ches opening on the surface of
the skin are developed in many species, but in most cases more so in
males than in females (fig. 3). As rule, bats produce only a single
offspring at a birth, which for some time is carried about by the female
parent clinging to the fur of her breast; but certain North American
bats commonly give birth to three or four young ones at a time, which
are carried about in the same manner.

[Illustration: FIG. 2.--Head and Neck of _Epomophorus franqueti_ (adult
male). From Dobson. The anterior (_a.ph.s_) and posterior (_p.ph.s_)
pharyngeal sacs are opened from without, the dotted lines indicating the
points where they communicate with the pharynx; _s_, thin membranous
partition in middle line between the anterior pharyngeal sacs of
opposite sides; _s.m_, sterno-mastoid muscle separating the anterior
from the posterior sac.]

[Illustration: FIG. 3.--Frontal Sac and Nose-Leaf in Male and Female
Masked Bat (_Phyllorhina larvata_). From Dobson.]

Bats are divisible into two suborders, Megachiroptera and
Microchiroptera.

_Megachiroptera_.

Fruit-eating bats.

The first of these comprises the fruit-eating species, which are
generally of large size, with the crowns of the cheek-teeth smooth and
marked with a longitudinal groove. The bony palate is continued behind
the last molar, narrowing slowly backwards; there are three phalanges
in the index finger, the third phalange being terminated generally by
a claw; the sides of the ear form a ring at the base; the tail, when
present, is inferior to (not contained in) the interfemoral membrane;
the pyloric extremity of the stomach is generally much elongated; and
the spigelian lobe of the liver is ill-defined or absent, while the
caudate is well developed. This group is limited to the tropical and
sub-tropical parts of the Eastern Hemisphere.

All the members of this suborder are included in the single family
_Pteropodidae_, the first representatives of which are the African
epauletted bats, forming the genus _Epomophorus_. In this the dental
formula is _i._ 2/2 (or 1/2), _c._ 1/1, _p._ 2/3, _m._ 1/2. Tail short or
absent, when present free from the interfemoral membrane; second
finger with a claw; premaxillae united in front. The species are
strictly limited to Africa south of the Sahara, and are distinguished
by the large and long head, expansible and often folded lips, and the
white tufts of hair on