Moles and Bats. 1 1 5 



velvety skin, and the rudimental eyes and outer ears, 

 give it the greatest degree of fitness for its subter- 

 ranean life. Moles are common in America and 

 Great Britain, but are absent from Ireland. The 

 shrew-mouse and the hedgehog are equally common 

 types ; the former can be easily distinguished from 

 the true mice by the structure of the teeth. The pigmy 

 shrew of S.E. Europe is the smallest known mammal, 

 being only about two inches long. The flying lemurs 

 of the East Indian archipelago, which form the last 

 family of this order, have a wide parachute-like mem- 

 brane stretching from the fore-limbs to the hind, and 

 thence to the tail. They form a connecting link be- 

 tween this order and the next. 



69. Order 15, Cheiroptera (Bats). This curious 

 group of mammals includes the only forms in the 

 entire class which have any true powers of flight, the 

 so-called flying phalangers, flying squirrels, and flying 

 lemurs having only the power of taking long leaps, 

 In the bats the fore limbs are very long, the fingers 

 are enormously lengthened, and are united together 

 by an extensive and thin membrane, which stretches 

 from finger-tip to finger-tip, and from thence to the 

 hind limb; the thumb alone is free, and it is always 

 armed with a claw. The outline of this membrane 

 is shown by the dotted line in fig. 57. They are 

 mostly nocturnal, with smooth brains and feeble 

 powers of sight, and are rarely of large size. To 

 move the wings they are provided with powerful 

 pectoral, or breast muscles, and there is often an im- 

 perfect keel on the sternum, for muscular attachment. 

 They have also long and strong clavicles. Their hind 



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