A general term for various marine animals of the order Cetacea, including the most colossal of all animated beings. From their general form and mode of life they are frequently confounded with fish, from which, however, they differ essentially in their organization, as they are warm-blooded, ascend to the surface to breathe air, produce their young alive, and suckle them, as do the land mammalia. The cetacea are divided into two sections:
1. Those having horny plates, called baleen, or "whalebone," growing from the palate instead of teeth, and including the right whales and rorquals, or finners and hump-backs (see these terms).
2. Those having true teeth and no whalebone. To this group belong the sperm-whale, and the various forms of bottle-noses, black-fish, grampuses, narwhals, dolphins, porpoises, &c. To the larger species of many of these the term "whale" is often applied.