PLATANISTA. 431 



the entire animal being 10 inches shorter than the largest female from the Hughli, 

 in which the condition of the teeth was that of a fully mature, but not aged 

 animal. Another female from the Hughli with its teeth indicating adolescence, and 

 having a long, attenuated, and not deep snout, has its skull only a quarter of an inch 

 shorter than the skull of Mr. Clay's dolphin, and its adolescence is so pronounced 

 that we may justly conclude that the animal would haye attained to the dimensions of 

 the largest recorded female from the same river. But the condition of the skull and 

 skeleton of Mr. Clay's specimen leads to the conclusion that its period of growth was 

 passed. Mr. Clay's specimen, it will be observed, was from the neighbourhood of Dacca, 

 and as the differences that exist between it and the adult from the Hughli lie chiefly 

 in size, it may be that there is a smaller race, for the skulls are so alike in all their 

 essential features that the Dacca skull cannot be regarded as of a specific type. 

 Moreover, I have had the opportunity to compare, side by side, in the flesh, two 

 dolphins, one of the male and the other of the female sex, the former from the 

 Hughli and the latter from Dacca, and after a most careful observation of these, in 

 view of this question of the probability of the existence of more than one species 

 of Flatanista in the Gangetic and Brahmaputra systems, I have failed to detect any 

 character by which they could be separated. However, if we take the condition of 

 the alveolar sockets of Mr. Clay's specimen, as indicating that the animal was aged, 

 which I believe we are entitled to do, then it follows that it is as old, if not older, 

 than a skull of another specimen from the Ganges opposite to Chupra. in the Saran 

 district, and which was caught in May 1870 and for which I am indebted to 

 Mr. Garret, C.S. But this skull is 7 inches longer than the skull from Dacca, and is 

 thus of great size. The few teeth that remain in the jaw are all flattened, and some 

 of them are 0*68 inch in breadth. All the bottom of the alveolar groove is filled 

 up as in Mr. Clay's dolphin, but the sockets are not so obliterated. With these facts 

 in view it seems highly improbable that the latter could ever have attained to the 

 dimensions of the large Chupra skull, which, in its features, has such a close resem- 

 blance to the largest females from the Hughli, that I am disposed to consider it of 

 the same sex. Not having seen the Chupra specimen in the flesh, I can say 

 nothing regarding its external characters. In its rostrum, however, it differs some- 

 what from large females from the Hughli in that the end of the snout, instead 

 of being upwardly directed, is downwardly bent; but this character is probably 

 the effect of age, as it occurs in other dolphins, and has been noticed by Professor 

 Plower in Inia and JPontoporia, the former being nearly allied to Tlatanista. The 

 lower jaws of both are alike. Some of the males from the Hughli conform more 

 to the Chupra skull than to the skull of Mr. Clay's specimen, but that they could 

 never have attained to the same size is conclusively proved by the complete ossi- 

 fication of their epiphyses. 



The large skull of Mr. Garret's specimen measures 30 inches in extreme length, 

 and is thus about 2*75 inches longer than the largest female skull from the Hughli, 

 and 10*60 inches longer than the largest male skull from the same river, the male skull 

 (No. 6) being fully adult, the teeth being very broad at their bases, but still more or 



