390 HYDROPHID^. 



Family, HrDROPHID^. 



Sea Snakes. 



Body sub-cylindrical anteriorly, more or less compressed posteriorly. 

 Tail strongly compressed, elevated, paddle-sliajDod. Head shields gene- 

 rally abnormal. Loreal none. Nostrils situated on the upper side of the 

 head (except in Platurus). Eye small. Pupil round. Venom fang 

 small, grooved in front, with a canal terminating in a short slit. 



Very widely distributed. 



All are venomous, and attain from 2 to 8 feet in length. 



Hab. — Ti'ophical parts of the Indian and Pacific Oceans. 



Hydrophis, Daiul. 



Posterior part of the body strongly compressed. Head short, or of 

 moderate length, shielded above. Only one pair of frontals. Nostril 

 superior, in a single nasal shield, both nasals being contiguous to each 

 other. Scales imbricate or not imbricate, generally with a tubercle or a 

 keel. Ventrals narrow, rudimentary, or absent. Lower jaw without 

 notch in front. 



Hydrophis Stewartii, Anderson ; Fayrer, Thanatophidia, p. 28. 

 Neck moderately long and slender. Head rather short, not much 

 broader than the neck. Body much compressed. Rostral considerably 

 broader than high. I^he nasals are as broad posteriorly as they are long ; 

 third and fourth labials under the orbit, the former not in contact with 

 the nasal. Temporals three ; the anterior the largest. Two post-oculars. 

 Vertical pointed behind. Occipitals long and narrow. Two paii'S of chin 

 shields, almost quadrangular, in contact with each other. Thirty-three 

 rows of scales round the neck. Scales hexag-onal, not imbricate, with a 

 feeble central tubercle. Ventrals 387, smooth, the first forty about four 

 times as large as the adjoining scales, becoming narrow posteriorly, to 

 within six inches of the tail, where they are hardly discernible. Two 

 pairs of small scale-like anals. Tail broad, markedly dilating from 

 its root. Lips yellowish. Upper surface of head, neck and. trunk 

 greenish olive ; under surface of head, sides of the neck and trunk 

 salmon coloured. Fifty-seven very obscure darker olive almost black 

 bars on the dorsal area of the neck and compressed portion, but not 

 extending on to the light coloured sides. Tail greenish olive, mottled 

 and tipped with black. Attains to 40 inches. 



Occurs on the Sind Coast, and at Bombay (Bassein). Dr. Anderson's 

 description is from a specimen obtained at Pooree on the Cuttack 

 Coast. 

 Hydrophis spiralis, Shriw, Zool. iii. p. 564; tab. 125; Gray, Vip. 



Snakes, p. 54; Gunth. Rep. Br. hid. p. 366, pi. xxv. 



Fayrer, Thanatophidia, p. 29. Hydrophis mela- 



nurus, Wagler, cjr. A^nph. tab. 3. 



Head of moderate size and width. Neck and 



body somewhat elongate. One post-ocular; the 

 Hydrophis spiralis, ^hird and fourth labials enter the orbit. Three 

 temporals on the side of each occipital, the anterior largest. Two pairs 



