and on the Fossil Remains contained in them. 139 



In this bed, among the gravel and the shells, are frequently 

 found fragments oi' fossil bone, which possess some striking 

 peculiarities. They are seldom more than half an inch in 

 thickness, two inches in width, and twelve in length; al- 

 wavs having tliis flat form, and generally marked with small 

 deiits or depressions. Their colour, which is brown, light 

 or dark, and sometimes inclining to a greenish tint, is evi- 

 dently derived from an impregnation with iron. From this 

 impregnation they have also received a great increase of 

 weiglK and solidity; from having been rolled they have ac- 

 quired a considerable polish; and on being struck by any 

 hard body ihey give a shrill ringing sound. These frag- 

 ments, washed o^ut of the stratum in which they had been 

 imbedded, are found on the beach at Walton, but occur in 

 much greater quantity at Harwich. 



Of the flat rounded pieces described above, no conjecture 

 can be formed as to the particular bnne or particular animal 

 to which they belonged. But within thes^e few years an 

 Essex gentleman found, on the beach at Harwich, a tooth 

 which was sopi^osed to have belonged to the mammoth. 

 This fossil was kindly obtained, at my request, for the pur- 

 pose of being exhibiU'd to the members oF the Geological 

 Society, by my late friend Dr. Menish ; and certainly it 

 appeared to be part of a tooth of that animal. It had been 

 broken and rounded by rolling, but its characters were still 

 capable of being ascertained. It possessed, in the softer 

 parts, the colour and appearance of the Essex mineralised 

 bones so distinctly, as to leave not a doubt of its having 

 been imbedded in this stratum; whilst in the enamel it 

 manifested decided characters of the tooth of some species 

 of the mammoth, or mastodon of Cuvier. 



The actual limit of this stratum has not been ascertained ; 

 it is however known to extend through E-se:;, iMiddlesex, 

 part of Kent, and Surry, and through Hertiortishire, h'uck- 

 inghau'shire, and indeed much further b-th to the north- 

 ward and westward, in many parts its continuity has been 

 interrupted, apparently by partial abruptions uf ii, together 

 even with a portion of the strat'.m) on which it rests. The 

 shells of this stratum have hitherto been discovered only in 

 the parts already no;ici.d. 



Blue Clay Stuatum. — This, the next sul>jacent bed, is 

 formed of a ferruginous clay exceeding two hundred feet in 

 thickness. Its colour h)r a few feet lu the upper part is a 

 yellowish-brown, but through the whole ot its ren)aining 

 depth h of a dark-bluei^h gray, verging on black. It is 

 jiot only characterized by these circumstances, but by the 



numerous 



