■ir^ VEItTEBIlATE ANIMALS. 



various diseases. A iiearl}- allied species is the Llue-tailed Lizard 

 (Srincns/dsriiftus) uf tbe United States. 



The Geckos ((lerkotiAa-) fnniia large group of iiightdoviug Lizards, 

 which are fuuud in uio.st jjarts of the world, and chiefly deserve 

 notice frcjm the fact that their eyes are not jirnviiled with movable 

 eyelids (tig. llXi). Tlie Chainadoiis, al.so, cannot lie said to possess 

 movable eyelids, for the eye is covered with a single lid, leaving only 

 a central a|>erture fur the pujiil. The common .species {Chamceleo 

 Afrimnvjt) occurs abumlantly in the north of Africa, and has long 

 been known for the changes of colour whicli it has the power of ex- 

 hiliiting. It is a sluggish animal, and catches insects by darting out 

 its long and wurm-likc tongue with extreme rai)idity. 



Order IV. Crocodilia. 



The last and highest order of the living Eeptile.s is that of the 

 C'rocodUia, conijjrising the Crocodiles, Alligators, and Gavials, and 

 characterised by the following peculiarities : The outer or integu- 



Fig. 107. — A, rica'l fiii<l .^^ltl>l■ior■ ])nrliiin of the body of rrnrniUlna jxnuUcei-ianns ; 

 M, Ilhiil-fn.it, .iniir sanic. (.VftrrGiiutlii'V.) 



meni;iry skeleton consists ]iaitly (if Imrny sc.-des ilrvelnjied by the 

 oiid'i l.iyci- iif the skin, and ]iartly uf large bony plates produced by 

 till- inn,. I- l.iycr (if the .skin (Hg. lilT). The bunes of tile skull and 



