Gut forked, two suckers, the posterior sucker (acetabulum) terminal or ventro-terminal behind the genitalia, or at most embraced by the vitellaria. Skin with no spines. Excretory bladder a simple sac opening dorsally near hind end. Testes in front of ovary. Genital pore, median in anterior third of body. Thick flukes, almost circular in cross section.
Family. Paramphistomidæ, Fischoeder, 1901.
Amphistomata: Body not divided into a conical anterior portion and disc-like caudal portion. Ventral pouch absent.
Sub-family. Paramphistominæ, Fisch., 1901.
Paramphistomidæ: Oral sucker without evaginations. Not in man.
Sub-family. Cladorchiinæ, Fisch., 1901.
Paramphistomidæ: Oral sucker with evaginations; testes, two, deeply cleft (fig. [137]). Genera: Watsonius, Cladorchis, etc.
Family. Gastrodisciidæ, Stiles and Goldberger, 1910.
Amphistomata: With body divided into a conical cephalic and disc-like caudal portion (fig. [138]). Posterior sucker ventro-terminal. Oral sucker with evaginations. Genera: Gastrodiscus and Homalogaster.
Group. Distomata, Retzius, 1782.