Readers of this Beiheft of Nova Hedwigia will find articles on a large variety of diatoms, from fossil to recent, marine to freshwater, established species and genera to new ones. Fifty-two authors have contributed to this volume by their diversity of interests. Topics range from morphology, taxonomy, ecology and distribution of diatoms found all over the world (from Europe to Russia and Asia, from the entire American Continent and even the Antarctica) and from past to recent. The variety of the papers presented in this volume reflects the diversity of scientific interests of Nina Strelnikova, to whom this Beiheft is dedicated. This volume is of interest for every scientist working on diatoms and interested in the variety of diatom research. It should not be missing in any library.