Dr. Murai Éva szerk.: Parasitologia Hungarica 16. (Budapest, 1983)
Examining the evolutionary trends in the group studied it was visualized that three changes have been recognized which affected the diplodiscid way of life reflecting in phenotypic change: 1) reproductive function, 2) feeding activity and 3) ability of attachment. Construction of the cladogram of the genera (Fig. 19) was based on the character-series which were specified on page 4-5. SURVEY OF THE FAMILY DIPLODISCIDAE The family Diplodiscidae, in the sense of the present paper, comprises two subfamilies Diplodiscinae Skrjabin, 1949 with the genera: Diplodiscus Diesing, 1836; Australodis cus n. gen. ; Catadiscus Cohn, 1904; Dermatemytrema Price, 1937; Progonimodiscus Vercammen-Grandjean, 1960; Pseudodiplodiscus Szidat, 1939 and Opisthodiscinae Skrjabin, 1949 with the genera: Megalodiscus Chandler, 1923; Opisthodiscus Cohn, 1904. Due to the restriction of the extent of the family Diplodiscidae an amendation of its characters is necessitated. Family DIPLODISCIDAE Diagnosis : Diplodiscoidea. Body with more or less conical in shape. Pharynx with different histomorphological structure, anterior sphincter present, primary pharyngeal sacs reaching beyond wall of pharynx or embedded in it. Oesophagus short or long, with oesophageal bulb. Caeca short or long. Testes: one or two, usually in middle third of body. Cirrus pouch small, rarely well developed. Genital opening median, at bifurcation or pre - or postbifurcal; musculature poorly developed. Ovary posttesticular, usually median. Vitellaria extending along caeca or grouped at middle third or posterior part of body. Uterine coils usually intercoecal, rarely extracoecal, more or less developed; eggs embryonated or not. Excretory pore anterior and dorsal to acetabulum. Lymph system with one or two pairs of longitudinal stems. Acetabulum poorly developed with different histomorphological structures. Parasites of amphibians, reptiles and fishes. Type subfamily: Diplodiscinae Skrjabin, 1949. Key to subfamilies of Diplodiscidae: 1. One testis, caeca short or long, oesophagus longer than pharynx Diplodiscinae 2. Two testes, caeca long, oesophagus shorter than pharynx Opisthodiscinae Subfamily DIPLODISCINAE Skrjabin, 1949 Diagnosis: Diplodiscidae. Body pyriform or elliptical. Pharynx with different histomorphological structure, primary pharyngeal sacs reaching beyond pharynx or embedded in it. Oesophagus longer than pharynx, oesophageal bulb present. One testis, median in middle third of body. Cirrus pouch small or well developed. Genital opening median at about bifurcation, rarely postbifurcal. Ovary posttesticular ,usually submedian. Vitellaria extending along caeca, or grouped at middle third or posterior part of body. Uterine coils intercoecal, more or less developed; eggs embryonated or not. Acetabulum weakly developed with different histomorphological structure. Parasites of amphibians, reptiles and fishes. Type genus: Diplodiscus Diesing, 1836
