446 Prof. G. Baur on the Trionychian Genus Pelochelys. 



Prof. Angelo Heilprin, a skull of Pelochelys from the Philip- 

 pines preserved in the Philadelphia Academy. This skull 

 is totally different from the skull of Pelochelys Cantoris, 

 Gray ; it resembles more that of P. Poljakowii, but it is also 

 different from this. 



The skull in the Philadelphia Academy, no. Ill (W. W. 

 Wood), has the interorbital space larger than the diameter of 

 the orbit, the postorbital arch larger than the interorbital, and 

 the proboscis elongated as in P. Poljakowii' In general 

 shape it is nearest to the latter species, but it differs from it 

 by its broader postorbital arch and its parietals, which are 

 not so much expanded mesially. 



The following table gives the measurements of the type of 

 Pelochelys Bibronii, Owen, in the Royal College of Surgeons, 

 London, kindly sent to me by Prof. Stewart, of P. Poljakowii, 

 Strauch, taken from the figures, and of the Philadelphia 

 specimen. 



P. Bibronii, P. Poljakowii, P. spec. 

 Owen. Strauch. (Philippines), 



millim. millim. millim. 



Preorbital arch (from nasal 



opening to orbit) .... 7*5 



Interorbital arch 11 



Postorbital arch 14 



Horizontal diaui. of orbit. . ?* 



The locality of the type of Pelochelys Bibronii, Owen, is 

 not known ; the type of Pelochelys Cantoris, Gray, is from 

 Penang. According to Boulenger P. Bibronii and P. Cantoris 

 are identical ; but according to him also the forms from the 

 Philippines, which had been described as P. Cumingii, are 

 not different. That the Philippines contain a species of Pelo- 

 chelys different from the P. Cantoris there can be no doubt ; 

 the only question now is whether the specimens in the British 

 Museum from the Philippines agree with the specimen in the 

 Philadelphia Academy. In this case the name P. Cumingii 

 has to be applied for this species. Pelochelys occurs also in 

 Borneo ; and it would be interesting to know whether this 

 genus is represented by a peculiar species on this island, or 

 with which of the other forms it is identical. 



Clark Univ., Worcester, Mass., 

 March 30, 1891. 



* It appears from the figures published of P. Cantoris that the inter- 

 orbital space is smaller than the horizontal diameter of the orbit. 



