In this article once more a new mollusc is mentioned for the marine fauna of the Netherlands. One living specimen of Trophon (Trophonopsis) barvicensis Johnston was found on cork, that was washed ashore south of Katwijk aan Zee on 15 October 1938. The specimen is not full-grown but shows all characteristics of the species. The origine might be southern as well as northern. Besides this mollusc representatives of 20 species of Evertebrata and 7 species of plants have been found on the cork.