What passes in those remote depths—what beings live, or can live, twelve or fifteen miles beneath the surface of the waters—what is the organisation of these animals, we can scarcely conjecture. However, the solution of the problem submitted to me may modify the form of the dilemma. Either we do know all the varieties of beings which people our planet, or we do not. If we do not know them all—if Nature has still secrets in ichthyology for us, nothing is more conformable to reason than to admit the existence of fishes, or cetaceans of other kinds, or even of new species, of an organisation formed to inhabit the strata inaccessible to soundings, and which an accident of some sort, either fatastical or capricious, has brought at long intervals to the upper level of the ocean. “If, on the contrary, we do know all living kinds, we must necessarily seek for the animal in question amongst those marine beings already classed; and, in that case, I should be disposed to admit the existence of a gigantic narwhal. “The common narwhal, or unicorn of the sea, often attains a length of sixty feet. Increase its size fivefold or tenfold, give it strength proportionate to its size, lengthen its destructive weapons, and you obtain the animal required. It will have the proportions determined by the officers of the Shannon, the instrument required by the perforation of the Scotia, and the power necessary to pierce the hull of the steamer.