Includes bibliographies.

List of publications by Leslie Harvey (p. xi-xii).--Mann, K. H. The analysis of aquatic ecosystems.--Hartland-Rowe, R. C. B. The limnology of temporary waters and the ecology of Euphyllopoda.--Chaston, I. Non-c atastrophic drift in lotic systems.--Kennedy, C. R. Parasite communitie s in freshwater ecosystems.--Wootton, R. J. The evolution of insects in freshwater ecosystems.--Raymont, J. E. G. Some investigations into the biochemical composition of marine zooplankton.--Brafield, A. E. Some a daptations of low environmental oxygen in marine beaches.--Harris, T. S ome observations upon the methods of incubation in the genus Spirorbis and their possible zoo geographical significance.--Sleigh, M. A. Featur es of ciliary movement in the ctenophores Beroèe, Pleurobrachia and Ces tus.