Index of Fungi: Petrak's Lists 1920–1939. Cumulative Index. Part 1 comprising the Index of Generic Names and the Index of Specific Epithets. Pp. 1–168, 1956. 20s. Part 2 comprising Host Index, Index of Host Genera, and Other Substrata Index. Pp. 169–307. 20s. (Commonwealth Mycological Institute, Kew, Surrey.)