L. Hably szerk.: Studia Botanica Hungarica 22. 1990 (Budapest, 1990)

Table I. The leaf-size of the Platanus neptuni Locality Age Minimum Mean Maximum Minimum Mean Max imum breadth breadth breadth lenqth lenqth lenqth Budapest, Kiscellian 0.9 1. 87 2.9 5.0 7.55 10.0 H-drillings Verőcemaros Egerian 1. 9 2.6 3 . 3 6.0 8.6 12.0 Vértesszőlős Egerian 0.95 2. 9 5.4 4.5 8.6 14.0 The mean value of width and length of the pieces is interesting as well; we can see that the mean values for the Egerian floras are almost identical, but they are considerably different from that of the Kiscellian mean value of the Platanus neptuni

, being more than a whole unit longer. This fact seems to support the statement that the formation of the leaf surface of P. neptuni is considerably depending on the climate. In the dry climate of the Kiscellian, a much smaller surface of the leaf was adequate, while in the more humid Egerian not only the maximal leaf size is more than in the Kiscellian, but also the mean value is well surpassing the Kiscellian average. The two Egerian floras are situated in different formations. During the Egerian, possibly a continuous forest of P. neptuni could exist here. The actual distance between the localities is certainly not so great that we would be compelled to suppose disjunct areas. This hypothesis is further supported by the occasional occurrence of P. neptuni in the Egerian assemblages of the localities lying between them. The species is very abundant in the Hungarian Oligocène. It was found practically at all sites of the Lower Oligocène Tard Clay Formation (Kiscellian Stage), e.g., from the Budapest surface outcrops and boreholes, as well as the Kiseged flora lying close to the town Eger. From the Upper Oligocène (Egerian), apart from the locality of Vértesszőlős, it is known from Verőcemaros, Pomáz, Kesztölc, Nagysáp (HABLY 1980, 1982, 1988) and the Wind's Brickyard section from Eger. These sites are practically covering the complete extent of the Hungarian Oligocène. The westernmost occurrence of P. nep tuni in Hungary is, according to our present knowledge, that of Vértesszőlős. Its easternmost occurrence - so far the easternmost occurrence of the species in Europe - is that of the Wind's Brickyard section. The P. neptuni is a thermophylous Palaeotropical element. According to KNOBLOCH (19 73) it is appearing bound to definitely warm periods. On the territory of Hungary, it used to live amidst subtropical climatic relations in the Kiscellian, the Egerian as well as the Lower Miocene. In respect of precipitation, the plant could adapt to varying circumstances, because it was characteristic of the dry Kiscellian as well as the humid Egerian and the Lower Miocene as well. The recent equivalent of the P. neptuni is P. kerrii

, currently living in South-Eastern Asia, on the territory of Laos #

under subtropical, tropical climate as an evergreen member of the forest. BU2eK (1971) considered it to be a Palaeotropical element. It is known to occur in Hungary in the Lower Kiscellian amidst palaeotropical elements only, while later, during the Egerian (in the first place, on this site) it is mixed with Arctotertiary elements. Ulmaceae Ulmus L. Ulmus pyramidalis Goeppert Pl. XVII, Figs. 3-4; Pl. XVIII, Figs. 2-3; Pl. XIX, Figs. 1-3; Pl. XX, Figs. 1-2; Pl. XXI, Fig. 1; Figs. 84, 87-93, 110. 1845 Ulmus bronni Ung. partim ; Unger, PI. 26, Fig. 1., non Figs. 2-4. 1845 Ulmus longifolia Ung.; ibid.. Pl. 26, Figs. 5-6. 1847 Ulmus bronni Ung. partim; ibid., p. 100. 1847 Ulmus longifolia Ung.; ibid., p. 101. 1855 Ulmus pyramidalis Goepp

. ; Goeppert, p. 28, PI. 13, Figs. 10-12. 1859 Carpinus pyramidalis (Goepp.) Heer; Heer, p. 177, Pl. 87, Fig. 7f; Pl. 150, Figs. 27-28. 1866 Ulmus pyramidalis Gaudin; Ettingshausen, p. 49, Pl. 15, Figs. 5-9, Fig. 21.