Mr, Godivin-Austeris Address. 475 



water-beds and shells (Mcrgelleret). These successive lines show 

 that the rise of the land through the 200 feet in question was at 

 intervals. 



The marine fauna of this higher sea level is given first in its 

 littoral, and next in its deeper- water facies. Taken together, we 

 have this result — that all the species are now living, that it is an 

 Arctic-basin assemblage, and not at all that of the neighbouring seas. 

 This is the '' Glacial formation " series. 



Below the 300-feet level there occurs a belt or interval 150 feet 

 broad, over which " shell-banks " are not met with, below which a 

 second series occurs. The shells contained in these beds differ from 

 those of the higher series in being less arctic. Certain of these 

 characteristic forms have disappeared, numerous boreal shells have 

 made their appearance, together with forms of the Lusitanian region. 

 Altogether this marine fauna approximates to that of the neighbour- 

 ing seas, only that some members of the earlier or more arctic series 

 linger on. 



The subdivision of the East-Anglian Kainozoic series is as 

 follows : — 



A. Prgeglacial ; B. Glacial ; C. Postglacial. 



A. Prceglacial. — Crag, in Suffolk, is a local agricultural name for 

 any sandy, gravelly soil ; but the early geologists and shell-col- 

 lectors soon found that it was something more ; its very perfect 

 shells were recognised as in part agreeing with those of the neigh- 

 bouring seas, in part as unknown or foreign. Mr. S. Woodward, in 

 his ' Outline of the Geology of Norfolk,' 1833, has a detailed account 

 of this formation. His own views are admirable ; the range of the 

 Crag formation, as he gives it, from Cromer, by Norwich, to the Suf- 

 folk coast is nearly exact. Nor did the estuarine character of the 

 formation about Norwich escape him. Apart from this local condi- 

 tion, he considered the Norfolk and Suffolk beds to be " decidedly 

 contemporaneous." 



It was not till 1835 that a subdivision of the Crag was proposed 

 by Mr. Charlesworth ; and it was amended (in 1838) by the follow- 

 ing classification : — 



4. Upper Crag of Norfolk and Suffolk — 



a. Without mammalian remains. 

 h. Beds with mammalian remains. 



5. Ked Crag. 150-200 species of marine shells. 



6. Coralline Crag. 300-400 species of marine shells. 



Thus far back Mr. Charlesworth separated the Norwich Crag from 

 that of Suffolk. The Eed Crag at Tattingstone, Eamsholt, and Sud- 

 boume was said to overlie a worn and uneven surface of the white 

 or Coralline; from this consideration their relative dates or ages was 

 inferred. This nominal subdivision may be said to have been 

 adopted from that time onwards down nearly to the present. 



The Bryozoan Crag overlies London clay, and is under 20 feet 

 thick. It is a good division, because it is an indication of a definite 

 range of depths, where the sea-bed was not within reach of surface 

 disturbance, yet where the drifting power was considerable, and 



