order of marine mammals containing whales, 1830, Modern Latin, from Latin cetus "any large sea creature" (whales, seals, dolphins), from Greek ketos "a whale, a sea monster," of unknown origin, + -acea. Hence cetology "the study of whales," first attested 1851 in "Moby Dick."
The cetacea and Sirenia are examples of creatures organized for a completely aquatic life—for never coming to land.
Among the marine animals of Moreton Bay are two cetacea of great interest.
In almost all mammals except the cetacea, these are found terminating the digits of both limbs.
As in the cetacea, the nasal bones are limited in size, and the premaxillae send up processes to join the frontals and the nasals.
Zeuglodon′tia, a suborder of cetacea, represented by the zeuglodonts.
These final bearers are usually either fishes, birds, cetacea, or seals.
I have placed cetacea after Carnivora, and Edentata at the end.
They belong to the group that come to the surface of the water to breathe, as do the cetacea and phocas among the Mammifera.
According to the views of some systematic naturalists, the cetacea have, strictly speaking, no voice.
He praises, and deservedly, no doubt, the exertions of M. Eschricht to collect a proper Museum of the cetacea.