22 paleocop ostracods are described from the Upper Ordovioian of the Oslo Region in Norway. A chart shows their stratigraphical and geographical distribution (p. 101). The following species are new: Bolbina tuberculata, Öpikium porkuniensis, Primitia osloensis, Platybolbina tiara, Laccochilina tarda, Bollia accentuata, Pseudulrichia norvergica, and Moncceratella bos. The Calcareous Sandstone (5b) is included in the Ordovician and is placed together with the Gastropod Limestone (Sa) in a new division of the Upper Ordovician of the Oslo Region, called the Dalmanitina Series. The underlying Tretaspis Series is restricted to 4c and 4d. Many of the ostracocls of the Dalmanitina Series were first clescribed from glacial drift boulclers in N. Germany. The fauna resembles that of the Swedish Leptaena Limestone and of the Esthonian Porkuni (Borkholm) Limestone. Some of the drift species are recorded for the first time from in situ material.