Among the so-called Glacial beds, none fills a larger place in geological literature than the Chalky Clay of Eastern England. I prefer to call it the Chalky Clay, as Searles Wood named it, rather than the Chalky Boulder-clay, because boulders in the true sense of the word, such as characterize the genuine Boulder-clays of North Britain, are infrequent in it. The term Chalky applied to this clay depends on the fact that it is more or less crowded with chalk rubble and chalk fragments of various sizes, and that it has also incorporated in it a considerable quantity of chalk dust, whence its colour and superficial appearance. These peculiarities, which mark it over a wide area from Yorkshire to Finchley, and from Southwold to Warwickshire, are, nevertheless, a secondary, and not a primary, feature of the clay, and have disguised and confused the problem of its explanation.