But when the waves, after dashing on either of the two places and being carried to the tops of the promontories, have descended again into the sea flowing beneath, then again with loud bellowing and great and swift eddies the sea boils up, and is lifted on high from the depths in confusion, and assumes alternately all kinds of hues, for it appears at one time dark, at another blue, and often of a purplish colour: but no creeping thing can endure either to hear or to see the quick rush and length of this sea, and besides these its ebb, but all flee to the low lying skirts of the mountains; but, when the heaving of the billows ceases, the eddies are borne on high, making such various twistings that they seem to produce movements resembling the coils of presteres, or some other large snakes.