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 {382} 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_[263] 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."