370 MR. G. E. DOBSON ON THE GENUS SCOTOPHILUS. [May 4, 
bases ; upper premolar large, exceeding the molars in vertical ex- 
tent, and quite close to the canine: last upper molar consisting of a 
transverse plate only ; first lower premolar small, crushed in between 
the canine and second premolar, which exceeds the molars in vertical 
extent. All the molar teeth very strong, with acute cusps. 
Distribution.—Africa, Asia, and Australia. In Africa probably 
not south of Port Natal: in Asia confined to the warmer parts, ex- 
tending from Afghanistan to Southern China and the Philippines: 
in Australia probably extending throughout the whole country. 
This genus, though difficult to define, and approaching Vesperugo, 
Keys. & Blas., in many points, especially through certain species of 
that genus, contains a very natural group of Bats of very wide dis- 
tribution (as above described) throughout the tropical and sub- 
tropical regions of the Eastern Hemisphere. They are distinguished 
specially by possessing a single pair of upper incisors separated by a 
wide space and placed close to the canines; by the small transverse 
first lower premolar crushed in between the approximated canine 
and second premolar, yet standing in the tooth-row ; and, generally, 
by their short, conical, naked muzzle, and rather short and narrow 
ears; by their heavy bodies and strong limbs with remarkably thick 
and nearly naked leathery membranes ; and by their short fur, gene- 
rally olive- or chestnut-brown above, and yellowish or reddish white 
beneath. 
Owing to the wide distribution and variableness in size‘and colour 
of the species of this genus, many different names have been given 
to the same species*; and this variableness and a close external 
resemblance between different species inhabiting distant countries has 
caused considerable difficulty in determining species from descriptions 
either very imperfect or based upon general characters only, such as 
the colour of the fur and measurements. 
It is evident, therefore, that if some characters be found by which 
the species may be divided into subordinate groups or subgenera, 
the difficulty of determining the different species will be much 
lessened. Such characters I have found in the form of the internal 
basal lobe of the ear and in that of the tragus. 
The species may therefore be arranged as follows :— 
A. Internal basal lobe of ear angular, inferior mar- 
gin straight, forming with the ascending mar- 
gin almost a right angle: tragus with a narrow 
prominent ridge passing across its front surface 
from the base of its inner margin ...........-..2005 (Scotophilus.) 
a. Upper incisors close to canines; premaxillary 
bones very narrow, leaving a wide space be- 
tween them in front, nasal opening very large. 
a, Cingulum of the upper incisors very nar- 
POW Sietes scence entre crs sean cadates ocusdgncen dee se S. temminckii, Horsf. 
8. Cingulum of the upper incisors forming a 
broad horizontal shoulder behind, scarcely 
raised above the level of the gum ........ S. borbonicus, Geoff. 
* EH. g. Scotophilus temminckii, Horsf.,= Vespertilio belangeri, Is. Geoft.,= 
Vespertilio noctulinus, Is. Geoff.,= Vespertilio castaneus, Gray,=Nycticejus 
luteus, Blyth, = Nycticejus flaveolus, Blyth. 
