HYDROPHID M. 
The members of this family may be recognised at once by the 
peculiarities of their conformation, which is adapted to an 
aquatic mode of life. 
They are all venomous, and inhabit the salt-water estuaries 
and tidal streams; they have a very wide range of distribution, 
being found in the Indian and Pacific Oceans, from Madagascar 
to the Isthmus of Panama. They are most numerous, Gunther 
says, in the Eastern Archipelago and in the seas between 
Southern China and North Australia, “being represented on 
the outskirts of the geographical range mentioned by only 
one species, and that the most common —Pelamis bicolor 
I propose to describe some of those only that are found on 
the Indian coasts. They are very numerous, and many of 
them closely resemble each other, so that I shall figure and 
describe only the most remarkable. 
The sea snakes have great varieties of form, but the transitions 
from one to another are very gradual. Some of them attain 
a considerable size; Gunther speaks of some species attaining 
to the length of twelve feet. The longest I have seen is under 
five feet; there is no reason to believe that they attain to so 
great a size as certain fabulous stories would suggest. 
They are very poisonous. The case related of a sailor of 
H.M.’s ship Algerine, who was bitten by one recently caught 
at Madras, proves them to be so. I am informed by Mr. 
Galiffe that a fisherman bitten by a salt-water snake somewhere 
near the salt lakes, died in one hour and a quarter. And my 
own experiments and those of Mr. Stewart at Pooree prove, 
that not only when able to bite voluntarily, but even when 
weak and unable to bite, when the jaws were compressed on 
the animal, death resulted. The fishermen on the coast know 
their dangerous properties and carefully avoid them. 
They have smaller jaws and much smaller fangs than the land 
snakes generally, with open grooves, though not always com¬ 
pletely open, as supposed by some naturalists ; but the virus is 
veiy active, and appears to act as speedily and certainly as that 
of the terrestrial poisonous colubrine snakes. They have an 
elongated body like the land snakes; in some instances it is 
short and thick, whilst in others it is very thick towards the 
tail and most disproportionately elongated and attenuated in 
the neck; the head is very minute. The hinder part of the 
body and tail is flattened and compressed vertically, almost 
like the fin or tail of a fish, and it answers the same purpose, 
for with it they swim with grace and rapidity. They swim 
like fish, and live, with some exceptions, continually in the sea 
or tidal water. When thrown on the land by the surf, as they 
constantly are at Pooree and other places along the coast, they 
are helpless and almost blind. Their food consists of fish and 
other aquatic animals, which they pursue and overtake in the 
salt water. There are certain parts of the Bay of Bengal in 
which they are often seen in great numbers, and their movements 
m the clear blue water are very agile, graceful, and beautiful. 
The Platurus seem to be a transitional stage between the sea 
and land snakes; its general formation and large ventral scutse 
indicate its power of going on land and probably seeking its 
food there as well as in the sea. The Hydroplddce generally 
have no ventral plates well marked. The abdominal scales 
differ little from those of the rest of the body, which are gene¬ 
rally hexagonal, laid side by side, occasionally slightly imbricate 
and in some tubercular, a small tubercle being found in the 
centre of each scale. Platurus has abdominal scutas like the 
land snakes, and is sometimes found in marshy ground near 
the sea. 
The nostrils, eyes, and head shields of the sea snakes are 
peculiar. The eyes are small with circular pupils, which 
contract so much when the snake is taken out of water that it 
is said to be almost blind. The nostrils are on the surface, so 
that they can breathe when only the surface of the snout is 
above water. The openings are protected by a valvular 
apparatus internally. 
The head shields are peculiar and differ in their arrangement 
from the head shields of the land snakes. 
The nasals are large and replace the anterior frontals, which 
are absent. 
There is a single pair of frontals, a vertical, a pair of supra- 
ciliaiies, and a pair of occipitals; one ocular and one or two 
post-oculars : no loreal. The labials are irregularly arranged 
and subdivided. 
“ There is a triangular mental shield in front of the lower 
jaw, behind which the first pair of lower labials form a suture 
together; one or two pairs of clnn shields follow.” Pithy d/rina, 
has a peculiar notch m the lower jaw, by which the gape can 
be much increased. This notch is filled by a lobular process of 
the rostral shield, which fits into it when the mouth is closed ; 
on each side of this notch there is an opening for the points 
of the tongue to protrude. This again is shorter in Hydrophidai 
than in terrestrial snakes ; it is used as a feeler in the usual way. 
They are said to be very delicate and to die rapidly in capti¬ 
vity, even when preserved in tanks of salt water. Mr. Stewart 
of Pooree found that he could keep them alive for a short time 
by placing them in holes in the ground into which the sea¬ 
water percolated, and I am informed by Mr. Y. Bichards that 
he has succeeded in keeping Pnhydrina bengalensis alive in salt 
water for weeks. A very fine specimen of Hydrophis coronata 
caught near Calcutta, and sent to me by Mr. Galiffe, lived 
about ten days in a cage, occasionally being put into a jar of 
fresh water, although many experiments were made to make it 
bite, in which its very small head must have been considerably 
bruised. 
There are seven genera of this family :— 
Platurus. 
Aipysurus. 
Disteira. 
Acalyptus. 
Hydrophis. 
Enliydrina. 
Pelamis. 
But of these only four, I believe, are represented in the 
Indian Ocean, viz.:— 
Platurus. Enhydrina. 
Hydrophis. Pelamis. 
Of these, Platurus has two species : Hydrophis about twenty- 
seven ; Enhydrina one, or according to some naturalists, two ; 
Pelamis one species. 
PLATUBUS. 
Gunther gives two species of this genus, Platurus scutatus 
and Platurus fischeri. A very fine specimen from the Indian 
Museum, caught in one of the tidal streams near Port Canning, 
