1. Fine structure of the eyes of Pseudoceros canadensis (Turbellaria, Polycladida)

   • Richard M. Eakin
   • Jean L. Brandenburger

   OriginalPaper Pages: 1 - 16

2. The structure of the double-eyes of Baetis and the uniform eyes of Ecdyonurus (Ephemeroptera)

   • Frank Burghause

   OriginalPaper Pages: 17 - 34

3. Bau und Funktion des Süßwasserschwamms Ephydatia fluviatilis L. (Porifera)

   • Norbert Weissenfels

   OriginalPaper Pages: 35 - 45

4. Ergänzende Untersuchungen zur Ultrastruktur von Trichoplax adhaerens F.E. Schulze (Placozoa)

   • Karl G. Grell
   • Gertrud Benwitz

   OriginalPaper Pages: 47 - 67

5. Fine structure and function of the digestive tract of Cyathura carinata (Krøyer) (Crustacea, Isopoda)

   • Johann-Wolfgang Wägele
   • Ulrich Welsch
   • Waltraud Müller

   OriginalPaper Pages: 69 - 88

6. Observations on the moving colonies of the genus Tethya (Demospongia, Porifera)

   • Lev Fishelson

   OriginalPaper Pages: 89 - 99