A taxonomic review of the hyperiidean amphipod families Mimonectidae and Proscinidae, superfamily Sciniodea, is pre-sented, based predominantly on collections held by the Zoological Museum, University of Copenhagen, Denmark. Priorto this review the family Mimonectidae consisted of two genera, Mimonectes with five species and Pseudomimonecteswith one species, and the family Proscinidae consisted of three genera, Proscina with five species, Mimoscina with twospecies and Cheloscina with one species. The five nominal species of Mimonectes are also recognised in this review withthe addition of three new species, M. alexanderi sp. nov., M. colemani sp. nov. and M. neosphaericus sp. nov. No morespecimens of Pseudomimonectes were found, and this genus is still known only from the unique type. A critical review ofthe family Proscinidae is presented arguing that its taxonomic distinction from the family Mimonectidae cannot be main-tained. Amongst the genus Proscina, P. scinoides (Woltereck, 1906) is considered a species of Mimoscina and P. magnaStephensen and Pirlot, 1931 a junior synonym of Mimonectes loveni Bovallius, 1885. The remaining three species are con-sidered valid for the time being and are transferred to the genus Mimonectes. Thus, eleven species of Mimonectes are rec-ognised in this review. Cheloscina, still known only from the unique type, is also similar to Mimonectes, apart from themorphology of the first antennae, and is here included in the family Mimonectidae. Mimoscina however possesses severalcharacters distinguishing it from other members of the Mimonectidae and a new family, Mimoscinidae fam. nov. is pro-posed to accommodate it. The two nominal species of Mimoscina are also recognised in this review with the addition ofone new species, M. galbraithae sp. nov. Amongst the extensive Dana collections is one specimen that clearly belongswith the Scinoidea but possesses several unique characters that preclude it from all other currently recognised families.Thus, a new family, Microscinidae fam. nov. is proposed to accommodate this new genus and species, Microscina rostratagen. et sp. nov. Keys are provided for all families, genera and species, together with diagnoses, and all species are illustrated.