Abstract In this paper the author divides the Drift of the country extending from Flamborough Head to the Thames, and from the Sea on the east to Bedford and Watford on the west, as follows:— a , the Upper Drift, having a thickness of at least 160 feet still remaining in places, b and c , the Lower Drift, consisting of an Upper series ( b ), having a thickness of from 40 to 70 feet, and a Lower series ( c ), with a thickness, on the coast near Cromer, of from 200 to 250 feet, but rapidly attenuating inland, c comprises the Boulder-till and the overlying contorted Drift of the Cromer coast, which along that line crop out from below b a few miles inland. In an attenuated form, c also ranges inland as far south as Thetford, and probably to the centre of Suffolk, cropping out from below b by Dalling, Walsingham, and Weasenham, and appearing at the bottom of the valleys of central Norfolk, b consists of sands, which on the east coast overlie the Fluvio-marine and Red Crag, but change west and south into gravels, which pass under a and crop out again on the north, south, and centre of Norfolk, and west of Suffolk and Essex, extending (but capped in many places by a ) over most of Herts. The Upper Drift ( a ) consists of the widespread Boulder-clay, which overlaps b for a small space on the south-east, in Essex, and again at Horseheat, near Saffron Walden, but overlaps it altogether on the north-weset, resting on the secondary rocks in Huntingdonshire and Lincolnshire. The distribution of b indicates it as the deposit of an irregular bay, afterwards submerged by the sea of a, which over-spread a very wide area. a now remains only in detached tracts, having been extensively denuded on its emergence at the beginning of the post-glacial age, so that wide intervals of denudation (separating the tracts) indicate the post-glacial straits and seas which washed islands formed of a . The author considers the so-called Norwich Crag of the Cromer coast as not of the age of the Fluvio-marine Crag of Norwich, but as an arctic bed forming the base of c ) into which it passes up uninterruptedly. The author regards the beds b as identical with the Fluvio-marine gravels of Kelsea, near Hull, and thinks that the Kelsea bed is not above a , as hitherto supposed, but below it, having been forced up through a into its present position. He also regards the Upper Drift ( a ) as the equivalent of the Belgian Loess, and the beds b as the equivalent of the Belgian Sables de Campine.