308 DR. T. CANTOR ON PELAGIC SERPENTS. 
small pelagic crustacea, while the adult ones prey upon fishes of the following kind, all 
of which were found with their heads towards the bottom of the stomach : 
PERCIDE. 
Polynemus quadrifilis, Cuvier. 
Sillago acuta, Cuvier. 
ScLENIDE. 
Sciena pama, Cuvier. 
Corvina nigrocaudata, Cantor’s MSS. 
Muei.ipz. 
Mugil corsula, Hamilton. 
SILURIDE. 
Bagrus aor, Cuvier. 
Pimelodus gulio, Hamilton. 
—-— pangasius, Hamilton. 
—? Vana motta, Russell, No. CLXXI. ‘ Bummaloh.’ 
CLUPEID2. 
Clupea affinis, (Hardwicke’s ‘ Indian Zoology.’) 
The Siluride, which appear to be the favourite food, are all ground fish. Through 
the clear water of the tanks and streamlets cut across the rice-fields, I have often ob- 
served the Tropidonotus dora, Russell, II. No. V., one of the most common of the in- 
nocuous serpents in Bengal, lying in ambush at the bottom, with the head against the 
stream, behind some object sufficiently large to hide the animal, until chance brings a 
passing fish near enough, when the enemy darts upon the prey, before it is able to resort 
to flight ; from which I should conclude a similar mode is pursued by the pelagic ser- 
pents, when in search of food at the bottom of the sea or estuaries. 
From M. Péron’s observations, the sharks appear to be the natural enemies of the 
pelagic serpents : in two fishing eagles (Halietus) which were shot in the Gangetic Delta 
I found remains of these serpents in the stomach. 
The process of changing the integuments appears to occur very frequently, and du- 
ring all seasons, when the skin comes off in pieces, as in the larger kind of terrestrial 
serpents ; whereas the Homalopsis and Cerberus, although aquatic, shed the integuments 
entire. 
The terrestrial serpents are known to be infested with parasitic insects (Ivodes’). 
I have observed animals attaching themselves in great numbers to the pelagic. Unlike, 
however, the former parasites, which derive their nourishment from the animals upon 
which they are found, the latter derive no more nourishment from the pelagic serpents 
than they would from the rocks or any other objects the sea might offer as places of 
1 Ixodes ophiophilus. Vide Noy. Act. Acad. L. C. Nat. Cur. Tom. xy. Pars II, p. 233. 
