SNAKES. 



195 



the Snake in the act of changing its garment 

 As the convexity of the eyes in the slough is now 

 inward, that circumstance alone is a proof that 

 the skin has been turned ; not to mention that 

 now the inside is much darker than the outer. 

 Thus it appears that Snakes crawl out of the 

 mouth of their own sloughs, and quit the tail- 

 part last, just as eels are skinned by a cook-maid. 

 While the scales of the eyes are be- 

 coming loose, and a new skin is forming, the 

 creature in appearance must be blind, and must 

 feel itself in a very awkward and uneasy situa- 

 tion." 



Genus Natrix (Laur.). 



The distinctive characters of this genus are the 

 following. The head is well marked, of a long- 

 oval form, flattened and covered with plates ; the 

 gape is wide ; the body is very long, nearly cylin- 

 drical, but slightly 

 flattened ; the tail 

 cylindrical and slen- 

 der; the scales over- 

 lapping, placed in 

 longitudinal series, 

 lance-shaped, gene- 

 rally keeled ; the 

 plates or shields on 

 the belly are simple and arched at the margin ; 

 those beneath the tail arranged in a double series. 



Our own common Ringed Snake {Natrix tor- 

 quata, Ray.) is a familiar example of this genus. 

 It reaches the length of three, and even occa- 

 sionally four, feet ; and is of a pale olive or 



BELLY AND TAIL OF SNAKE. 



