TRUE REPTILES. 2 1 1 



authentic cases are known of boas having attacked human 

 beings. 



VALUE. The oil of the large boas is much used for various pur- 

 poses ; the skin is tanned, and made into boots, saddle-cloths, bags, etc. 



Allied are the ground fanged snakes. The Tree- 

 Snakes {Dendrophid<z) have long, slender bodies, adapted 

 for movement in the trees, and in many their rich green 

 coloring affords them complete protection. They are 

 tropical, and often found coiled up in birds' nests. About 

 thirty-five species are known. The whip-snakes are allied 

 forms. Fresh-Water Snakes (Homalopsida). In this 

 family of fifty species are snakes that live more or less 

 in fresh-water streams, and are found in all parts of the 

 world, but especially in the East. The desert snakes are 

 allied forms, and the curious Dasypeltis, that lives upon 

 eggs, swallowing them entire. 



In the Colubrida represented by two hundred and sev- 

 enty species, which include many of our American snakes, 

 there are no rudimentary limbs. Both jaws are armed 

 with teeth. The striped snakes, Eut(znia y a common form 

 in the Middle States, attain a length of two feet ; hiber- 

 nating in holes or burrows during the winter, appearing in 

 great numbers in early spring. They prey upon toads, 

 frogs, and other small animals. The garter-snake is vivipa- 

 rous, and often protects its young by receiving them into 

 its mouth. They are extremely prolific, bearing at times 

 seventy-eight young. The viviparous spotted spreading 

 adder is even more remarkable in this respect, producing 

 eighty-seven young at times. The hog-nosed snakes of 

 North America have a short, thick body, with a large head. 

 The black-snakes are a lustrous, metallic black, and attain 

 a length of five feet. They are harmless, preying upon 

 animals either in the trees or on the ground. The crack- 

 whip snakes are incorrectly supposed by some to seize 

 their tails in their mouths and roll along. 



