MR. ST. GEORGE MIYART ON THE SKELETON OF THE PRIMATES. 
335 
the lower Cebidse ( e . g. Pithecia, Nyctipithecus) this eminence resembles that of Man. 
In Indris there is a certain thickening near the inner end of the acetabulum * * * § ; but in 
Galago a distinct small process is developed near to, but separated from, the spine of 
the pubis. In the Nycticebinse a sharp-edged, ridge-like prominence appears to answer 
to both the last-mentioned processes united. The ileo-pectineal eminence is absent, or 
very slightly marked in Lemur, but it is rather marked in Cheifomys *j*. 
The spine of the pubis is a less constant process. It is generally well developed in 
Man, but is indistinguishable in Troglodytes and Simia J. On the other hand, it is immense 
in the Siamang, and large in almost all Hylobates. In the lower Simiidse it is generally 
absent, and but very rarely much developed §, and appears to be absent in the lower 
forms of the order, except that in Indris there is sometimes a minute process (quite 
close to the symphysis), and in Galago a distinct projection like a second ilio-pectineal 
eminence. 
The so-called horizontal ramus of the pubis has its anterior (in Man superior) surface 
very narrow, forming a sharp ridge, except in the Simiinse and Man. Of all Apes it is 
broadest and most flattened in the Gorilla, but never in that species it is so much so as is 
generally the case in Homo. 
The body of the pubis is relatively longer and more antero-posteriorly extended in 
the Simiidse and some Cebidse than in Man and most Lemuroidea; but in Loris it is 
at its maximum of development in the whole Order. 
The subpubic groove, which is generally so marked a feature in the human os inno- 
minatum, is very rarely present in any other form. It is distinct, however, in the Gorilla, 
Orang, and Siamang, and is slightly marked in other species of Hylobates. I have only 
observed it besides in Mycetes and Lagothrix. 
The ascending ramus of the ischium is very slender in many Lemuroidea, especially 
in Loris ; it is broader in Man and the Cebidse ; but in the Simiidse, especially in the 
Gorilla, Hylobates, and Cynocephalus, it becomes exceedingly broad, concave externally, 
and with an everted posterior (inferior of Man) margin. 
The tuberosity of the ischium is always a marked and more or less rugose enlargement 
of the bone ; but in the Simiidse below Simia it is flattened and very much developed, 
and so much everted that sometimes (in Cynocephalus) its transverse exceeds its 
antero-posterior diameter. In Hylobates it is continued inwards almost to the sym- 
physis pubis. In Troglodytes and Simia it is much larger than in Man, but not 
flattened ; in the Cebidse and Lemuroidea it is small and more or less rounded, but 
in none, except some of the Nycticebinse, is it prolonged upwards near to the ace- 
* De Blainville, ‘ Osteographie,’ Lemur, p. 11, speaks of a large ileo-pectineal spine in Lemur ; but from 
what he says of Indris (p. 22), he evidently means the process corresponding to the anterior inferior spinous 
process of Man. 
f Owen, Trans. Zool. Soc., vol. v. p. 53, and pi. 21, figs. 19 & 20. 
+ Unless what has been spoken of as an ilio-pectineal eminence be really the spine of the pubis. 
§ As in the specimen No. 4720 in the Osteological Collection of the Royal College of Surgeons. 
