CoLUBBiNE Serpents. REPTILES. Pelagic Serpents. 49 
Suborder II.— COLUBEINE SEEPENTS {Colubrina). 
The Colubrine Serpents are distinguished from the 
Viperine Serpents by their having strong javi's, both 
of which are furnished with one or more series of teeth. 
In some of the species the upper jaw is provided with 
fangs in front, which are fixed, not hollow, but grooved 
on the hinder edge, which groove communicates with a 
gland placed on the side of the face. The head is of 
moderate size compared with the body, and the crown 
is often covered with large plates or shields. A great 
proportion of the species belonging to this extensive 
and numerous suborder are perfectly harmless, but 
there are a small number, those having grooved fangs 
communicating with a iioison gland, which are truly 
venomous, and some among them dangerously so. 
This suborder contains two sections, whicli again are 
divided into several families ; but these, as they differ 
very much in their habits and method of living, will be 
best described separately. 
The first section is characterized by the belly being 
covered with narrow elongated shields or scales, nearly 
resembling those of the back. 
This section contains two large Families, the Water- 
serpents {Hydridce) and the Boas {Boidce), 
Family I. — WATER- SERPENTS {Hydridca). 
The Water-serpents {Hydridce), as their name im- 
ports, are all natives of the salt or fresh w'ater, and 
are chiefly natives of the Eastern seas. Their nar- 
row belly-scales are hexagonal or band-like. The 
nostrils are placed on the upper part of the muzzle, 
and are furnished with valves. The eyes are situated 
towards the upper part of the head, and are furnished 
with a small round pupil. The fangs, when present, 
are of moderate size, and are intermixed with the max- 
illary teeth. In some the tail is con. pressed, but in 
others it is round. Many of these serpents are found 
exclusively in the sea, in the months of rivers, or in 
salt-water lakes, whilst others live entirely in fresh 
water. 
THE SEA OR PELAGIC SERPENTS (Rydrina) are 
not very numerous in species, thirty-two only being 
described in Dr. Gray’s catalogue ; but thej^ are ex- 
tremely abundant in individuals, and unlike the terres- 
trial serpents, are always met with in numbers together. 
So much is this the case, that their appearance serves 
as a mark to mariners that they are nearing the shore. 
“ On my approach to Bombay,” says Dr. Cantor, “ I 
remember the sailors looking out for this phenomenon, 
until shoals of these animals made their appearance as 
signs of approaching land.” My own experience con- 
firms this fact, while approaching the mouths of the 
Hoogly from the Bay of Bengal. Their geographical 
distribution is entirely limited to the tropical seas, and 
although the flood-tide carries them as high up the 
rivers as the brackish water, yet they are purely 
pelagic, and as Dr. Cantor well observes, are no more 
VoL. II. 6^ 
found in fresh water than on dry ground ; they form 
par excellence the natatorial type of the order Ophidia. 
We do not know a very great deal of their habits, but 
their whole organization proves that these reptiles are 
destined only to live in the water, and that their organs 
of locomotion arc in no way formed for progressing on 
land. Their body, in order more easily to cleave the 
waves, becomes slender towards the two extremities, 
and much compressed or flattened towards the tail. 
The belly is narrow and most frequently prolonged 
into a more or less sharp keel — “ a conformation,” says 
Sc.hlegel, ‘‘ absolutely similar to the keel of a ship.” 
The tail short, but so compressed or flattened as to 
offer little breadth compared with its extraordinary 
height, is the chief organ of locomotion ; for by this 
form, by its vertical position, and its great degree of 
flexibility laterally, it exercises at once the double 
function of oar and rudder. The head is small, more 
or less elongated, conical towards the snout, and almost 
of the same proportion as the neck ; so that it is weli- 
fitted for overcoming the resistance offered by the water. 
The eyes, placed laterally, are directed a little upwards 
and forward, and thus these serpents are enabled to 
look in all directions, so as to be able to seize their prey 
or escape the dangers they are incessantly threatened 
with. The muzzle is elongated into a downward but 
pointed shield, which closes the mouth and thus pre- 
vents the water from entering ; and in order to effect 
respiration without the serpent having need to expose 
any part of its body out of the water, the nostrils are 
placed near each other upon the summit of this muzzle, 
and are provided with a membranous valve which opens 
to admit the air, and closes to prevent the entrance of 
the water. A single instant suffices the creature to 
perform the act of breathing ; which effected, it plunges 
again into the depths of the sea, the water of which 
cannot enter either by the nostrils or the mouth. The 
tongue is much less developed in the sea than the 
terrestrial serpents. As long as they are below the 
surface of the water they never make use of this organ; 
but when they are out of the element, and the animal 
is blinded, as it were, by the light, it appears of material 
use as a feeler. The eyes are generally small, and the 
pupil is always round. The mouth is only of moderate 
size, and the jaw-bone is sufficiently long to give room, 
in addition to the fangs, to several small solid teeth. 
Hence it follows that these sea-snakes cannot erect 
their fangs so much as the viperine serpents, and in 
biting their prey, they retain hold of it with their jaws. 
The fangs are marked on their hinder edge with a 
furrow, which communicates with the orifice of the 
duct which conveys the poison from the gland. They 
are much smaller than in the colubrine venomous 
snakes, and therefore have escaped the observation of 
many naturalists, who, like Dr. Patrick Russell, deny 
their existence in several of the species. The other 
teeth are exceedingly small and numerous. The 
