David Williamson has now added his collection of Desmid Illustrations to the Freshwater Biological Association. Over 10,000 of his own drawings, of individual taxa, are filed in labelled folders in three 2-drawer filing cabinets within the Fritsch Collection. It is his wish that these be available to anyone interested in Desmids, so all are welcome. Each illustration is accompanied by the location and date, and size, as well as the name of the Collector if not from his own material. David Williamson has produced many published papers and several books, the most recent being the new Ray Society volume A Monograph on some British Desmids. A.J. Brook and D.B. Williamson. Edited by J.H. Price and N.J. Evans. 2010. He has also contributed to the new edition of The freshwater algal flora of the British Isles: an identification guide to freshwater and terrestrial algae.