208. HYDROPHIs. 271 f 
208. HYDROPHIS. 
Hydrus, part., Schneid. Hist. Amph. i. p. 233 (1799) ; Wagler, Syst. 
Amph. p. 165 (1830). ; 
Hydrophis, part., Daud. Hist. Rept. vii. p. 872 (1803) ; Wagler, lc. ; 
Schleg. Phys. Serp. ii. p. 488 (1887) ; Gray, Cat. Sn. p. 49 (1849) ; 
Dum. § Bair. Erp. Gé. vii. p. 1841 (1854); Fischer, Abh. 
Naturw. Hamb. iii. 1856, p. 41; Jan, Elenco sist. Ofid. p. 109 
(1863) ; Giinth. Rept. Brit. Ind. p. 360 (1864). 
Pelamis, part., Merrem, Tent. Syst. Amph. p. 188 (1820). 
Enhydris, part., Merr. 1. c. p. 140. 
Disteira, part., Fitzing. N. Class. Rept. BS 29 (1826). 
Microcephalophis, Lesson, in Bélang. Voy. Ind. Or., Rept. p. 320 
(1834); Gray, Cat. p. 46. 
Liopala, Gray, Zool. Misc. p. 60 (1842). 
Aturia, part., Gray, l. c. p. 61. 
Thalassophis, part., Schmidt, Abh. Naturw. Hamb. ii. 1852, p. 75. 
Hydrophis, Bouleng. Faun. Ind., Rept. p. 898 (1890). 
Maxillary longer than the ectopterygoid, not extending forwards 
as far as the palatine; poison-fangs large, followed by a series of 
7 to 18 solid teeth. Head small; nostrils superior, pierced in-a 
single nasal shield, which is in contact with its fellow ; head-shields 
large ; preocular present; loreal usually absent. Body long, often 
very slender anteriorly ; scales on the anterior part of the body 
imbricate ; ventrals more or less distinct, very small. 
Indian and Pacific Oceans, from the Persian Gulf to Southern 
China and Northern Australia. 
Synopsis of the Species. 
I, Head moderately small; neck moderately slender, its diameter 
not less than half the greatest depth of the body. 
A. A single anterior temporal. 
Scales imbricate, 38-35round the body 1. spiralis, p. 273. 
Scales juxtaposed, 45 round the body. 2. polyodontus, p. 274. 
B. Two superposed anterior temporals., 
1. 32 scales round the neck, 43-47 round the body. 
Frontal slightly longer than broad, 
about as long as the nasals ...... 3. schistosus, p. 274. 
Frontal much longer than broad, as 
long as its distance from the end 
of the siiab! o0. eet es tees 54 4, hybridus, p. 274. 
2. 28-30 scales round the neck, 34 round the body. 
5. longiceps, p. 275. 
II. Head very small; neck very slender, its diameter not half the 
greatest depth of the body. 
A. Two superposed anterior temporals; ventrals 285-331. 
1. 34-38 scales round the neck. 
