xii PLATANISTA AND INI A 381 



The following are its main characters : Dorsal fin absent. Eyes 

 rudimentary. Pectoral fins large and truncated at the extremity. 

 Teeth, about twenty-nine in each half of each jaw. Scapula with 

 the acromion coinciding with its anterior edge. Skull with enormous 

 maxillary crests, and with the palatines entirely concealed by the 

 pterygoids. The length of the above definition will serve to 

 indicate how anomalous in many particulars is the structure of 

 this " Dolphin." 



There is apparently but one species, P. gangetica. the " Susu." 

 The Indian vernacular name is derived from the sound that the 

 animal makes when spouting. It is an inhabitant of the Ganges 

 arid the Indus, together with their tributaries, and ascends very 

 high up its streams. It is also thought to be purely fluviatile 

 and never to desert the rivers for the sea. Platanista lives 

 chiefly by grubbing in the mud for prawns and fish. Grains 

 of rice have also been found in the stomach, but this would seem 

 to be accidental. The long snout of the Susu has been compared 

 to the long snout of the Gharial, a native of the same region. 

 This Whale grows to a length of over 9 feet, but this length is 

 exceptional. Its anatomy has been elaborately described by Dr. 

 Anderson. 1 



The next genus, Inia, is thus to be characterised : Dorsal fin 

 rudimentary ; pectorals large and ovate. Teeth, as many as thirty- 

 two on each side, often with an additional tubercle. Skull without 

 large maxillary crests ; palatines not hidden by pterygoids, but 

 divided by vomer. The vertebrae of this genus are few in 

 number, only forty-one in all, which are thus distributed : C 7, 

 D 13, L 3, Ca 18. The peculiarities of the vertebral column 

 are several. In the first place, as has been mentioned in the 

 definition of the family, all the cervicals are separate and 

 individually of some length. Secondly, the axis has a better 

 trace of an odontoid process than in any other Whale except 

 Platanista, where it is even more obvious. The lumbar region is 

 remarkable on account of its restriction to three vertebrae. The 

 sternum, by what we must regard as convergence, is somewhat 

 like that of the Whalebone whales. It consists of one piece only, 

 of a roughly-oval form, to which apparently only two pairs of 

 (cartilaginous) sternal ribs are attached. In the fore-limb the 

 proportions between the humerus and the radius are more like 



1 Anatomical Researches Yunnan Exp. 1878, p. 417. 



