Twenty years ago Professor J.W. Judd, in a paper * which has become classical, described to this Society the Clays which emerge from beneath the Chalk at Speeton on the coast of Yorkshire, and showed that they comprise the fullest development of marine beds of Lower Cretaceous or Neocomian age to be found in England; and, in a later paper†, he pointed out that the section at this place furnished the key by means of which might be identified the more or less isolated and fragmentary exposures of beds of this age scattedred over the whole of the great North-European area. He showed, moreover, more clearly that had hitherto been done, that the uppermost beds of the Jurassic formation were also represented in the series, and defined the limits of the two systems. In spite of the acknowledged importance of the section and the uncertainty which still pertained to parts of it, there has been practically no addition to our knowledge of the of the locality since these papers were published — the reason for this being, no doubt, the generally obscure and difficult state of the cliffs, as it is rarely, except in the winter or in stormy weather when this bleak coastline has few visitors, that the conditions of the section are favourable for observation. It neeeds a high and stormy tide, to reveal a fresh unweathered surface of clay at the foot of the slopes, or a heavy onshore gale, to sweep aside the sand and shingle of the beach, before the student of the section can make any really satisfactory progress either in collecting the fossils or in studying the sequence of the deposits; and many repetitions of such conditions are necessary before the many difficulties of the section can be grasped.