• (n.) Any species or marine hydroids, of the genus Hydractinia and allied genera. These hydroids form, by their rootstalks, a firm, chitinous coating on shells and stones, and esp. on spiral shells occupied by hermit crabs. See Illust. of Athecata.
Found on
http://thinkexist.com/dictionary/meaning/hydractinian/
Hy`drac·tin'i·an noun [ See
Hydra , and
Actinia .]
(Zoology) Any species or marine hydroids, of the genus
Hydractinia and allied genera. These hydroids form, by their rootstalks, a firm, chitinous coating on shells and stones, and esp. on spiral shells occupied by hermit cr...
Found on
http://www.encyclo.co.uk/webster/H/74
No exact match found.
