The present paper is based on a new study of the material from all the prehistoric sites so far excavated in the Maltese Islands. This was made in the course of preparing for publication a Corpus of all the known monuments and material of the islands (for the Royal University of Malta). The results achieved, especially those gained by the intensive study of the pottery (much of it hitherto unpublished), seemed to justify more rapid publication than could be expected for the Corpus itself, and I have to thank the Archaeological Survey Advisory Committee of the Royal University of Malta for very kindly granting me permission to publish this preliminary report on the advances made so far. At the same time I should like to record my best thanks to the Director of the Valletta Museum, Dr J. G. Baldacchino, and his Assistant, Mr C. G. Zammit, for their wholehearted co-operation in granting me every facility for the pursuit of my studies, and for the help which they have given in innumerable ways in forwarding the work of the Survey. Lastly, it is a pleasure to thank Prof. L. Bernabò Brea for his great kindness during a week spent with him in Syracuse and Lipari, and for much help from his unique knowledge of Sicilian archaeology.