Source : Webster's Revised Unabridged Dictionary (1913)

Actinia \Ac*tin"i*a\, n.; pl. L. {Actini[ae]}, E. {Actinias}.
   [Latinized fr. Gr. ?, ?, ray.] (Zo["o]l.)
      (a) An animal of the class Anthozoa, and family
          {Actinid[ae]}. From a resemblance to flowers in form
          and color, they are often called {animal flowers} and
          {sea anemones}. [See {Polyp}.].
      (b) A genus in the family {Actinid[ae]}.

Source : WordNet®

actiniae
     See {actinia}