Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 15. 1992. (Budapest, 1992)

űary veins branch off the midvein at an angle of 50-60, in intervals of 0.8-1.5 cm. The tertiary veins are percurrent, quaternary veins are orthogonal. The species was originally described from a swamp. All of the specimens known so far originate from localities of swamp vegetation. The species occurs in great abundance, it is quite often the dominant floral element. The most frequent accessory elements associated with the species are Gfyptostrobus, Byttneriophyllum, and Nyssa. Alnus cecropiaefolia (ETT.) BERGER was distributed in Europe from the Vienna Basin through Hungary, Czechoslovakia and Yugoslavia to Rumania, from the Sarmatian to the Upper Pliocene. Ulmaceae Ulmus L. Ulmus sp. Text-fig. 3: 2,4. Material: sample No 424, depth 507.3-507.2 m, No 491, depth 606.8-606.7 m The material consists of fragments, characteristic specific features cannot be observed. The venation is craspedodromous. The secondary veins are rigid. The genus Ulmus is an Arctotertiary element appearing in Hungary in the Late Oligocène and present here ever since, represented by numerous and diverse species. Its species are mainly members of the riparian vegetation but some of them belong to the swamp vegetation. Salicaceae Salix L. Salix sp. Text-fig. 2:6. Material: sample No 22, depth 43.1-43.0 m, No 27, depth 50.5-49.7 m, No 102, depth 157.9-157.8 m, No 141, depth 193.3-193. 2 m The genus is typical of the Arctotertiary flora. In Hungary it first appears in the Middle Miocene and becomes dominant by the Pannonian only. It is also present, sporadically, in older assemblages but such occurrences are rare and their assignment to Salicaceae is uncertain. The Early Oligocène species identified as Salix are mainly species belonging to Laurophyllum. Their first representatives are reported from Upper Oligocène strata in Hungary. Salix, similarly to other pioneering Arctotertiary elements, penetrated the Palaeotropical vegtation at its acme during the Oligocène in form of extrazonal assemblages. Related to the deterioration of climate, the disappearance of the Palaeotropical elements became more and more significant. Palaeogeographical and edaphic relations were especially favourable for Salix during the Pannonian time. Not surprisingly, it is known to occur within the Humgarian palaeoflora in greatest abundance and diversity at this time.