Malayan Peninsula and Islands. ] 29 



sixth upper labial is the largest, in some individuals covering the check 

 and bordering above the occipital. Of the seven or eight inferior 

 labials the four anterior are very large ; above the third there is one or 

 two small triangular shields ; the other three or four posterior labials 

 are very small elongated. There is no horizontal series of labials as in 

 II. striatus, and the two elongated pairs of mentals immediately border 

 the labials. The neck is covered by 33, the thickest part of the trunk 

 by 53 longitudinal series of scales. Those examined by M. Schlegel, 

 the length of which exceeds those come under my own observation, 

 had 27, 29 to 31 series of scales. Those of the anterior part of the 

 back are rhomboidal, those of the posterior part rhombic with round- 

 ed apex and slightly imbricate ; those of the sides hexagonal : all have 

 either a sharply raised keel or a central tubercle, both of which fre- 

 quently become obliterated. The central series of abdominal scales are 

 a little larger than the rest, frequently divided in two hexagonal, and 

 with a small tubercle on each side, which often becomes indistinct, or 

 obliterated. The anus is covered by 3 or 4 very large, or by a series 

 of small scales. The largest of six individuals was of the following 

 dimensions : 



Length of the head, ft. 0| inch. 



Ditto ditto trunk, 2 Of 



Ditto ditto tail, 



8 



Of) 



~ 8 



2 ft. 3| inch. 

 Circumference of the neck, f ; greatest do. of the trunk, 2 inch. 



Vau. ? (See PL XL. Fig. 8.) 



Crown shields olive green with a blackish band from the eyes over 

 the anterior part of the upper lip ; the posterior part and the lower lip 

 pale yehow ; ground colour of the trunk greenish lead grey above, pale 

 yellow on the sides, beneath buff, with numerous black transveral bands. 

 Iris amber-coloured with the orbital margin dark grey. Central abdo- 

 minal series of scales 235-}-38. 



It differs from the preceding in the following particulars. The 

 head is proportionally shorter, broader triangular, the muzzle more 

 pointed, and the upper surface from the vertical shield very declivous. 

 The eyes are much larger than the nostrils, with a single prse-and post 

 orbital, but bordered beneath by the third and fourth upper labial 



