434 



MANUAL OF ZOOLOGY 



some groups of Lacertilia, on the other hand, such as the 

 Blind-Worms (Anguts), limbs are entirely absent, or are 

 represented only by mere vestiges (Fig. 245) ; and numer- 

 ous intermediate gra- 

 dations exist between 

 these and forms, 

 such as Lacerta, 

 with well-developed 

 limbs. The limbless 

 Lizards bear a very 

 ^ close resemblance to 

 "I the Snakes, not only 

 ^ in the absence of the 

 < limbs, but also in the 

 ^ general form of the 

 * body and the mode 

 of locomotion. 

 . g The body of a 

 , Snake is elongated, 

 ^ narrow and cylindri- 

 cal, usually tapering 

 o towards the posterior 

 end, sometimes with, 

 more usually without, 

 a constriction behind 

 the head. In the 

 absence of limbs the 

 beginning of the 

 short caudal region 

 is only indicated by 



the position of the cloacal opening. The fore-limbs are 

 never represented even by vestiges ; in some Pythons 

 there are inconspicuous vestiges of hind-limbs in the form 



