The largest animals found in the Indian Sea are the pistrix and the balæna; while of the Gallic Ocean the physeter[2215] is the most bulky inhabitant, raising itself aloft like some vast column, and as it towers above the sails of ships, belching forth, as it were, a deluge of water. In the ocean of Gades there is a tree,[2216] with outspread branches so vast, that it is supposed that it is for that reason it has never yet entered the Straits. There are fish also found there which are called sea-wheels,[2217] in consequence of their singular conformation; they are divided by four spokes, the nave being guarded on every side by a couple of eyes. CHAP. 4. (5.)—THE FORMS OF THE TRITONS AND NEREIDS. THE FORMS OF SEA ELEPHANTS. A deputation of persons from Olisipo,[2218] that had been sent for the purpose, brought word to the Emperor Tiberius that a triton had been both seen and heard in a certain cavern, blowing a conch-shell,[2219] and of the form under which they are usually represented. Nor yet is the figure generally attributed to the nereids[2220] at all a fiction; only in them, the portion of the body that resembles the human figure is still rough all over with scales. For one of these creatures was seen upon the same shores, and as it died, its plaintive murmurs were heard even by the inhabitants at a distance. The legatus of Gaul,[2221] too, wrote word to the late Emperor Augustus that a considerable number of nereids had been found dead upon the sea-shore. I have, too, some distinguished informants of equestrian rank, who state that they themselves once saw in the ocean of Gades a sea-man,[2222] which bore in every part of his body a perfect resemblance to a human being, and that during the night he would climb up into ships; upon which the side of the vessel where he seated himself would instantly sink downward, and if he remained there any considerable time, even go under water. In the reign of the Emperor Tiberius, a subsidence of the ocean left exposed on the shores of an island which faces the province of Lugdunum[2223] as many as three hundred animals or more, all at once, quite marvellous for their varied shapes and enormous size, and no less a number upon the shores of the Santones;[2224] among the rest there were elephants[2225] and rams, which last, however, had only a white spot to represent horns. Turranius has also left accounts of several nereids, and he speaks of a monster[2226] that was thrown up on the shore at Gades, the distance between the two fins at the end of the tail of which was sixteen cubits, and its teeth one hundred and twenty in number; the largest being nine, and the smallest six inches in length.