19 



The fine flint-gravel in the vicinity of Cambridge is next 

 treated of, and its extent to the North and East of that town 

 briefly noticed ; Mr Seeley records the occurrence of shells at 

 the Observatory, at Barnwell, Chesterton and Oakington, and 

 teeth of Rhinoceros tichorhinus from a patch near Comberton. 

 He minutely describes the character and contents of the Barnwell 

 Gravel, giving a list of the Mammalian remains and of the Land 

 and Freshwater shells. 



Lastly he refers to the Coarse Gravel on the Gog-Magog 

 Hills, from which he had collected boulders of the Palaeozoic 

 rocks of North Euijland, fraoftnents of the Yorkshire Oolites 

 and of the Red-rock of Hunstanton ; he remarks that the 

 flints are often unbroken and that there is a rough stratification; 

 he states also that descending on the east side towards Fulbourn 

 "it becomes Boulder Clay," by which expression Mr Seeley 

 probably intends to refer to a stiff' sandy loam, like re-arranged 

 Boulder Clay, now seen to overlie part of the gravel on this 

 side. The remainder of the paper is occupied with theoretical 

 considerations, which only appear in abstract. 



These were subsequently printed in the Geol. Mag. Vol. iir. 

 p. 495, under the title of "Theoretical Remarks on the Gravel 

 and Drifts of the Fenlands." These only demand a brief notice, 

 as some of his conclusions have already been shown to be 

 without foundation, and others are disproved by the observa- 

 tions recorded in future portions of this Essay. 



(1) In the Boulder Clay of Ely, he states that he has found 

 old and thick specimens of Tellina like those in the Lower 

 Boulder Clay of Norfolk ; from this and the [supposed] fact that 

 it rests on beds which have since been removed by denudation 

 from the country, he concludes that it is the oldest Drift in the 

 Cambridge district, and correlates it with the Brown Clay or 

 Till of Cromer. 



(2) Coarse Gravel ; he mentions three cases of such gravel 

 overlying Boulder Clay, viz. in the Ely pit ; on the Hogs-back 

 going to St Neots, and on the Gog-Magogs. His observations 

 on these coarse gravels agree in the main with my own, and 

 his facts quite warrant him in concluding that their materials 

 were derived from the destruction of the glacial Clay, which 

 was at that time more widely spread. In his own words : "The}^ 



