660 CHIROPTERA 
surface of the muzzle, near its extremity) to the low band connect- 
ing the bases of the large ears; the sides of this depression being 
margined as far back as the eyes by small horizontal cutaneous 
appendages. All the species resemble one another closely, and are 
mainly distinguished by the form of the tragus and the size and 
relative position of the second lower premolar. With the exception 
of .V. javanica, they are all limited to the Ethiopian region. 
Family VESPERTILIONIDE. 
Nostrils opening by simple crescentic or circular apertures at 
the extremity of the muzzle, not surrounded by distinct foliaceous 
cutaneous appendages ; premaxillz small, lateral, and separated by 
a wide space in front; tragus distinct. In addition to these char- 
acters, it may be observed that the skull is of moderate size, the 
nasal and frontal bones not being much extended laterally or vertic- 
ally, nor furrowed by deep depressions. The number of incisors 
varies from 3 to 4, rarely (in Antrozous only) 4, premolars 3, or 2, 
or 3, rarely (in Vesperugo noctivaguns of North America) 3; the 
upper incisors are small, separated by a wide space in the middle 
line, and placed in pairs or singly near the canine; the molars are 
well-developed, with acute W-shaped cusps. 
This family, which may be regarded as occupying a central 
position in the suborder, includes the common simple-faced Bats of 
all countries, of which the well-known Pipistrelle and the Whiskered 
Bat (Vespertilio mystacinus) may be taken as familiar types, and its 
species number more than 150, or considerably more than one-third 
the total number of the known species of the entire order. The 
various genera may be conveniently grouped into the Plecotine, 
Fespertilionine, Miniopterine, and Thyropterine divisions. 
In the Pleeotine division, of which the common Long-eared Bat 
(Plecotus auritus) is the type, the crown of the head is but slightly 
raised above the face-line, the outermost upper incisor is close to 
the canine, and the nostrils are margined behind by grooves on the 
upper surface of the muzzle, or by rudimentary nose-leayes ; the 
ears also are generally very large and united. 
Plecotus.1—Dentition : i 3, ¢ 4, p 3, m 3; total 36. Outer 
margin of ear-conch ending abruptly near the angle of the mouth, 
the inner margin with a more or less prominent rounded projection 
directed inwardly above the base ; tragus very large, tapering up- 
wards, with a lobe at the base of its outer margin, rounded, and 
placed half horizontally. This genus is represented by the Euro- 
pean Long-eared Bat (P. auritus), and P. macrotis, restricted to 
North America. The latter is distinguished by the great size of 
? Geoffroy, Deseript. de l Egupte, vol. ii. p. 112 (1812). 
