FREE-TAILED GROUP. 



295 



specimens has been to continu these inductions, made upon the evidence ot" 

 structural peculiarities. 



The mastiti-bats are an American group, found in the tropical and subtropical 

 regions of both divisions of the Western Hemisphere. With the exception of two 

 species, in which the number of the lower incisor teeth is reduced to a single pair, 

 thej' have either 26 or 28 teeth, of which \ on either side are incisors, while the 

 cheek-teeth number either \ or j. The upper incisors are placed close together in 

 the middle line ; and tlie large ears, which have a small tragus (occasionally absent) 

 ai'e united by their inner margins. In connnon with two nearly allied genera of 

 bats, they have very capacious lips, which in most of the species are thrown into a 

 number of wrinkles or puckers ; and they are further chai'actensed by their long 

 and slender wings. Tin' great lengtli and narrowness of the wings indicates, as Dr. 

 Dobson observes, rapid Higlit : and since tiiey also possess the power of varying the 

 length of tlie membrane between the legs by a " reefing " process, they must have 

 great dexterity in sud<lenly changing their direction, as when they ai'e compelled to 

 double in pursuing swift! j' Hying insects ; and, again, their expan.sive and capacious 

 lips aid the teeth in seizing and retaining the round and solidly armoured bodies 

 of tlie larger beetles ; so tliat it would seem that they are better adapted than -Awy 

 other members of the order for captui'ing insects of very swift flight. 



Of the red mastitf-bat {Molossus 7'ufus) an account is given by Mr. P. H. Gosse, 

 from which it appears that this bat inhabits tlie I'oofs of houses and the hollow trunks 

 of palm trees, where colonies of large size may sometimes be found. It is more 

 active when on the ground than any other species ; and, indeed, on such occasions 

 its motions are so rapid that some dexterity is required to en.sure its capture. In 

 the act of ninning it rests on its wrists, with the fore-part of the bodj^ considerably 

 raised. In the hollow stem of a palm tree, examined by another observer, it was 

 found that wliile in cme place the males of this species were collected together to 

 a number approaching two hundred, in another spot the assemblage consisted 

 almo.st entirely of females, with only a solitary male among them here and there. 

 This distinction of the resting-places of the two sexes has also been noticed in 

 certain other liats. 



In describing the habits of another species, the chestnut mastifF-bat {M. 

 glaucinus), Mr. Gosse writes that " soon after sunset we hear the scrambling of 

 little claws along the plaster (in the loft above) gradually tending towards the 

 point where the hole under the eaves is situated ... I judge that they crawl along 

 one after another in a straight line to the outlet, in parties. The family assured 

 me that after the mastift-bats had emerged a few hours, they invariably returned 

 into the hole again ; and they several times directed my attention to them when 

 returning. They return between eight and nine o'clock, and issue forth again 

 before the morning twilight. When handled, its impatience of confinement is 

 manifested by a continuous screeching, not very loud, but exceedingly harsh and 

 shrill. The ears are commonly so pendent as completely to cover the eyes ; but 

 they are occasionally retracted so as to expose the eyes, especially if the face be 

 touched." 



In certain parts of the Amazon Valley tlie mastifF-bats, together with some 

 species belonging to the under-mentioned nose-leafed family, are so numerous as to 



