324 
MB. ST. GrEOBGrE MIYABT ON THE SKELETON OE THE PRIMATES. 
The proximal end always articulates more or less with the trapezium and magnum. 
The proximal articular surface is sometimes strongly concave transversely, as in most 
Anthropoidea ; sometimes it has a very strong projecting ridge, as in Loris, or the 
surface may be even, as in Lemur. In Indris it sends a remarkable lateral process to 
the radial side of the magnum. 
Third Metacarpal . — This metacarpal is the one which attains the greatest absolute 
length in the whole order, which it does in Simia. Its proportion in length to the whole 
manus is greatest in Simia, Troglodytes, and Cynocephalus, where it is nearly two-fifths 
the length of that segment. It is always more than one quarter, except in Arctocebus, 
where it is a little less. It is the longest metacarpal of all in the same manus in many ; 
namely, sometimes in Troglodytes and Simia, in almost if not all Cebidee (except Pithecia), 
in Hapale, and in all the Lemuroidea, except Indris (Indrisinee 1), above all in Cheiromys *. 
It is never the shortest metacarpal of any manus. It projects most distad of any 
in the same manus in Simia, sometimes in the lower Simiidee, in Lagothrix, Cebus, 
Nyctipithecus, Chrysothrix, Hapale, the Nycticebinee, Tarsius, and Cheiromys. 
There is an angular projection at the radial side of the proximal end of the dorsum, 
in Man, and to a much less extent in the Simiinee. I have not observed this in lower 
forms. 
The proximal articular surface is concavo-convex in Man and the Simiinae. In lower 
forms it is generally more or less strongly and exclusively convex ; rarely it is decidedly 
concave, as I have found it in Ateles. 
Fourth Metacarpal . — This is the longest one of the manus in Pithecia and Indris, but 
it is never the shortest one. 
It projects slightly the most distad of all in Ateles, Pithecia, Indris, Lemur, and 
Perodicticus. The proximal articular surface is generally strongly convex antero- 
posteriorly, as in the lower Simiidee and Cebidee. It is less convex in Lemur, very 
slightly so in Indris. In Man and Troglodytes it is concavo-convex, and more or 
less, though sometimes very slightly, so in the other Simiinee and in Ateles. 
Fifth Metacarpal . — This metacarpal is never the longest of all in the same manus, 
except sometimes (as rarely in the lower Simiidee) when its backwardly projecting 
process is included in the measurement. 
It is the shortest of all except the pollex in Man, the Simiidee, most Cebidee, Hapale, 
and sometimes in Lemur. It is shortest of all, including the pollex, in Tarsius. 
It never projects more distad than the other metacarpals, but it does so least, 
excluding the pollex, in Man, the Simiidee, Lagothrix, Cebus, and lower Cebidee. It 
does so least of all (pollex included) in Tarsius. 
The proximal articular surface is always more or less strongly convex. 
A process sometimes extends backwards from its proximal end, outside the carpus, 
like that of the homotypal bone of the pes. This, however, is large only in the lower 
* In Cheiromys alone is it almost double the length of the second metacarpal, and nearly one-third longer 
than the fourth, being at the same time very much more slender than any of the other metacarpals. 
