Foraminiferen und (?) Phoronidea als Kommensalen auf den Hartgründen der Maastrichter Tuffkreide

Small vertical borings in the hardgrounds of the ,Maastrichter Tuffkreide<~ (Upper Maastrichtian) are frequently surrounded by agglutinating foraminifera (especially Bdelloidina vincentownensis Hofker) at their upper ends. From that mode of growth may be concluded that these straight borings have been made by a wormlike quiver bearing organism whose cylindrical quiver was encrusted and moulded by the tests of the foraminifera where it surmounted the level of the hardground. The borings remind very much of the tunnels of the recent Phoronidea and have provisionally been determined as (?) Phoronopsis. The mode of association suggests commensalism between both organisms