134 



PEOCEEDINGS OP THE GEOLOGICAL SOCIETY, 



annexed table I recapitulate this relation of the fauna of the Coral- 

 line Crag, 





Extinct. 



Living. 



Total. 



■ /'Bracliiopoda 



1 

 23 



28 



4 



126 



2 



132 

 1 



5 

 149 



2 



160 



1 



g Conchifera 



,5 -^ Solenoconchia 



^ G-astr opoda 



^ Pteropoda 



Bryozoa 



52 



265 



317 



65 

 15 

 47 

 2 

 4 

 13 



30 

 3 



53 

 1 

 6 

 3 



95 



18 



100 



3 



10 



16 





Foraminifera 



Corals 



Cirripedes 







146 



96 



242 



General Considerations. 



Between the period of the London Clay and that of the Coralline 

 Crag the area now forming the Eastern Counties seems to have 

 been dry land. Parts, however, of France and Belgium, together 

 with parts of the south of England, had continued longer sub- 

 merged, though successive elevations had brought much land to the 

 surface during the later Eocene and early Miocene periods. The 

 sea, however, stiU occupied the western area of Belgium and Hol- 

 land. This sea gradually encroached in a westerly direction, 

 and at the Pliocene period had spread over part of the eastern 

 counties. As it spread in one direciion the land rose in another ; 

 and at the time of the formation of the Coralline Crag a portion of 

 the Miocene and older Pliocene area of Belgium and the north- 

 west of France (as, for example, the top of the chalk hills round 

 the basin of Boulogne), and probably of Kent (Lenham and other 

 parts of the North Chalk Downs), had been raised and exposed to the 

 denuding action of the sea, in which the newer beds were in process 

 of formation. 



As the sea extended northward, and the land rose to the south, the 

 climate became colder, and we have evidence of ice-action even at 

 the earliest period of the Coralline Crag ; for I do not see how other- 

 wise than by transport by ice to account for the large block of por- 

 phyry before mentioned in the basement-bed at Sutton, It is still 

 a question whence this block may have been derived, I know 

 of nothing analogous to it in the rock-specimens from the north of 

 England and Scotland ; whether it came from Scandinavia or the 

 Ardennes remains to be determined. The Oolitic remains were pro- 

 bably derived from strata in Central England*, The abundance of 

 London-clay fossils shows a great local denudation, and possibly also 



* Mr. Boyd Dawkins refers the Pliosaurian vertebra to the Oxford or the 

 Kimmeridge Clay. 



