CAHIROPTERA 647 
the Rhinclophide, the only family of insectivorous Bats wanting the 
tragus, the auditory bull reach their greatest size, and the highly 
sensitive nasal appendages their highest development; and that in the 
typical group of the Aolossine the ear- 
conch is divided by a prominent keel ; 
and the antitragus is unusually large 
in those species in which the tragus is 
minute (see Fig. 298, a). In the frugi- 
vorous Bats the form of the ear-conch 
is very simple, and but slightly variable 
throughout the various types. 
In all Bats the ears are extremely 
mobile, each moving independently at 
the will of the animal. This has been 
observed even in the frugivorous Pferv- 
podide, in which the peculiar vibratory 
3 Z : Fra. 298. —Head of Molossus glaucinus. 
movements first noticed in 7fileus (prom Dobson, Proc, Zool. Soe. 1876.) a, 
perspicillatus may also be seen when Antitragus; , keel of the ear-coneh ; ¢, 
th e animals are alarm e d notch behind antitragus. 
a a ala . 
The opening of the mouth is anterior in most species, but in 
many it is inferior, the extremity of the nose being more or less 
produced beyond the lower lip,—so much so indeed in the small 
South-American species Lhynchonycteris naso as to resemble that of 
the Shrews. The lips exhibit the greatest variety in form, which 
will be referred to under each family. The absence of a fringe 
of hairs is characteristic of all fruit-eating Bats, and probably 
always distinguishes them from the insectivorous species, which they 
may resemble in the form of their teeth and other respects. 
The cesophagus is narrow in all species, and especially so in the 
sanguvorous Desmodont Phyllostematidie. The stomach presents two 
principal types of structure, which correspond respectively to the 
two great divisions of the order, the Megachiroptera and the Micro- 
chiroptera ; in the former (with the exception of Harpyia) the 
pyloric extremity is more or less elongated and folded upon itself, 
in the latter it is simple, as in the Insectivora Vera; a third 
exceptional type is met with in the Desmodont Phiyllostomutide, 
where the left or cardiac extremity is greatly elongated, forming a 
long narrow excum-like appendage. The intestine is comparatively 
short, varying from one and a half to four times the length of the 
head and body, being longest in the frugivorous and shortest in the 
insectivorous species. Only in Lhinopoma microphyllum and Aleqa- 
derma spasma has a very small cecum been found. 
The liver is characterised by the great size of the left lateral 
lobe, which oceasionally equals half the size of the whole organ; the 
right and left lateral fissures are usually very deep ; in the Mega- 
chiroptera (Harpyia excepted) the Spigelian lobe is ill-defined or 
