CHAPTER XXII. 

 POISONOUS SNAKES. 



SNAKES belong to the class Reptilia and the order Ophidia. They 

 are divided into colubrine snakes (Colubridae) and viperine snakes 

 (Viperidae). 



Of the Colubridae the Hydrophinas or sea-snakes with rudder-like compressed 

 tail and the Elapinae with round tails are most important. 



Many of our harmless snakes such as the garter-snake and blacksnake belong 

 to the Colubridae. 



The cobras belong to the subfamily Elapinae and are best known by a neck-like 

 expansion or hood. The only poisonous colubrine snakes in the United States are 

 the beadsnake (Elaps fulvius) often called the Florida coral snake, and the sonoran 

 coral (Elaps euryxanthus). 



The beadsnake is black with about seventeen broad crimson bands, which 

 bands are bordered with yellow. 



Although small, they are very venomous. The upper jaw has anteriorly grooved 

 fangs, which appendages are not present in the nonpoisonous coral snakes, these 

 latter having teeth in the upper jaw so that the wound shows four rows of punc- 

 tures instead of two rows and one larger puncture on each side to mark the entrance 

 of the fangs. 



In Asia there are many important poisonous colubrine snakes; the cobra (Naja 

 tripudians), the King cobra (Naja bungarus) and the Kraits (Bungarus fasciatus). 



All of the Australian poisonous snakes are colubrines. 



The Viperidae which are characterized by a triangular head and tubular poison 

 fangs are the most important poisonous snakes in America. The rattlesnake 

 (Crotalus), the copperhead (Agkistrodon), and the water moccasin being widely 

 distributed in the United States. 



There are many harmless snakes which more or less resemble these "Pit Vipers" 

 as the rattlers, moccasins, and copperheads are called. This term refers to a deep 

 hole or pit found on the side of the head between the nostril and the eye. It is a 

 blind sac. 



Some divide the Viperidae into the Crotalinse, which possess the pit and the 

 Viperinte which do not have this structure. 



The poison fangs are grooved or perforated and connected with the poison 

 glands which resemble salivary glands and may be almost an inch in length in large 

 snakes. The tongue is slender and forked and is a tactile organ. 



The jaws are remarkable for their great extensibility, not only vertically, but 

 laterally, by the ligamentous connections of the two halves of the mandible or 

 lower jaw. 



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