216 



VERTEBRATA 



FIG. 248. Spotted adder nearly three feet long. 

 Photograph. 



pasture grounds and 

 woods east of the 

 Mississippi, attains a 

 length of seven feet, 

 but is entirely harm- 

 less. It is fond of 

 birds' eggs and birds 

 which it often climbs 

 trees to secure. 



Crotalidce is the 

 family including all 

 our poisonous snakes, 

 except one species, 

 the bead snake, rang- 

 ing from Virginia to 

 Arkansas and the 



South. There are no external features which enable one 



to determine with 



certainty at sight 



whether any snake 



is venomous or 



harmless, but a 



flattened head, 



constricted neck, 



short tail, and pit 



in front of the eye 



give unmistakable 



evidence that the 



reptile is a veno- 

 mous one. Two 



fangs perforated or Ko . ^.. Bl!Mksu ^ tam (eet long . Photograpl , 



