4 6 



Vertebrata. 



eyelids are confluent and transparent, forming the 

 clear glassy surface of the eye, and thus giving to the 

 serpent the stony, unwinking stare peculiar to them. 



The boas of the New World, and pythons of the 

 East, are remarkable among snakes for their size and 

 for the strength of their teeth, as well as for the pos- 

 session of two rudimentary hind limbs in the form of 

 spur-like processes placed one on each side of the 

 cloaca. Some of these serpents, like the anaconda of 



FIG. 19. 



Poison fangs showing their internal hollows. 



America, have been known to reach the length of 

 forty feet, and even larger specimens are described. 



The Colubrine snakes, such as the common Amer- 

 ican striped snake (Eutcemia sertalis), are all harmless 

 creatures, mostly of small size, and having all the 

 teeth solid, not grooved. 



