1865.) . AXIAL SKELETON IN THE PRIMATES. 581 
tenth, and anapophyses not before the eleventh, dorsal vertebra ; 
sacrum always consisting of five vertebree, without counting the last 
lumbar, which rarely anchyloses with it ; three sacral vertebrae gene- 
rally articulate with the ilium; sacrum concave anteriorly, both antero- 
posteriorly and transversely ; sacro-vertebral angle very marked ; no 
anapophysial process at posterior end of sacrum ; ribs twelve pairs, 
with strongly marked angles, and with their proximal portions arch- 
ing much backwards, more so than in any other Primate, also with 
the vertical sigmoid twist at its maximum ; breadth of thorax to its 
depth as about three to two; transverse process of third cervical 
vertebra always bifurcated ; spinous processes of second, third, fourth, 
and fifth cervical vertebrze generally bifurcated, never very elongated ; 
of the cervical spines, that of the seventh cervical vertebra the 
longest. 
Simin &. 
Spinal column with a scarcely perceptible sigmoid curve; sacrum 
very elongated relatively, and generally flattened anteriorly. If three 
sacral vertebree join the ilium, then one answers to the last lumbar 
of Man. Sacro-vertebral angle very slightly marked; an anapophysial 
process on each side at posterior end of sacrum; ribs twelve or thir- 
teen (rarely fourteen) pairs, and forming a thorax the transverse dia- 
meter of which is still very considerable ; spinous processes of third, 
fourth, fifth, and sixth cervical vertebree never bifid; transverse 
process of third cervical vertebra very rarely bifurcating. 
The first two genera of this family have much in common, thus:— 
TROGLODYTES AND SIMIA. 
Dorsal and lumbar vertebrze, taken together, seventeen in number; 
ribs twelve or thirteen pairs ; transverse processes of lumbar vertebrae 
inclined somewhat upwards ; spines of most cervical vertebree very 
elongated, but not bifurcated ; axis-spine more or less bifid or trifid ; 
anapophyses very slightly developed; bodies of dorsal vertebre in- 
creasing but slightly in breadth posteriorly ; last lumbar vertebra 
very often anchylosed to sacrum; lumbar vertebra never more than 
five in number. 
TROGLODYTES. 
Ribs normally thirteen pairs ; neural foramina of sacrum much 
smaller than in Man; sacro-vertebral angle exceedingly slight ; sa- 
crum very flat anteriorly. 
Sternum of 7. gorilia much wider (below the manubrium) than 
that of 7. niger. 
Sruta. 
Ribs only twelve pairs; neural foramina of sacrum as large or 
larger than in Man; sacro-vertebral angle more marked than in T’ro- 
glodytes ; antero-posterior concavity of anterior surface of sacrum 
generally very marked ; anterior margin of manubrium much thick- 
ened; sternum peculiarly composite ; anapophyses often scarcely 
perceptible in lumbar region; transverse process of sixth cervical 
vertebra sometimes imperforate. 
