Four closely related but forgotten species of Rhipidocotyle Diesing, 1858 (Digenea: Bucephalidae) in fishes from European seas.

The following species of Rhipidocotyle are described: R. minima (Wagener, 1852) from Chelidonichthys gurnardus, C. lastoviza and Aspitrigla cuculus at various localities off the British Isles; R. nicolli n. sp. from A. cuculus off Plymouth, SW England; R. triglae (van Beneden, 1870) from C. lucernus in the Gulf of Marseilles, western Mediterranean; and R. viperae (van Beneden, 1870) from Echiichthys vipera at various localities off the British Isles. The distinguishing features of the species are discussed in detail. A list of the bucephalid species reported from the Mediterranean Sea is appended.