MR. ST. GEORGE MI V ART ON THE SKELETON OF THE PRIMATES. 
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inwards. In the other Anthropoidea it is intermediate, approximating to Man in the 
higher forms, though still differing considerably from him. 
The tuberosities often project upwards slightly above the articular head, as in the Cy- 
nocephali, and very slightly in Cheiromys. Generally they are about on a level with its 
top, or slightly below it, but they are decidedly below it in Lagothrix and Ateles, and 
still more so in Simia and Hylobates. 
The insertion of the infraspinatus is generally very marked, especially in Indris. 
There is sometimes a projecting tubercle for the insertion of the teres minor. 
The ulnar tuberosity is almost always so placed as to hide the neck of the bone when 
its front surface is looked at, the long axis being vertical. This is not the case, how- 
ever, in Man, nor in Hylobates, the Chimpanzee, nor sometimes Ateles. Very often 
not only the neck but a great part of the head is also hidden by it, as in the lower Si- 
miidee and Cebidse, Hapale, Lemur, Indris, Tarsius, and Cheiromys. In Indris this 
tuberosity is bent backwards in a peculiar way (Plate XII. fig. 6). In Cheiromys it is 
almost as large as the radial one'. 
The bicipital groove is sometimes more or less strongly overlapped by its lateral mar- 
gins. It is much so in the Sirniinse, especially in the Chimpanzee, in which it is some- 
times spanned by a bridge of bone ■*. 
The radial border of the bicipital groove attains its maximum of development in the 
Lemuroidea, especially in Indris and Perodicticus, but it is also very prominent in the 
Cynocephali (Plate XII. fig. 4). Its ulnar border is generally faintly marked. 
The surface for the insertion of the deltoid is generally more or less defined by the 
radial margin of the bicipital groove on one side, and by a ridge (giving origin to the 
external head of the triceps) on the other. It attains its maximum in the Cynopithe- 
cinse (Plate XII. fig. 4). 
The position of the foramen for the nutrient artery presents even individual varia- 
tions, being at, above, or below the middle of the bone ; its direction, as far as I have 
observed, is always distad. 
The supinator ridge is generally well developed, especially in Cynocephalus, Cebus, 
Hapale, Lemur, Perodicticus, and Galago ; but above all in Cheiromys and Micro - 
rhynchus. In Man and the Simiinse it is only slightly developed. 
The external condyle is distinct in Man and the Simiinse, being more prominent in 
them than in him ; and it is also marked in Indris (Plate XII. fig. 6), Loris, Nycticebus, 
and Perodicticus. In the other genera it is closely applied to the capitellum, and in 
all of them, except Ateles and Lagothrix, looks more or less entirely outwards instead 
of forwards. 
The. internal condyle projects inwards and more or less backwards. It is least back- 
wardly directed in Man, the Simiinee, Hapale, and Indris (Plate XII. fig. 6). In almost 
all the Cebidse (PI. XII. fig. 5) it is so bent downwards that its extremity is quite or 
*' As in a mounted specimen in the Osteological Collection of the British Museum. 
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