THE REPTILIA 333 



pecially worthy of mention are the green turtle, the diamond- 

 back terrapin, and the soft-shelled turtle. It seems possible that 

 turtle farms might prove commercially successful in some parts 

 of this country if established on land useless for other purposes. 

 Certain lizards, such as the iguana of tropical America, are 

 a valuable addition to the food supply in their localities. 



The skins of the crocodilians are used rather extensively for 

 the manufacture of articles that need to combine beauty of sur- 

 face with durability. The alligators in this country have de- 

 creased so rapidly because of the value of their hides that they 

 will be of no great economic importance unless they are con- 

 sistently protected or grown on farms. Of less value are the 

 skins of certain snakes. Tortoise shell, especially that pro- 

 cured from the horny covering of the carapace of the hawk's-bill 

 turtle, is widely used for the manufacture of combs and orna- 

 ments of various kinds. 



As previously stated, the poisonous snakes of the United 

 States are of very little danger to man. In tropical countries, 

 especially India, venomous snakes cause a larger death rate 

 than that of any other group of animals. The gila monster, 

 which is one of the few poisonous lizards, and the only one in- 

 habiting the United States, very seldom attacks man, and 

 probably never inflicts a fatal wound. 



REFERENCES 



The Reptile Book, by R. L. Ditmars. — Doubleday, Page and Co., N. Y. 



City. 

 Reptiles of the World, by R. L. Ditmars. — Sturgis and Walton Co., N. Y. 



City. 



