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."
Examples from the Web for cetacea
Among the marine animals of Moreton Bay are two cetacea of great interest.Narrative Of The Voyage Of H.M.S. Rattlesnake, Commanded By The Late Captain Owen Stanley, R.N., F.R.S. Etc. During The Years 1846-1850. Including Discoveries And Surveys In New Guinea, The Louisiade Archipelago, Etc. To Which Is Added The Account Of Mr. E.B. Kennedy's Expedition For The Exploration Of The Cape York Peninsula. By John Macgillivray, F.R.G.S. Naturalist To The Expedition. In Two Volumes. Volume 1.|John MacGillivray
Whales have no tear glands in their eyes, and the whole order of Cetacea are tearless.
The tapetum lucidum is found in Ungulata, Cetacea and Carnivora.
The Cetacea are the most perfectly aquatic of all mammals; they never leave the waters which they inhabit.The Cambridge Natural History, Vol X., Mammalia|Frank Evers Beddard
These final bearers are usually either fishes, birds, cetacea, or seals.Parasites|T. Spencer Cobbold