ATLANTIS, ATALANTIS or ATLANTICA, a legend ary island in the Atlantic ocean. Plato in the Timaeus describes how Egyptian priests, in conversation with Solon, represented the island as a country larger than Asia Minor with Libya, situ ated just beyond the Pillars of Hercules (q.v.). Beyond it lay an archipelago of lesser islands. Atlantis had been a powerful kingdom nine thousand years before the birth of Solon, and its armies had overrun the Mediterranean lands, when Athens alone had resisted. Finally the sea overwhelmed Atlantis, and shoals marked the spot. In the Critias Plato adds a history of the ideal commonwealth of Atlantis. It is impossible to decide how far this legend is due to Plato's invention, and how far it is based on facts of which no record remains. Mediaeval writers, receiv ing the tale from Arabian geographers, believed it true, and had other traditions of islands in the western sea, the Greek Isles of the Blest, or Fortunate Islands (q.v.) ; the Welsh Avalon, the Portuguese Antilia or Isle of Seven Cities (q.v.), and St. Bren dan's island, the subject of many sagas in many languages. All except Avalon were marked in maps of the 14th and 15th cen turies, and formed the object of voyages of discovery; St. Bren dan's island until the i8th century. Somewhat similar legends are those of the island of the Phaeacians (Homer, Od.), the island of Brazil (q.v.), of Lyonnesse (q.v.), the sunken land off the Cornish coast, of the lost Breton city of Is, and of Mayda or Asmaide, the French Isle Verte and Portuguese Ilha Verde or "Green Island." The last appears in many folk-tales from Gibraltar to the Heb rides, and until 1853 was marked on English charts as a rock in 48' N. and 26° 1o' W. After the Renaissance attempts were made to rationalize the myth of Atlantis. It was identified with America, Scandinavia, the Canaries or Palestine. Ethnologists saw in its inhabitants ancestors of the Guanchos, the Basques or the ancient Italians. Even in the 17th and 18th centuries the credibility of the legend was seriously debated, and sometimes admitted, even by Montaigne, Buffon and Voltaire.