496 CETACEA. 



The Skeleton or the Gangetio Dolphin. 



Cuvier' was tlie first anatomist to point out the great maxillary crests arching 

 upwards and inwards over the blow-hole ; the extraordinarily laterally compressed 

 upper jaw ; the long symphysis of the lower jaw ; the remarkable development of the 

 temporal fossa ; the great size of the zygomatic process of the temporal ; its application 

 to the post-orbital process of the frontal; the small size of the orbits; the great 

 thickness of the crests between the basilar and lateral parts of the occipital bone, 

 which inwardly confine the vault under which the ear is situated ; the union of the 

 bulla tympani to the petrous, which latter is firmly wedged in between the temporal 

 and surrounding pai'ts of the occipital bone ; the free character and great length for a 

 Cetacean of the cervical vertebrse and the development in them of the lower transverse 

 processes as in whale-bone whales ; the large character of the scapula, the absence of 

 a supra-spinous fossa, the presence of a large acromion and the rudiment of a 

 coracoid. It was on such facts as these that Cuvier urged that the dolphin of the 

 Ganges was a distinct genus remarkably different from any other dolphin, although 

 he did not assign to it any distinct position among the toothed whales. 



The next anatomist to throw a flood of liglit on its structure was Eschricht, 

 in his well-known Memoir, in which he followed Cuvier's description step by stcjD, 

 adding to it and correcting some of Cuvier's observations. His most important 

 contribution to the anatomy of the skull was his explanation of the structure of 

 the temporal fossa and his indication of the j)robable site of the palatines in the 

 nasal chamber, and his account of the pterygoids. The whole of his Memoir, 

 however, is replete with information regarding the structure of the dolphin and is 

 rich in comparisons of it with other Cetaceans, especially Syperoodon, which he 

 considered to be its nearest ally, although in some respects it was related to the 

 Whitefish and to the allied great toothed whales, and in other regards to Inia, 

 the fluviatile dolpliin of the Amazon, whilst he held it to be quite isolated by other 

 features of its structure. 



By its maxillary crests the Gangetic dolphin in Eschricht' s opinion was more 

 closely allied to Syperoodon than to Micropteron or any other fossil Cetacean. He 

 admitted that the analogy in the structure of the cranium with the Syperoodon, 

 and partly with the cachalot, is altogether lost as regards the rest of the skeleton, 

 in which there are striking differences between the two forms. 



To the late Dr. Gray^ belongs the credit of being the first to bring out pro- 

 minently the affinity manifested by Flatcmista to Inia; but although Eschricht 

 allowed that this attempt by Dr. Gray to express the relationship of the animal 

 was equally successful with that by Wagner who placed it between Inia and 

 Micropteron, yet he held that d'Orbigny's incomplete account and figure of Inia did 

 not reveal any of the peculiarities of the cranium of the Gangetic dolphiu, and that 



' Ossemens Fossiles, vol. viii, PL 1836, p. 88, et seq. et p. 128. 

 - Voyage, Erebus and Terror, 1846, p. 45. 



