Review of: Systema Porifera, edited by J. N. A. Hooper and R. W. M. van Soest. Kluwer Academic Publ., Dordrecht, Netherlands, 2002, 1708 pp., ISBN 0-306-47260-0 This seems to be a time for the publication of big compendia. One would have thought that in this age of the internet one would be turning to convenient web-sites to find the latest catalogues of data and information about biodiversity of animal groups. Indeed, such do exist, and many of them are remarkably detailed and informative. Nevertheless, there has been a steady stream lately of traditional hardcopy volumes presenting systematic and taxonomic overviews of various groups of animals. This handsome two-volume set is amongst the latest example of these kinds of books to appear.