314 REPTILIA 



bifid protrusible tongue, frequently fanged, movable, displaceable 

 maxillary and palatine bones, numerous vertebrae, movable ribs 

 and ventral scutes. They lack tympani. Eustachian tubes, sternum, 

 and appendages. Their eyelids are fused. The lungs are asym- 

 metrical, some species having a degenerate right and others a de- 

 generate left lung. The urinary bladder is absent and the urine, 

 chiefly uric acid, as in birds, solidifies in the air. The temperature 

 of snakes varies from 68° to 84° Fahrenheit. 



"The limbless serpent can outclimb the monkey, 

 Outswim the fish, 

 Outleap the zebra, 

 Outwrestle the athlete. 

 And crush the tiger." 



(Owen.) 



The yellow-headed worm snake {Glauconia albijrons) reaches a 

 length of eight inches. It lives in ant hills and is a formidable 

 enemy of termites. 



The Boidae {pythons and boas) have vestigial hind legs, a pair 

 of strong movable spurs attached to vestiges of the pelvic bones. 

 Among the common pythons are the regal python, which may reach 



Fig. 172. West Indian boa. (Courtesy of N. Y. Zool. Soc.) 



a length of thirty feet, and can swallow a small antelope; and the 

 smaller Indian python, which is much used in side-shows, as it is 

 easily tamed. The Anaconda or water boa is extremely vicious. 

 It is viviparous, Ditmars recording one specimen that gave birth 



