are distinguished from the other
group by being essentially quadrupedal, and usually provided
with a tail, which is never prehensile. The femur and tibia,
taken together, are longer than the humerus and the radius.
The outer inferior incisors are not larger than the inner ones,
but are often smaller. The crowns of the molar teeth present
two transverse ridges, a third being present, in some genera
on the last inferior molar.
All the Cynomorpha
have ischial callosities, which sometimes
attain a very large size, and are brightly colored.
The dorso-lumbar region of the spinal column is concave
toward the ventral aspect, and the lumbo-sacral angle is very
large. The atlas has narrow transverse processes. The ordinary
number of dorso-lumbar vertebrae is nineteen, of which
twelve, or thirteen, are dorsal; and seven, or six, lumbar.
The middle cervical vertebrse have short spines, which are not
bifurcated at their extremities. In the posterior dorsal and
anterior lumbar vertebrae, the mammillary and accessory processes
may be enlarged and interlock. The long transverse
processes of the lumbar vertebrse bend forward. The sacrum
usually contains only three anchylosed vertebrae. The caudal
vertebrae vary in number, from three in Inuus
form little more than a coccyx), to as many as thirty-one. In
the anterior part of the tail the vertebrae are provided with
subvertebral, or chevron, bones.
The thorax is laterally compressed, and the manubrium of
the sternum is broad; but the six or seven sternebrae which
follow it are compressed and constricted.
The skull presents a considerable range of variation. In
the frontal region is rounded,
the facial angle is comparatively large, and the ascending portion
of the ramus of the mandible is high. In the Macaci
, on the other hand, the supra-orbital ridges become
so much enlarged as to hide the forehead; and the horizontal
portion of the ramus of the mandible is much larger
than the ascending portion, in accordance with the great production
of the upper jaw, and the consequent low facial angle.
In many of the Cynocephali,
longitudinal osseous ridges are
developed upon the maxillae, and greatly increase the brutishness
of their aspect. Sagittal and lambdoidal crests may appear
along the lines of the corresponding sutures. There is
no distinct mastoid process; and the styloid process is not
The parietal bones do not unite with the alisphenoids,
being separated from them by the union of the squamosals
with the frontals. The brain-case is flattened and elongated,
and the convex roofs of the orbits project into it, and
greatly diminish the capacity of its frontal portion. The olfactory
fossae are very deep, and sometimes almost tubular. The
two frontal bones send thick processes across the base of the
skull, which unite over the junction of the presphenoid and
the ethmoid, and thus narrow the entrance to the olfactory
fossae. The basicranial axis is shorter than the cerebral cavity,
but is still proportionally long. The occipital foramen lies in
the posterior sixth of the base of the skull, and it looks obliquely
backward and downward. The premaxillo-maxillary
suture never disappears until long after the second dentition
as complete, and may persist throughout life. The palate is
long and narrow. The nasal bones are fiat, and early anchylose
into one bone.
The scapula is relatively longer and narrower than that
of Man; but the spine lies at right angles to the vertebral
border, and the supra-spinous is much smaller than the infraspinous
The axis of the articular head of the humerus is not directed
upward and inward, but upward and backward; the
bicipital groove lies on the inner side; and the shaft of the
bone is so bent that it is convex forward. In all these characters
the fore-limb shows its relation to the function of support.
The radius exhibits modiiications which have the same
signification. Its proximal head is transversely elongated,
and lies somewhat in advance of the ulna, articulating more
largely with the humerus than in the higher Apes. The neck
of the radius (between the head and the bicipital tuberositv)
fits more closely to the ulna, and hence the movements of pronation
and supination are restricted.
There are nine bones in the carpus. The pisiforme is
much elongated, making a sort of heel for the manus. Together
with the cuneiforme, it furnishes an articular face for
the ulna. The distal articular surface of the trapezium is
saddle-shaped, and the pollex is usually complete, though
short relatively to the other digits. In Colobus
it is rudimentary.
The pelvis is long and narrow. The ilia are narrow bones
with much-excavated posterior and outer faces. Their crests
generally lie opposite the transverse processes of the penultimate
lumbar vertebra. The long axis of the ilium and that
of the anterior ramus of the pubis cut one another nearly at a
right angle; while the long axis of the ilium and that of the
posterior ramus of the ischium lie nearly in one straight line.
The symphysis pubis is very long, and the subpubic arch correspondingly
reduced. The posterior ends of the ischia are
everted, broad, and rough, for the attachment of the callous
pads of integument. The femur has a round ligament. The
tarsus has not more than one-third the length of the foot.
The calcaneal process is flattened from side to side, and has a
pulley-like excavation upon its posterior extremity. The
tibial facet of the astragalus is inclined slightly inward, as
well as upward, and its outer edge is raised. The distal division
of the tarsus, consisting of the cuboid and navicular,
with the cuneiform bones, is capable of a considerable amount
of rotatory motion upon the astragalus and the calcaneum.
The ento-cuneiform bone is large, and has a transversely-convex
articular surface for the metatarsal of the hallux. Consequently
the latter (which is short, reaching to only about the
middle of the proximal phalanx of the second digit) is capable
of free motion in abduction and adduction.
