Upper Ordovician (Harjuan) oncoceratid nautiloids from the Boda Limestone, Siljan District, Sweden

Ten species of oncoceratid nautiloid cephalopods, assignable to the families Oncoceratidae, Diestoceratidae and Karoceratidae are reported from the Upper Ordovician (Harjuan) Boda Limestone of the Siljan District, province of Dalarna, Sweden. Seven of these species are apparently restricted to the Boda Limestone and three are known from the Upper Ordovician rocks of Norway. One species has been previously reported from Estonia. Two new genera, Dalecarlioceras and Kallholnoceras, and seven new species are described. The new species include Beloitoceras siljanense, Cyrtorizoceras dalecarlicum, Dalecarlioceras bodense, D. constrictum, Diestoceras parallelum, Dowlingoceras kallholnense and Kallholnoceras cornutum. The Family Karoceratidae is reexamined.