158 



Gunn — The Anglo-Belgian Basin. 





Upper Chalk 



Lower Chalk 





■with flints. 



without flints. 



CoNCHiFERA. MoNOMYAHiA {continued). 







Gryphea globosa 



* 





Ostrea, various sp 



« 



* 



Dentalium difforme 



* 





Bipponyx 



* 





Scalaria compacta 







Pleurotomaria perspectiva. 

 Turbo 



* 



^ " Chalk- > 

 Rock,"» ( 



Aporrhais stenopteris 







Belemnites 



* 





Nautilus 



* 





Ammonites varians 



Ammonites 



Turrilites triplicatus 



T*THr*T?fl 



Ptychodus mammillaris ... 



« 





„ decurrens 



* 





„ latissimus 



♦ 



« 



„ polygyrus 



♦ 





Corax falcatus 



« 





Saurodon 



* 



* 





Enchodus 



Otodus appendiculatus 



* 





Lamna acuminata 



* 



« 



Notidanus microdon 







Coprolites of Macropoma... 







EFTILIA. 







Ichthyosaurus 









Chalk Marl 



& Tottemhoe 



Stone. 



V I. T HE A N G L 0-B ELGIAN BaSIN. 



By the Eev. John Gunn, M.A., F.G.S. 



THE principal object of a paper wliicli I read at the British. 

 Association was to point out the connection between an ancient 

 river running on the Continent, in the direction of the Ehine, and 

 the estuarine deposit of the Forest bed, on the eastern coast of this 

 country. Many geologists have maintained that such a river ran 

 from south to north, which would be in the direction of the Straits 

 of Dover. In proof of the correctness of this supposition, I men- 

 tioned that numerous vertebrae of whales had been found in the 

 estuary, which indicated an opening to the sea, and also arctic shells, 

 which indicated a northerly direction; at the same time that the 

 immigration of elephants and other animals proved the junction of 

 this country with the Continent. 



The way over, then, for such animals was on the south side, by 

 the ridge of chalk hills, now severed, between Dover and Calais ; 

 and I mentioned that this ridge of hills formed a barrier to the influx 

 of boulders and Boulder-clay in France and the South of England. 

 Professor Eamsay (the President of the Geological Section), while 

 admitting the absence of the Boulder-clay from France, expressed his 

 opinion that it would be found to the south of the Thames. This, 

 probably, is correct, as the chalk hills of the Downs may have served 

 as a barrier to the south of the Thames ; and ice-action and striated 



1 See Mr. Whitaker's Paper, Quart. Journ. Geol. Soc, vol. xvii. p. 166. 



