ABSTRACT
Populations of the British regular echinoid Echinus esculentus from three localities in the British Isles have been surveyed bydiving teams for several successive years. Results are given of comparisons of test size and shape for two years in the case of populations from W, Scotland and S.W, Ireland, and three years for S.W. England, One site in W, Scotland showed an increase in mean size over the year. A survey of a series of sites in a long narrow bay in S,W, Ireland showed the possible effect of degree of exposure on sea-urchin shape in shallow water, At a site in S.W. England, urchin populations disappeared from shallow water over the period of one year, but re-appeared after a further year.
