VIPERS. HYDRIDE, OR WATER SERPENTS. 



573 



and thus taking advantage of its warmth for the development of 

 her offspring. The Viperidas of tropical regions are much more 

 venomous ; their bite being fatal to Man. Among these we 

 may mention the Cerastes, or Horned Viper, so named from a 



little pointed horn which rises 

 from the upper edge of each 

 eye ; the Indian Naja, Cobra 

 di Capello, or Spectacle- 

 Snake, which has a curious 

 mark resembling a pair of 

 spectacles, on the loose skin of 

 its neck ; the Egyptian Naja, 

 or Asp, which (in common 

 with the preceding) has a sort 

 of hood, formed by the loose 

 skin of the neck, that rises 

 when the animal is excited ; 

 the Hamadryas, another In- 

 dian Serpent, which some- 

 times attains the length of 

 twelve feet; and the Trigonocephalu*, or Lance-headed Viper, 

 of Martinique, which also is extremely dangerous from its size 

 and venomous power. 



511. The Marine Snakes, belonging to the family HYDRIDJE, 

 are characterised by the compressed form of their bodies, and by 

 the vertical flattening of the tail, which adapts them to move 

 through the water with facility. In their general aspect and 

 movements they strongly resemble Eels ; but they are altogether 

 destitute of fins, and are covered with scales. They appear 

 seldom or never to quit the land ; and they can only live for a 

 short time out of salt water. Little is known of their habits ; 

 but it has been proved (contrary to the general opinion), that 

 all the species are venomous, some of them extremely so. These 

 Serpents, of which more than fifty species are known, are peculiar 

 to the seas of tropical Asia and New Holland. 



FIG. 241. EGYPTIAN NAJA. 



