The Kimeridge clay, named as the next stratum in the bore of the Woodhall well, crops up first about Halstead Hall in Stixwould, and continues through Woodhall to Horncastle, and so on to Wragby and Market Rasen. It abounds in fossils. Mr. Skertchly {92} found in the first of the pits just named, that this clay was divided into three layers, the upper being a line of Septaria (or nodules) full of serpulæ one foot in depth, then soft dark-blue clay, 6ft.; and below that another course of Septaria; and Professor J. R. Blake records from this pit the following fossils{93a}:—Belemnites nitidus, Ammonites serratus, Rissoa mosensis, Avicula ædiligensis, Cyprina cyreneformis, Ostrea deltoides, Lima ædilignensis, Thracia depressa, Arca, Serpula tetragona. In other pits in the neighbourhood several other fossils have been found. {93b} [For a list of fossils found about Woodhall see Appendix II.] A peculiarity of this stratum is that the upper part of it contains bands of “inflammable shales,” being blue, laminated, bituminous clays, which burn readily. It was the presence of these which has tempted explorers to throw away their money in search of coal; as in the case at Donington on-Bain, where Mr. Bogg drove a bore to the depth of 309ft., but only found clay and thin bands of inflammable schist. {93c} In the case of Woodhall Spa, the money thrown away on one purpose has brought health and wealth to others, from a source then undreamt of in man’s philosophy. We cannot leave the Kimeridge clay without noting that its presence at Woodhall, in the position where it is, as the _first_ geological formation below the surface drift, opens to us a vista—reveals to us a yawning _hiatus_—which embraces a vast expanse of time.