338 ME. ST. GrEOEGrE MIYAET ON THE SKELETON OE THE PEIMATES. 
The proportion borne by the transverse diameter of the femur to its length is far 
greatest in the Gorilla, where it is more than a tenth, and but little less in the Chim- 
panzee and Orang. In the rest it is as much as one-twentieth, except sometimes in 
Hylobates, and in Tarsius. 
The shaft of the femur is very often almost completely straight, as in Hylobates 
generally, and in most Cebidse and Lemuroidea. It is decidedly curved, with the con- 
cavity backwards, in Man, Troglodytes, the lower Simiidse, and sometimes in Hapale. 
It is slightly curved, with the concavity forwards, in the Nycticebinse, and sometimes 
in Lemur. 
In all the Anthropoidea, except Hylobates, a straight line cannot be drawn from the 
most prominent point of the great (peroneal) trochanter to that of the condyles without 
cutting or meeting the front surface of the shaft ; but in all the Lemuroidea this can 
easily be done. 
The lateral expansion of the shaft downwards takes place gradually in the Gorilla and 
generally in Hylobates, in Mycetes (Plate XIII. fig. 4), the Pitheciinse, Nyctipithecus, Cal- 
lithrix, sometimes in Lemur and in Loris. It takes place suddenly in Man, the Chim- 
panzee, and mostly so in the lower Simiidse ; but it does so to a marked degree in In- 
dris, Galago, Arctocebus, Perodicticus, andTarsius. 
The shaft is especially angular in Man, the linea aspera being so prominent in none 
others as in him. Nevertheless the shaft is decidedly angular in Cynocephalus, and 
sometimes in Lemur. The linea aspera is also very distinct sometimes in Hylobates* 
and the lower Simiidse as a longitudinal median groove bounded by two raised lips ; these 
are very distinct also in Ateles and Mycetes. 
The shaft is sometimes much compressed antero-posteriorly in the Gorilla and Orang, 
also in Mycetes and the Pitheciinse. In Tarsius it is laterally compressed. 
In the other genera it is more or less completely cylindrical. 
The ridges, which in Man proceed from the linea aspera to the condyles, are rarely 
much marked in other species. That going to the inner condyle, which is moderate but 
distinct in Man, Cynocephalus, and Mycetes, is very faint or absent in all others. The 
branch going to the external condyle, which in Man is very prominent, is so in no 
other Primate, but almost or quite disappears, except in Troglodytes and Cynoce- 
phalus. 
The neck of the femur is especially long and well defined in Man and the Simiinse, 
but least so of these in the Gorilla. It is particularly short in Llapale and the Le- 
muroidea, especially in Indris, Galago, the Nycticebinse, and Tarsius. 
The great (peroneal) trochanter is generally pointed at its upper end, but in Man and 
the Simiinse, Mycetes and Perodicticus, I have found it truncated. It is smaller in Ateles 
than in most other Anthropoidea, but it is particularly small in Galago and the Nyctice- 
binse. Its extremity often projects forwards, especially in Hylobates, Cebus, Hapale, 
Lemur, Perodicticus, and Tarsius.' It sometimes rises higher than the summit of the head 
* E. g. No. 5026 in the Museum of the Koyal College of Surgeons. 
