Revision of the brachiopod <i>Cyrtina rigauxi</i> MAILLIEUX, 1909 and description of a new ambocoeliid genus (<i>Dionacoelia</i> n. gen.) from the Frasnian of southern Belgium
Cyrtina rigauxi MAILLIEUX, 1909 is transferred to the genus Acutatheca STAINBROOK, 1945 thus mentioned for the first time in the Frasnian of the Dinant Synclinorium and Roly "Massif (Neuville Formation, Lower Palmatolepis rhenana Zone). MAILLIEUX (1940, 1941) included Acutatheca rigauxi in Cyrtina demarlei BOUCHARD (nomen nudum) and C. heteroclita (DEFRANCE, 1824). The specimens identified as Martiniopsis (Elivella) rigauxi by MAILLIEUX (1940, 1941) [= Echinocoelia rigauxi sensu VANDERCAMMEN (1956)] do not belong to C. rigauxi MAILLIEUX, 1909. They are redescribed as Dionacoelia secessus n. gen., n. sp., a species occurring with certainty in the Ermitage Member of the Moulin Liénaux Formation (Palmatolepis punctata Zone)
