1912. | N. ANNANDALE: The Indian Mud-Turiles. 167 
that Anderson in describing and figuring the plastron of his speci- 
men did not remove the outer integument, which still adheres to 
the bone, and that in consequence he believed the surface to be 
smoother than actually was the case. As a matter of fact it is 
more nearly smooth than that of any Indian species, although by 
no means devoid of sculpturing. 
The bony carapace of specimen No. 1094 measures 40°3 cm. 
by 50°6 cm.; that of No. 755 was, according to Anderson, slightly 
smaller. The median processes of the hyoplastra in this species 
are single, slender and pointed. ‘They are never bifid at the tip. 
T. phayrei is connected with T. gangeticus through T. nigricans, 
from which it differs chiefly in having only one neural plate 
between the first pair of costals. The skull is also broader than 
that of T. nigricans, in fully adult individuals. 
7. Trionyx formosus, Gray (pl. v, fig. 6). 
Boulenger, Fauna, p. 14: Siebenrock, p. 598. 
DISTRIBUTION.—The Irrawaddi, Sittang and Salween Rivers. 
In the Irrawaddi this species is found near the Chinese frontier, 
as well as in the lower reaches. Numerous individuals, many of 
which are deformed, are kept in a small pond at the Arrakan 
Pagoda in Mandalay. I take it they belong to this species. It is 
very possible that statements regarding the occurrrence of T. hurum 
in the Malay Peninsula actually refer to T. formosus, but the 
latter species has not been definitely recorded from any Malay 
locality. 
SPECIMENS :— 
BURMA. 
1786 (skl.) .. Moulmein .. Maj. Sladen. 
277-8 (spirit) .. Mandalay a He 
634 (skull) .. Bhamo .. Maj. Lowndes. 
1837 (skl. juv.) .. Burma .. Dr. J. Anderson. 
1063 (skull) oh . ..' Hon. A. Eden. 
605 (skl.) as - .. Maj. Sladen. 
685 (sk1.) .. Irrawaddi .. Maj. Lowndes. 
687 (spirit) As ae .. Hon. A, Eden. 
1051 (carapace and .. . .. Dr. F. Stoliczka. 
palastron) 
766 (skl.) oe uaa .. Hon. A. Eden. 
This appears to be a comparatively small species. The bony 
carapace of the largest specimen in the collection measures only 
27°4 X% 26°5 cm.; its skull appears to be fully adult. In this 
specimen there are actually two neural bones between the first 
pair of costals, but the suture is asymetrical and there can be no 
doubt that the condition is abnormal. In most cases the median 
process of the hyoplastra is short, single and rather stout, its 
