Bible Dictionaries
Hydractinian

Webster's Dictionary

(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.

Bibliography Information
Webster, Noah. Entry for 'Hydractinian'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​h/hydractinian.html. 1828.