Hydractiniid is a hypernym of hydractinian.
As nouns the difference between hydractiniid and hydractinian
is that hydractiniid
is (zoology) any member of the hydractiniidae while hydractinian
is (biology) a marine hydroid of the genus (taxlink
) or a closely-related genus.
(zoology) Any member of the Hydractiniidae.
(biology) A marine hydroid of the genus (taxlink) or a closely-related genus