The subfamily Emarginulinae, common name keyhole limpets and slit limpets, is a taxonomic subfamily of limpet-like sea snails, marine gastropod molluscs in the family Fissurellidae, the keyhole limpets and slit limpets. The subfamily consists of the following tribes: * Tribe Children, 1834 - synonyms: Rimulidae, Anton, 1838; Zeidoridae Naef, 1913; Hemitominae Kuroda, Habe & Oyama, 1971; Clypidinidae Golikov & Starobogatov, 1989 * Tribe Odhner, 1932: this tribe has been raised to the rank of subfamily Diodorinae Odhner, 1932 * Tribe Pilsbry, 1890 * Tribe Christiaens, 1973