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

MEGGITT (1927) was of the opinion as regards the taxonomical relationship within the genus that the "genera above mentioned possess rostellar hooks of a definitive shape differing from any others and without transitional forms", and that the shape of the hooks is not a generic character. He considered the development of the uterus and the paruterine organ as the most important diagnostic character. In B. cordifera these organs develop differently from those of the other species. Similarity may be seen between Biuterina mertoni, B. fallax

, and the new species in the complex of uterus and paruterine organ, figured by FUHRMANN and MEGGITT on post-mature proglottides (Figs 17-18). The abovementioned authors observed stages of these species in which the bilobed uterus is surrounded by the paruterine tissue. In neither of these species did the authors have any fully mature proglottides available for study, and both only supposed that there would later develop an egg capsule in the paruterine organ (FUHRMANN, 1911, p. 258; MEGGITT, 1928, p. 316-317, Plate XIX). Therefore it is possible that the process of development of the uterus observed in B. cordifera sp.n. is a characteristics of a species group within the genus, but this trait may possibly be of generic value. For comparison we studied specimens of Biuterina passerina Fuhrmann, 1908 from Emberiza citrinella (1st Hungarian Parasitological Expedition, Szentgál , Bakony Mts.). In this species the paruterine organ appears as the upper third of a truncated cone in the pre-mature proglottides. In the mature proglottides it extends conically backwards. The uterus is curved and bilobed, it is connected with a narrow canal. A lasso-like coiled tube develops in the paruterine tissue of post-mature proglottides. This becomes disdented with the maturation of the eggs, occupies a position along the longitudinal axis of the proglottides, and the mature eggs gradually become pushed into this paruterine tube. The figures for B. passerina and B. triangula given by SPASSKAJA and SPASSKY (1971) (Figs 19-20) show this type of paruterine organ. SUDARIKOV (1950) described B. sobolevi belonging to this morphological group of paruterinids. Table 1 Measurements of rostellar hooks in three Biuterina species examined in Hungary (all measurements in /am) Species Len I. row gth II. row Ba I. row sis II. row Gu£ I. row rd II. row Length inc I. row /guard ex II. row B. passerina B. triangula B. cordifera 20-22 63-65 56-61 16-18 44-50 33-40 16-17 37-45 31-35 13-15 24-30 23-25 12 30-32 23 11 22-23 13 1.5-1.6 2.0-2.1 2.7-3.2 1.7-2.0 2.0-2.4 2.5-3.0 *(each data the mean of 10 rostellar hooks placed into side view). The hooks of various Biuterina species may be divided into three forms as based on their shape: A) The shape of hooks in both rows is a characteristic "triangle" with little difference in size between those of the two rows. In our material B. passerina Fuhrmann, 1908 belongs to this group, with length of hooks 20-22um (1st row) and 16-18jum (2nd row) (Fig. 16), as well as B. motacnia Fuhrmann, 1908 and B. trigonacantha Fuhrmann, 1908. B) There is considerable difference between the size of the hooks of the two rows, the larger one with very short handle, the smaller one with short handle. In our material this group includes the hooks (Fig. 15) of the probably B. triangula (Krabbe, 1869) individuals (very young) from Luscinia megarhynchos and B. campanulata (Rudolphi, 1818). !J8