It seemed useful to correct some errors which have crept into the text of volume 4 as well as to add some additional data which came to our knowledge and are worth recording. Valuable help in general was rendered by Dr R. C. BAKHUIZEN VAN DEN BRINK Jr, for additions to the Burmanniaceae by Dr F. P. JONKER, for Chenopodiaceae by Dr C. A. BACKER, for Viburnum by Mr J. H. KERN, for Xyris by Dr P. VAN ROYEN, and for a grass by Dr P. JANSEN. Printing errors have only been corrected if they may give rise to confusion. The page numbers a and b denote respectively the left and right column.