Mr. A. C. G. Cameron, of the Geological Survey of England and Wales, published in 1893 an account of a boulder of chalk so large that the village of Catworth has been built upon it, while springs arise between it and the clays which underlie the mass. Sir A. Geikie now reports the interesting discovery that “a cake or floor of chalk, lying at the base of the Boulder-clay, may be traced over an area of more than twenty square miles in the west and north of Huntingdonshire and in northern Bedfordshire. It crops out more or less continuously along the brow of the hills under the Boulder-clay and rests on the Oxford Clay. It probably consists of many large sheets of chalk which, at the beginning of the deposit of the Boulder-clay, were transported from the chalk hills lying to the east and north-east.”