PRIMATES 681 
the clavicles are well developed ; and the radius and ulna are never 
united. The scaphoid and lunar of the carpus, and commonly also 
the centrale, remain distinct from one another. There are usually 
five digits furnished with well-developed nails in both the manus 
and the pes; but the pollex may be rudimentary or wanting. The 
hallux, except in Man, is opposable to the other digits, and has a 
flat nail (absent in Simia) ; and the pollex, 
when present, is usually also more or less 
opposable. The terminal phalanges of 
the digits are flattened (except in the 
second digit of the pes of the Lemu- 
roidea), and not cleft at their extremities. 
The fingers and toes generally do not 
taper towards their extremities, but (ex- 
cept in Chiromys) are dilated, flattened, 
and rounded at their tips. The humerus 
has no entepicondylar foramen, nor the 
femur a third trochanter. In the ali- 
mentary canal (Fig. 324) the stomach is 
generally simple, although sacculated in 
the subfamily Semnopithecine of the 
Cercopithecide ; and there is always a 
cecum, which is generally of large size. 
The placenta may be either non-deciduous, 
or discoidal and deciduous. There are 
always two mammez in the pectoral 
region, except in Chiromys; and the gg 394 alimentary canal of 
testes descend into a scrotum. Galago, the greater part of the small 
The Lemuroidea are decidedly low in itestine being omitted. d, duo- 
: a a denum; 7, ileum; em, cecum; 7, 
the scale of organisation, their placenta- yoctum, 
tion being of a lower type than that 
of the Insectivora; and all the Primates retain generalised features 
in their pentadactylate limbs and more or less bunodont cheek-teeth. 
In respect to cerebral characters and other features the higher 
representatives of the order have, however, acquired a specialisation 
clearly indicating their right to occupy the highest position in the 
animal kingdom. So far as the available material admits of forming 
an opinion, fossil forms appear to indicate an intimate connection 
between the Lemuroidea and Insectivora, so that in some cases it is 
almost impossible to determine whether an extinct type should be 
referred to the former or to the latter group. It is noteworthy 
that while in all existing Primates the upper molars are of a quadri- 
tuberculate type, in the extinct Lemuroid genus Anaptomorphus 
they are trituberculate. 
