1212 



THE CETACEANS 



It thus seems to pitch heels over head, but does not show the tail fin. Besides 

 this peculiar motion [which seems to be very similar to that of the Gangetic 

 dolphin] , it is distinguished from the tucuxi by its habit of generally going in pairs. 

 Both species are exceedingly numerous throughout the Amazon and its larger tribu- 

 taries, but they are nowhere more plentiful than in the shoaly water at the mouth 

 of the Tocantins, especially in the dry season. In the upper Amazon, a third pale 

 flesh-colored species is also abundant.* In the broader parts of the Amazon, from 

 its mouth to a distance of fifteen hundred miles in the interior, one or other of the 

 three kinds here mentioned is always heard rolling, blowing, and snorting, espe- 



THE AMAZONIAN DOLPHIN. 



(One sixteenth natural size.) 



cially at night, and these impressions contribute much to the impression of sea-wide 

 vastness and desolation which haunts the traveler." 



As the native inhabitants of Amazonia have a great objection to killing the 

 fresh-water dolphins, specimens are only procured with difficulty. 



The small La Plata dolphin (Stcnodtiphis blainvillei), from the 

 estuary of the Rio de la Plata, differs from the preceding forms in the 

 presence of a well-marked back fin and the extreme elongation of 

 the jaws, which carry from fifty to sixty teeth on each side. The blowhole, in- 

 stead of forming a longitudinal slit, is cresent shaped and placed transversely. In 



*Sotalia pallida, p. 1235. 



The La Plata 

 Dolphin 



