SNAKES. 



21 



found in the southern parts of England, and the Common or 

 Ringed Snake (Tropidonotus natrix). The Tree- or Whip- 



Fig. 17. 



X* 



Skull of Common Snake (Tropidonotus natrix}. 



an. Angular. 

 ar. Articular. 

 bo. Basioccipital. 

 bs. Basisphenoid. 

 ca. Coluraella auris. 

 a. Dentary. 

 eo. Exoccipital. 

 epg. Ectopterygoid. 



/. Frontal. 



m. Maxillary. 



n. Nasal. 



p. Parietal. 



pi. Palatine. 



pm. Pr3?maxillary. 



prf. Praef rental. 



pro. Prootic. 



pg. Pterygoid. 



pff. Postfrontal. 



q. Quadrate. 



so. Supraoccipital. 



ste. Supratemporal. 



v. Vomer. 



Snakes are exceedingly slender and elongate, and some are 

 exquisitely coloured, green being the predominant hue. They 



