MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 177 
There may or may not be a conspicuous foramen, for a nutritious vessel, towards the 
middle of the upper part of the infraspinous fossa; and one or two such foramina may 
exist in the anterior half of the supraspinous fossa, near the base of the spine. 
This base, or attached border of the spine, sometimes extends forwards rather nearer 
to the margin of the glenoid surface than it does in Man, and always approaches it 
more nearly than in the Gorilla, though not more so than, sometimes not so much as, 
in the Chimpanzee. ‘The antero-external border of the spine is concave, as in Man 
and Troglodytes, but, as in the latter, is somewhat shorter (apart from the acromion) 
than in the human scapula. The acromion is flattened in the direction opposite to 
that of the spine, but is longer and narrower! than in Man or Troglodytes ; its surface 
also is more roughened, and the facet for the clavicle is closer to the extremity of the 
acromion than in the last-mentioned genera. The degree of curvature of the process, 
and its prolongation towards a point over the middle of the glenoid surface, vary some- 
what from individual to individual (Pl. XX XV. figs. 4 & 5). 
The supraspinous fossa is generally about equally deep at its anterior and posterior 
ends, the base of the spine (otherwise than in Man or Tvoglodytes) being nearly parallel 
to the upper margin of the scapula. Sometimes, however, it is decidedly deeper at 
its glenoidal end; and rarely the vertebral end very slightly exceeds the rest of the 
supraspinous fossa in depth. 
The infraspinous fossa is concayo-convex, as in Man and Troglodytes, the convexity, 
however, being sometimes more marked than in the latter genus, and always more 
extensive than in the Chimpanzee. Simia, however, agrees with Troglodytes in that 
the ridge of the axillary margin does not expand, as in Man, into a wide flattened 
surface for the teres major, but, on the contrary, only into a very narrow one. ‘The 
infraspinous fossa is always, in the Orang, narrower, vertically, than is the supra- 
spinous one at the glenoidal end of the spine, reversing the conditions which exist 
in Man. This excess of the supraspinous fossa is greater than in the Gorilla, but 
rarely, if ever, so great as in the Chimpanzee. 
The subscapular fossa is not so concave as in Man, on account of the less inflexion 
inwards of the part of the blade which forms the supraspinous fossa. It is also less 
concave than in the Chimpanzee, and than in some specimens of the Gorilla. As in 
Troglodytes, the oblique ridges traversing this fossa are less marked than in Man. 
The superior border of the scapula is the shortest one, but is longer absolutely, 
and still more so relatively, than in Man and Troglodytes. 
It is slightly concave and nearly horizontal, instead of, as in Man and Troglodytes, 
sloping sharply down to the coracoid process? (Pl. XX XV. fig. 2), There can scarcely 
be said to be a trace of the suprascapular notch®. The vertebral margin is no longer, 
* Owen. Trans. Zool, Soe, vol. i. p. 364. 
2 This slope is much more gradual than is generally the case in Man, in the scapula of an Andaman Islander, 
No. 1 NB, in the British Museum. 3 This notch is almost indistinguishable in the same Andaman Islander, 
VOL, VI.—PART IV. 2G 
