These curious creatures, which seem to have been the basis of much of the old mermaid legend, have puzzled many eminent naturalists. Before they were placed in an order by themselves, Linnaeus had classed them with the Walrus, Cuvier with the Whales, and another French zoologist with the Elephants. They are popularly regarded as the cows of the sea-pastures. Their habits justify this. i have often watched dugongs on the Queensland coast browsing on the long grasses, of which they tear up tussocks with sidelong twists of the head, coming to the surface to breathe at short intervals.
Omitting the extinct Rhytina, otherwise known as Steller's Sea-cow, which was exterminated in the Bering Strait not very long after civilized man had first learnt of its existence, we have to consider two distinct groups, or genera, of these sirenians. The DUGONG is the representative of the first, and the two MANATEES belong to the other.
The dugong is found on the coasts of Northern Australia, in many parts of the Indian Ocean (particularly off Ceylon), and in the Red Sea . It is easily distinguished, by even superficial observation, from the manatees. Its tail is slightly forked, somewhat like that of the whales: the tail of manatees, on the other hand, is rounded. The dugong's flippers, to which we also find a superficial resemblance in those of the whale, show no traces of external nails: in those of the manatees, which show projecting nails, there is a considerable power of free movement (the hands being, in fact, used in manipulating the food), which is not the case in the limbs of the whale. The body of the Dugong is almost smooth, though there are bristles in the region of the mouth: that of the manatees is studded with short hairs. The male dugong has two large tusks: in neither sex of the manatees are such tusks developed. Finally, a more detailed examination of the skeletons would reveal the fact that, whereas the dugong has the usual seven bones in the neck, that of the manatees has only six.
When we come to the Whales, we shall encounter that very characteristic covering known as "blubber"; and, though it is present in smaller quantity, these sirenians have blubber as well. Complex stomachs they also have, like the whales, only in their case both the nature of the food and the structure of the teeth point clearly o a ruminating habit., which, for reasons that will be given in the right place, seems inadmissable in the whales. In both dugong and manatees the mouth is furnished with singular horny plates, the precise use of which does not appear to have been satisfactorily determined; and the upper lip of the manatee is cleft in two hairy pads that work laterally. This enable the animal to draw the grass into its mouth without using the lower lip at all.
In their mode of life the dugong and manatees differ as widely almost as in their appearance; for the former is a creature of open coasts, whereas the manatees hug river-estuaries and even travel many miles up the rivers. Of both it has been said that they leave the water at night, and the manatees have even been accused of plundering crops near the banks. the few, however, which have been under observation in captivity have always been manifestly uncomfortable whenever, by accident or otherwise, the water of their tank was run off, so that there is not sufficient reason for believing this assertion.
This group of animals cannot be regarded as possessing any high commercial value, though both natives and white men eat their flesh, and the afore-mentioned rhytina was, in fact, exterminated solely for the sake of its meat. there is also a limited use for the bones as ivory, and the leather is employed on a small scale,- a German writer has, in fact, been at great pains to prove that the Tabernacle, which was 300 cubits long, was roofed with dugong-skin, and the Red Sea is certainly well within the animal's range.
