William Whitaker

“ In some cases a marked gravelly layer was clearly seen to be at one spot in the Crag and at another in the sand; and in one pit a hand-specimen could be got of such a bed, half containing the actual shells, and the other half with casts only. In some pits large masses of shelly Crag are to be seen quite surrounded (in section) by the shelless sand—a fact difficult of explanation on any other view, but comparatively easy to understand as brought about by irregular dissolving action, checked in places by local hardness or slight decrease of permeability in the beds. ”

“ Confirmatory evidence was given by the not uncommon occurrence in the upper sand of layers or masses of ironstone or iron-sandstone, which were often found to contain impressions and casts of the shells that had been dissolved out; and these, as far as could be told, were of Crag species. They occur in the area in which the sand has been thought to be unfossiliferous ”