I’m choosing this one because I like one of the quotes given as a reference to usage.
Actinia
Zool.
prop. A genus of Zoophytes belonging to the family Actiniadæ; pop. extended to any animal of the family, whether of the genus Actinia or one of its congeners; a Sea-Anemone, or animal of the Sea-Anemone group.
1767 ELLIS Actinia in Phil. Trans. LVII. 428 The Actinia, called by old authors..Urtica marina, from its supposed property of stinging, is now more properly called by some late English authors the Animal flower.