New Caradocian ostracodes from the Oslo-Asker district, Norway

Ten new ostracode species are described from the Middle Ordovician Chasmops beds of the Oslo-Asker district, Norway: Piretia reticulata sp. nov., Steusloffia spinosa sp. nov., Bullaeferum forneboensis gen. nov., sp. nov., Sigmobolbina histiospinosa sp. nov., Valdarella laciniata gen. nov., sp. nov., Crenabolbina norvegica gen. nov, sp. nov., Eolomatella biloba sp. nov., Grammolomatella norvegica sp. nov., Urdia barbata gen. nov., sp. nov., and Primitiella reticopunctata sp. nov. Different ostracode assemblages occur in the Lower and in the Upper Chasmops beds respectively.