L. Hably szerk.: Studia Botanica Hungarica 22. 1990 (Budapest, 1990)
Betula sp. type 1. Pl. XXIV, Fig. 2; Pl. XXVI, Fig. 1; Figs. 99-100, 102-103. Material: No.: 76.11.1.; 76.84.1.; 76.125.1.; 76.149.1. 4 pieces Description: Three leafprints of relatively poor state of preservation as well as a small fragment was assigned to this taxon. The length of the leaves is around 10-12 cm, their width ranging between 6-6.5 cm. The apex is acute, the basis is fragmented at all specimens. The margin of the leaf is toothed as it is observable on one of the specimens, in case of the other two prints the margin is dim. The venation is craspedodromous . The secondary veins are branching off from the midvein relatively far from each other. The distance of the secondary veins on the specimen 76.11.1, starting from the basis towards the apex is as follows: 1.0, 1.1, 1.05, 1.0, 0.85, 0.8, 0.7 cm. The veins start from the midvein with a slight arch, they are bent again near the margin, in the medial parts, however, they are straight. Lacking important characteristic marks, the specimens were not assigned to species. Betula sp. type II. Pl. XXV, Fig. 2; Fig. 101. Material: No.: 76.119.1. 1 piece Description: The length of the leaf is 7.3 cm, its width is 4.5 cm. The lamina is fairly asymmetrical, the midvein is dividing it into two unequal parts. The form of the leaf, due to the considerable asymmetry, is difficult to determine; reminding, however, most to elliptic or ovate. The basis and the apex are fragmented, but the apex used to be in all probability acute. The venation is camptodromous. The secondary vein system is fairly irregular, the distance of the starting points from the midvein are changeable and there are considerable differences in the curvature of their line as well. Some of the secondary veins are relatively straight, other reach the margin in a bent arch. The margin of the leaf is toothed, the teeth are small. As the distance of the veins is great, not all of the teeth have a secondary vein running up to its top. The teeth are frequently composite, that is, under them a smaller tooth is visible in some cases. The apical side of the teeth is generally concave or straight while the basal side is convex or straight. The apex of the tooth is acute, the sinuses between the teeth also being acute. Betula sp. type III. Pl. XXVII, Fig. 1. Material: No.: 76.216.1. 1 piece Description: The form of the leaf cannot be exactly determined, due to its fragmentary state. Only a 1.5 cm long phase of the margin was preserved, where the teeth are fairly well visible. They are set at equal distances from each other, but they are not regular. The secondary veins join only every second teeth, the tooth between these receiving a branch-off from the vein lying immediately over it. This tooth is , however, no smaller than the rest. The shape of three subsequent, complete teeth are considerably differing from each other. One of them seems to be obtuse, however, it is possible that the apex of the tooth is broken, because the other two teeth are acuminate. The apical side of the teeth having the secondary vein running up to them is acuminate, their lower side is also acuminate or convex. The intermedial tooth having no vein of the secondary order attached to it is different, both of its sides being concave. The sinuses are obtuse. 28
