2592 SCALED REPTILES 



shields, and by their habits. Not only are these snakes frequently found at some 

 distance from water, but in Sumatra a specimen was captured nearly a day's march 

 inland. 



In common with all the other members of the subfamily, the parti- 



af c" Qk c l re d sea snake (ffydrus platyurus) has the nostrils placed on the 

 upper surface of the muzzle; and the under surface of the body and 

 tail in this species are scaled like the rest, although in some of the genera traces of 

 enlarged shields still persist. In the skull, the maxilla is considerably longer than 

 the tranverse bone, and carries a pair of short fangs, followed, after an interval, by 

 seven or eight solid teeth; the muzzle is elongated; the head shields are large, the 

 nasals being in contact with one another; and the scales on the relatively-short 

 body hexagonal in form and with their edges in apposition. This snake attains a 

 length of a yard; and in color is either yellowish with symmetrical black transverse 

 bands or spots, or uniformly black above and yellow, with or without black spots 

 below; the yellow tail being ornamented with either black spots or bars. It is the 

 sole representative of its genus, and has a wider distribution than any other mem- 

 ber of the group, ranging over the whole of the Indian Ocean and the tropical and 

 subtropical portions of the Pacific. The typical sea snakes, forming the large 

 genus Hydrophis, differ in having from seven to eighteen solid teeth in the maxilla, 

 by the longer body, on the anterior part of which the scales are imbricating, and by 

 the presence of more or less distinct small shields on the lower surface. 



The black-banded sea snake {Distira cyanocinda) may be taken as 



an example of another large genus differing from the preceding in that 



the fangs are followed in the maxilla by from four to ten solid teeth 



with their .front surface grooved. In these snakes the body is more or less elon- 



gated, and generally has the scales on its front portion slightly overlapping, while 



the under surface carries small shields. The figured species, which grows to a 



length of six feet, is of a greenish olive above, with black transverse bars or rings, 



which are sometimes connected by a longitudinal stripe on the under surface. This 



snake ranges from the Persian Gulf to the Malay Archipelago and Japan, and is 



one of the most abundant in the Indian seas. 



There are several points in which the sea snakes differ from their land cousins 

 as regards habits, in addition to those already noticed. In the first place, the skin 

 is changed piecemeal, instead of entire; the casting taking place at very frequent 

 intervals. Moreover, the tongue is very short, and only the extreme tips of its two 

 extremities are exserted through small notches on either side of the rostral shield 

 of the head, which is prolonged downward so as to close the mouth. When, how- 

 ever, these snakes are cast ashore and almost blinded by the unaccustomed light, 

 the tongue is used in the ordinary manner as a feeler. 