In the Cynomorpha,
and even in the so-called "tailless"
, proper caudal muscles are present. In the limbs
there is a levator claviculae
which passes from the transverse
process of the atlas to the acromion; a dorso-epitrochlearis
consisting of a muscular bundle detached from the latissimus
near its insertion, and passing to the distal and inner
end of the humerus, or even farther down; a scansorius,
the ventral edge of the ilium to the great trochanter, which
sometimes becomes confounded with the glutoeus minimus
special abductor ossis metacarpi quinti
; and a peronoeus
arising from the fibula, between the peronoeus
passing behind the external malleolus, and
sending its tendon to the extensor sheath of the fifth digit.
The extensor primi internodii pollicis
and the peronceus
are absent in this, as in the preceding group.
The biceps femoris
usually possesses only an ischial head,
and the soleus
arises only from the fibula. The flexor brevis
arises partly from the tendon of the plantaris,
where this passes over the pulley on the posterior surface of
the calcaneal process to become continuous with the plantar
fascia, and partly from the tendons of the long flexor. The transversus pedis
is usually fully developed, but has only two
heads of origin from the distal ends of the second and third
metatarsals. The interossei pedis
are just visible on the dorsal
aspect of the foot, but none are, properly speaking, dorsal.
None of them are penniform muscles arising from adjacent
sides of the metatarsal bones; but they are attached, in pairs,
to the plantar and lateral aspects of the metatarsal bones of
the digits to which they appertain. They are inserted into
the sesamoid bones, of which each digit has two, and into the
bases of the proximal phalanges, and give off no distinct tendons to
the extensor sheaths. Additional muscles may arise
over the proximal ends of the metatarsal bones, and pass to
the three fibular digits.
The interossei manus
are very similar to those of Man,
being divided into a dorsal and a palmar set, and sending slips
to the extensor sheaths of the digits, without that complete
subdivision which is seen in the Anthropomorpha,
There is a complete double set of extensors in the four
ulnar digits of the manus, the extensor minimi digiti
a tendon to the fourth digit, and the extensor indicis
the third digit. The extensor ossis metacarpi pollicis
distinct slip to the trapezium, and thus precisely corresponds
with the tibialis anticus,
which has two tendons, one for the
ento-cuneiform, and one for the metatarsal of the hallux. The flexor digitorum profundus
and flexor longus pollicis
by one muscle, a slip from the ulnar side of the tendon
of which usually goes to the pollex.
The tendons of the flexor perforans digitorum
unite to form the deep flexor tendons of the pedal
digits in very variable proportions. The flexor acccssorius
very generally present.
The anterior upper premolar has its outer cusp peculiarly
modified and sharpened. The anterior lower premolar has
the anterior margin of its crown prolonged and cutting, so
that it works like as cissors-blade, against the posterior edge
of the upper canine. In the upper jaw, the premolars have
three roots; in the lower two. The molars in both jaws have
four cusps connected by two transverse ridges. Sometimes
there is "heel" behind the posterior ridge of the last lower
The formula of the milk dentition is d.i.
2.2/2.2=20; and the anterior milk molar resembles the permanent
premolars, while the posterior is like a permanent molar.
The permanent canines make their appearance before, or,
at latest, contemporaneously with, the hindermost molar in
both jaws. They are large and long, and are separated, by
a well-marked diastema, from the outer incisor above, and
from the first premolar below.
very generally possess cheet-pouchea,
which serve as pockets for the temporary stowage of food.
The stomach is usually simple, with a globular cardiac extremity
and an elongated pyloric portion; but, in Semnopithecus
the stomach is divided into three compartments,
the middle of which is sacculated. A groove with
raised edges leads from the cardiac end of the gullet to the
The caecum, though distinct, is relatively small, and has no
The liver varies much in the degree of its subdivision into
lobes, being least divided in the Semnopitheci,
and most in
the Baboons. The innominate artery generally gives origin
to both carotids, as well as to the right subclavian, the left
subclavian arising directly from the arch of the aorta.
When laryngeal air-sacs are developed, they are not
formed by dilatations of the lateral ventricles of the larynx,
but a single sac, with a median aperture, is formed in the
thyro-hyoidean space immediately beneath the epiglottis.
This median air-sac is very large, extending down over the
front of the neck, and sending processes into the axillae, in
The right lung is usually
four-lobed, the left two-lobed.
The kidney has only a single papilla.
The posterior lobes of the cerebrum project beyond the
cerebellum in all the Cynomorpha
; they are shortest in the Semnopitheci,
and longest in the Cynocephali.
sulci and gyri which are found in the human brain are always
indicated; but the external perpendicular fissure is strongly
marked. The posterior cornu of the lateral ventricle is large,
and there is a strongly-marked hippocampus minor.
There is usually, if not always, a bone in the penis, which
is provided with two special retractor muscles. The females
are subject to a periodical turgescence of the sexual organs,
sometimes accompanied by haemorrhage, and comparable to
menstruation. The placenta is often bilobed.