Dr. Murai Éva szerk.: Parasitologia Hungarica 20. (Budapest, 1987)
Remark Diagnosis of this type of terminal genitalium was described by PRUDHOE (1975) but the type was not named. 2. Pertinax type (Fig. 26) Genital papilla stout and broad, muscle units of sphincter papillae loosely spaced. Genital fold and genital sphincter absent. Radial muscle fibres poorly developed. (Valid for Macro- pothrema pertinax.) 3. Zygocotyle type (Fig. 27) Characterized by having poorly developed structural elements, musculature and size. Genital papilla small, with some fibres of radial musculature. Circular muscle units entirely absent. True genital fold absent but the body wall forming a muscular area without being papillae-like in appearance. (Valid for Zygocotyle lunata and Wardius zibethicus. ) Acetabulum The ventral sucker or acetabulum usually large, stout muscular organ at the posterior end of body. It exhibits significant variability both in size and appearance, depending on groups of amphistomes. Of the structural elements the muscle fibres are the most important ones which may be circular, longitudinal, radial and oblique. The circular muscle units running along the outer and inner margin of acetabulum show characteristic arrangement, seen in median sagittal section. The diagnosis of structural elements of the acetabulum was given by NÄSMARK (1937), and further details were added by REINCHARDT (1969), EDUARDO (1982), SEY (1983). The schematic representation of a general type of acetabulum, adopted from NÄSMARK (1937) (Fig. 28) includes all parts necessary for characterization and differentiation. The types of acetabula based on gross-:morphological and histomorphological features were divided by NÄSMARK (19 37) into three groups and a possible fourth with an uncertain position. A comprehensive survey of a great number of different types of acetabula indicates that NÄSMARK's fourth group can be placed in to group II as regards the shape and arrangement of musculature. Accordingly, three groups of acetabula can be differentiated here. Acetabula belonging to group I have various forms in appearance and development of acetabular cavity and musculature. The number of dorsal and ventral exterior and interior circular series equal or dissimilar. D.e.c. series does not divide into d.e. 1 and d. e. 2 series. Acetabula of group II are typical sucker-like in form, with well-developed musculature, acetabular wall and acetabular cavity. Of the d.e.c. muscle units there is either one, relatively short series, or it divides into d. e. c. 1 and d. e. c. 2'. series. In group III the acetabula are characterized by having typical acetabular form with sometimes well-developed acetabular wall in the middle part. Dorsal exterior circular series longer or shorter but without division into two parts. Types of acetabula of group I. This group embraces 10 already known types (Cladorchis Näsmark, 1937; Dermatemytrema Sey, 1983; Diplodiscus Näsmark, 1937; Megalodiscus Sey, 1983; Nematopnila Sey, 1973; Pfenderius Näsmark, 1937; Pseudocladorchis Näsmark, 1937; Schizamphistomum Näsmark 1937; Neocladorchis Sey, 1986; Zygocotyle Sey, 1975) and 18 new types described below. 1. A s per type (Fig. 29) Size enormous with papillae in its inner surface and with poorly developed acetabular wall
