What is "rytina stelleri"

Rytina \Ryt"i*na\, n. [NL., fr. Gr. "ryti`s a wrinkle.] (Zo["o]l.) A genus of large edentulous sirenians, allied to the dugong and manatee, including but one species ( Rytina Stelleri); -- called also Steller's sea cow, stellerine and steller. [Written also Rhytina.]

Note: 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.