INTRODUCTION

Between 4 May 1973 and 29 March 1975 we did not visit Duckpool. Indeed after the 1973 visit (Wilson, 1974, pp. 429–30) the intention had been to discontinue observations on colony formation and growth, for it seemed unlikely that much more data of value were obtainable, and that is still true. However, at Easter 1975 Monsieur Yves Gruet, who has done much excellent work on Sabellaria associations on the coast of France (references in Wilson, 1974), visited Plymouth with his family and wished to see Duckpool. We went there on 29 March and arising out of that visit my wife and I were again there the following October, with one main object in view as explained below, and this in turn led to a further visit in November. This paper records observations made during those visits.