Retrospective Criticism, 181 



connected with the chalk, clearly proves this ; for that word, 

 as used by the learned authors of the Description Geologique 

 shows where the beds of true unaltered white upper chalk 

 commence, and so distinguishes the line of demarcation 

 between the diluvially altered beds above and the regular 

 undisturbed strata below. The bed d (d) is more interesting 

 than at first appears ; for it is decidedly coincident with the 

 diluvial beds that cover a great portion of Norfolk, Suffolk, 

 and Essex, and are there locally termed " rubble," consisting 

 of yellow clay, containing egg-like portions of chalk, of which 

 I possess numerous memoranda, some of them deserving of 

 publication. The bed e (e) is the upper surface of the chalk, as 

 changed and discoloured by the infiltration, &c, from above ; 

 and numerous examples of this nearly superficial chalk may 

 be found all over the chalk district of this country, as well as 

 of France, where, I trust, Mr. Moggridge's researches have 

 been in general more successful than in this " singular in- 

 stance." Mr. Lyell [Geological Transactions, vol. ii. new 

 series, p. 84?.) has these words, in speaking of the junction of 

 the plastic clay beds and the chalk at the Old Harry rocks, 

 in Studland Bay, Dorsetshire (about three miles directly 

 from the spot in which I write) : — " the chalk for two feet is a 

 soft marl, and minutely striated with yellow and white lines, 

 occasioned, perhaps, by stains derived from the breccia," 

 which lies next to it ; a parallel case to that of some of the 

 beds above alluded to. In The Outlines of the Geology of 

 England and Wales, by Conybeare and Phillips (p. 62.), there 

 is a reference to the surface of the chalk at the locality in 

 question, namely, at Lower Meudon, near Paris, the Meredon* 

 of Mr. Moggridge ; and at p. 63. (note), instances are quoted 

 from England. Mr. Moggridge does not say where the other 

 instances are which he met with in his late researches ; but they 

 are probably those alluded to by Cuvier and Brongniart, and 

 treated of by them at p. 134. 137. 141. of their work. (Vide 

 Description Geologique, p. 327.) 



Mr. Moggridge would have rendered " his sketch" and 

 " explanation" more worthy of notice, had he reproduced the 

 observations of the authors from whom he borrowed, namely, 

 that the stag's horn was not discovered in the chalk, but in a 

 cavity in the chalk filled with the chalky breccia (or rubble), 

 washed in thither before the vegetable soil b (b) was de- 



* This change of Meudon to Meredon is wholly our deed. The manu- 

 script had been singed (in truth, a little burnt) where this word occurred, 

 and by the tops and bottoms of the letters left remaining we determined 

 the word to be Meredon, as it now appears erroneously, as it should have 

 been Meudon. — J.D. 



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