Lichenology: Progress and Problems. Edited by D. H. Brown, D. L. Hawksworth and R. H. Bailey. [Systematics Association Special Volume No. 8.] Academic Press, London, New York and San Francisco. April 1976. Pp. xii + 551, plates 52, figures 113, tables 53. Price £19, US S48.25 [also at a reduced rate to members of the British Lichen Society and the Systematics Association].