2 PEOCEEDINGS OF THE NATIONAL MUSEUM. vol.60 



as those of the median row, without spine or keel; second and third 

 basal rows smaller, smooth, polygonal; nuchal crest measured from 

 lower edge of third basal row equals distance from orbit to halfway 

 between nostril and tip of snout; dorsal scales small, smooth, not 

 pointed, scarcely imbricate, without any appreciably enlarged ones; 

 ventral scales much larger, smooth ; limbs above with subequal smooth 

 scales; third and fourth fingers equal; the adpressed hind limb 

 reaches the orbit; tail without crest, strongly compressed, with 

 keeled, slightly serrated upper edge; upper caudals smooth, lower 

 ones larger and strongly keeled; length of tail not quite twice that 

 head and body. Color (in alcohol) greenish above, with dark 

 longitudinal reticulations; tail with regular dark annuli. 



Dimensions. 



Total length 360 mm. 



Tip of snout to tympanum 34 mm. 



Width of head 25 mm. 



Tip of snout to anus 143 mm. 



Fore limb 79 mm. 



Hind limb 106 mm. 



Tail 217 mm. 



Remarks.— In comparing this specimen with adult females of Gon- 

 ocepJialus chamaeleontinus from Sumatra, I find that the latter differ 

 from it in several striking characteristics: 



1. The female G. chamaeleontinus has the dorsal and nuchal crests- 

 formed of comparatively long and sharply pointed lanceolate spines. 

 The highest nuchal spines are about three times as high as their 

 greatest width. The upper outline of the crest when viewed in pro- 

 file shows a maximum elevation just back of the tympanum, with a 

 sudden lowering in height above the shoulders, from which point the 

 dorsal crest continues to decrease regularly in height. In the male 

 G. chamaeleontinus there is a slight increase in the height of the dor- 

 sal crest for a few scales behind the depression, after which the dor- 

 sals decrease regularly. The crest of G. abhotti does not have any 

 depression above the shoulders, but lessens gradually from above the 

 tympanum to the tail. The first row of scales at the base of the 

 median series forming the crest is mush larger in G. abhotti, being 

 approximately of the same size as the median series of the crest. In 

 G. abhotti these scales^re flat, smooth, without keels or spines, while 

 in G. chamaeleontinus they have a spine on the upper margin and 

 are distinctly keeled. 



2. The new species has no enlarged scales on the sides of the head. 

 In G. chamaeleontinus the large conical scales above and below the 

 tympanum are a prominent feature. There is a series of 8 or 9 en- 

 larged tubercular scales on the sides of the body in G. chamaeleon- 

 tinus. These are from three to six times the diameter of the sur- 



