longitudinal vomerine ridges. The premaxillaries have considerable backward expansion
to meet the vomer, and are perforated by two round foramina. The
anterior extremity of the maxillary furrow is occasionally perforated by a prominent
round foramen. The palatine foramen is longitudinally oval, large, and sometimes
two or four small foramina occur near it. The base of the skull has
considerable lateral expansion, and is flat. The symphysis of the lower jaw is erect,
not deep, and culminates in a feeble hook. The posterior two-thirds of the alveolar
edge is rather deeply grooved. The coronoid is neither prominent nor high.
The vertebral bodies in T. elongata are placed close to the neural plates, but
in T. platynota at a considerable distance from them, and the bodies in T. elongata
are broad, but in T. platynota much laterally compressed. However far removed,
or however near to the neural plates the bodies of the vertebrae may be, they ultimately
become connected, throughout their length, with the neural plates by the
growth of a delicate osseous partition which originates at the extremities of the
bodies and grows from the neural plateS and from the neural arch of the. bodies as
well; the line of suture, however, between the neural plates being preservedjn
this partition.
The number of vertebrae which by means of transverse processes and ribs support
the pelvis, would seem to be variable. In this species, I have observed as
many as five distinct vertebrae brought into connection with the ilium, the first two
having the distal ends of their processes abutting against the eighth costal plate on
a broad surface applied to the ilium, with the rib of the next vertebra broad and
large, and the succeeding rib more feeble,' and the next still more so, the penultimate
being anchylosed to the body of its vertebra; whilst in T. platynota I have
observed only three sacral ribs. Generally only two or three sacral ribs are applied
to the ilia in the other genera, such as Batagur, JSmys, Cyclemys, &c.1
In this species, transverse processes occur on the third vertebra after the last
sacral, and are strongly developed, far within the limits of the pelvis, but this is
a very different condition of things to what prevails in T. platynota, in which
all the caudal vertebrae are provided with lateral autogenous processes, which are
quite distinct from the centres of the vertebrae, in a female in which all the costal
plates have grown up to the marginals. The terminal caudal vertebrae which in
the male bear the claw-like scale, occasionally become firmly united with one another.
The difference in the length of the tail of the s,exes is due to the much larger
and longer vertebrae of the male, which is the case_ also in the fresh-water tortoises,
and indeed in Chelonia generally.
The stomach has the general character of the group. The small intestine
is 21*50 inches in length in a male, the carapace of which is and the large
intestine in the same individual is 12 inches. There is a sacculated-like portion
or rudimentary caecum on the sides of the large intestine at its beginning.
1 In an adult Chelonia vvrgata I observe that complete amalgamation of the sacral ribs with the vertebrae takes
place, although some anatomists have stated that anchylosis never occurs. The series of skeletons of Chelonia in the
Indian Museum would seem to make it probable that anchylosis in the adult state is not unfrequent.
The liver is very large, and, unlike the Batagv/rs and their allies, is devoid of a
gall bladder. The bile duct is about 3 inches long and opens into the intestine about
the same distance from the pylorus. At its origin in the liver it is somewhat dilated,
but it does not constitute a bladder. The kidneys are compact, and have somewhat
the form of the mammalian gland. They are one inch and a quarter in
length by 0"*63 breadth at the hilum, by 0"*75 across the part anterior to that.
The allantoic bladder is of considerable size. The peritoneal canal is prolonged in
the female as far as the sides of the glans, where it terminates as a closed tube.
The glans clitoris consists of three transverse folds, placed one before the other,
but intimately united to each other. The proximal fold consists of three parts, two
lateral and one internal; the first part is triangular and pointed, and the other is a
median ridge expanding into an oval extremity. The second fold is simple, while
the third forms a rather long pointed process. The oviduct, in an adult, measured
25 inches in length, and was much thickened and distended in its last three
inches.
On one occasion, I was attracted by a peculiar cry to a spot where some of this
species were. There I found a solitary pair, and that the cry was produced by
the male, evidently under great sexual excitement, as his mouth was open, a rare
circumstance in a Cheloniant except in the act of eating, and his tongue was protruding.
He was holding on to the back of the female with his front legs, and, with
outstretched neck, was trying to lay hold of her head. I watched them for some
time, and observed that he occasionally came to the ground and violently butted his
Companion from behind by the front part of his shell, rushing at her, and rapidly
withdrawing his head at each stroke. This curious scene went on for some time,
when I at last removed them, and found that the under surface of the posterior
portion of both shells, and the ground beneath them, was smeared with a clear
gelatinous fluid.
Hutton, in his interesting account of T. actinodes, refers to this habit which
these tortoises have of butting, but he did not connect it with the sexual act. He,
however, plausibly, but improbably, suggests that the hollow nature of the plastron
of the male may be a sexual differentiation to permit of the successful accomplishment
of the sexual act by enabling the male to retain his hold on the female during
the act, but in females referable to T. platynota, Blyth, the plastron is somewhat
concave.
A number of this species which I let loose in a garden eat freely of plantains,
but, on one occasion, I observed one specimen, a female, eating greedily of dead
prawns and fish which had been procured to feed Trionyces. They were generally
restless at night, but whether they are nocturnal in their natural state, I do not
know.
This species is active in its movements, and the males do not evince any
timidity whatever; the females generally withdraw themselves at once into their
shells when handled, in this contrasting with the confiding male, which will eat from
the one hand, while it is held in the other.