Oar-fishes are the largest deep-sea fishes known, the majority of the specimens observed measuring 12 feet in length; but some are recorded to have exceeded 20 feet. Their range in the great depths of the ocean seems to extend over all seas, from the North Sea to the South Atlantic, from Mauritius and Japan to the coasts of New Zealand. But, however numerous they may be in the depths which are their home, it is only by rare accident that specimens reach the surface; and of these a very small proportion only have come under the observation of naturalists, and been actually recorded. Thus from the coasts of Great Britain only about twenty captures are known in the long space of a century and a half, and not more than thirteen from those of Norway. Oar-fishes have been considered by naturalists to have given rise to some of the tales of “sea-serpents,” but their size as well as the facility with which they are secured when observed render this solution of the question of the existence of such a creature improbable. When they rise to the surface of the water they are either dead or in a helpless and dying condition. The ligaments and tissues by which the bones and muscles were held together whilst the fish lived under the immense pressure of great depths have then become loosened and torn by the expansion of the internal gases; and it is only with difficulty that the specimens can be taken entire out of the water, and preserved afterwards. Every specimen found has been more or less mutilated; and especially the terminal portion of the tail, which seems to end in a delicate tapering filament, has never been perfect;—it is perhaps usually lost as a useless appendage at a much earlier period of the life of the fish.