Twee receptaculieten uit de Wilsumer Bergen

Two receptaculitids from the Wilsumer Bergen (County of Bentheim, F.R.G.) are described. One of them is probably Ischadites koenigii Murchison, 1839. The other belongs to an unknown genus. It consists of two conical walls, which are connected by some needlelike columns. The innerwall shows a pattern of pores, connecting the central cavity with the inter-wall space. Both silicified fossils are most probably of (Upper-) Ordovician age.