306 
MR. ST. GEORGE MIVART ON THE SKELETON OE THE PRIMATES. 
In Ateles and Lagothrix, with a suprascapular foramen, it is of course large, but 
•as compared with the rest of the coracoid, it attains its maximum in the lower Simiidse, 
in some of which it sometimes almost equals in size the latter (Plate XI. fig. 3, a , b), 
-It is sometimes well developed in the Nycticebinse. 
The point of attachment for the long head of the Biceps becomes in many a promi- 
nent tubercle. This is particularly developed hi the lower Simiidse and the Nyctice- 
binas, and rather so in the lower Cebidse. In Simia it is much more developed than 
in Homo and Troglodytes, and more so in Ateles than in Hylobates, in which last 
it is peculiar in projecting rather over the infraspinous fossa than over the glenoid 
surface. 
When the scapula is so placed that the long axis of the glenoid surface is vertical, 
if that surface be placed opposite the eye of the observer, then the acromion process 
generally does not rise nearly so high as the summit of the coracoid. In Simia, Lemur, 
and Galago, however, it about equals it, and almost always exceeds it in Man, Troglo- 
dytes, and Hylobates, and sometimes in Ateles, and, indeed, sometimes also in Lemur. 
In the Nycticebinse it is much below it, because of the peculiar production inwards of 
the summit of the glenoid surface in that subfamily (Plate XII. fig. 2). 
The approximation of the end of the acromion to the prolongation upwards of a ver- 
tical line traversing the long axis of the glenoid surface is very close in Man, the Si- 
miinse, Ateles, and Mycetes, but it diverges widely in the other genera. 
The extremity of the coracoid diverges from the glenoidal margin in Man and the 
Lemuroidea (Plate XII. fig. 2) ; it approaches it much more nearly in the other An- 
thropoidea. 
The Clavicle. 
The absolutely largest clavicle of the Order is that of the Orang, and then follow 
those of Man and the Gorilla. 
Its relative length, as compared with that of the vertebral column, is greatest in Hy- 
lobates * and Simia, in which genera only it exceeds one-fourth the length of that 
column. The proportion exceeds one-fifth in Man and Troglodytes, and does not fall 
much below in Lagothrix, Ateles, and Mycetes. In most other forms it is as about 
14 or 16 to 100, but in Colobus the Nyctipithecinse, Hapale, Arctocebus, Lemur, and 
Indris, it is about an eighth or less; in Lemur being sometimes as little as 9 - 7 to 100. 
The length of the clavicle, in proportion to that of the scapula (the latter being mea- 
sured from the anterior end, or summit, of the glenoid surface to the posterior vertebral 
angle), is in excess (11L8 to 100) only in Hylobates. It is next longest in Simia and 
Man, where alone it is nine-tenths the length of the scapula. It is shortest in the 
lowest Simiidce, Hapale, Lemur, and Tarsius, in all of which it but little exceeds half 
the length of that bone. 
This bone is of very exceptional slenderness, in Mycetes f its breadth, near the middle, 
* Its unusual length in Hylobates is noticed by Prof. Ouraasr, Comp. Anat. of Vertebrates, vol. ii. p. 544. 
f As remarked by De Blaintille, Joe. cit. Cebus, p. 16. 
