1875.] W. Theobald — On Indian and Burmese Species of Tvionyx. 173 



T. chin, Gray, Syn. Eep. 47, t. 10. 



T. hurum, in part of Anderson, Gray, and other authors. 



T. Gangeticus, Gray, Sup. Cat. S. E. p. 97, " 3 half grown specimens." 



T. ocellatus, in part of Gray, Anderson, Theobald, and other authors. 



T. Gangeticus, Theobald or part P. A. S. B. 1874, p. 77. 



This species is based on a figure of Buchanan Hamilton, which Gray in 

 his paper on the mud-tortoises of India (A. & M. N. H. Vol. X, 1S72, p. 336) 

 thus describes — " The upper surface of the head uniform olive with a distinct 

 yellow spot on each side of the crown." From these yellow spots on the tem- 

 ples this species was regarded by Dr. Anderson as ' ocellatus 7 ( = hurum), 

 and by myself from the characters of its skull as a young Gangeticus. Ac- 

 cording to Dr. Gray (Mud-tortoises, 1. c.) this species has either four or six 

 ocelli and he figures its skull in the P. Z. S. for January, page 50. This 

 skull, as I remarked in my previous paper, exactly resembles a skull I ex- 

 tracted from a spirit specimen in my own possession, which fairly agreed, as 

 I then thought, with the figure of ocellatus. There are among the spirit 

 specimens in the Indian museum very few young specimens in the ocellatus 

 livery, and no prepared skulls, but among the former I found some possessing 

 the abrupt outline of head as in Gangeticus, and others with the more tapering 

 skull of typical ocellatus. It is thus clear that the species' with outline of 

 head of Gangeticus is not a mere phase of growth of ocellatus, and, al- 

 though there are no specimens of very young Gangeticus here for comparison, 

 it is certain from Gray's figures (P. Z. S. 1873, PL VIII), that the colour- 

 ation is identical with that of larger individuals and wholly unlike Buchanan 

 Hamilton's ' sewaare,' which name will therefore stand. 



Of this species very little is known, save that it differs from its nearest 

 allied species, ocellatus, externally, by wanting the broad yellow band across 

 the snout (though displaying the temporal blotches), and internally by its 

 skull and shorter face, which has the profile seen in Gangeticus. Its 

 sternal characters are not known, nor is the adult, unless the figure of 

 ' chhim 7 should be intended for it. 



Among Buchanan Hamilton's drawings is a very beautiful one of a 

 large Trionyx named ' chhim,'' which shows two temporal patches and no band 

 across the nose, and this drawing, I have little doubt, represents the adult, but 

 no profile view of the head is given, and it is wrongly identified by Gray 

 (who would seem to have misspelt the name ' chin' 1 ') as ' hurum 7 in Syn. 

 Rep. tab. X. I prefer, however, adopting the name of the immature stage 

 ' sewaare 7 as ' chhim 7 (or ' sim 7 as corruptly pronounced) is the name ap- 

 plied in Eastern Bengal to the chitra, and would perpetuate error. 



There is some confusion here, General Hardwicke calls the ' chitra 7 

 ' seivteree 7 — a name I believe still applied to it along the Ganges (' chhim 7 or 

 ' sim 7 being used in Eastern Bengal), whilst Buchanan Hamilton terms it 



