So HANDBOOK OF FOSSILS. 



bones and teeth of whales, sharks, etc. Amongst the shells the 

 Reversed Whelks (Fustis contrarius}, Fectenopercnlaris, Pec tun- 

 cnlus glycimeris, several kinds of Maclra and Cardinm, etc., are 

 the commonest. Walton-on-the-Naze, Felixstowe, and Wood- 

 bridge are the best known localities. 



c. The White or Coralline Crag is generally of a pale buff 

 colour, and is in places almost entirely composed of the remains 

 of Polyzoa. These (formerly called Corallines, whence the 

 name Coralline Crag) are beautiful objects for a low-power 

 microscope, or pocket lens, and are easily mounted in deep cells 

 on slides. The bits of shell and sand that stick to them should 

 be carefully removed with the point of a needle. A very large 

 number of shells occur in this crag : of bivalves, the Pecten is 

 very abundant, and its valves are frequently thickly grown 

 over with Polyzoa ; Cyprina IsZandica, Cardita Senilis are also 

 plentiful ; and of univalves, the genus Natica is common. The 

 Coralline Crag is best seen in the neighbourhood of Aldborough, 

 Orford, Woodbridge, and other places in Suffolk. 



2. Miocene, possibly represented in the British Isles by a small 

 patch of clays and lignites at Bovey Tracey. 



3. Eocene, divided into 



a. Upper Eocene, consisting of a series of very fossiliferous 

 sands, clays, and limestones, exposed in the cliffs at the eastern 

 and western ends of the Isle of Wight and on the neighbouring 

 coast of Hampshire. They are partly of fresh water origin, when 

 they contain the remains of freshwater shells such as Limnaa 

 Paludina, Planorbis, etc. ; partly of marine origin, when shells 

 belonging to such genera as Ostrea, Venus, etc., take their 

 place ; partly of estuarine, when the brackish water mollusca 

 are found with bones and scutes of crocodiles and tortoises. 



b. Middle Eocene, or the Bagshot Beds, composed of sands 

 and clays. The beautiful coloured sands of Alum Bay, the sands 

 of the Surrey and Hampstead Heaths, are familiar examples 

 of the beds of this age. Very few fossils indeed have been 

 found in them. The clay-beds on the contrary as seen at Barton 

 and Hordwell on the Hampshire coast and again in the Isle of 

 Wight, abound with shells belonging to genera such as Conns, 

 Voluta and Venus, that inhabit warm seas. With them are the 

 Nummulites, looking externally very like buttons, but on the 

 inside divided into innumerable chambers in which the com- 

 plex animal that formed the nummulite dwelt. 



c . Lower Eocene, the well-known London clay, may almost be 

 said to compose this division, for the underlying sands, gravels, 

 and clays are in mass comparatively insignificant. The London 



