CHALK. l6l 



scattered through the chalk, so they are found 

 living Oil the chalky floor of the Atlantic Ocean; 

 and the modern representative is sometimes very 



allied to the ancient fossil. 

 The chalk is no exception to the law that the 

 fossils change with every few feet of a deposit 

 from its base to the top. Thus there are nu- 

 mer era of sea-eggs of the order termed 



i ., some living and others extinct found 



in the Lower Chalk Muh as Salema y Pstudodiadema 

 ami Ffolaster, AnanchyUSy Galerites, Micraster and 



ma characterise the Upper Chalk. This 



. >n of fossils m the several beds of chalk 

 m the chalk itself, at 



least i . l rig ind, of its deposition coming to an 



end. Its newest beds at Norwich give no sign 

 of shallow water conditions. 1 1 > highest beds in 

 Holland, h< .are the yellow granular lime- 



•:i< ht, which indicates a nearer ap- 



than the chalk of England. In 



.mark univalve shells, which from time to time 

 lived in the chalk sea on definite horizons, like 

 the 1 tten 5 and the Chalk Rock, are 



found in the newest chalk to include shells which 



not known oth< till the tertiary period, 



■ Oliva and Afitra. They 



indicate that the shore conditions of the chalk 

 turning in its newest beds in conse- 

 quence of a general upheaval of the sea-bed into 

 land in the European region. 



ii 



