Family Zancleopsidae Bouillon, 1978

Diagnosis: Polyps known for Zancleopsis only; colonies stolonal; hydrocaulus short to moderately long, simple, arising from a hydrorhiza embedded in host sponge; perisarc thin, covering both the hydrorhiza and the hydrocaulus; hydranth slightly pyriform to cylindrical, with proboscis-like hypostome and dicapitate tentacles in one or two alternating whorls around broadest part of body; gonophores developing among tentacles as free medusae.

Medusa with conical or dome-shaped umbrella, with or without apical projection; manubrium flask-shaped, with quadrate or cruciform base, mouth simple, cruciform or circular, with or without lips; two or four tentacles, with or without capitate branches; bulbs with adaxial hemispherical projections equipped with nematocysts; with or without abaxial ocelli; gonads aradial to interradial, with interradial grooves.