THE 



LONDON AND EDINBURGH 

 PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



JANUARY 1837C 



I. Observations on the Crag, and on the Fallacies involved 

 in the ^present System of Classification of Tertiary Deposits. 

 By Edward Charlesworth, Esq., F.G.S., S^c.^ 



1DID not venture to propose a separation of the marine 

 deposits above the London Clay in Suffolk, until I con- 

 sidered myself in possession of something more than merely 

 conjectural evidence to justify my division of these fossiliferous 

 strata. That the immense accumulation of testaceous reli- 

 quiae forming the Crag might in some places be seen to be 

 separated from the subjacent beds of clay by a deposit the 

 characters of which did not accord with the general aspect of 

 either of these formations, was a statement involving mere 

 personal observation, and which could therefore at any time 

 be readily refuted or confirmed. But that this coralliferous 

 stratum should be looked upon as holding an intermediate 

 place not only in geological position, but in age, when consi- 

 dered in relation to the beds above and beneath it, was sug- 

 gesting a notion which appeared to me so far admissible, that 

 its adoption or rejection would entirely depend upon the results 

 attending continued investigation. Anticipating the nature 

 of the objections which 1 thought might probably be urged 

 against my views, I endeavoured, in my first memoirf; to show 

 that there were strong grounds for believing that the apparent 

 agreement between the organic remains of the Coralline Crag 



* Communicated by the Author. 



t See Lond. and Edii^b. Phil. Mug. for August 1835 : vol. vii. p. 81. 



Third Series. \^ol. 10. No. 58. J«?z. 1837. B 



