ME. ST. GEORGE MIYART OX THE SKELETOX OE THE PRIMATES'. 
ODD 
almost always much so in Lemur. It developes a slight prominence sometimes in Hy- 
lobates and the lowest Simiidae, which prominence becomes much marked in Myeetes, 
Callithrix, Chrysothrix, and Hapale. 
In certain Lemuroidea a peculiar condition obtains, in that the part answering to the 
ventral (or anterior) margin of the Anthropoidea runs obliquely backwards and upwards 
(in Man it would be downwards and backwards) over what is the external surface of the 
ilium so as to form an oblique ridge outside that bone, and reaching to the anterior 
(in Man superior) margin of the acetabulum, or even to a point above (behind) that 
cavity. This is the case in Galago, the Nycticebinse (Plate XIII. fig. 3), and Tarsius, 
and an approach to the same condition is exhibited by Cheiromys. 
There is a distinct superior anterior spinous process of the ilium in Man ; but in no 
other primate is it so distinctly developed, but is represented only by the thickened 
end * of the crest of the ilium. In Indris and Lemur this is much produced in a direc- 
tion which in Man would be forwards (Plate XIII. fig. 2). 
The process of the ilium answering to the inferior anterior spinous one of Man attains 
its maximum of development in Indris, where it has a quite peculiar form (Plate XIII. 
fig. 2, sp.). Though sometimes indistinguishable, it is generally more or less marked 
throughout the order, especially in the Lemuroidea, except Tarsius and the Nyetice- 
binse, where it is minute or absent. Of all the Anthropoidea it is most marked in 
Man ; in the Simiidae it is little prominent, except in Cynocephalus, and in Ateles alone 
of the Cebidae. In the latter family, it often, as is also the case in Hapale, appears to 
be fused with the prominence which in them, as has been said, projects from the 
ventral margin of the ilium. 
There is a distinct superior posterior spinous process in Man, but I have not found 
such in any other Primate, it being represented, in all the rest of the order, only by the 
more or less thickened upper (posterior) end of the crest of the ilium. 
The part answering to the inferior posterior spinous process of Man is very rarely so 
sharp and distinct as in him f, and never so approximated as in him to the spinous pro- 
cess in front of (in Man above) it, except in Loris, the proportion borne by the distance 
between the processes to the length of the os innominatum taken at 100 being in Loris 
only 15’7 and in Man 17*7, while in the Gorilla it is 32-6, in the Chimpanzee 23 - 9, in the 
Orang 27*9 ; while in all the rest it is above 25, except in Tarsius, in which it is 23’9, 
and Nycticebus, where it is only 21 - 2. 
The external surface of the ilium is generally more or less concave, and concave only. 
In Man, Troglodytes, and Simia, however, it is more or less convex, but in Man only is 
there that extensive anterior convexity and posterior concavity which determines, the 
beautiful sigmoid curvature of the crest. The gluteal lines I have found distinctly 
marked only in Man. 
* This is very thick sometimes in Simia, as in the specimen Xo. 3 c in the British Museum. 
f I have found this process sometimes sharply marked in Cynocephalus, Ateles, Cebus, the Xyctipithecince 
Hapale, Indris, Lemur, Galago, and Tarsius. 
2 z 2 
