those of terrestrial mammals; i.e. the humerus is distinctly the longer, the converse usually obtaining among Whales. But Platanista again agrees with Inia. 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, Inia 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 Sotalia 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[1] 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 Inia, 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 Inia, 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 Inia. 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 Inia. 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 joining 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
- ↑ Flower, Trans. Zool. Soc. vi. 1867, p. 106; and Burmeister, Proc. Zool. Soc. 1867, p. 484.
