808 JOUliNAL y BOMBAY NATURAL HIST. SOCIETY, Vol. XXVI. 



Dentition, — Maxilla. — Two fangs and 3 to 5 small teeth behind 

 Palatine — 5 to 6. Pterygoid — 15 to 16. Mandible — 16. 



HYDRUS PLATURUS (Linne). 



Linne's Seasnake. 



History — Described by Linne in 1766. Figured by Russell in 

 1796 on the XLI plate of his 1st volume. 



Nomenclature. — (a) Scientific — The generic name is from the 

 Greek " udor " water, the specific from the Greek " platys," flat, and 

 " oura," tail. 



(/;) English. — Linne's seasnake. 



(c) Vernacular. — According to Fayrer this snake is called 

 " kullundur " by natives about Puri. 



General characters. — It is the most eel-like of all the marine 

 forms. The head is relatively large, and depressed, and the snout 

 unusually long. The body anteriorly is not nearly so constricted 

 as in many seasnakes, and is compressed. The back is sharply 

 ridged. The tail is a vertical paddle as in other seasnakes. 



Identification. — The scale rows anteriorly (40 to 54) are un- 

 usually numerous for a marine species, and there are no marginals. 

 Only one other species, viz., E. valakadyn, agrees in these respects, 

 and this is known by the downward projecting rostral, the groove 

 in the chin, and the suture running from the nostril to the 1st 

 labial, all features not seen in II. platurus. Osteologically it differs 

 from the other marine species in that the pra3 frontal bones do not 

 meet the parietal or postfrontals, and in the possession of a sub- 

 parietal crest or keel. The snake, however, is very distinctively 

 marked and once seen could hardly be mistaken for any other. 



Colouration. — There are several colour varieties which may be 

 grouped as follows. 



Variety (J.) (== the bicolor of Schneider, and variety E of 

 Boulenger's Catalogue, Vol. Ill, p. 268). Head chocolate or black 

 above, yellow beneath. Body with a broad stripe dorsally of the 

 same colour as the head. The lower edge of the stripe is straight, and 

 sharply demarcated from the pale yellow of the sides and belly. 

 Tail with black dorsal bars, and lateral spot. 



This is by far the commonest variety on our coasts. Some 

 specimens have a series of black costal spots in the yellow, or these 

 may be confluent and form a more or less irregularly-outlined stripe. 

 (Variety C of Boulenger's Catalogue.) Such specimens are not 

 infrequent. 



I have seen specimens in the Indian Museum from Ceylon and 

 Puri. A specimen in the Bombay Natural History Society's 

 collection from Madras, and another in the Indian Museum from 

 the Nicobars, have the posterior part of the dorsal stripe festooned 



