51 



four lower labials in contact with the anterior chin-shields; 

 latter shorter than the posterior which arc separated by scales. 

 Scales in 19 rows, smooth, those on sacral re^^ion and tail 

 striated and feebly keeled; ventrals 136; anal divided; sub- 

 caudals 53. 



Dark brown above, sides lighter, with black vertical bars, 

 spotted with white; a white line across the snout, a white, 

 oblique streak behind the eye, widening towards the mouth; 

 a pair of light spots on the parietals near their suture; five 

 anterior labials with a small spot each. Lower surface whitish 

 with black transverse bars, most of them interrupted and 

 alternating, continued from the bars of the flanks; subcaudals 

 black, each with a whitish spot. Length of head and body 

 263 mm.; tail 87 mm. 



Type-specimen examined in the British Museum. 



Habitat: Sumatra !. 



Only one specimen known. 



7. Opisthotropis Gimther. 



(GiJNTHER, Ann. Nat. Hist. (4) IX p. 16, 1827). 



Head small, not distinct from neck; eye small; pupil round; 

 nostril directed upwards; nasals divided or partly divided; 

 internasals small, crescentic or triangular; loreal present. Maxil- 

 lary and mandibular teeth small and equal, 20 — 25 in each 

 maxillary. Body round, covered with keeled and striated scales, 

 without pits, in 17 or 19 rows; ventrals rounded. Tail mode- 

 rate; subcaudals in two rows. 



Distribution. W. Africa; S. China; Sumatra; Borneo. 



Key to the In do-Australian species. 



A. Scales in 17 rows; nasals separated 1. O. rngosa p. 51. 



B. Scales in 19 rows; nasals in contact Z. O. typica p. $2. 



I. Opisthotropis rugosa (Lidth). 



Lepidognathus ruo;osi/s^ v. Lidth de Jeude in M. Weber, Zoolog. Ergehn. Reise 



N. O. Ind. I 1890/91, p. 187, pi. XVI, fig. 1 — 5. 

 Opisthotropis 7-tigosa^ Roulenger, Cat. Sn. I 1893, p. 284. 



Head depressed; rostral as deep as broad; nasal divided, 

 separated from its fellow; internasals crescent-shaped, together 

 forming a triangle with a rounded top; loreal large; a pair 



