VAMPIRES. 303 



THE BLOOD-SUCKING VAMPIRES. 

 Genera Desmodus and DiphyUa. 



The two species of blood-sucking vampires, each the solitary representative of 

 a distinct genus, with which we close our account not only of the vampires, but 

 also of bats generally, present the following distinctive characters : 



Firstly, they may be recognised by their very short and conical muzzles, 

 surmounted by a small though distinct nose-leaf ; as well as by the shortness of 

 the membrane between the hind legs, and by the total absence of a tail. Secondly, 

 they are characterised by the fewness and peculiar structure of their teeth; 

 of which the total number is only twenty in one species, and twenty-four in the 

 other. In the former there are no molar teeth, although a small rudimentary 

 one is present on each side of the jaws of the latter. In the upper jaw there is 

 a single pair of very broad-crowned incisors, which fill up the whole of the space 

 between the tusks or canines, and have keen and sharp-cutting edges like chisels. 

 The premolar teeth, of which there are two pairs in the upper and three in the 

 lower jaw, have likewise trenchant cutting-edges working against one another, 

 and being quite unlike those of any other bat. When we add to these character- 

 istics the sharp tusks with which each jaw is provided, it will be evident that 

 the teeth of the blood-sucking vampires must be specially adapted for some 

 particular purpose that purpose being blood-letting. 



It is not by any means only in their teeth that these bats are adapted 

 for their mode of sustenance, the structural modification also extending to their 

 internal organs. Thus, whereas in other bats the stomach has the usual sub- 

 globular form common to Mammals in general, in the blood-sucking vampires it 

 becomes an elongated organ of a tube-like form ; blood naturally requiring little or 

 no process of digestion before being absorbed into the tissues of the animal by 

 which it has been swallowed. 



The common blood-sucking vampire (Desmodus rufus) is a comparatively small- 

 sized bat, measuring only about 3 inches in length, and of a reddish-brown colour 

 above, and usually some shade of yellowish-brown beneath. It has no true molar 

 teeth, and likewise no spur on the ankle for the support of the membrane between 

 the legs. The geographical range of this species is large, extending from Central 

 America to Southern Brazil on the east of the continent, and to Chili on the west. 



The smaller blood-sucking vampire (DiphyUa ecaudata) serves to connect the 

 common species with the other members of the family, having a small rudimentary 

 upper molar tooth on each side of both jaws, and also a tiny spur on the ankle. It 

 is further distinguished by the middle portion of the membrane between the hind- 

 legs being quite undeveloped, as well as by certain features connected with the 

 lower incisor teeth, which are peculiar in having distinct notches on the summits 

 of their crowns. The colour of this bat is very similar to that of the common 

 species ; but the size of the animal is slightly less. This smaller vampire, which 

 appears to be confined to Brazil, is stated to be far from common ; and we have 

 not met with any account of its having been caught in the act of blood-sucking, 

 although there can be no doubt that this is its constant habit. 



VOL. i. 20 



