A modern revision of the Pteropoda after the monograph by J. J. TESCH in ‘Das Tierreich’ (1913) is a most welcome extension of our knowledge of these molluscs in half a century. In his doctor thesis VAN DER SPOEL deals with only one group of pteropods, the Euthecosomata, including the genera Limacina, Creseis, Styliola, Hyalocylis, Clio, Cuvierina, Diacria and Cavolinia. The other genera of the Thecosomata and the Gymnosomata will be treated in two further publications.