On the 6th March, 1874, I communicated a paper on the “Geology of the Neighbourhood of Nottingham” to the Geologists' Association, which was subsequently printed in extenso in their Proceedings. Up to that time I believe the definition laid down by the Government Survey, and imported into text-books, of the distinction between the so-called Permian and the New Red Sandstone formations had not been called in question very prominently. Like other students of geology, I myself accepted in good faith the dictum as to a great break existing between the two formations, indicating, of course, an enormous period of time.