1. The sphaeridia of sea urchins: ultrastructure and supposed function (Echinodermata, Echinoida)

   • Konrad Märkel
   • Ute Mackenstedt
   • Ursula Röser

   OriginalPaper Pages: 1 - 10

2. Photoreceptors with mitochondrial lenses inPogaina suecica (Plathelminthes, Rhabdocoela)

   • Beate Sopott-Ehlers

   OriginalPaper Pages: 11 - 15

3. A new glandular sensory organ inCatanema sp. (Nematoda, Stilbonematinae)

   • Monika Nebelsick
   • Michael Blumer
   • Jörg Ott

   OriginalPaper Pages: 17 - 26

4. On the spinning apparatus and the structure of the capture threads ofDeinopis subrufus (Araneae, Deinopidae)

   • Hans M. Peters

   OriginalPaper Pages: 27 - 37

5. Morphology and ultrastructure of the gills of terrestrial crabs (Crustacea, Gecarcinidae and Grapsidae): Adaptations for air-breathing

   • Caroline A. Farrelly
   • Peter Greenaway

   OriginalPaper Pages: 39 - 49

6. The filtration apparatus for food collection in freshwater sponges (Porifera, Spongillidae)

   • Norbert Weissenfels

   OriginalPaper Pages: 51 - 55

7. Spermatogenesis in the earthwormMicrochaetus pentheri (Oligochaeta, Microchaetidae)

   • A. N. Hodgson
   • B. G. M. Jamieson

   OriginalPaper Pages: 57 - 66