On the rocky shores of the British Isles three species of Fucus are commonly found as components of the intertidal algal belt, namely, F. spiralis L., F. vesiculosus L. and F. serratus L. A fourth species, F. ceranoides L., occurs in places subject to the influence of fresh water but, although it may be important in connexion with the interacting processes to be described below, F. ceranoides is omitted from the present discussion because as yet too little is known of its autecology. Under the conditions prevailing in the characteristically zoned algal flora of an undisturbed region of a rocky coast, descriptions of the three species can be applied which fairly effectively distinguish one from the others. The chief characters used for this purpose are shown in Table I.

The diatom flora inhabiting the muddy shores and bottoms off Plymouth has received little attention in comparison with the fauna associated with such muds. Since a large number of the microfauna depend, to a great extent, upon the diatoms as a source of food (Mare, 1942), a knowledge of the latter is there-fore desirable.

The family Myidae is represented in British seas by the two large and well-known species, Mya arenaria L. and M. truncata L., which burrow deeply into muddy sand and into stiff mud or clay respectively, and by the much smaller Sphenia binghami Turton. Interest in members of this family of Eulamellibranchia was aroused during 1949 when studying two species which are common along the coast of California, namely Platyodon cancellatus (Conrad) and Cryptomya californica (Conrad). These differ most interestingly in habitat. The former bores into soft rocks between tide marks, and the latter, although practically devoid of siphons, burrows deep in the mud of tidal estuaries, always in association with burrows made by various large invertebrates. The species most usually involved is Callianassa californiensis, a large anomuran prawn (McGinitie, 1935). The almost sessile siphons open into the sides of the burrows. Accounts of both species have been prepared for publication in California.

The Council has to record with deep regret the deaths of the following former members of Council: Mr H. G. Maurice, C.B., who had represented the Ministry of Agriculture and Fisheries and the Zoological Society, and was a Vice-President; Prof. H. Gordon Jackson who had represented the British Association for the Advancement of Science; Dr R. S. Clark, a former member of the Scientific Staff of the Plymouth laboratory; and Sir Sidney F. Harmer, F.R.S., a member of Council since 1895, who had represented the Royal Society, and was a Vice-President; also Mr R. Hansford Worth and Mr Arthur W. W. Brown, Founders of the Association, the latter having been the last survivor of the original members.