394 HYDROPHID^. 



round the neck, but further on tlie scales become regularly hexagonal, 

 a little higher than long, and are in 40-44 series round the middle of 

 the body. There are 400-415 scales in a line between the angle of the 

 mouth and the vent, and 52-56 in a longitudinal row along the tail, the 

 terminal scale is moderately enlarged, but not forked. Each scale ou 

 the body has a minute central keel, and on the side of the tail the 

 keels of the succeeding scales become continuous, forming thin ridges. 

 Ventral scales each with two short keels ; they are 328-334 in num- 

 ber, anteriorly twice as large as the adjoining scales, but posteriorly 

 their size considerably decreases, and many of them become split in 

 two shields. Two pairs of prse-anal scales, the outer twice as large as 

 the inner. 



Head olive blackish, tinged with red, brightest on the lower side, an 

 c/Z shaped vermilion mark on the top of head, composed of more or 

 less isolated spots, the upper convexity rests on the f rentals, the lateral 

 branches run along the supraciliary edge, and the ends curve outward 

 towards each angle of the mouth ; this vermilion mark becomes rather 

 obsolete with age. 



Of two specimens the smaller one is 23 inches, of which the tail is 

 a little above two ; the body is moderately compressed, of almost 

 equal height throughout, encircled with 58 black rings, separated 

 above, bat united by a black line along the ventrals ; the rings are 

 only slightly contracted at the middle of the sides, being separated by 

 narrower yellow bands ; the tail has besides eight black rings, the 

 terminal three or four confluent on the lower side, and the tip is 

 entii-ely black. 



Another more adult specimen is 27 inches, of which the tail is 

 nearly 2*5 ; the body is in the middle twice as high as at the back ; 

 there are 46 transverse blackish rings on the body, and six round 

 the tail ; each ring is blackest along the back, contracted to nearly half 

 its breadth at the middle of the sides, and from there to the broader base 

 strongly tinged with yellow, which is the general colour of the snake. 



Hab. — Kurrachee ; in tidal waters. 



This species is evidently closely allied to the New Guinean H. helcheri, 

 differing from it by the smaller number of scales on neck, the hexagonal 

 ones on the body, keeled ventrals, and by its colouration. Another, as 

 regards colouration, almost identical species is if. tuberculata, {Anderson, 

 Jotirn. A. S. B., xl. p, 18), but it has 38 rows of scales round 

 the neck, two keels in a line on each scale, and several keels on each 

 ventral. The scales on the side of the body are also slightly more 

 elongate, and there exists a noticeable difference in the arrangement 

 of the labials, and the form of the head shields. 



Hydrophis robusta, Gnnth. Bep. Br. Ind. p. 364. H. nigrocincta, 

 Sckleg. Phys. Serp, ii. p. 505. pi. 18. (not synon.) Fischer. Abhandl. 

 Natur. Hamb. iii. p. 46. tab. 1. 



Head of moderate size and width. Neck and b®dy not elongate. 

 Two or three upper labials below the orbit. One post-ocular. Anterior 

 temporal shield large. Two pairs of chin shields in contact with each 



