1912. | N. ANNANDALE: The Indian Mud-Turtles. 157 
a’. Disk of young with four ocelli; inner margin 
of mandible without a ridge........ T. leithit. 
tr. A single neural plate between the first pair of costals ; 
a strong longitudinal ridge on the mandibular symphysis. 
A. Epiplastra widely separated immediately in front of 
EMRCMEGMIS EEA More <2 sss oa vis oe ee Ee T. formosus. 
B. Epiplastra in contact in front of the entoplastra. 
a. Plastral callosities feebly developed, finely sculp- 
(EOIREG Ln by chee.) ae eee nee eae T. phayret. 
a'. Plastral callosities well developed, deeply sculp- 
UE Cian 60 6.660 ee T. cartilagineus. 
The above key is based on the one given by Mr. Boulenger 
on pp. Io and 11 of his volume in the ‘‘ Fauna,’’ but has been 
modified to include the species omitted by him. 
A table of measurements of the skulls of this genus and of 
Dogama preserved in the Indian Museum is given at the end 
of this paper. 
2, Trionyx gangeticus, Cuvier (pl. v, figs. 1, Ia, 2). 
Boulenger, Fauna, p. 12: Siebenrock, p. 596. 
DISTRIBUTION.—The Indus, the Ganges, the Mahanaddi and 
their tributaries; probably also the Brahmaputra system. Mr. 
Boulenger is wrong in suggesting that this species does not occur 
in the Indus, for specimens from Karachi are identical, at any 
rate so far as head-markings and skull-characters are concerned, 
with those from Lower Bengal. The species, although not so 
abundant in the Calcutta market as T. hurum, is sold for food in 
considerable numbers, being brought from different places in the 
Gangetic delta, especially from Khulna. 
SPECIMENS :— 
BENGAL. 
1805 (no skull) Calcutta. Purchased. 
1808 ie * < 
1806 (skl.) = 
1080-3 : 1089 (skulls) - 
78-9 (skull) i 
3870 (skulls) 5 _ 
1720-2 (stuffed) Ay $s 
1724 2? 99 2 
1716 ”) ”) 9? 
1893 (carapace & skull) Ap Dr. J. Anderson, 
1895 (skl.) i 
1052-3 (skulls) Ganges. 2 
1054 ») ays “ x 
288 (spirit) Hughli. ? 
87097(32' bark. S..B.) Calcutta. E. Blyth, Esq. 
88x (32 d. A. S. B.): juv ne ie 
