ME. ST. GEORGE MIV ART ON THE SKELETON OF THE PRIMATES. 
315 
the ulna than is the comparatively rudimentary head of the bone. In Lemur it is formed 
on the same type. In Hapale and Indris it is long, but in the Nycticebinse it is very 
so, and curved, except in Perodicticus, in which it is exceedingly long but nearly 
straight, attaining perhaps the maximum of relative length in the whole Order *. 
The foramen for the medullary vessels is always situated more or less above the 
middle of the bone, and is, as far as I have observed, always directed upwards. 
Manus. 
This segment attains its greatest bulk in the Gorilla ; its absolute length, however, 
is greatest in the Orang, then in the Gorilla and Chimpanzee, and afterwards in Man. 
In Ateles and Indris it is longer than in any of the lower Simiidse, except the Cyno- 
cephali. 
The proportion borne by the whole length of the manus to that of the spine is greatest 
in Tarsius, Cheiromys, and Hylobates, where it is more than half, and then in Simia, 
where it is but little less. In the rest it varies between this and one-fourth, except in 
Cercopithecus, the Nycticebinge, Lemur, and Chrysothrix ; being shortest in Arctocebus, 
where it is rather less than one-fifth. 
The length of the manus, as compared with that of the rest of the pectoral limb, is 
far greatest in Cheiromys, where the first is more than four-fifths of the latter ; then in 
Indris, Nyctipithecus, Galago, and Tarsius, where the proportion is as much as, or more 
than, 45 to 100 ; in the rest it varies between this and three-tenths, except in Loris, 
where it is scarcely more than one-quarter. 
The length of the manus, as compared with that of the radius, is far greatest in 
Cheiromys, where the former is much more than once and a half the length of the 
latter. In Tarsius the manus is considerably longer than the radius, and in Brachyurus 
and Hapale the two segments are about equal. The manus is always more than half 
the length of the radius, except in Loris, where it is a little lessf . In Man it appears 
to be generally a little more than three-fourths of its length. 
Carpus. 
The largest carpus is that of the Gorilla ; that of the Orang about equals Man’s, 
while the Chimpanzee’s is slightly smaller. 
This segment, excluding sesamoids, consists of eight or nine bones, except where an 
extra ossicle exists in the transverse carpal ligament J. 
Its length (measured from the summit of the semilunare to the distal end of the 
* See Van Campen’s representation, plate 1, fig. 3, in the Yerhandelingen dor Koninklijke Akademie van 
Wetenschappen. Zevende Deel, 1859. 
f As mentioned by De Blainville, Joe. cit. Lemur, p. 17. 
t Only the case, as far as I have been able to ascertain, in Perodicticus (see Plate XIV. fig. 5). It is 
described and figured by Van Campen in his Memoir on the Potto of Bosman in the Verhandelingen der 
Koninklijke Akademie van Wetenschappen. Zevende Deel, 1859, p. 18, and plate 1, figs. 4, 10. 
MDCCCLXVII. 2 X 
