Two species of halipegine derogenids are redescribed in detail from marine fishes off Corsica. Following a study of specimens from blennies off Corsica and museum material, Tyrrhenia Paggi & Orecchia, 1975 is considered to be a synonym of Magnibursatus Naidenova, 1969, and its type-species, T. blennii Paggi & Orecchia, 1975, is transferred to the latter genus as M. blennii(Paggi & Orecchia, 1975) n. comb. M. blennii differs from all species of Magnibursatus in possessing suckers of a similar size, numerous uterine loops in the forebody, and a sinus-sac which is small in relation to the forebody and which has relatively thin, muscular walls. This species is recorded from Salaria pavo (Risso), Paralipophrys trigloides (Valenciennes) and Parablennius sp. and distinguished from similar species of the genus. Arnola microcirrus (Vlasenko, 1931) is recorded from Boops boops (L.), which appears to be its main host off Corsica, Diplodus sargus (L.), D. annularis (L.) and Spondyliosoma cantharus (L.). The material from Corsica is compared with previous descriptions and material of this species, and differences were considered to be within the bounds of intra-specific variation.