During the last two or three years we have been mapping and working out the geological structure of the small islands in the eastern part of the Bristol Channel. Visits to these can only be made periodically, and our work is thus likely to extend over some considerable time. We consider it desirable, in fairness to other workers and to those interested in the Lower Carboniferous rocks, to publish the main facts as far as we have established them, leaving details and any discussion until the work is completed.