BM _Bembridge Marls._ BL _Bembridge Limestone._ O _Osborne Beds._ H _Headon Beds._ BS _Barton Sand._ B _Barton Clay._ Br _Bracklesham Beds._ Bg _Bagshot Beds._ L _London Clay._ R _Reading Beds._ Ch _Chalk._ P _Pebble Beds._ S _Sandstone Band._ Above the Chalk we come first to a thick red clay called Plastic clay. It is much slipped, and the slip is overgrown. The only fossils found in the Island are fragments of plants; larger plant remains on the mainland show a temperate climate. This clay was formerly worked at Newport for pottery. The clay is probably a freshwater deposit formed in fairly deep water. On the mainland we find on the border shallow water deposits called the Woolwich and Reading beds. (The clay is 150 to 160 ft. thick at Whitecliff Bay, less than 90 ft. at the Alum Bay.) We come next to a considerable thickness of dark clay with sand, at the surface turned brown by weathering. This is the London clay, so called because it underlies the area on which London is built. At the base is a band of rounded flint pebbles, which extends at the base of the clay from here to Suffolk. In it, as well as in a hard sandstone 18 inches higher up, are tubular shells of a marine worm, _Ditrupa plana_. The sandstone runs out on the shore. About 35 ft. above the basement bed is a zone of _Panopaea intermedia_ and _Pholadomya margaritacea_, at 50 ft. another band of _Ditrupa_, and at about 80 ft. a band with a small _Cardita_. In the higher part of the clay are large septaria,--rounded blocks of a calcareous clay-ironstone, with cracks running through them filled with spar. _Pinna affinis_ is found in the septaria. The thickness of the clay in Whitecliff Bay is 322 feet. It can be seen on the shore, when the tide happens to have swept the sand away. Otherwise the lower beds are hardly visible, there being no cliff here, but a slope overgrown with vegetation. In Alum Bay the London clay, about 400 ft. in thickness, consists of clays, chiefly dark blue, with sands, and lines of septaria. In the lower part is a dark clay with _Pholadomya margaritacea_, still preserving the pearly nacre. There are also _Panopaea intermedia_, and in septaria _Pinna affinis_. All these with their pearly lustre, are beautiful fossils. A little higher is a zone with _Ditrupa_, and further on a band of _Cardita_. Other shells also are found in the clay, especially in the lower part. They are all marine, and indicate a sub-tropical climate. Lines of pebbles show that we are near a beach. In other parts of the south of England remains from the land are found, borne down an ancient river in the way we found before in the Wealden deposits.