358 COLUBEIDjE. 



b. Vertebral scales much enlarged, nearly as 



broad as long in middle of body. 

 a'. Prseocular reaching upper surface of 



head D. ceylonensis, p. 359. 



b'. Praeocular not reaching upper surface 

 of head. 



a". Scales in 21 rows D. gokool, p. 300. 



b". Scales in 17 or 19 rows D. mulfimaculata, p. 360. 



B. Anterior palatine teetli but little longer 

 than posterior ; anterior niandibular teeth 

 considerably larger than posterior ; scales 

 in 17 to 21 rows, vertebrals much en- 



larged but longer than broad in middle of 

 body. 



V- 



a. Prseocular not reaching upper surface of 



head , D. hexagonotus, p. 361. 



b. Praeocular reaching upper surface of head ; 



uniform green above D. cyanea, p. 301. 



C. Anterior palatine and mandibular teeth con- 

 siderably larger than the others; scales 

 in 25 or 27 rows D.forstenii, p. 302. 



444. Dipsas trigonata. 



Russell, 2nd. Serp. i, pi. xv. 



Coluber trigonatus, Schneid. in Bechst. Uebers. LacSp. iv, p. 156. 



Dipsas trigonata, Boie, Isis, 1827, p. 549 ; Dum. Sf Bibr. Erp. G6n. 

 vii, p. 1136 ; Gilnth. Rept. B. 1. p. 312 : Jan, Icon. Ophid. 38, pi. iii, 

 fig. 2; Theob. Cat. p. 196 ; Blatif. J. A. S. B. xlviii, pt. 2, 1879, 

 p. 131 ; Murray, Zool. Sind, p. 383. 



Anterior palatine and mandibular teeth scarcely larger than the 

 posterior. Eye as long as its distance from the nostril ; rostral 

 broader than deep ; internasals shorter than the praefrontals ; 

 frontal longer than its distance from the end of the snout, shorter 

 than the parietals ; loreal as long as deep or deeper than long ; one 

 praeocular, not extending to the upper surface of the head ; two 

 postoculars ; temporals 2 + 3; upper labials 8, third, fourth, and 

 fifth entering the eye ; 4 or 5 lower labials in contact with the 

 anterior chin-shields, which are about as long as the posterior. 

 Body moderately compressed ; scales in 21 (rarely 19) rows, dis- 

 posed obliquely, vertebrals very feebly enlarged. Veutrals 229-269 ; 

 anal entire ; subcaudals 79-92. Yellowish olive or pale grey above, 

 with a white black-edged zigzag band along the back ; head with 

 two brown bands edged with black, diverging posteriorly ; belly 

 white, with or without a series of small brown spots along each 

 side. 



Total length 3 feet ; tail 7 inches. 



Hob. India generally, Western Himalayas, and Baluchistan. 

 This species is more terrestrial than its congeners and is found in 

 arid tracts in Baluchistan and Sind ; it bears a considerable resem- 

 blance in general shape and colour to Ecliis carinata, which has 

 nearly the same distribution in India. 



