- 7 - lique strata of sandstones and clays are visible, as well as a fairly great layer of pebble conglomerates. This terrace, raised rather early in geologic time, under- went a prolonged and intense physical and chemical weathering. As a result the rocks heavily decomposed, limonitized with a characteristic ochreous colour. The remnants of plants and ani- mals occurring in them were nearly completely oxidized,dissolved and leached. Only the impressions of leaves are preserved in the upper strata of clay. In the lower strata, although the phytoli- mes still occur, only rarely does one succeed in obtaining epi- dermal prints. The spores and pollen, usually well preserved, are also destroyed in these deposits. Where vegetative remains were buried, clays with unusually fine-grained composition ensured a magnificent preservation of their impressions. Thus, for instance, parts of a shoot of Ru- p pia maritima with leaves, a long peduncle and a small fruit at its tip have been found. Appropriate procedures permitted the preparation of Halesia corollas for considering their possible structure: the corollas were sympetalous and pentapetalous;there were 14 stamens coalescent at the base, with well-preserved an- thers and with the connective awlshaped apically, the apiculum up to 0.2 mm long. The denticles on leekes are also well made out, while in Quercus kubinii (Kov.) Czez. even thin bristles at the ends of denticles have been preserved. This is taken as ade- quate proof that those leaves belong to oaks from the Cerris section, rather than chestnuts. The rich Pliocene flora of Kodor, buried in certain layers of this Tertiary terrace is of great interest, since it was de- veloped under refugium conditions. Because of the protection by the mountain range to the north and the proximity of the sea,the climate of the district was more consistent than in Europe to the north and north-west. Even the glacial period did not great- ly change this fact. Evolution of plants in Abkhazia proceeded continously from the Mesozoic Era , since during all subsequent time the Caucasus remained a mountainous region. At first the area was an island