gorilla. These are divided by a groove, which, 
however, scarcely invades the peroneal margin of the proximal surface. ‘This surface 
may be distinguished from the homotypal one in the manus by its becoming much 
narrower downwards and by the absence ofa marked concavity on its upper part. 
Fourth Metatarsal. (Plate XLIII. figs. 48-51). 
In the Orang, as in the Gorilla, the proximal surface of this metatarsal is destitute 
of the concavity which exists in Man, and is besides much more convex. 
Its inferior margin is straighter than in Man or the Gorilla, and the tibial side of the 
bone (Pl. XLIII. fig. 50) has two articular facets for the third metatarsal, instead 
of one as in them. These facets are separated by a wide and deep groove. The 
peroneal side of the bone (PI. XLIII. fig. 51) has one long surface (for the fifth 
metatarsal) which is more vertically extended than in Man or the Gorilla. Compared 
with the homotypal surface of the manus, the proximal one of this metatarsal is more 
convex, the convexity extending on the peroneal side up to the dorsum, instead of 
being interrupted by a concavity as in the manus. > 
Fifth Metatarsal. (Plate XLIII. figs. 52-54). 
The fifth metatarsal of Simia has a proximal surface which is both more convex 
vertically and concave tranversely than that of the Gorilla, and still more so than that 
262 
