CHAPTER XXII 

 POISONOUS SNAKES 



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

 two families to which poisonous snakes belong are the colubrine snakes 

 (Colubridae) and viperine snakes (Viperidae). 



Of the Colubridse the Hydrophinae 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 fuhius) 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 punctures 

 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 snakesj 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 (Ancistrodon contortrix), and the water moccasin 

 (A . piscivorus) are 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 Crotalinae, which possess the pit and the 

 Viperinae 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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