The species recognition criteria have been confused for cubomedusae, leading to underestimates of biodiversity and nomenclatural errors in the group. At least nine different species have been described with crescentic gastric phacellae, T-shaped rhopaliar niche ostia, and/or 3 velarial canals per octant; all were subsequently included in the synonymy of the oldest name, Carybdea alata, which lacks both a type specimen and an unambiguous identity. To stabilize the nomenclature of the group, the new genus Alatina is proposed based on a common form for which type material and DNAsequences are available. Two species from northern Australia are herein described for the genus. The other nine species previously associated with the name Carybdea alata are herein reevaluated and determinations are made as to their validity. The validity of another species, Manokia stiasnyi, has been questioned, and was not previously appreciated as belonging to this morphogroup.
Reexamination of the holotype confirms that the taxon is distinct, and allied to Alatina; a
redescription is provided. A new family, Alatinidae, is proposed to accommodate Alatina
and Manokia. The family Carybdeidae and the genus Carybdea are redefined.