636 



OPHIDIA 



CHAP. 



with tlie exception of one species of Distirn, D. semperi, which 

 is confined to the ktn4-k>cked freshwater Lake Taal at Luzon in 

 the Philippines. They live on fish, and range from the Persian 

 Gulf to Central America. In conformity with their absolutely 

 aquatic life they are viviparous, and they die when kept out of 

 the water for any length of time. About fifty species are known. 

 Enhydrina valakadien s. hengalensis has scales with a small 

 tubercle or keel, which is stronger in the males ; the ventrals are 

 very small, forming a scarcely enlarged series. The maxillaries 





P^N*f^'J* ^— :!^=55=-====-2 



( ^(jiTLL sjii-'ilmeu) 



Fig. 170. — Enhydrina valakadien (lelt uppei* figiire) aud Hydrojjhis obscura 



(right lower figure), x \. 



carry two or more small grooved teeth in addition to the poison- 

 fangs. The Ixick is olive or dark grey, with Idack transverse 

 bands, which are most distinct in the young. The under parts 

 are white. 1'liis species ranges from Persia to the Malay 

 Lslands. 



ffydrophis e.g. //. olisciim. — The body is long ; the head and 

 neck are very slender, tlie body becoming much tliicker farther 

 back. The small teeth behind the poison-fangs are not grooved. 

 The ventral scales are very small, the others are keeled, strongly so 



