65 



great numbers the slow-moving labyrintlis of the rivers and creeks 

 which intersect the delta of the Granges, but they are also known to 

 have ascended that river to more than a thousand miles above Calcutta. 

 They, however, confine their limits of range to within the bounds of 

 rivers, never venturing out into the open ocean. 



Plataitista Indi, Blyth. The Susu of the Indus. 

 Synonyms — Platanista Qangetica (minor), Owen. Cat. Coll. Surg. 



Flatanista Indi, Blyth. Journ. Asiat. Soc, Bengal: Gray, 

 B.M.C., 1866 ; Suppl., 1871, p. 62. 

 As the name implies, this dolphin inhabits the river Indus and its 

 tributaries, and in colour, size, and habits, bears a great resemblance to 

 the species first described ; it differs, however, in possessing a larger and 

 more robust skull, and in the teeth, although equal in number, being 

 shorter, and more ground down by attrition. 



Oenus Inia', Gray. 

 Teeth, £i to g|? = 104 to 132. 



Conical, permanent, firmly set, with compressed roots ; anterior ones 

 simple, sharp, slightly incurved; posterior with a broad, rounded 

 tubercle towards the base of the crown ; beak of the skull three- 

 quarters of the entire length of the skull ; pectoral fin large, ovate, 

 obtusely pointed. The lower jaw, being terminated by a long cylindrical 

 muzzle, afibrds, like the Platanista, an exact miniature resemblance to 

 that of the Cachalot. 



Inia Geoppeotensis, de Blainville. The Inia. 



Synonyms — DelpMnus Geoffroyii, Desm. ; Mamm. 

 Delphinorkynchws frontatus. F. Cuvier. 

 Inia Boliviensis, D'Orbigny. Voy. Amer. Merid. 

 Inia Geoffroyii, Gray, B.M.C., 1866. Suppl., 1871, p. 64. 

 Inia Qeoffroyensis, Mower ; Tran. Z. Soc, vol. 6, part 3. 



This animal is at the present the only one of the genus, but from the 

 great variation in the number of the teeth,^ presented by several skulls 

 in European museums, the probability arises that more than one kind 

 will hereafter be distinctly determined. 



The female Inia Geoifroyensis, when adult, measures about 7 feet ; 

 the male, it is said, arrives to a much larger size ; the colour of both is 

 of a pale blue on the upper portions of the body, and reddish under- 

 neath. 



This dolphin is a native of South America, and, iu groups of three or 

 four, locates not only the remote tributaries of the Amazon, but, at vast 

 distances from the sea, the elevated lakes of Peru, and thus may ba 

 considered as a true fresh-water cetacean. 



' Iniaj so named by the native Indians of Boliyia. 



' ,0n this point see Qtraj, Suppl., p. 64, and Flower T. Z. S., vol. 6, p. 87. 



