The Collaborative International Dictionary
Actinula
Actinula \Ac*tin"u*la\, n. pl. [NL., fr. Gr. ?, ?, a ray.] (Zo["o]l.) A kind of embryo of certain hydroids ( Tubularia), having a stellate form.
Wiktionary
actinula
n. (context zoology English) A kind of embryo of certain hydroids (Tubularia), having a stellate form.