A POPULAR TREATISE ON INDIAN SNAKES. 859 



aquatic type as one might expect, in adaptation to its natatory pro- 

 clivities, bat preserves the rounded contour typical of the terrestrial 

 forms. The eye is moderately large, the iris flecked with gold or golden 

 green, and a dense zone of gold demarcates the pupillary margin, and 

 reveals the rotund conformation of the pupil. The neck is constricted 

 sufficiently to be evident. The body closely ridged by the carination of 

 the costal scales, is robust, rounded, and reduces in girth decidedlj 

 before the vent. The tail is ample in both sexes, being one-fourth to 

 one-third the total length, and tapers gradually, the dorsal ridge* 

 being preserved almost to its extreme tip. 



Colour. — The colour and markings of this snake are exceedingly 

 variable, as a glance at our plate will, in some measure, serve to 

 indicate. 



The ground colour may be dull green, olive-green, olive-brown or 

 brown of almost any shade, light or dark. 



Some specimens are uniform, or almost uniform, in colour, but the 

 majority show some chequering, and usually of black which mav 

 occur in specks, spots, or blotches, and vary from a few marks confined 

 to the sides of the neck and forebody, to a wholesale distribution 

 chequering the entire body and tail. These marks are usually 

 arranged quincuncially in 5 or 6 longitudinal rows, and the blotches in 

 some examples are confluent, and so large that black becomes the 

 prevailing colour. 



Some specimens are decorated with a similar draught board pattern , 

 but sombre hues replace the black, and sometimes buff or whitish tints 

 form the most conspicuous chequering. 



Again, soui9 are specked, spotted, or blotched with red which mav 

 vary from salmon or rose pink to a brilliant scarlet like sealing- 

 wax. 



This lively ornamentation is as capricious in its distribution as the 

 black above alluded to, and may vary from a few marks on the side of 

 the neck and forebody to a profuse adornment of the whole dorsum. 

 All these decorative hues are almost entirely confined to the basal halt 

 of each scale, and especially to their margins, where the scales overlap 

 one another, so that they are seen to their best advantage when the 

 snake under excitement dilates itself. 



The crown of the head is similar to the dorsal ground colour 

 and two black oblique streaks are almost always in evidence proceeding 



