SNAKES OF CEYLON. 413 



the same relationship. Again, Fraser and Elliot, as just 

 mentioned, do not attach too much importance to the results 

 they obtained from a single sample of curtus poison . The lethal 

 dose of this venom per kilogram weight for rats being '0006 

 grammes and that for the cobra being '0005, shows that to 

 the rat the former is slightly less virulent. If man is as 

 susceptible as the rat the lethal dose of the poison would be 

 about '00175 grammes. As the glands of an average adult 

 specimen only yield about '00284 grammes of venom they 

 contain less than two lethal doses. 



(e) Toxins : Apparently exactly similar to those of Enhy- 

 drina valakadyen (q.v.) 



(/) Symptoms : Fraser and Elliot, from experiments on the 

 lower animals, conclude that the symptoms are almost exactly 

 the same as in cobra poisoning. The one marked difference 

 noted by them was that respiratory embarrassment is much 

 more severe than in cobra poisoning, and this is due to a much 

 greater degree of paralysis of the ends of the phrenic nerves 

 than is the case in cobra poisoning, over and above the para- 

 lysis of the respiratory centre. The vaso -motor centre and 

 the vagi are not affected, unlike cobra poisoning. 



(g) Illustrative Case : None is available, there being no 

 record in past literature of a casualty attributable to curtus. 



(h) Treatment : This should be as recommended for cobra 

 poisoning. Fraser and Elliot have demonstrated that 

 Calmette's antivenene affords a feeble measure of protection 

 against the venom of Shaw's seasnake. 



Lepidosis. — (a) Typical — Rostral : Broader than deep. 

 Nasals : A suture from the nostril passes to the second supra- 

 labial. Prefrontals : Touch the second supralabial. Frontal : 

 Entire ; the fr onto -parietal sutures longest. Supraoculars : 

 Length half to three-fourths the frontal, breadth two-thirds 

 to three-fourths the frontal. Parietals : Disintegrate, usually 

 divided into three subequal parts. Prseocular : One. Post- 

 oculars : One. Temporals : Small, variable. Suprakibials : 

 Seven or eight ; first 3, 4, or 5 entire, the rest subject to 

 division and much variation, and forming the so-called lower 



