'The Expedition for the survey of the rivers Euphrates and Tigris, carried on by order of the British government, in the years 1835, 1836, and 1837; preceded by geographical and historical notices of the regions situated between the rivers Nile and Indus. In four volumes. With fourteen maps and charts, and embellished with ninety-seven plates, besides numerous wood-cuts. Volume the first.' [‎733] (833/905)

No- V.J
APPENDIX. 733
No. V.
REPTILES. 1
Species 1. Trionyx (or Gymnopus, according to MM. Dumt5ril and Bebron).
The following description is drawn up by W. Martin, Esq. from a dried
specimen, of which the sternum was unfortunately removed by the animal pre
server.
Total length, from the tip of the muzzle to the end of the tail, two feet;
width, about one foot; head and neck, measuring to the anterior edge of the
carapace, seven inches and three-quarters. Carapace slightly convex and
oval, slightly truncated posteriorly ; composed of nine costal plates, the ribs
being eight in number: a double mesial furrow runs along the back leaving
a s lig htly convex elevation between them : between the first, and most ante
rior, of these plates and the second are two depressions, each about half an
inch in diameter, placed near the mesial line, and separated by a space less
than a quarter of an inch in extent. The whole upper surface of the carapace,
excepting at the margin, irregularly reticulate. The depressions between
the costal plates are well marked. The length of the carapace is nine inches,
and the breadth seven inches and three-quarters; on the sides of the body
the coriaceous membrane extends about two inches beyond the lateral margins
of the carapace, the ribs themselves extending about one inch and a half
beyond the carapace. Towards the hinder part of the body the membrane
gradually increases in width, and over the tail it had attained a width of
nearly six inches, of which about two inches and a half are free. The head
is in the form of an elongated triangle; the snout is considerably produced
and attenuated: the width of the head,at the base is two inches and a quarter;
the total length of the skull is three inches five lines ; the space from the eye
to the upper lip beneath the nostrils is eleven lines ; the space between the
orbits is five lines: on the vertex above and between the orbits the skull is
smooth and convex. In both the fore nnd hind feet the first or front claw is
the lareest. The tail is rather short and thick; its length is abont four
inches and a half. When alive this animal was of an uniform mud colour,
sliffhtlv tinted with olive green. __
In many respects this animal agrees with the
( Trionyx JEgy V tia*us), as described by M. Bebron, bnt neither the he«l
Tte ^^fbetidt rrUr?—'depressions, ^m the anterior
0 c