Subfamily Platylepadinae Newman & Ross 1976: 44

Type genus. Platylepas Gray, 1825; by original designation of Newman & Ross (1976: 44).

Diagnosis. 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 having several conspicuous 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.

Genus and species included. Platylepas coriacea Monroe & Limpus, 1979; Platylepas decorata Darwin, 1854; Platylepas hexastylos (Fabricius, 1798); Platylepas h. ichthyophila Pilsbry, 1916; Platylepas indicus Daniel, 1958; Platylepas krugeri (Krüger, 1912); Platylepas ophiophilus Lanchester, 1902; † Platylepas wilsoni Ross, 1963 .

Remarks. Monroe & Limpus (1979) examined the type specimens of Platylepas multidecorata Daniel, 1962 and found them to be synonymous with P. decorata .