284 On the Occurrence o/" Pelochelys in China. 



especially cranial, characters it is, however, necessary to 

 make allowance for variations due to age, and these changes 

 Dr. Strauch has unfortunately neglected to consider in 

 proposing for the Foo Choo specimens a new species, Pelo- 

 chelys Poliakowii. He compares the skulls of nearly adult 

 specimens with the figure given by Gray, and reproduced by 

 me, of P. Cantoris, representing a small specimen. Now all 

 young Chelonians have the orbits proportionally larger than 

 the adult ; hence the snout is shorter and the interorbital space 

 narrower in proportion. It is just upon such a difference that 

 P. Cantoris is supposed to be distinct from P. Poliakowii. 

 But in my description I have explicitly stated that the inter- 

 orbital space is broader than the diameter of the orbit, my 

 remarks applying of course to the adult skull. 



On comparison of the adult skull with the photographs 

 given by Strauch I entertain no doubt as to the identity of 

 the two species. Dr. Strauch appears to have been also misled 

 by the figure in Giinther's ' Reptiles of British India ' which 

 represents P. Cantoris; but Gray has drawn attention to the 

 fact that " the form of the animal figured in l Indian Reptiles ' 

 is from the Museum specimen of this species, with the 

 markings and colour added from General Hardwicke's figure 

 of the living Chitra indica. Dr. Gunther believed they 

 represented the same animal " *. As the true Pelochelys 

 Cantoris very closely resembles Trionyx chinensis in colour, it 

 is not surprising that Dr. Strauch was not struck by any 

 peculiar markings in his specimens before the removal of the 

 soft parts. 



I therefore hold that P. Poliakowii is a synonym of 

 P. Cantoris, the range of which embraces the mouth of the 

 Ganges, Burma, the Malay Peninsula, Borneo, the Philip- 

 pines, and China. There is nothing particularly surprising 

 in the very wide distribution of this species, for it is known, 

 from the observations of Cantor, to be estuarine and even 

 marine ; and most marine or semimarine reptiles have a wide 

 distribution, for example Crocodilus porosus, the Hydrophids, 

 and Homalopsids, not to mention the true marine Turtles. 

 Dr. Strauch does not contest the soundness of the generic 

 separation of Pelochelys from Trionyx ; why then, I should 

 like to know, does he not accept the separation of Cycloderma 

 from Cyclanorbis, the cranial differences between the two 

 being quite as great and of the same kind ? 



* Suppl. Cat. Sh. Kept. i. p. 91. 



