We undertake a re-interpretation of eighteen sheets of the 1: 100,000 Geological Survey map of Italy. Developing the tectonic discoveries of G. Steinmann and S. Lencewicz we group the pre-Middle Miocene rocks of the district in four structural units beginning with the lowest as follows: (1) The rocks seen through the Carrara Window; (2) Spezia Nappe; (3) Liguria Nappe; (4) Genoa Nappe. Our account mainly concerns the Liguria Nappe. In it we find too much layering to admit of G. I. Migliorini's invocation of successive piecemeal landslips. We also cannot agree with certain important features of R. Staub's synthesis of Mediterranean tectonics.