CONTENTS:  1. Introduction; Section A. Minor Acoelomate Phyla 2. Phylum : Mesozoa; 3. Phylum : Ctenophora; Section B. Minor Pseudocoelomate Phyla  4. Phylum : Nemertinea or Rhynchocoela (The Ribbon Worms); 5. Phylum : Entoprocta or Endoprocta (Calyssozoa); 6. Phylum : Acanthocephala (Spinny-headed Worms); 7. Phylum : Nematomorpha or Gordiacea (The Horse-hair Worms); 8. Phylum : Rotifera or Rotatoria (The Wheel Animalcules); 9. Phylum Gastrotricha; 10. Phylum : Kinorhyncha (Echinodera); Section C. Minor Coelomate Phyla 11. Phylum : Bryozoa (Ectoprocta); 12. Phylum : Brachiopoda; 13. Phylum : Phoronida; 14. Phylum : Chaetognatha (Arrow Worms); 15. Phylum : Priapulida; 16. Phylum : Sipunculida; 17. Phylum : Echiuroidea; 18. Phylum : Pogonophora or Brachiata; Important Questions; Bibliography.