394 
MR. ST. GEORGE MIYART ON THE SKELETON OE THE PRIMATES. 
most, though it is very much so sometimes in some, e. g. the larger Cynopithecinse, 
Ghrysothrix, and Hapale. 
The radial margin is unusually sharp, yet not so much so as it is in the Cynopithecinae, 
•and sometimes in Cebus, Lemur, and Galago. 
The ulnar angle of the surface for the scapho-lunar articulation is slightly produced, 
but not so much so as in some, as, e. g ., the Gorilla, while in very many species it is not 
at all so. 
The styloid process is exceptionally long, rivalled, however, by that in some Simiinae. 
The grooves for the extensor tendons are unusually distinct ; and that for the extensor 
secundi internodii pollicis* I have only found distinct in the Chimpanzee and Orang 
amongst Apes. 
The ulna is separated by a wider interval from the shaft of the radius in Man than in 
most Primates, but not so much so relatively as in some, e. g. as in Troglodytes, Cebus, 
Indris. 
The greater sigmoid cavity is exceptionally broad, differing in this from all others ex- 
cept Troglodytes and Simia. 
The lesser sigmoid cavity looks outwards and not forwards, in which it differs from 
almost all Primates, and is most nearly approached by Troglodytes, Simia, and the Nyc- 
ticebinse. 
The olecranon is very broad, indeed at its maximum in breadth compared with length. 
It is most closely approached, however, in this respect by the Simiinse. It is not much 
excavated at its apex, as is so often the case ( i . e. much excavated) in the Order. 
The anterior surface of the bone is distinctly marked off from its inner (ulnar) side, 
by which it differs from the great bulk of the order, by Troglodytes and, to a less 
degree, by Simia only resembling it. 
The fossa for the extensores pollicis is marked in a way existing in no other of the 
Simiidse except Simia and Hylobates. However, the genera Chrysothrix, Hapale, Lemur, 
Galago, Nycticebus, and especially Arctocebus, resemble Man in this fossa being distinct. 
In the last of these it is more marked than that for the flexor prof undus digitorum. 
The surface for the supinator brevis is deep and broad, as only in Troglodytes besides, 
being narrower in the other Simiidse. 
The ridge for the attachment of the pronator quadratus is less marked than in many 
of the Order, but more so than in others. 
The head of the ulna is large and rounded, and bears a proportion to the styloid 
process larger than that existing in any other of the Primates except the Simiinse. 
The styloid process is moderate, not so long as in many (espBeially Ateles and the 
Nycticebinse), but longer than some (e. g. Gorilla and Orang). 
Manus. — The whole manus of Man is exceeded in actual length by that of Troglodytes 
and Simia only. Its length, as compared with that of the spine, however, is less than in 
* This is not constant in Man; at least no trace of it exists in the Boschisman and the Australian (No. 5184) 
in the Museum of the Royal College of Surgeons. 
