In a recent paper on the Marble District of the Apuan Alps or Carrara Mountains I showed that the gneissose schists which form the nucleus of that range, and upon which rests the Triassic marmiferous formation, are, not of Archæan, but, upon irrefutable palæontological evidence, of Palæozoic age, and that, upon equally conclusive lithological and stratigraphical evidence, they must be assigned to the later part of that period, that is, to the Lower Permian. The former conclusion was first arrived at in the course of the geological survey of the range by Lotti and Zaccagna and upon the palæontological authority of the late Professor Meneghini; the latter conclusion was chiefly the result of the striking analogy, first pointed out by Zaccagna, between the stratigraphical sequence and lithological characteristics of the Apuan Alps and the Montgioie range of the Maritime Alps which forms the divide between Southern Piémont and the Western Italian Riviera.