This volume of Nova Hedwigia Beihefte includes papers covering a broad range of topics in
diatom and chrysophyte research - including historical analyses of taxa names and name changes
- through descriptions of novel taxa observations of fine details of valve and cell morphology
and ultrastructure in many cases in an ecological and or biostratigraphic context to attempts
at clarifying some hard-to-resolve questions on the evolutionary history of diatoms. Although
there is no single common scientific thread connecting all contributions they are all
influenced in some way by the work of R. M. Crawford. Some highlight the still substantial
extent of undiscovered terrain in the realm of diatom (and microalgal) ultrastructure
regarding variations on the fine construction of both frustules and organic cell components an
area of research in which R. M. Crawford laid important groundwork. Other papers add to our
understandingof individual taxonomic groups in which R. M. Crawford raised a heightened
interest such as the genus Corethron which features the most elaborate movements of cell wall
parts during cell division in diatoms or the diverse genera of melosiroid diatoms where the
work of R. M. Crawford was instrumental in recognizing the extent of (functional-)morphological
and ecological variability. Combining diverse perspectives and methods this volume will be of
interest to researchers of diatoms chrysophytes and other microalgal groups. The volume is
dedicated to Richard M. Crawford who spent a lifetime researching dinoflagellates and diatoms
particularly their morphology and taxonomy utilizing various microscopical techniques. He is
perhaps best known for his pioneering works on the dinoflagellate genera Oxyrrhis and
Woloszynskia and the centric diatoms Aulacoseira Melosira Ellerbeckia Paralia and
Corethron. He was one of the contributors to the famous blue book (The Diatoms: Biology &
Morphology of the Genera) and was the curator to the Hustedt Diatom Collection in Bremerhaven.
