420 



COLLEGE ZOOLOGY 



Figure 291. Indian python [Python) in its natural habitat. This is one of the world's largest 

 snakes; it reaches a length of 25 feet. (Courtesy of N.Y. Zoological Society.) 



those in the shell of the turtles. The nostrils 

 and ears are provided with valves and are 

 closed when the animal is under water. 



The limbs are well developed. There are 

 5 digits on the forelimbs and 4 more or less 

 webbed digits on the hindlimbs. The tail is 

 a laterally compressed swimming organ. The 

 "anus" is a longitudinal slit. Two pairs of 

 musk glands are present— one on the throat 

 and one in the cloaca. 



Only 21 species of living crocodilians are 



known. One belongs to the family Gaviali- 

 dae, 13 are included in the family Croco- 

 dylidae, and 7 are placed in the Alliga- 

 toridae. The American crocodile (Fig. 294) 

 is an inhabitant of Florida, Mexico, and 

 Central and South America. The African 

 crocodile is one of the few man-eating 

 species. Formerly it was held sacred by the 

 Egyptians, and many specimens were pre- 

 served as mummies. There are two species of 

 the genus Alligator; the American alligator 



