SERPENTS. 



355 



naturalists give a family value. Xenopeltis lias eight labial plates, and the ventral 

 scales well developed ; it is represented by a single species, A', unicolor, winch inha- 

 bits Borneo, Sumatra, Java, the Celebes, and other neighboring islands, as well as a 

 portion of Britisii India. In its habits it is nocturnal, an<l obtains its prey of small 

 mammals by entering their burrows. Being a large and stout animal, sometimes reach- 

 ing the length of four feet, it has little difficulty in overpowering its victims. 



The third family embraces the Erycid.e, or sand-snakes. Members of this group 

 have a small conical prominence on each side of the vent, somewhat resembling the 

 anal spurs of the Boida? ; the tail, however, is much shortened, and, instead of being 





Fig. 210. — Ili-i/x jucalus, s;iml-sn:ike. 



used as a prehensile organ, is so developed as to act as a lever, assisting the animal in 

 working its way into the coarse gravel of the barren plains which it inliabits. Nearly 

 every desert has its representatives of these most interesting reptiles : America has 

 (Jharina plumbea. Eryxjacidus is restricted to southern Europe and Persia, while in 

 India is found the harmless Erijxjohnii, which the serpent-charmers so mutilate about 

 the short, rounded tail, as to give the animal the appearance of having a posterior 

 head, — a monster regarded with the utmost horror by the ignorant natives. In confine- 

 ment this Indian form constantly remains hid in the gravel of its cage, from which it 

 cannot be induced to ap])ear, except by offering it the most teni])ting morsels. In its 

 native haunts, the treeless deserts, the animal is probably crepuscular, as its food —mice 



