Bellerophon? norvegicus Brøgger, from the Ceratopyge Limestone (3aγ) is redescribed and designated the type species of Sinuitella, new genus. Seven specimens of Pararaphistoma (Pararaphistoma) qualteriatum (Schlotheim) and one specimen of Proturritella sp. are described from the "transition beds" immediately overlying the Orthoceras Limestone (3c). Scattered information on the stratigraphic distribution of these two genera elsewhere in Scandinavia suggests that they may indicate beds older than Middle Ordovician.
Early Ordovician gastropods from the Oslo Region, Norway.