page eee eh; On OrG- l CAT YN OF BSA ND 
DEHOCREPTITONS. 
By N. ANNANDALE, D.Sc., F.A.S.B., Superintendent, Indian 
Museum. 
(Plate xxxiii.) 
Trionyx sulcifrons, sp. nov. 
(Plate: xxxiii, fies. 1, 1a, 2;) 
The head is relatively small, triangular in shape and some- 
what flattened; the tubular nostrils are relatively long and have 
a well-developed median longitudinal groove on the dorsal sur- 
face; the interorbital space is narrow and in fresh specimens the 
supercillary regions are raised. 
A number of small longitudinal grooves originate between the 
eyes and, proceeding forwards, diverge on the forehead. ‘These give 
an excuse for the specific name. 
The disk is sub-circular, coarsely tuberculate in front of and 
behind the bony carapace; there is no dorsal ridge or groove, but 
a large prominence occurs on the bony carapace in front. 
In the young (pl. xxxiii, fig. 2) the head is olivaceous, with a 
smallish yellow spot beneath each eye, and another rather larger one 
at the junction of the jaws; the following black linear marks 
occur on the dorsal surface—a sinuous line originating behind the 
lower part of each eye, proceeding upwards and then bending 
downwards and running along each side of the head to disappear 
on the nape, and a large Y-shaped mark situated in the middle 
of the dorsal surface some distance behind the eyes and con- 
nected somewhat indefinitely with diverging lines on the nape. 
In the adult these dark marks break up as shown in fig. 1 
(p. 342) and perhaps disappear finally. The yellow spot at the 
junction of the jaws persists but its limits become somewhat 
indefinite. In the adult living animal the eyelids are reddish-brown 
and such dark marks as persist are bordered with a brighter shade 
of the same colour. ‘The disk of the young bears (? 4 or) 5 
relatively small ocelli, the ground-colour being dark olivaceous 
obscurely reticulated ; there is a narrow yellow margin. In the 
adult the ocelli disappear and the whole disk becomes dark oliva- 
ceous green obscurely marbled with a paler shade. 
The pupil of the eye (in the only living individual, an adult 
female, examined) was black and the iris dark olivaceous with a 
yellow ring internally. 
