38 fi SNAKES OF CEYLON. 



Dentition. — From three skulls in my collection . Maxillary : 

 Postnodal, 7 to 9;* feebly scaphidont. Palatine: 8 to 10 ; 

 anododont, isodont ; no edentulous space posteriorly. 

 Pterygoid : 12 to 16 ; anododont, feebly scaphiodont ; posterior 

 two-fifths edentulous. Mandibular : 17 to 19 ; anododont, 

 scaphiodont. 



There is one species, viz., jerdoni. 



Kerilia jeedoni (Gray). 

 (Named in honour of the late Dr. T. C. Jerdon, the distin- 

 guished Ornithologist and Naturalist of the Madras 

 Medical Service.) 

 Jerdon's Seasnake. 



('!) Tamil: " shiddU " (RusseU). 



Synonymy.- — Hydrus nigrodnctus, H. cantori, Distira jerdoni. 



History. — I discovered what I take to be the type in the 

 Royal College of Surgeons' Museum (No. 528). It was one of 

 Russell's collection, and a comparison with Plate XII. of 

 Russell's Volume II. left no doubt in my mind that it was 

 the subject of the plate. On the other hand, Boulenger 

 claims as the type a specimen in the British Museum from 

 Madras collected by Dr. Jerdon. Cantor's name given in 

 1847 is invalid as he confused two species. In consequence, 

 Gray stands as its official godfather, and his name given in 

 1849 is retained to denote the species. 



General Characters. — A snake of moderate size and stout 

 habit, growing to about 3 feet in length. Head moderately 

 elongate, moderately depressed, and considerably broader 

 behind than before the eyes. Snout of moderate length, 

 narrowing terminally, much bowed in profile, and slightlj- 

 projected downwards. Eye rather large for a hydrophid. 

 Commissure of mouth slightly turned up behind. Neck 

 hardly evident. Body robust everywhere, cylindrical 

 anteriorly, compressed in midbody and posteriorly ; the 

 extreme depth hardly or not t'odce the depth anteriorly. 



Identification. — One of the easiest of the seasnakes to iden- 

 tify. The costals anteriorly numbering 17, posteriorly 19 to 

 21, with a rostral touching only four shields will suffice to 



* I have examined these teeth in many other specimens. 



