De Twentse Krijtsponsen

Different erratic cretaceous sponges from Twente (Netherlands) are described, and comparisons are made with sponges from the Upper Chalk (Senon) in Westphalia, Hannover and an unknown district, which is probably situated in the area of the Baltic sea. In opposition to the apprehension of some authors, who describe Westphalia as the district of origin of all cretaceous sponges found in Twente, an attempt is made here to prove that these sponges are originating not only from Westphalia, but also from the two other named districts. Described are sponges in the Dutch geologic collections ANDERSON, SCHOLTEN, E. DE VRIES and KRUL, and specimen of the collection Westphalian sponges in the Geologic Museum in Münster (Germany).