8. SCOTOPHILUS. 257 



tribution (as above described) throughout the tropical and subtro- 

 pical 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, conicai'''SriJfeftTBuzzle, 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, 

 generally 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 resem- 

 blance 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. 



Sy)iopsis of Subgenera and Species. 



A. Internal basal lobe of the ear angular, in- 



ferior margin straight, forming with the 

 ascending margin almost a right angle ; 

 tragus with a narrow prominent ridge 

 passing across its front sm'face from the 



base of its inner margin Subgen. Scotophilus. 



a. Upper incisors close to canines; pre- 



maxillary bones very narrow, leaving 



a wide space between them in front, 



nasal opening very large. 



fit'. Cingulum of the upper incisors very 



narrow. 



a. Forearm 2"-.3 — 2"-45 1. Sc. temminckii, p. 258. 



b'. Cingulum of the upper incisors form- 

 inq: a broad horizontal shoulder be- 

 limd. 



^. Forearm 2" 2. Sc. borbonicus, p. 260. 



y. Forearm 3"-4 3. Sc. giyas, p. 261. 



B. Internal basal lobes of the ear convex, 



evenly romided ; front surface of the 



tragus smooth Subgen. Scoteinus. 



a. Ears nearly as long as the head, internal 



basal lobe commencing in a long lo- 

 bule projecting backwards ; forearm 

 2"-2 4. Sc. emarginatus, p. 262. 



b. Ears much shoi-ter than the head, inter- 



nal basal lobe commencing in a short 

 lobule. 

 a'. Cingulum of the upper incisors with 



a small cusp posteriorly ; forearm 



2" 6. Sc. rucppelhi, p. 2G3. 



