FISH-EATING BATS 235 



the majority are characterised by a shorter muzzle ; 

 the margins of the ear, instead of meeting at the 

 base, are inserted at a little distance apart, and 

 have a membranous lobe springing from near their 

 base, and the tragus, or anterior lobe of the ear, 

 largely developed. Many have curious leaf-like 

 appendages on the nose (as in the case of our 

 British Horseshoe Bats), the tail usually long, with 

 an expansive interfemoral membrane, and no claw 

 upon the index finger. The molar teeth have sharp 

 tubercles, separated by transverse furrows, pro- 

 ducing a pattern like a W on each tooth. 



These are the characteristics which, roughly 

 speaking, enable us to decide offhand to which of 

 the two great sub-orders any particular species of 

 bat may belong ; and although, as a general 

 proposition, it may be asserted that the 

 Megachiroptera are frugivorous, and the Micro- 

 chiroptera insectivorous, the observations of 

 naturalists in different parts of the world go to 

 prove that there are exceptions to the rule, and 

 that with certain species of both groups the food 

 is, at least occasionally, of a mixed character, the 

 result probably of a gradual adaptation of habits to 

 altered conditions of life. 



We have a good illustration of this in Noctilio 

 leporinus, a bat which is widely distributed in 

 Central and South America and the West Indies, 

 and which, although stated by a good authority to 

 be a member of the fruit-eating group of bats, 

 belongs, in fact, to the insectivorous sub-order, as 

 appears by the characteristic dentition and other 



