328 SNAKES OF CEYLON. 



(b) Early Life : The young appear to double their length in 

 the first year of life, and are then about 635 to 760 mm. (25 to 

 30 inches) long. 



(c) Maturity : I have had gravid females measuring 702, 

 705, 712, 730, and 737 mm. (27J to 29 inches). I think there 

 can be no doubt that these were only one year old. If, as 

 seems probable, the period of gestation is as protracted as in 

 land snakes, such as Vipera russelli, then this species mates, 

 and is sexually mature, when six months old. 



(d) Maximum Length : My largest of well over sixty 

 specimens was 933 mm. (3 feet and f of an inch). Boulenger, 

 however, gives 1,020 mm. (3 feet 8 inches) as the outside 

 measurement. 



Poison. — Nothing known. No casualties are on record, and 

 the venom has not been experimented with. 



Lipidosis. — This is one of the few hydrophids that shows 

 wonderful constancy in the number and arrangement of its 

 head shields. 



{a) Typical — Rostral: Height greater than breadth ; slightly 

 projecting downwards ; visible portion above subequal to 

 or rather greater than the suture between the nasals. Nasals : 

 No sutures radiate from the nostrils. Prefrontals : Touch 

 the 2nd supralabials. Frontal : Entire ; longer than broad ; 

 small, about two -fifths its distance from the end of the snout, 

 and two -fifths the length of the parietals ; the fronto -parietal 

 sutures subequal to, or a little longer than, the fronto -supra- 

 oculars. Parietals: Entire; touching the postoculars. Prse- 

 oculars : One. Postoculars : One. Temporals : One large 

 anterior, as long as the supraocular; and one posterior as 

 large or larger. Supralabials : Six ; all entire ; the 1st and 

 2nd touching the nasals, 3rd and 4th the eye, 5th and 6th the 

 anterior temporal, and the 6th the posterior temporal. Sub- 

 linguals : Two pairs, the fellows of each in contact ; the 

 posterior touching the 3rd and 4th infralabials. Infralabials : 

 Eour ; the 1st longer than the suture between the anterior 



