Dr. Murai Éva szerk.: Parasitologia Hungarica 16. (Budapest, 1983)

in small groups in thin-walled capsulacules. The two lobes of the uterus maintain their shape even in fully gravid proglottides. Wall of last proglottides detached from strobila hardly noticable. Egg capsulacules remain unchanged in the disintegrating proglottides (Figs 12, 13). Eggs global or oval-shaped measure 31-37 x 22-26jum, diameter or embryo 25 urn, varying between 18x27 and 20x 25jum (Fig. 3). Length of embryonal hooks 13-14um. Egg capsulacules containing 5-11 eggs, 80-110jjm in diameter. The scolex and hooks of B. cordifera parasitizing Acrocephalus species (all immature specimens) are similar to the holotype as regards shape and size. 1st row: 52-65 jum long, basis 32-37jam, guard 17-21 um long. 2nd row: length ofhooks 34-41 urn,those of basis 21-25nm, guard 12-15jim, handle 21-23jjm long. Handle and guard strongly thickened (Fig. 6). Number of hooks varying between 24 and 30, but probably more, as the scoleces were in a badly macerated state. In one of the immature specimens (No. 7 582 from A. scirpaceus) we found the uterus characteristic for the species (Figs 8-9). Habitat: All the hosts of B. cordifera sp. n. nested in the same locality. Specimens were obtained in the July of two successive years, from the reedbeds of strongly alkaline lakes of Szivós-szék, near Fülöpháza. We may presume that the occurrence of the species is a consequence of the presence of an arthropod intermediate host living in sodic grassland or swamp. Type material (preserved in the Parasitological Collection of the Hungarian Natural History Museum, Budapest - henceforth HNHM). Holotype: (HNHM No 7915) one adult specimen in 3 slides, ex Lusciniola melanopogon, K.N. P. Fülöpháza, Szivós-szék, 18 July, 1978, leg. F. MÉSZÁROS. Paratypes: (HNHM No 7 580) two juvenile specimens in 2 slides, ex Acrocephalaus schoenobaenus, K.N.P. Fülöpháza, Szivós-szék, 28 July, 1977, leg. F. MÉSZÁROS"; (HNHM No 7 584) one immature and two juvenile specimens in 3 slides, ex Acrocephalus schoenobaenus, K.N.P. Fülöpháza, Szivós-szék, 26 July, 1977, leg. F. MÉSZÁROS; (HNHM No 7582) two immature specimens in 5 slides, ex Acrocephalus scirpaceus, K.N.P. Fülöpháza, Szivós-szék, 28 July, 1977, leg, F. MÉSZÁROS. Differential diagnosis: The new species is distinguished from all other known species of Bi uterina by the relation of the paruterine organ to the uterus (the mature eggs remain in the lumen of the uterus, and no common capsule is formed in the paruterine organ to receive the Fig. 14: Biuterina cordifera sp. n. Fig. 15: Biuterina triangula (Krabbe, 1869) shape of rostellar hooks (orig.) shape of rostellar hooks (orig.) X Not identical with the egg capsel of other paruterinid species.