SNAKES OF CEYLON. 411 



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I have lately seen many specimens in the Madras aquarium. 

 It moves ejcpeditiously by lateral undulations, and is 

 extremely graceful in its movements, looking at first sight 

 much more like an elongate fish than a snake. Occasionally 

 a minute pearl-like bubble is seen at each nostril, which in 

 coiu'se of time is freed and floats up to the surface. Visits 

 to the surface for a fresh intake of air are few and far between. 



Food. — Remains of fish in the stomachs of many show that it 

 depends upon this form of diet in common with other hydro- 

 phids. I have not been able to procure any fish in a suitable 

 state to make identification probable. 



Breeding. — (a) The. Sexes : Out of 49 specimens collected in 

 Juno and July, 1917, which I sexed, 21 were, males and 28 

 females. The tubercles on the scales in females are feeble, 

 but in males are stronger, and on the lowest costal rows in old 

 adults actually spinose. The male claspers are not bifid. 



(6) Method of Reproduction : It is definitely known to be 

 viviparous. 



(c) Season : The young are born between May and August. 

 I had twelve gravid females from Madras between June 20 

 and Juty 12, 1917, the foetuses ranging between 215 and 355 

 mm. (8J and 14 inches). Nine other specimens already bom 

 ranged between 350 and 445 mm. (13f and 17| inches). Prom 

 this it is probable that the 445 mm. specimen had been born 

 in May or even earlier, and that the 350 mm. specimens would 

 not have been born till August or possibly later. 



{d) Period of Gestation : Not known. 



(e) The Brood : This species shares with Microcephalophis 

 gracilis the distinction of being the least prolific of all the 

 seasnakes known to me. Of twelve gravid females that have 

 passed through my hands, four contained a single foetus, and 

 seven only two young. One specimen contained four embryos. 

 Some of the sacs containing the young measured as much as 

 108 mm. (4J inches) in length. 



Growth. — (a) The Hatchling : I have found unborn embryos 

 measuring as much as 355 mm. (14 inches), and I have had 

 ^a 6(6)20 



