Trilobites of the family Calymenidae from the Ordivician, Silurian and Devonian systems of North-West Europe.

This work represents a revisional study of many of the species of the family Calymenidae Milne Edwards, 1840 (Trilobita) from the Ordovician, Silurian and lower Devonian of NW Europe. Taxa from Britain. Norway, Sweden and Czechoslovakia have received particular attention, and where appropriate comparisons have been made with non-European species. Most of the chapters are arranged on a taxonomic basis; one deals with the calymenid fauna from a single region (Middle Ordovician calymenids from Norway), and another is concerned with some evolutionary trends in Ordovician md Silurian species (Chapter F ). One new subfamily (Flexicalymeninae), three new genera (Quadricalymene, Tapinocalymene, Palacalymene), and thirteen new species are erected.