nRytina(Zoöl) A genus of large edentulous sirenians, allied to the dugong and manatee, including but one species (Rytina Stelleri); -- called also Steller's sea cowstellerine and steller.☞ It is now extinct, but was formerly abundant at Bering's Island, near Bering's Straits. It was twenty-five feet or more in length, with a thick, blackish, naked skin. The last were killed in 1768 for their oil and flesh.
Webster's Revised Unabridged Dictionary
NL., fr. Gr. "ryti`s a wrinkle
In the manatee it is rounded, in the dugong forked like that of a whale, in the rytina crescent-shaped.
"Sea Monsters Unmasked and Sea Fables Explained" by Henry Lee