"The Tubularidae are a family of hydroid polypes are for the most part social animals, frequently possessing a polypidom, which, however, when present, is of much less firm consistence than the horny framework of the Sertularidae. The polypes are never entirely retractable within their tubes; the upper extremity is enlarged into a clavate head, surrounded by a variable number of tentacles." — Goodrich, 1859

Tubularia coronata

"The Tubularidae are a family of hydroid polypes are for the most part social animals, frequently possessing…

Colonial, plant-like animals closely related to jellyfish, with stinging cells, Any member of the invertebrate order Hydroida (class Hydrozoa, phylum Cnidaria). Hydroids have three basic life-cycle stages: (1) a tiny free-swimming planula larva about 1 mm (0.04 inch) long, which settles and grows into (2) a sessile (attached), usually colonial hydroid stage, which in turn liberates (3) medusa.

Medusa of a Hydroid

Colonial, plant-like animals closely related to jellyfish, with stinging cells, Any member of the invertebrate…