Family Saccopsidae Lützen, 1964

This family of highly transformed copepods was established by Lützen (1964b) to accommodate Saccopsis Levinsen, 1878 but Bresciani & Lützen (1975) later recognised that Saccopsis was a junior synonym of Melinnacheres M. Sars, 1870 . Subsequently Boxshall (1977) relegated Oestrella M’Intosh, 1885 to synonymy with Melinnacheres . Boxshall & Halsey (2004) provided a key to the four valid species of Melinnacheres . Prior to the present study the family comprised only the single genus, although a possible relationship with the genus inquirendum Flabellicola Gravier, 1918, found on Flabelligera diplochaitus (Otto, 1820) in the Mediterranean (Gravier 1918), was noted by Boxshall & Halsey (2004).