HYPSIRHINA ENHYDEIS. 281 



greyish-olive above, uniform or with an irregular dorsal series of small black spots. The 

 two or three outer series of scales yellowish, each scale spotted or edged with brown ; lips 

 and lower parts yellowish ; a black central zigzag line along the subcaudals. 



This species is not common, but widely spread, inhabiting Java, Borneo, Celebes, Formosa, 

 the southern parts of China, Pachebone, and the Malayan Peninsula. It attains to a lengtli 

 of 21 inches, the tail measuring 2| inches. 



Hypsirhina ENHYDEIS. (Plate XXII. figs. K, K'.) 



Mutta Pam, Ally Pam, Russell, Ind. Serp. i. p. 35. pi. 30. 



Hydrus enhydris, Schneid. Hist. Amph. p. 245. 



Homalopsis aer*, Boie, Ms, 1827, p. 550. Schleg. Phys. Serp. ii. p. 347. pi. 13. figs. 10 & 11 . 



Hypsirhina aer, JVagl. Syst. Amph. p. 170. Ch-ay, Viper. Snakes, p. 73. 



Coluber aer, Eydoux ^ Gerv., Voy. Favor, v. p. 74. pi. 30. figs. 2 & 3. 



Hypsirhina trilincata, bilineata, et furcata, Gray, Zool. Misc. p. 66. 



Homalopsis olivaceus, Cantor, Proc. Zool. Soc. 1839, p. 99. 



Hypsirhina enhydris, Dum. ^ Bibr. vii. p. 946. 



Homalopsis enhydris, Cantor, Mai. Rept. p. 99. 



This is a very variable species as regards form. Sometimes it is slender, with a thin 

 neck and narrow, elongate head; sometimes stout, with a somewhat slender neck and a 

 triangular head : the former appear to be males, the latter females. But intermediate forms 

 also occur. The scales are short, rhombic or rounded, without apical groove, constantly in 

 twenty-one series. Anterior frontal much broader than long, in contact with the loreal ; 

 vertical elongate. Loreal square, or longer than high ; one prgeocular, just reaching to the 

 upper surface of the head ; two postoculars. Eight upper labials, the eye being above the 

 fourth. Temporals scale-like, l-j-2 + 3. Two pairs of chin-shields, the posterior rather 

 longer than the anterior, and not touching each other in the median line. Ventral shields 

 159-166 ; subcaudals 62-69. Each maxillary is armed with sixteen teeth, subequal in 

 length, the last being stronger and grooved. Brownish olive above, the three outer series of 

 scales and the belly whitish ; a blackish line along each margin of the belly. 



Var. a. Back without bands, and belly without spots. 



Var. /3. Back with two light longitudinal bands, convergent on the head ; a brownish-red 

 streak within the white lateral streak ; belly without spots : //. furcata, Gray ; //. bilineata. 

 Gray. 



Var. y. Back mth or without bands ; belly with a central series of brown dots : II. tri- 

 lineata. Gray. 



This species is found in most parts of the East Indies, in Java, Borneo, the Malayan 

 Peninsula, on the coast of Tenasserim, in Siam, Bengal, China, and, according to Jerdon, in 

 Southern India; it attains to a length of 28 inches, the tail measuring 5 J inches. Cantor 

 has made the following observations on living specimens : — 



* From a name, Oulur oyer, given by the Javanese to this species. 



