The stupendous character of the natural convulsion that took place about 80,000 years ago, will be apparent from the fourth map. Daitya, the smaller and more southerly of the islands, has almost entirely disappeared, while of Ruta there only remains the relatively small island of Poseidonis. This map was compiled about 75,000 years ago, and it no doubt fairly represents the land surface of the earth from that period onwards till the final submergence of Poseidonis in 9564 B.C., though during that period minor changes must have taken place. It will be noted that the land outlines had then begun to assume roughly the same appearance they do to-day, though the British Islands were still joined to the European continent, while the Baltic Sea was nonexistent, and the Sahara desert then formed part of the ocean floor.