REPTILIA 



317 



of Mexico and South America, are opisthoglyphs that feed on lizards. 

 The Proteroglypha include two sub-families, the Hydrophinae 

 which are marine forms, and the Elapinae which include Old World 

 Cobras and the New World coral snakes Their fangs are hollow 

 and connected with venom glands secreting powerful poison. The 

 fangs are rigidly attached on the anterior portion of the upper jaw 

 instead of folding back against the roof of the mouth as in the 

 viperine snakes. 



Fig, 174, Sea snake, (Courtesy of N. Y. Zool. Soc.) 



One of the Hydrophinae^ the yellow-bellied sea snake {Hydrus 

 platurus), is found in salt water off the coast of Central and tropical 

 South America, The sea snakes swim in schools of 20 or more. 

 They are preyed upon by fish and sea birds. Their venom is ex- 

 tremely powerful and produces a benumbing of the nerve centers. 

 (Figure 174.) 



The Elapine snakes have a slender body and a narrow head. 

 Their fangs are short, always erect and situated on the anterior 

 portion of the jaw. But one genus of these reptiles is found In 

 America. 



The Spectacled Cobra or " Cobra-de-Capello " ( Naja tripudians) 

 Is found In India and the Malay Archipelago. Although the fangs 



