NEOTROPICAL MONOGENOIDEA - 34 - SPECIES OF DEMIDOSPERMUS (DACTYLOGYRIDAE, ANCYROCEPHALINAE) FROM THE GILLS OF PIMELODIDS (TELEOSTEI, SILURIFORMES) IN ARGENTINA

The diagnosis of Demidospermus Suriano, 1983, is emended, and 9 specie s (5 new) are described or reported from the gills of 4 species of Pim elodidae (Siluriformes) from Argentina: D. armostus sp. n. from Pimelo dus albicans and Pimelodus clarias; D. bidiverticulatum (Suriano and I ncorvaia, 1995) comb. n. from Pimelodus clarias and P. albicans (new h ost record); D. cornicinus and D. leptosynophallus spp. n. from Iherin gichthys westermanni; D. idolus and D. majusculus spp. n. from Pimelod us albicans; D. paravalenciennesi, Gutierrez and Suriano, 1992, and D. uncusvalidus Gutierrez and Suriano, 1992, from Pimelodus clarias; and D. valenciennesi Gutierrez and Suriano, 1992, from Parapimelodus vale nciennesi. Omothecium Kritsky, Thatcher and Boeger, 1987, and Parampho cleithrium Suriano and Incorvaia, 1995, are considered junior synonyms of Demidospermus.