CETE, in natural history, the seventh order of Mammalia, in the Linnwan sys tem of animals, including the four gene ra ; Monodon, or narval ; Balxna, whale ; Physeter, cachalot ; and Delphinus, dol phin. The cetaceous tribe has one or more spiracles placed on the fore part of the skull ; no feet ; pectoral fins without nails, and tail horizontal. The cetaceous order of animals has nothing peculiar to fish, except living in the same element, and being endowed with the same powers of progressive motion, as those fishes which are intended to move with consi derable velocity. The popular idea of cetaceous animals being fishes is so strong ly impressed on the public mind, that it can never, perhaps, be entirely removed; for the critical observations of naturalist's appear too abstruse to be generally ex ambled, and of consequence to be com monly understood. The cetaceous tribes live in the same element as fishes, and, partaking somewhat of their external figure, will ever be considered as apper taining to that class of animals by the less informed portion of mankind.
Cetaceons animals, or, as Dr. Shaw ex presses them, " fish-formed mainmalia„" have lungs, intestines, and other internal organs, formed on the same principle as in quadrupeds ; and, indeed, on stria comparison, the principal differences that exist between them will not be found very considerable ; one of the most ma terial seems 'to consist in their want of posterior legs, the peculiar structure of the tail supplying that defect, this being extremely strong and tendinous, and di vided into two horizontal lobes, but which has no internal bones. Like quadrupeds,
they have a heart furnished with two auri cles, and two ventricles, and their blood is warm and red : they breathe by their lungs, and not by means of gills, as in true fishes. In their amours they agree with quadrupeds ; the female produces her young alive, which rarely happens among fishes, and she suckles them with her teats, as in the true mammalia. The structure of their brain, their sexual or gans, stomach, and liver, resemble those of mammiferous animals. Their skin is smooth, or not covered with scales ; and their tail is placed in a position the very reverse of fishes, in being always flat and horizontal, instead of vertical. The cetaceous animals, the cachalot and dol phin genera, have the mouth armed with conic teeth; the whales with horny lamina in the upper jaw ; and the narval with teeth, or tusks of enormous length. They are neither sanguinary nor ferocious. Their stomachs are large, and divided into chambers to the number of five, as in the whale and porpoise, or even seven, as in the narval. In the last particular they seem to constitute an intermediate link between carnivorous and herbivorous ani mals, approaching nearly to ruminating quadrupeds ; but .differ, in subsisting on animal food, as they live chiefly on acti nix, medusa, and other zoophytes, on crustaceous animals, and on small fish. See MosonoN, BALRINA, PII/SETER, and DELPHI/ITS.