2 j6 Chillesford Beds. 



rena, &c., most of which are of living species. Besides 

 these, there are found in it the bones of Mastodon Ar- 

 vernensis, Elephas meridioncdis (?), E. antiquus, 

 and Hippopotamus major (?) together with the Horse, 

 Equus fossilis, Castor fiber (beaver), the common Otter 9 

 Deer, &c. 



The Chillesford Clay and Sand are generally con- 

 sidered to form part of the Norwich Crag series of 

 strata. In the Chillesford district, which is inland, the 

 Clay may lie to some extent unconformably on the Eed 

 Crag at Chillesford, and on the Coralline Crag near 

 Slid bourne. In the Norwich district, it is a somewhat 

 inconstant bed, or set of wedge-shaped beds, which, 

 according to Mr. Horace Woodward, occur at different 

 horizons in the Norwich Crag series. It is a very 

 insignificant subformation, as regards thickness, and its 

 marine fossils found in the sands are almost all of 

 living species. The Bure valley beds, characterised 

 by the presence of Tellina Balthica, may possibly 

 form an upper part of the Norwich Crag series. 

 They lie on the well-known Forest bed of Cromer, 

 and together these may connect the uppermost Crag 

 beds with the succeeding Glacial epoch. 



It is frequently impossible to identify these minor 

 subdivisions in areas even a small distance apart, for 

 their identity is assumed to rest on the occurrence of 

 certain assemblages of shells, and opinions on some 

 points are so conflicting, that while some geologists 

 consider the Forest bed to be older than all of the 

 Norwich Crag deposits, others maintain that it is 

 newer. 



The last great Glacial epoch, Bone caves, Eiver 

 gravels, &c., will be treated of in succeeding chapters. 

 These, less or more, belong to the age of human history, 



