170 Records of the Indian Museum. [Vom eViiic 
SPECIMENS :— 
BENGAL. 
1776; 1113 (skl.)<. ) Caleutta: ta Purchascd ACO ramae 
Anderson.) 
Zoological Gardens, Peer Bux. 
3543 2a Calcutta. 
1040 (skull) .. R. Hughli, Calcutta ? 
1055 - te pp Dacca) At a IDeneialuen inn alorealiaase: 
16753 (ski.) .. Probably from Khulna B.L. Chaudhuri, Esq. 
UNITED PROVINCES. 
483 (spirit): juv... Allahabad ie. J -Gockburn (Esq: 
Chitra indica is apparently the largest of the Indian Triony- 
chids. The bony carapace of the largest specimen examined 
measures 52°3 cm. X 59°77 cm: The length of its skull) (pias 
figs I, 2) measured from the tip of the snout to that of the 
articular condyle is 17°8 cm., and the greatest breadth 10 cm. 
The carapace may be distinguished from any purely Indian species 
of Tvionyx by possessing only one neural bone between the first 
pair of costals. The epiplastra are more widely separated from 
one another than in T. hurum and T. gangeticus and the anterior 
part of each is shorter than in most species of Tvionyx. There are 
three or four processes on the inner margin of each hyoplastron.! 
Genus EMYDA, Gray (1831). 
Boulenger, Fauna, p. 49: Siebenrock, p. 590. 
A consideration of this genus, which probably occurs only in 
the Indian Empire and in Ceylon, raises questions of considerable 
taxonomic and geographical interest. As a genus it is easily dis- 
tinguished from all other Trionychids of the Oriental Region by 
the fact that the hind limbs are protected by cartilaginous flaps or 
valves which can be closed over them on the ventral surface. 
Mr. Boulenger recognizes three species in the ‘‘ Fauna,’ but 
expresses a doubt as to whether two of them are really distinct. 
After examining a large series of skeletons and specimens in spirit 
and seeing living individuals in different parts of India, I find it 
possible to recognize only one species with several local races or 
subspecies. 
The branchial skeleton resembles that of Tvzonyx but differs in 
having the basihyals in close contact, the lateral margin of each 
basihyal produced into a blunt horn, the posterior margin of the 
posterior basibranchials deeply emarginate and the hypobranchials 
(with which the ceratobranchials are perhaps fused) very long and 
slender. 
1 Siebenrock, S.B.K. Akad. Wiss. Wien, CXI (1), p. 845, fig. 18, 1902. 
