Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 52. (Budapest 1960)

Agócsy, P. ; Pócs, T.: Data to the mollusk fauna of Hungary

csony consists of basalt and its decomposed products, and as such it is not favourable for a mollusk fauna. In spite of that, we found an abundance of snails comparable to the richest localities of the Mts. Bükk, consisting of limestone. Experiments shew that the soil is of a neutral reaction. The seemingly monotonous hilly area of Zala, west of the Balaton plateau, conceals interesting Illyrian and dealpine elements. Here too, we have found Goniodiscus perspectives, its locality being a connecting ling between the Alpine and the Central Hungarian (mountainous) localities. The mud-inhabiting snailcoenosis of the river Kerka in Tormaföld was very interesting ; there live about 100 specimens of Amphimelania holandri and var. afra, some 10 Fagotia acicidaris and one or two Theodoxus danubialis var. strangulatus per square meter on the surface of the silt. Fagotia was hitherto unknown from the water system of the Drave (S o ó s 1943, 1955—59). Z. Mészáros submitted interesting data from this area, having collected Theodoxus danubialis also from the waters of the Zala at Zalaszentgrót, the same as Vertigo moulinsiana, Caeciloides acicula and Cepea nemoralis in its neighbourhood. Szakonyfalu is situated, near Szentgotthárd, in the triangle formed by the Yugoslavian, Hungarian and Austrian borders. We found here first five, and some weeks later, eleven Papillifera bidens, among the roots of a fallen tree in the old beech-forest of the humid side-valley of the Szakonvfalvi brook. One of the specimens was alive ; we preserved it in alcohol. The occurrence of this species in Hungary is very striking, since it lives nearest to our country in the Italian Alps and on the seaside at Rijeka on the Adriatic. It is improbable that it might have have been introduced to a habitat so natural and so far away from human habitations. This datum also runs parallel with the occurrence here of the plant Polygala carniolica ssp. nicaensis, of a SE-Alpine-Ulyrian range. Further away to the East, around the "Szentkút" near Vasvár on the Vasi Plateau, we reencountered the phenomenon experienced at the Castle of Füzér. The same mollusk species which can be found but singly in the litter layer of the beechwoods (Iphigena ventricosa, Cochlodina laminata) appear in high individual numbers around the altar, built of limestone rocks, of the place of pilgrimage in the forest. The malaco-faunistically most neglected area of the country is the Great Plains. One of its causes is the factual poorness of its mollusk fauna. This monotonous and scanty material had no attraction on the collectors. Its most interesting part is the NE Nyírség and the adjacent Plains of Com. Bereg-Szatmár. The faunistical difference between the Nyírség and the other districts of the Great Plains is striking. The soil here is slightly, at other places, strongly, acidic. The pH values of the ground and of the natural waters fluctuate between 5,8 and 7. With the exception of the deepest lying areas, sandy soils predominate in the Nyírség, and clayey ones in the Bereg Plain. Large areas of this latter unit are covered by marshes, swampy forests and copses. We collected in these places in 1957 and 1958, having found 21 snail species in Petneháza and 12 in the woods of Baktalórántháza, only 9 km away from the first localitv. Montane and plain elements intermingle in an interesting way both in the fauna and in the flora (cf. Simon 1952, 1954). Aside of the typically paludicolous species, as Viviparus contectus, Planorbarius corneus, Limnea stagnalis, or those frequenting marshy fields, as Cochlicopa lubrica, Carychium minimum and Succienea species, we found many individuals of Acanthinula aculeata and Caecilioides acicula in the alderwood swamps. This latter species was not vet surely shown from the Great Plains.