While I was engaged in surveying the Drift-deposits of the neighbourhood of Warrington, Runcorn, and the Peckforton Hills near Chester, my attention was called to what appeared to be a good boundary-line in the middle of the Lower Keuper Sandstone, separating the Waterstones from the Conglomerates underlying them. The sections at Runcorn and Frodsham, where I first saw this line exposed, have been already described with many others in the Survey Memoirs on the Neighbourhood of Prescot (3rd edition) and on the Neighbourhood of Chester. They showed that there was no passage from the Waterstones down into the Conglomerates, but that there was on the contrary a sharp division between them; and as on following this line further south, I found that it was persistent, and everywhere separated beds of a very different nature, it was decided that it should be engraved on the Map, the new classification of the Keuper of this neighbourhood, as contrasted with the old, being shown in the accompanying figure.