Isthmiophora Lühe, 1909 and Euparyphium Dietz, 1909 (Digenea: Echinostomatidae) re-defined, with comments on their nominal species.

The validity of Isthmiophora Lühe, 1909 in relation to Euparyphium Dietz, 1909 is discussed and confirmed. Isthmiophora melis Schrank, 1788) [the type-species] and I. inermis (Fuhrmann, 1904) n. comb. are redescribed, and diagnoses are given for both genera, along with lists of their presently-accepted constituent species which are commented upon where necessary. A similar list of species previously allocated to these genera is also presented with comments on their current status. A key to the species of Isthmiophora is included. New combinations for species previously attributed to Euparyphium are: Isthmiophora inermis (Fuhrmann, 1904) n. comb., I. beaveri (Yamaguti, 1958) n. comb., I. lukjanovi (Chertkova, 1971) n. comb., I. citellicola (Kadenatsii in Skrjabin & Bashkirova, 1956) n. comb., I. hortensis (Asada, 1926) n. comb., Echinostoma pindchi (Khan & Chishti, 1985) n. comb., Echinoparyphium tripathii (Gupta & Gupta, 1982) n. comb., E. hirundonis (Fischthal & Kuntz, 1976) n. comb., and Hypoderaeum longitestis (Verma, 1936) n. comb. Species attributed to Euparyphium which are here considered species inquirendae are: E. lobata Farooq & Yousuf, 1986 sp. inq., E. ochoterenai Cerecero, 1943 sp. inq., E. sobolevi Ryzhikov, 1965 sp. inq., and E. taiwanense Fischthal & Kuntz, 1976 sp. inq.