I n 1960 some thin shale layers were found directly above the main development of the Upper Tremadocian Ceratopyge Limestone (3a?) in a new section of the future underground station at Töyen in Oslo. One of these shale layers is especially rich in graptolites. The faunal assemblage found consists essentially of the dendroid genera Clonograptus, Bryograptus, Kiaerograptus and possibly Adelograptus; additional material provisionally referred to Didymograptus is described. The material is mostly fragmental and very few specimens are preserved in full or half relief in pyrite. The faunal assemblage is similar to that described by Monsen (1925) from the Middle Tremadocian Ceratopyge Shale (3aß). The only new form at this horizon is Didymograptus? stoermeri n. sp. The Tremadocian aspect of the graptolite fauna in this shale horizon strongly supports the generally adopted inclusion of the underlying Ceratopyge Limestone (3a?) in the Tremadocian Series. A thin nodular Iimestone layer containing Ceratopyge and other characteristic trilobites of the zone 3a? rests upon the previously mentioned graptolite-bearing horizon, so that this latter itself is to be included in the zone 3a?.