666 



BLACK-BACKED HYDRUS. 



H3rdrus Bicolor. H. capite oblongo, corpore supra nigro, infra 

 Jiavidoj Cauda moLulosa. 



Hydrus with oblong head, body black above and yellowish be- 

 neath, with spotted tail. 



Hydrus bicolor. Schneid* Amph. 1. p, 240. 



Anguis Platura. Lin, Syst. Nat. p, 391. 



Nixboa Quanquecolla, seii serpens rara Mexicana Cauda lata, 

 Seb.2.p.SO.t,77.f.l. 



Nalla Wahlagillee Pam. Russ. Ind. Serp. p. 47. pL 41. 



This species is readily distinguished by the re- 

 markable distribution of its colours ; the head and 

 upper parts being of a deep black, the lower parts 

 pale yellow, and the tail spotted : along the sides 

 runs a row of smaller scales than the rest, and of 

 a brighter yellow : the head is black, and is of an 

 elongated form in front, bulging behind, subcon- 

 vex above, and a little compressed laterally ; it is 

 covered with large scales : the mouth is wide ; the 

 teeth small and numerous, there being a marginal 

 and two palatal rows in the upper jaw : the body 

 is compressed, and the back highly cari'nated : the 

 scales orbicular and very minute : the general 

 length about two feet and a half ; the tail about 

 three inches. It is a native of the Indian seas, 

 and is said to be common near the coasts of the 

 island of Otaheitee, where it is called by the name 

 of Etoona-toree, and is used as an article of food. 



