Some of the beliefs and legends bequethed to us by Antquity are so universally and firmly established that we have become accustomed to consider them as being almost as ancient as humanity itself. Nevertheless we are tempted to inquire how far the fact that some of these beliefs and legends have so many features in common is due to chance, and wether the similarity between them may not point to the exestience of an ancient, totally unknown and unsuspected civilization of which all other traces have disappeared.