A puzzling name, and one not provided by Leland - the Roman name for St David's Head was Octapitarum promontorium. Possibly Harrison felt the need to account for the `Limnu insula deserta' named by Ptolemy as one of the islands between Ireland and Britain - it has been identified as Lambay Island, a few miles north-east of Dublin; Claudii Ptolemaei Geographia ed. C. Muller (Paris, 1893), I, 81. There seems to be no foundation for the suggestion that it is Ramsey Island, less than a mile from St David's.