FAMILY BALANIDAE LEACH, 1817

Diagnosis: Monophyletic by molecular analysis. Wall of six or four plates; parietes tubiferous or solid; tubiferous shell, with tubes basically in a single uniform row formed between inner and outer laminate, although supplementary tubes may form basally; interlaminate figures complex, arborescent; radii either solid or tubiferous; basis commonly calcareous and tubiferous or membranous.

Comments: There are no clear morphologically based apomorphies for this family compared with the Pyrgomatidae . The genus Wanella is sister group to all remaining species as yet analysed by molecules, and this could argue for a separation within two subfamilies. Many genera are polyphyletic, and more low-level taxonomic revision is therefore needed.