194 

 I. Hipistes hydrinus (Cantor). 



Homalopsis hydrina^ Cantor, Cat. Mai. Rept. 1847, p. 104, pi. XL, fig. 4. 

 Hipistes hydrinus^ Boulenger, Cat. Sn. Ill 1896, p. 24; Rept. Malay Penin. 

 1912, p. 166, fig. 52. 



Frontal narrow, twice as long as broad, as long as or longer 

 than its distance from the tip of the snout; a praeocular; a 

 small postocular and a subocular; seven upper labials, sepa- 

 rated from the eye; five lower labials in contact with the 

 anterior chin-shields; posterior chin-shields very small. Scales in 

 35 — 43 rows; ventrals 153 — 172; anal divided; subcaudals 21 — 35. 



Greyish or brownish above, with black transverse bands as 

 broad as the interspaces or narrower. Lower surface whitish. 

 Length of head and body 435 mm.; tail 50 mm. 



Habitat: Sumatra (Ramunia in Deli!). — Pegu; Siam; 

 Malay Peninsula; Penang; Singapore. 



Feeds on fish; often captured in fishing-stakes. The head 

 shows much resemblance with a Hydrophine snake. 



Subfamily Dipsadomorphinae. 

 Key to the In do -Australian genera. 



A. Pupil vertical, or vertically elliptic. 



1. Body compressed; maxillary teeth sub-equal; 



scales in 17 —31 rows, vertebral scales enlarged 45. Dipsadoinorphus p. 194. 



2. Body round ; third and fourth maxillary teeth 

 enlarged; scales in 17 or 19 rows, vertebral 



scales not enlarged 46. Psammodynastes p. 202. 



B. Pupil horizontal. 



1. One or two middle maxillary teeth enlarged; 

 scales in 15 rows; vertebral scales slightly 



enlarged 47- Dryophis p. 204. 



2. Maxillary teeth subequal; scales in 15 rows; 



vertebral scales not enlarged 48. Dryophiops p. 20S, 



C. Pupil round. 



1. Scales in 21 rows, the vertebral row enlarged. 49. Dipsadoides p. 210. 



2. Scales in 17 rows, vertebrals not enlarged . 50. Chrysopelea p. 211. 



Terrestrial or arboreal snakes. 



45. Dipsadomorp hus Fitz. 



(FiTZiNGER, in Tschudi, Fauna Per. Herp. p. 55, 1845). 



Head very distinct from neck; eye moderate or large; pupil 



