SYNOPSIS Original material for almost all of the polycystine radiolarian species described by Christian Gottfried Ehrenberg (~80 genera, ~530 species) are housed in the Museum fr Naturkunde, Berlin. Eleven type specimens of 10 spongodiscid and stylodictyid radiolarian genera were found in Ehrenberg's original mica strips. These micas are from six different sample locations and range in geological age from (approximately) late Eocene to Holocene. Ten specimens are confirmed as those sketched by Ehrenberg and are designated as lectotypes. Consequently, Dictyocoryne profunda is the senior valid synonym of Euchitonia furcata and Rhopalodictyum abyssorum. The Ehrenberg collection contains several specimens identified as F. concentrica, the type species of the genus Flustrella. After careful examination, the best preserved specimen was defined as the lectotype and, as a result, Flustrella (type species: F. concentrica) is confirmed as a valid name, while Porodiscus (Trematodiscus orbiculatus) and Trematodiscus (T. orbiculatus) are junior synonyms of Flustrella. The type species of Spongodiscus (S. resurgens), Spongaster (S. tetras) and Dictyocoryne (D. profunda) possess concentric internal structures, suggesting close phylogenetic relationships with Flustrella. Lectotypes of Stylodictya (S. gracile), Perichlamydium (Flustrella praetexta), and Stephanastrum (S. rhombus) are designated.