42 ReptiKa and Amphibia from Central India. [No. 4, 



so broad a straight hinder margin as in the specimens from central 

 India, the extent to which it is truncated behind in young animals 

 varies. In the third vertebral a great change also takes place with 

 age, while the fourth in old shells loses its diamond shape and as- 

 sumes the outline of a flask. In the sternum, the pectoral shields 

 become shorter in older specimens, in proportion to the postgnlars 

 and abdominals, and the angular ridge on each side of the sternum 

 is blunter, while the extent of black on the sternal plates is rather 

 greater. 



It is very clear that these variations tend in a great measure to 

 obliterate the distinction between P. tectum and P. tenton'a ; the on- 

 ly remaining difference being the more tumid form of the first 

 named species. But I doubt if this be a more valid character than 

 the form of the plates. In two Calcutta specimens in the Indian 

 Museum, I find the measurements to be in inches. 



1. 2. 



Length, 3.3 3.7 



Breadth, 2.7 2.5 



Height, 1.3 1.8 



Indeed, judging from G ii n t h e r 's figures and description, I 

 should rather have suspected my specimens from the Ilasdo to bo 

 a variety of P. tenton'a than of P. tectum. It is never quite 

 to conclude that a species is not distinct without comparison of spe- 

 cimens, but I cannot help thinking it highly probable that P. ten* 

 toria must be considered a variety of P. tectum. P. fluviv enter 

 has better grounds to distinction, and P. Smith ii is clearly a well 

 marked species. 



I may here remark that if the assignment by G r a y* and 

 Guntherf of figs. 3, 4 and 5 on the plate of Emt/s tectum in 

 Hardwicke's Illustrations of Indian Zoology to P. tentoriu be 

 correct, the species must fall at once, for those figures are most uu- 

 mistakeably taken from old specimens of P. tectum, and the differ* 

 ences of coloration pointed out by G r a y are of no importance 

 They may be in part seasonal, at any rate the brightly coloured 

 small specimens with an orange stripe down the centre of the ante 



* Cat. Shield Reptiles, p. 37. 



f Reptiles of British India, p. 34. 



