A MONOGRAPH OF THE SEA-SNAKES iHYDHOPHITN/fi). 



239 



Distira viperina (Schmidt). 



D Hydrophis obscurus, Jan, Icon. Gen., 1872, 40, pi. vi, fig 2 (non Daud.). 

 ,, viperina, Giinther , Rept. Brit. Ind., 1864, p. 378. 



Distira viperina, Boulgr. in Blanford .. Fauna Brit. hid. Rept. and Batrach., i8qo, 



P-4I3- 

 ,, ,, Boulgr., Cat. Brit. Mus., 1896, iii, p. 298. 



,, ,, Sclater, List Snakes Ind. Mus., 1891, p. 66. 



,, Wall in Proc. Zool. Soc Loud., 1903, p. 96, and in Mem. As. 



Soc. Bengal, 1906, p. 292. 

 Hydrophis jayakari, Boulgr. in Ann. and Mag. Nat. Hist., 1887 (5), xx p. 408. 

 nigra, Anderson in Proc. Zool. Soc. Lond., 1872, p. 399. 

 „ ,, Fayrer, Thanatoph. Ind., 1874, pi. xxv. 



„ Ewart, Pois. Snakes Ind., 1878, pi. 19, fig. 1. 

 „ „ Boulgr., Cat. Brit. Mus., 1896, iii, p. 274. 



Distira lapemidoides, Sclater, loc. cit., p. 66. No. 8269. 



B 



Fig. 55. — Distira vii>erina. 



ARC 

 Fig. 56. — Distira {Hydrophis) nigra (Anderson). After Fayrer, Thanatoph. Ind., pi. xxv. 



I have examined 21 specimens. No Hydrophid with the exception of jerdom 

 presents such well-marked characters to differentiate it from the rest of this genus. 

 It has at least two shields with characters peculiar to itself, and so pronounced that 

 either will suffice to declare its ident'ty. These are the frontal and the anterior 

 ventrals. 



In all the other species of this genus the frontal equals, or is rather greater in 

 breadth than, the supraoculars. In viperina it is at least twice as broad (often three 



