544 JOURNA L, BOMB A Y NA TURAL HISTORY SOCIETY, Vol. XVI. 



slight constriction near its middle. This horizontal outline endows this- 

 snake with a very remarkable range of vision. The forward setting of 

 the eye, together with its elongate pupil, and the pronounced farrow 

 in the face in front permit an unrestricted range of vision anteriorly, 

 and the elongation forward of the pupil also admits of rays of light 

 impinging upon the retina from a point far behind the eye. Proxi- 

 mately I estimate the range of vision as extending through an arc 

 of 330°. 



The neck is markedly contracted, and the body, which is very slender 

 throughout, exhibits a maximum calibre about its middle, and attenuates 

 in both directions. It is smaller in its lateral than in its vertical measure- 

 ment {i.e., compressed). The tail tapers very gradually, and is longer 

 relatively in this snake and its allies than in any other varieties, 

 measuring more than a third of the total length. The whole snake in its 

 tenuity of outline resembles the lash of an English carriage whip; hence 

 its familiar name. 



Colour. — The upper parts of head, body, and tail are bright verdant 

 green, the surface of the scales dull. The ridge from the eyebrow to 

 the snout is usually pale-green or yellow. Under ordinary circum- 

 stances no other colouration is apparent, but when under excitement the 

 creature expands its body it brings into view alternate streaks of black 

 and white (bluish in young specimens), which are directed obliquely 

 downwards and backwards from the vertebral region. These are most 

 apparent in the anterior two-thirds or so of the body, and upon close 

 inspection are seen to be mainly produced by the colour of the skin 

 between the scales ; however the lower borders of the scales themselves 

 are also narrowly tipped. A well defined narrow white or yellow line 

 runs along the entire body flank on the sides of the ventrals,and ends at 

 a variable distance along the tail. The chin and throat are white or 

 blue, sometimes mottled yellow to a variable extent. The belly is an 

 intensely brilliant green, of a hue distinctly lighter than on the back, and 

 resembles the delicate shade seen in some freshly opened foliage, such as 

 the mango or bamboo. A greenish colour is imparted to the spirit in 

 which the specimen is preserved. Very rarely specimens are met with 

 in which the colour is khaki, or olive brown. Another rare colour 

 variety is mentioned, and figured by Russell,* in which the belly is 

 cinereous grey between the flank lines, the rest of the snake being 

 * Ind. Serp. Vol. I, PI. XIII. 



