Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 12. (Eger, 1993.)

I. FINTHA-P. SÜMEGI-G. SZILÁGYI: A New Biotope of Chilostoma banaticum (Rossmässler, 1838) in Hungary and its Nature Conservational Asppects

roundings and if this can compensate the effects of human activities, the population survives, but if the activities disturb directly the wet microclimate of the soil surface (e. g. by clear cutting, burning, cutting out the shrub stratum) the population

. will disappear from the biotope. The species is also of a great importance from a faunahistorical point of view. Its fossils are known from Tertiary (Sarmata) formations in the Caipathian Basin as well (Siimeghy, J. 1923). It had a larger range in the Pleistocene than today (Kormos, T. 1909, Soós, L 1943, Ehrmann, P. 1956, Lozek, V. 1964), on the basis of these data it was distributed in Central and Eastern Europe. Large numbers of individuals were found in the sediments of the Riss-Wiirm interglacial period (Lozek, V. 1964, Krolopp, E. 1964). Lozek, V. (1964) uses the term „banatica-fauna" while Krolopp E. (1973, 1983) determines thes stratum as Phenicolimax annularis-Helicigona banatica biozone (Oppel zone) in Hungary. In Pleistocene sediments the species was found only in the Northern Mountains of Hungary (Krolopp, E. 1964, 1988, Hir, J. 1988). There is no data on the occurrence of the species on the Hungarian Great Plain from the Pleistocene, but it was found in Holocene sediments near the banks of the former bed of River Fekete-Körös (Domokos T. 1986). Its occurrence from the Lower Holocene at Bélmegyer is extremely important, where Mollusc and Vertebrate species were found in remarkable numbers together with Chilostoma banaticum (Domokos, T. et al. 1989). On the basis of biostratigraphic and paleontological studies the species established populations there at the begining of the atlantic phase in gallery and marshy forests (Domokos, T. el al. 1989) and became extinct because of the very powerful extinct because of the very powerful human activities (the area is a ploughed field). Hence former publications (Domokos, T. 1987, Bába, K.-Domokos, T. 1992) give statistical measurements, these were carried out in the case of the recently found population as well, using the method of Domokos, T. (1987) on 50 adult individuals. Height Width Height/Width Mean 1.580 2.531 0.625 Standard Error 0.013 0.016 0.004 Median 1.580 2.530 0.621 Mode 1.600 2.450 0.620 Stand. Deviation 0.090 0.115 0.030 Variance 0.008 0.013 0.001 Kurtozis -0.408 -0.317 -0.533 Skewness 0.375 0.160 0.416 Range 0.360 0.550 0.128 Minimum 1.410 2.250 0.574 Maximum 1.770 2.800 0.702 Sum 79.000 126.550 31.230 Confidence Level (95%) 0.025 0.032 0.008 On the basis of these measurements, statistical data of this population seem to be highly similar to that of near Vásárosnamény (Domokos, T. 1986, Bába, K.-Domokos, T. 1992), thus it can be concluded, that these two populations near the Upper Tisza originated from the same Transylvanian population, having colonized in two quite similar bi-