Order. _Digenea_, v. Beneden, 1858 230 Sub-order. _Prostomata_, Odhner, 1905 230 Group. _Amphistomata_, Rudolphi, 1801, ep., Nitzsch, 1819 230 Family. _Paramphistomidæ_, Fischoeder, 1901 231 Sub-family. _Paramphistominæ_, Fischoeder, 1901 231 _Cladorchiinæ_, Fischoeder, 1901 231 Family. _Gastrodisciidæ_, Stiles and Goldberger, 1910 231 Group. _Distomata_, Retzius, 1782 231 Family. _Fasciolidæ_, Railliet, 1895 231 Sub-family. _Fasciolinæ_, Odhner, 1910 231 _Fasciolopsinæ_, Odhner, 1910 231 Family. _Opisthorchiidæ_, Braun, 1901, emend, auctor. 232 Sub-family. _Opisthorchiinæ_, Looss, 1899, emend, auctor. 232 _Metorchiinæ_, Lühe, 1909 232 Family. _Dicrocœliidæ_, Odhner, 1910 232 _Heterophyiidæ_, Odhner, 1914 232 _Troglotremidæ_, Odhner, 1914 232 _Echinostomidæ_, Looss, 1902 233 Sub-family. _Echinostominæ_, Looss, 1899 233 _Himasthlinæ_, Odhner, 1910 233 Family. _Schistosomidæ_, Looss, 1899 233 THE TREMATODES OBSERVED IN MAN 234