HIPISTES. 381 



a praeocular, a supraocular, a postocular, and a subocular ; loreal 

 longer than deep ; one elongate anterior temporal, in contact with 

 the postocular and the subocular ; 5 upper labials ; 3 lower labials 

 in contact with the anterior chin-shields, which are not longer than 

 the posterior. Scales in 19 rows. Ventrals 266-278 ; anal divided ; 

 subcaudals 56-64. Blackish above, with white transverse bands, 

 which widen towards the abdomen ; these bands are very narrow 

 in the typical form, wider in the var. day ana, but constantly much 

 narrower than the black interspaces ; some white spots on the 

 head ; lower parts white, with greyish spots, the continuation of 

 the dorsal cross bands ; these bands may form complete rings on 

 the tail. 



Total length 3 feet ; tail 4 inches. 



Nab. Singapore, Borneo, and mouth of the Moulmein River, 

 where a single specimen was caught by Dr. Stoliczka in brackish 

 water. The latter differs somewhat in coloration, having the white 

 bands considerably broader ; but as it agrees absolutely in structure 

 with the typical form, I cannot regard it as more than a colour 

 variety. A second specimen from an unknown locality, agreeing 

 with Dr. Stoliczka's description in every respect, is in the British 

 Museum. 



Genus HIPISTES, 



Gray, Cat. Sn. p. 77, 1849. 



Maxillary teeth 8 or 9, followed by two small grooved fangs. 

 Head small, not distinct from neck ; lower border of rostral not 

 notched ; eye extremely small, with vertically elliptical pupil ; head- 

 shields small, parietals broken up into numerous shields ; nostril a 



Fig. 112. Head of Hipistes hydrinus. 



transverse slit between two nasals ; a single internasal, separating the 

 nasals ; a loreal. Body elongate, slightly compressed ; scales 

 smooth, in 35 to 42 rows, juxtaposed or subimbricate, without 

 apical pits ; ventrals narrow, with two sharp keels ; tail short, 

 feebly compressed ; subcaudals in two rows. 

 A single species. 



