COLLEGE ZOOLOGY 



western states. 

 There is only one 

 " boa-constrictor ' 

 with several varie- 

 ties. It belongs to 

 the genus Boa and 

 its specific name is 

 constrictor. It is a 

 native of tropical 

 South America and 

 reaches a length of 

 eleven feet. Boa- 



FiG. 460. The python, Python molurus, devouring , , 



a mammal. (From Gadow.) 



docile in captivity 

 and therefore preferred by snake " charmers." 



Family COLUBRID^:. - - This family contains about 90 per 

 cent of all living snakes and is so large that it is usually divided 

 into three series. 



Series A. AGLYPHA. - - The snakes placed in this series have 

 solid teeth, and no grooved nor perforated fangs. They are all 

 non-venomous and are found in every country inhabited by 

 snakes. Half a 

 dozen of the most 

 common species 

 found in the United 

 States are briefly 

 described below. 



The common 

 garter-snake or 

 striped snake, 

 Thamnophis sirtalis 

 (Fig. 46 1 ) , is usually 

 provided with three 

 longitudinal yellow 

 stripes, one on the 



FIG. 461. 



The garter-snake, Thamnophis sirtalis. 

 (From Gadow.) 



