A MONOGRAPH OF THE SEA-SNAKES (HYDROPHIINJK). 201 



characters, besides many other unusual ones found in cantoris, are all found in 

 gillespice. The slight and only differences apparent in Mr. Boulenger's descriptions of 

 the two, concerning the body scales, and the ventrals disappear within the range my 

 19 specimens cover. 



Description. — The body anteriorly is about one-third to one-fourth the greatest 

 body depth. The snout projects well over the chin, and the commissure of the mouth 

 resembles an italic / in profile. 



The headshields are very constant. 



Rostral, — the portion visible above is from three-fourths to greater than the 

 internasal suture. Prefrontals, — touch the third supralabial (the second also 

 rarely). Post oculars, — one (two rarely). Temporals, — one large anterior, 

 succeeded by another even larger posterior shield, the anterior touching the fifth and 

 sixth supralabials. Supralabials, — 6, not subject to division. Inf ralabials,— 

 4, the last in contact with only two scales behind ; the suture between the first as 

 long or longer than the suture between the anterior sublinguals. Marginals, — 

 none. Sublinguals, — two well developed pairs, the fellows of each in contact 

 (separated in one specimen). Costals, — anterior 21 to 25 (21 in one only), midbody 

 27 to 37, posterior 39 to 46; the anterior imbricate, posterior juxtaposed. Ventrals 

 377 to 474, entire anteriorly and twice or nearly twice the breadth of the last 

 costal row, divided by a median furrow in the posterior half of the body. 



Colour, — yellowish ventrally, olivaceous dorsally. Surrounded by 51 to 61 

 black rings in the young which become obscured ventrally, and converted into bars, 

 these in turn becoming more and more obscured as age advances Head black in 

 young, fading later. The bands much confluent ventrally anteriorly and usually 

 expanded vertebrally. All the specimens are from the Indian shores (Karachi to the 

 Gangetic Delta), except Cantor's specimen which is from Penang. A specimen in the 

 Indian Museum (No. 8260) measures 6 feet 1 inch. 



Distira obscura (Daudin). 



"Shootur sun," and " Kalla shootur sun," Russell, Ind. Serp., i8oi,ii, figs, vii 



and viii. 

 Hydrophis obscurus, paud., Rept., 1803, vii, p. 375 



chloris, Baud., loc. cit., p. ^yy , pi. xc. 

 ? Pelamis obscurus, Merrem., Tent., 1820, p. 139. 

 ? ,, chloris, Merrem., loc. cit, 



Hydrophis coronata, Giinther, Rept. Brit. Ind., 1864, p. 372, pi. xxv, M, and M'. 

 ? ,, ,. Anderson in Proc. Zo,pl. Soc. Lond., 1871, p. 192. 



,, ,, Fayrer, Thanatoph. Ind., 1874, pi. xxvi. 



,, ,, Boulgr. in Blanford, Fauna Brit. Ind. Rept. and Batrach., 



1890, p. 402. 



,, „ Boulgr. Cat. Brit. Mus., 1896, iii, p. 279. 



,, ,, Sclater , List Snakes Ind. Mus., 1891, p. 63. 



,, ,, Wall in Mem. As. Soc. Bengal, 1906, i., p. 282. 



