Ordovician ostracodes from Baltoscandia

From Middle and Upper Ordovician erratic boulders of northern Germany and Gotland (Sweden) the following new species of ostracodes are described: Bolbihitlhis abdominalis, Brevibolbina pontificans, Brevibolbina fissurata, Tvaerenella postpleta, Deefgella dajsiveteri, Pseudulrichia ullehmanni. The genus Deefgella of the Perspicillinae (Tetradellidae) is new.