388 



SERPENTS. 



tensive family, recognisable by having the head small 

 and covered with broad plates, and the tail, conical 

 and tapering; they are quite destitute of poison teeth. 

 Of these not fewer than three hundred and forty 

 different species have been described. 



The Common Ringed Snake (Coluber natrix) affords a good 

 example of the group. It has broad flat plates on the head, and 



v-,,. 



FlG.' 322. COMMON RINGED SNAKE. 



the belly is shod as it were with a single series of wide parallel 

 horny shields, placed transversely ; beneath the tail, these are disposed 

 in a double series (Fig. 321). 



The fifth family of Serpents (Amphisbcenidce) contains 



The Double Walkers (Amphisbaena\* so called because it is difficult 

 to make either head or tail of them, seeing that they progrese 

 equally well with either end foremost. They have much resem- 

 blance to the Slow-worms delineated in the next figure, feed chiefly 

 upon ants and other insects, and are perfectly harmless. The species 

 are few, and abound in the tropical parts of both hemispheres. 



ju^i's, ampliis, loth ways ; pcuvw, baino, to go. 



