Tabulata from Norway, Sweden and from the erratic boulders of Poland

The purpose of this paper is to describe the results of a detailed morphological and taxonomical investigation of the Tabulata from Norway , Sweden (Island of Gotland) and from the erratic boulders of Poland. The stratigraphical correlation of Silurian in the above mentioned areas and in Estonia is given. These studies have also thrown some new light upon the development of Tabulata during Silurian in the Scandinavian-Baltic region. A hundred and seven species assigned to twenty-six genera are described in the present paper. Thirty-six of the species and four of the genera are new. Moreover, a new family has been established. The material from Norway was made accessible to the author by Paleontologisk Museum in Oslo. This material comes from the collections of J. KIAER (1893-1902, 1905, 1908, 1910). Some specimens considered in the present account were also collected by L. ST0RMER in 1918, by P. SmRMER in 1938, and by TH. KJERULF. The collections from the Island of Gotland were put at the disposal of the present author by Institut Royal des Sciences Naturelles de Belgique in Brussels, and by Naturhistoriska Riksmuseets, Paleozoiska Avdelning, in Stockholm. Some additional material was collected by Prof. K. POZARYSKA, Palaeozoological Institute, Polish Academy of Sciences, Warsaw, and by the present author herself. The large collection from the erratic boulders of Poland was given to the present author by Palaeozoological Laboratory, Polish Academy of Sciences, Poznari, A part of the material described comes also from the collections of Prof. R. KOZLOWSKI and Prof. E. PASSENDORFER. Several specimens were collected by Dr. S. RUDOWSKI, Laboratory of Dynamic Geology, University of Warsaw, and by the present author. The work was completed in the Palaeozoological Institute, Polish Academy of Sciences in Warsaw, in 1962-1966. The comparative studies of the material described here with the Tabulata from Estonia were carried out in the Laboratory of Palaeozoology, Geological Institute of the Estonian Academy of Sciences in Tallinn. The classic development of Silurian and Ordovician sediments in Estonia and their similarity with the corresponding deposits in Sweden (Island of Gotland) and Norway (Oslo region) made possible the stratigraphical correlation of particular stages and substages, as well as the determination of the age of Tabulata from the erratic boulders. The present author studied the fine structure of walls in the Palaeontological Institute, Academy of Sciences of U.S.S.R. in Moscow, where similar investigations on the Devonian Tabulata of Kazakhstan have been carried on by Dr. I. I. TCHUDINOVA.