Subfamily Platylepadinae Newman & Ross, 1976
Diagnosis (emended after Ross & Frick 2011: 62)
Wall peltate or low-conical; mono- or bi-lamellar; parietes with a large internal midrib either with or without a corresponding external medial sulcus; midrib either smooth or having several alternating ridges incorporated into basal surface; external longitudinal sulci, when present, formed by T-shaped flanges; sutural elaborations absent; orifice worn by corrosion or abrasion, or dehiscent.
Included genus
Platylepas Gray, 1825 .