ME. ST. GEOKG-E MIYA1IT ON THE SKELETON OF THE PKIMATES. 
319 
cuneiforme, a cup for the reception of the end of that process. This cup may be well 
seen in the lower Simiidse, the Cebidse, and Lemur. 
In the Nycticebinse this bone is very small (as has been already remarked), and bend- 
ing distad, is applied to the outer surface of the unciforme, and has its extremity 
united to the palmar process of that bone. 
Trapezium. — This is often a very irregularly-shaped bone. It is most nearly quadrate 
in the lower Simiidse and Cebidse ; it is most compressed disto-proximally in Man, 
Troglodytes, and the Lemuroids, but especially in Indris and the Nycticebinse 
(Plate XIV. fig. 4). 
The radial tuberosity varies as to its development. It is sometimes enormous in the 
Gorilla * * * § and large in the Chimpanzee, but in Man, Simia, the Simiidse below the 
Simiinse, and in the American Anthropoidea it is slight. In Lemur this process pro- 
jects ulnad, and in Arctocebus it is large, and approaches within a short distance of the 
unciforme, to which it is united by a strong ligament. In Indris this process is conspi- 
cuous, and rather acute ; it is bent distally and rather ulnad. In Hylobates it is some- 
times developed to an extent rivalling that of the unciform process, being very long and 
projecting distad and ulnad. In Perodicticus it is very much developed, and is some- 
what like that of Hylobates, only that its width from disto-proximally is less compared 
to its transverse extent, and that it is directed more transversely and less distally than 
in Hylobates. It approximates to the unciform process, but is separated from it by an 
extra ossicle (Plate XIV. fig. 5). 
Very commonly a sesamoid exists (from Simia f downwards) at the radial border of 
the trapezium, and helps to complete the concavity for the reception of the radial end 
of the scaphoid. This sesamoid cannot be, as Dr. Lucae suspects $, a separated tubero- 
sity, because it exists separately (e. g. Hylobates, Perodicticus) when that process is at 
its maximum, and in Loris and Nycticebus it is present, together with two processes 
(Plate XIV. fig. 4). 
The surface for the reception of the first metacarpal is convex from the dorsal to the 
palmar surface of the bone, and sometimes it is more or less concave in the reverse 
direction, i. e. radiad from the trapezoides. In Man alone is this concavity constantly 
and strongly developed. 
In the highest Apes there appears to be much irregularity as to its develop- 
ment. Thus in the Gorilla it is sometimes very well marked, sometimes § very slightly. 
In the Chimpanzee it is generally developed slightly, but sometimes absolutely 
* Owen, Trans. Zool. Soc. vol. v. pi. 10, figs. 1 & 2. 
f Dr.. Lucae speaks of it in the Orang, and represents it (loc. at. pp. 304 & 305, and pi. 3. fig. 8). It is 
figured by Professor Yeolik in Todd’s Cyclopaedia of Anat. and Phys. vol. iv. p. 204, fig. 124, i. Mr. W. H. 
Floweb also informs me that he observed its existence in the wrist of an adult male Orang at the Museum of 
Leyden. 
$ Loc. cit. p. 305. 
§ E.g. No. 5179 a in the Osteological Collection of the College of Surgeons. 
