CHELONIA. 791 



!r. grayi is undoubtedly identical with the skull of the turtle figured in this work, and 

 with the skull of the type of T. peguemis. The skull of the turtle figured by 

 Theobald as T. stellatus is, as far as I am aware, unknown. The shape of the head 

 does not indicate a skull like the skull of T. peguensis. 



Mr. Theobald has described and figured^ a young turtle from Tenasserim under 

 the name of T. ephippium, and it will be observed on a reference to the figure of the 

 head that in its elongated form and in the dark reticulations spreading over the under 

 surface of the head, it corresponds much to the head figured as T. stellatus, Geofi". 

 There is also this noticeable feature of this supposed species, that its plastron is per- 

 fectly smooth like the plastron figvired as the plastron of T. careniferus, Gray (?) = 

 T. phayrei, Theobald. The head, however, of the latter corresponds to the heads of 

 eight turtles from the Irawady in the Indian Museum, Calcutta, which have their 

 plastra covered with coarse granulations, and which in the form of their entoplastron 

 piece exactly correspond to the plastron referred to T. stellatus and to the plastron of 

 T. grayi. The granular surfaces or callosities on these eight plastra exactly corre- 

 spond to the granulations figiu'ed on the plastron referred to T. stellatus and 

 T. grayi. The plastron of T. ephippium, on the other hand — a species which has a 

 head the equivalent in form and markings with the head figured as T. stellatus — has 

 a smooth plastron, with a heavy entoplastron like that of the smooth plastron referred 

 to T. careniferus, which is in Theobald's plate associated with a head specifically 

 distinct from that of T. epJiippium and T. stellatus. 



I have pointed out that the adult or adolescent skull referred by Gray to 

 T. formosus corresponds to the skull of T. hiirtmi. The skull (68, 4, 3, 142) removed 

 from the type is so smaU, that its specific characters are not sufiiciently marked to 

 enable it to be decided wherein it difi'ers from the skull of T. htirum, but it does not 

 appear to be that species which is confined to the Gangetic rivers. I am disposed 

 to consider it as the young of T. peguensis. 



From these facts it is apparent that considerable difficulty has been experienced 

 in determining the one species of Trionyx from the Irawady described in this work. 

 I have no hesitation, however, in identifying it with the Trionyx which has been 

 described by Gray as T. peguensis, and were it not that the plastron of the Trionyx 

 figured by Theobald under the name of T. careniferus. Gray, and T. phayrei, Theo- 

 bald, is described as smooth, and that its entoplastron is difi'erently formed from the 

 entoplastron of the specimens before me, I should have considered this species, from 

 the specific identity of its head with the head of the latter, as an example of the 

 same species. 



The smooth character of the plastron figured by Theobald might perhaps be 

 accounted for on the supposition that it was abnormal, but even were this so, such 

 an explanation would not explain away the difi'erence between its entoplastron and 

 the entoplastra of the eight Trionyces which I have examined from Moulmein and 

 from the Irawady. 



' Proc. As. Soc, Bengal, 1875, p. 177, pi, v. - 



