A HISTORY OF SUSSEX coated flints and pieces of ironstone. Some of the unworn flints in it undoubtedly are derived from the slow solution of the Chalk below, and a small part of the clayey matrix also may come from this source. The Upper Chalk of Sussex however is so pure that the removal of the soluble carbonate of lime would leave merely a stony desert of flints, without sufficient clay to fill the interstices. Such a stony waste is now gradually forming on parts of the Downs where no Tertiary material remains. The London Clay in Sussex is more sandy than the corresponding deposit in the London basin, though not nearly so different as the local name, 'Bognor Beds,' formerly used would imply. It is a dark-blue clay, more or less sandy, containing beds of sand in the upper part, and in places it has a mass of flint shingle at the base. Two of the sand-beds near Bognor have been consolidated into hard sandstone ; and as these sand- stones form conspicuous rocky ledges, the Bognor Rocks and the Barn Rocks, projecting seaward from a coast otherwise flat and sandy, they have been given more importance than their small thickness would warrant. The Bognor Rock however is of considerable interest, for the fossils contained in it, now difficult to obtain, are well preserved and are not compressed like those ordinarily found in the London Clay. The most common are Fectunculus brevirostris, P. decussatus, Cardita brongniarti, Panopcea intermedia, Pholadomya margaritacea, Pimia affinis, all common fossils of the London Clay elsewhere. There is also a peculiar volute. Valuta nodosa, and the flat-coiled Vermetus bognoriensis . The total thickness of the London Clay is about 320 feet. Like the Reading Beds, much of it is hidden by newer deposits ; but where exposed it forms heavy clay land principally covered by oak plantations. Bricks are made from it ; but not to any great extent in Sussex, where better and more easily worked brick-earth is to be found in the same districts. It is still somewhat uncertain whether Sussex contains any repre- sentative of the Lower Bagshot Beds. Sandy strata occur at the top of the London Clay on each side of the Selsey peninsula ; but they are difficult to examine, being hidden by gravel, and striking the coast just where everything is obscured by the mud of Pagham Harbour and of West Wittering. The sands cannot be thick, and no fossils have been obtained from them ; it is possible however that some of the deposits with driftwood occasionally to be seen on the foreshore near West Wittering may be referred to this formation. The Bracklesham Beds form one of the most interesting deposits of the county from a scientific point of view ; but as they are entirely hidden by drift, except on the foreshore, and are confined to the Selsey peninsula, they have little influence on the character of the scenery, nature of the soil, or position of the settlements. The thickness of these strata reaches however as much as 500 feet. From top to bottom they consist of greenish, more or less carbonaceous clays and marls, alternating with glauconitic sands. Fossils are abundant, in fact 14
