Preface; Part I. Biology of Diatoms: 1. Preamble; 2. The diatom cell; 3. Collecting and studying diatoms; 4. Culturing; 5. Silicon: occurrence, uptake and deposition; 6. Cell symmetry; 7. Life form; 8. Valve structure; 9. Complementarity and heterovalvy; 10. Portules; 11. Ocelli, pseudocelli and pseudonoduli; 12. Raphe; 13. Girdle bands (copulae); 14. Internal valves; 15. Resting stages and resting spores; 16. The organic casing; 17. The protoplast: plastids, mitchondria, dictyosomes, nucleus, vacuole; 18. The cell cycle; 19. Vegetative multiplication and cell size reduction; 20. Sexual reproduction; 21. Oogamy; 22. Physiological anisogamy and isogamy; 23. Automixis and parthenogenesis; 24. Auxospore development; 25. Motility; 26. Ecology; 27. Palaeoecology; 28. Concepts in diatom systematics; 29. Evolution and phylogeny; 30. Fossils; 31. Accounts of genera - preliminary notes; 32. Summary of classification; Part II. Generic Atlas: 33. Centric genera; 34. Araphid genera; 35. Raphid genera; Appendix I: new taxa; Appendix II: list of recently described genera; Appendix III: index nominum genericorum; References; Taxonomic index; Subject index.