Dr. Murai Éva szerk.: Parasitologia Hungarica 21. (Budapest, 1988)

ignates the superfamily Cladorchoidea Skrjabin, 1949, the ancient branch of the suborder and the Paramphistomoidea Stiles et Goldberger, 1910, the derived sister group of Paramphistomata (Fig. 1). Cladorchoidea Paramphistomoidea 0) Fig. 1. Phylogenetic relationships among families of amphistomes Analysing the morphological similarities of species of the taxon Cladorchoidea, five monophyletic groups with equal taxonomic level (family) have been separated: Cladorchiidae Skrjabin, 1949; Diplodiscidae Skrjabin, 1949; Gastrodiscidae Stiles et Goldberger, 1910; Balanorchiidae Ozaki, 19 37 and Brumptiidae Skrjabin, 1949. The monophyly of Cladorchiidae is justified by the simple structure of the cirrus pouch and by the presence of the primary pharyngeal sacs. Diplodiscidae is characterized by a single testis. Gastrodiscidae has a cirrus pouch with untypical structure (musculature of cirrus pouch poorly developed and pars prostatica and pars musc'ulosa are enclosed) and pharyngeal bulb and the secondary pharyngeal sacs are attached to the pharynx. The identity of Balanorchiidae is determined by the unique feature of its ovary being pretesticular. Brumptiidae is characterized by having hermaphroditic pouch and pharyngeal bulb and secondary pharyngeal sacs. Phyletic relationship of the families is depicted by the cladogram (Fig. 1) and the following key is given for distinction of the families. 1. Two testes present , 2 - One testis present Diplodiscidae 2. Ovary post-testicular 3 - Ovary pretesticular Balanorchiidae 3. Cirrus pouch present 4 - Hermaphroditic pouch present Brumptiidae 4. Primary pharyngeal sacs present Cladorchiidae Pharyngeal bulb and secondary pharyngeal sacs present Gastrodiscidae Of the families designated above, the family Cladorchiidae includes several subfamilies, the rest of them have no subfamiliar differentiation,