noun, plural ac·tin·i·ae [ak-tin-ee-ee] /ækˈtɪn iˌi/, ac·tin·i·as.
Examples from the Web for actinia
Cut off the tentacles of an actinia, and they are replaced in a short time, and the experiment may be repeated indefinitely.The Ocean World:|Louis Figuier
One of the most common among the many varieties of sea-anemones is the Actinia mesembryanthemum.
The first twelve mesenteries are disposed in couples, and do not differ from those of Actinia except in size.
The locomotive power of the anemone, or actinia, is very sluggish.
The Actinia gemmacia, which is like a gorgeous sunflower, is said to be the most voracious of its kind.