actinozoan (aktinozoan)

One of the Ac tinozoa; any member of that cla . actinozoön (akti-nō-zō'on), n. [NL., sing. of Actinozoa.] An actinozoan. actinula (ak-tin'ū-lä), n.; pl. actinulæ (-lē). [NL., dim. of Gr. ἀκτίς (ἀκτιν-), ray.] A name given by Allman to the larval condition of Hydrophora ( Hydrozoa ), appearing when the ciliated locomotive planula or embryo has become fixed by its aboral end, and has pa ed into the elongated gastrula-stage by the formation of the mouth with its circlet of tentacles. See planula. In most Discophora, the embryo becomes a fixed actin ula (the so-called Hydra tuba, or Scyphistoma). Huxley , Anat. Invert., p. 133.