Overlay maps were used to study locomotion by the externally brooding actinian Epiactis prolifera Verrill, 1869, in the rocky intertidal zone near Bodega Bay, California, USA. A greater proportion of non-brooding individuals moved than did brooding ones. Although brooding anemones that moved traveled twice as rapidly as non-brooders that moved, brooders were generally larger, and the relative rate of travel of the two groups was identical. The net distance traveled by all the anemones was only 36.0% of the gross, and most of the movement appeared to be undirected.