The general colour of the upper surface of the shell, in the bright-coloured phase
of the male, is rich brown, somewhat marbled with darker in the form of lines, the
under surface haying a rosy yellow tint. The area around the nostrils is pale bluish,
but all the rest of the head, and the under surface of the neck are deep black, passing
into a rich crimson on the base of the neck, the whole of the fore-limb being
brilliant rosy carm ine. The hind limb is dull reddish purple, and the tail and hinder
parts are of the same colour, only darker. The eye is a pale greenish yellow. The
alveolar or palatal surface of the plates of the jaws is always almost black in both
sexes, but darker in the male.
The skull is distinguished by the contraction of the facial portion, which
begins at the posterior margin of the prefrontals; the region posterior to this being
narrow and concave on its upper surface, with the prefrontals in the adult upturned
to a greater extent than in any other Batagur. Internal to the sharp finely serrated
margin of the maxillaries, there are two parallel strongly serrated ridges on either
side of the palate. The anterior ridges are separated from each other in front by a
deep mesial groove, continuous with the furrow internal to each, and which is
prolonged forwards into the premaxillary depression; the internal ridges are also
separated from each other by a sharp longitudinal ridge; this ridge expands anteriorly
between them, but they are separated from it by the furrow internal to each,
sending a narrow prolongation round the anterior extremity of each ridge into
the anterior furrow. The hinder border of the palate is slightly reverted, forming
the posterior wall of the second furrow. The posterior nares have their
lateral margins slightly anteriorly divergent and not prolonged so far forwards as in
B . Imeata ; they are thus broader than in that species. The post-palatal portion
of the base of the skull, around the nares, is broader and more expanded than in
B. Imeata, and B. duvaucelli resembles B. baska in this respect, rather than B.
Imeata. The pterygoid constriction of the base of the skull is also much broader
than B. lineata, and in this character B. duvaucelli also resembles it. I t equals
half of the space between the pterygoid angles of the post-palatal surface, a proportion
which also prevails in B. dmaucelli, while in B. lineata it is less than
one-third of that interspace. The base of the skull, in this region, does not project so
far downwards as in B. lineata. The area between the articular facets for the mandible
is only marked by two very shallow concavities on the pterygoids, while in B. lineata
there is a deep crescentic concavity, and external to it a deep furrow running
downwards and forwards. In B. duvaucelli, this concavity and furrow are merged
in one, defined by the ridge that runs inwards forwards and upwards from the inner
margin of the facet for the mandible. The concavity on the under surface of the
occipital is much larger than in B. lineata, which is the case also with B. duvaucelli,
although the superior lateral concavities of the basioccipital are larger and more
backwardly projecting in the former species. The parietal region of the skull is
also much more flattened than in B. lineata, as it is also in B. duvaucelli, although,
in its general form, the skull of the latter is more nearly allied to this species than
to the former. The eye, as in other species, is strengthened by a ring of sclerotic
bones, ten to twelve in number, PL lxxv, fig. 11, which constitute a strong supporting
ring to the sclerotic. The temporal fossa has a rather acutely pointed
anterior superior border, while in B. Imeata and B. dmaucelVi the same border is
obliquely transverse and broad.
As in B. Imeata, the lower jaw has a longitudinal groove between the posterior
symphysial margin and the post-alveolar ridge, but instead of stopping short
where it meets the angle of junction of the ridges of the opposite sides, it is
prolonged forward between them, terminating on the symphysis, while in B. Imeata
the ridges unite; a sharp but short ridge occurring at the angle of union, which is
the case also in B. dmaucelU, only in that species there is no groove posterior to the
post-alveolar, which has only a single narrow surface behind it nearly on its own
level. The groove behind the inner ridge of the lower jaw has a well-defined inner
border in B. baska, whereas, in B. Imeata, this border is not upraised, there is
consequently no true posterior groove, but only a broad shelf of bone.
In this species and B. Imeata, there is a concavity on the outer surface below
the alveolar border corresponding to the surface on which the superior maxillary
rests, but in B. dmaucelli no such concavity exists.
The skull of the large individual from Khyouk Phyoo measuring 5"'45 in extreme
length and 3"10 in width below the ear is fully adult, as the sutures on the anterior
portion of the upper surface of the head are disappearing; and since the skeleton
presents every appearance of full maturity, the dimensions given under that specimen
may be regarded as indicating the limit of growth of the female.
The first vertebra after the eighth dorsal is applied by its transverse process
in the same way to the eighth costal plate as occurs in B . Imeata, but the nodosity
so formed is applied to the ilium before the transverse processes of the first Of the
true sacral "vertebras, of which there are only two with distinct transverse processes.
The transverse processes, appear in the fifth and disappear in the fifteenth caudal
vetebra. In a female there axe 27 tail vetebrse. The axillary and inguinal septa
are developed almost to the same extent as in B. baska.
The tongue is very small, not more than half an inch in length, and is
marked by a longitudinal furrow, as in Baturgidce generally, leading to the laryngeal
orifice which is almost exactly below the posterior nares. The larynx is thus
placed much anteriorly. The surface of the mouth, and the oesophagus for
three inches behind the larynx, are covered with large and numerous rounded
villiform processes. The tubular intestiniform stomach is stretched across from
side to side between the anterior septa of the shell. Entering the visceral cavity,
at the upper end of the left septum, it passes a short way backwards and then
stretches across to the posterior margin of the right septum, from which it is
separated by the narrow transverse lobe of the liver. I t then turns backwards,
and, when opposite the gall bladder, it is covered anteriorly by the right division
of the liver, which arches over it, and from that point its backward curve is inwards.
The left lobe of the liver embraces anteriorly the oesophageal portion of the stomach
and lies hLthe lesser curvature. The total length of the greater curvature in one