THE AMAZONIAN DOLPHIN CHAP. 
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those of terrestrial mammals; i.e. the humerus is distinetly the 
longer, the converse usually obtainmg among Whales. But 
Platanista again agrees with Jnia. The teeth are remarkable 
for the fact that the hindermost ones of the series have an 
additional lobe; they are not purely conical as are those of 
Whales generally. 
There is but one species, nia geoffrensis, which inhabits the 
Amazons, and grows to a length of 8 feet. Its colour 
variations are rather extraordinary, unless they can be set down 
to sex, which has been denied. Some individuals are wholly 
pink; others are black above and pink beneath. This Whale is 
believed by the Indians to attack a man in the water, and it is 
added that the Sota/ia of the same streams will defend him from 
these attacks! Naturally, therefore, superstitious reverence 
attaches to this Dolphin, which is tiresome to the naturalist who 
wants specimens, as Professor Louis Agassiz found. 
In the genus Pontoporia’ the dorsal fin is well developed 
and falcate. The teeth are very numerous, 200 in all. The 
ribs articulate as in Dolphins. The skull closely resembles that 
of Znia, and the scapula is, as in that genus, “ normal.” 
The proper name for Pontoporia is really Stenodelphis, which 
name was first used by Gervais a month or two before Gray, who 
separated it from the vague Delphinus of its original discoverer, 
Gervais himself. It has a longer snout than /nia, which, being 
bent towards the extremity in a downward direction, curiously 
suggests the skull of a Curlew. In details, however, the skull is 
exceedingly like that of Znia. It is nearly symmetrical. The 
vertebral formula appears to be the following:—C 7, D 10, L 5, 
Ca 20 = 42, just one over the number of the vertebrae in 
Ina. The sternum is in two pieces. Of the ten pairs of 
ribs the first three are double-headed. These and the next have 
sternal moieties joing the sternum, of which the first three are 
ossified, the last being apparently merely a ligament. 
There is a single species of the genus, P. blainvillii. This 
Whale is described by Mr. Lydekker as being of a clear brown 
colour, harmonising with the waters of the estuary of the 
Amazons and the La Plata which it inhabits. The same colour 
characterises Sotalia pallida of those parts of the world, and 
1 Flower, Trans. Zool. Soc. vi. 1867, p. 106; and Burmeister, Proc. Zool. Soc. 
1867, p. 484. 
