1. Embryonale und larvale Schale einiger Prosobranchier (Gastropoda, Mollusca) der Oosterschelde (Nordsee)

   • Klaus Bandel

   OriginalPaper 01 April 1975 Pages: 3 - 22

2. Some notes on the algal vegetation of two brackish polders on texel (The Netherlands)

   • P. J. G. Polderman

   OriginalPaper 01 April 1975 Pages: 23 - 34

3. Diel and annual oxygen regimes in a small lake

   • Robert Lingeman
   • Ben J. G. Flik
   • J. Ringelberg

   OriginalPaper 01 April 1975 Pages: 35 - 44

4. Some aspects on the role of bacteria in deep water ecosystems

   • Th. E. Cappenberg

   OriginalPaper 01 April 1975 Pages: 45 - 47

5. Miscellanea

   • A. L. van Berge Henegouwen
   • C. van der Velde
   • L. W. G. Higler

   Announcement 01 April 1975 Pages: 48 - 50