76 W. Theobald — On Indian and Burmese species of Trionyx. [Maech, 



In May 1872, Dr. J. Anderson, Curator of the Imperial Museum at 

 Calcutta, published a brief but very important paper, almost wholly devoted 

 to pointing out the specific distinction between Tr. Tiurum, B. H., and of 

 Gray's Illustrations and Tr. gangeticus, Cuv., of which it had hitherto 

 ranked as a synonym. Also that Tr. ocellatus, Gray, is a synonym of Tr. 

 hurum, B. H. apud Anderson, and not of Tr. gangeticus, Cuv., as classed 

 by Gray ; and that Tr. javanicus of Gray's Illustrations is a synonym 

 merely of Tr. gangeticus, Cuv. 



In the next number of the Annals and Magazine for June 1872, Dr. 

 Gray publishes a criticism of Dr Anderson's paper, containing the follow- 

 ing statement respecting it : — " Here in 1872 we just have what Dr. Bu- 

 chanan Hamilton did at the end of the eighteenth century, and what I did 

 in the Synopsis of the Eeptiles published in 1831." This is so far true 

 that doubtless Buchanan Hamilton considered Tr. Tiurum a good species 

 when he made his drawing, and so may Dr, Gray when he published Tr. 

 Tiurum in 1829, but I fail to see how that invalidates the fact that, on this 

 point, Dr. Gray must have changed his mind at the date of publication of 

 his first catalogue in 1844, and his second catalogue of Shield Reptiles in 

 1855, where he sinks Tiurum to the rank of a synonym only, and where it so 

 remained till the appearance of Dr. Anderson's paper, that is to say, if we 

 may assume Dr. Gray's views to be represented in the above works bearing 

 his name. 



In the November number of the Annals and Magazine of Natural 

 History for 1872, Dr. Gray publishes a paper on the " Mud Tortoises of 

 India," and here for the first time that I can discover since the publication 

 of his catalogue of Shield Reptiles does Dr. Gray record Tr. Tiurum as an 

 independent species, and strange to say. Dr. Anderson, who so shortly before 

 had elaborated this view de novo, is not anywhere mentioned. Comment on 

 this is needless. 



An important question now arises whether the conclusions arrived at 

 by Dr. Anderson in the above paper, and adopted by Dr. Gray, are sound ? 

 Dr. Anderson is lucid and concise in his statements, but they are so start- 

 ling that I shall give a brief quotation. Speaking of the young of Tr. gange- 

 ticus. Dr. Anderson remarks : — " Young individuals with these characters 

 have greenish olive shells, vermiculated with fine black lines ; and of the large 

 series of specimens that has come under my observation, not one Tias present- 

 ed any trace of ocelli T On the other hand, Tr. Tiurum, as Dr. Anderson 

 would restrict it, usually possesses four ocelli in the young state ' ' with the 

 yellow spot on the temporal region, and another at the angle of the mouth 

 with a yellow band across the snout," &c. Now, without pretending to 

 anything like the experience which Dr, Anderson possesses, or the great 

 resources at his disposal, I greatly question, or rather altogether distrust, 



