Description nouvelle de Calvinaria megistana (Le Hon, 1870) et fixation de la position stratigraphique de ce rhynchonellide de la fin du Frasnien en Belgique et en France

Calvinaria megistana (Le Hon, 1870) was summarily described and figured in the original publication. As it is an important representative of the genus Calvinaria STAINBROOK, 1945, a new and full description, accompanied by numerous photographs, is given. The stratigraphic range of the species is specified and its absence outside of a restricted area in Belgium (Dinant Basin, Namur Basin, Vesdre Massif, Theux Window) and France (Dinant Basin) is confirmed.