Cetacea

se-tā′shi-a, n.pl. an order of mammals of aquatic habit and fish-like form, including the Toothed whales, or Odontoceti , and the Baleen whales, or Mystacoceti . To the former belong the Sperm whales, the Bottlenose, the genus Platan ist a and its allies, and the great family of Dolphins; to the latter, the Right Whale ( Balæna ), the Humpbacks, and the Rorquals.— n. Cetā′cean .— adj. Cetā′ceo us .— n. Cetol′ogy , that part of zoology which treats of whales. [L.,—Gr. kētos , any sea-monster.]