42 Geological Conditions of the Chalk, 



In describing the fossil teeth as being often very perfect, I 

 refer to the crown and body of the tooth ; for, in many spe- 

 cimens, where these parts have undergone no abrasion, the 

 lower part or roots are more or less wanting ; yet I am in- 

 clined to believe that they have not been water-worn or che- 

 mically decomposed. If the teeth of the elephant are pro- 

 truded from behind, their original roots must be more or less 

 absorbed to admit of the tooth being moved forward in a 

 nearly horizontal direction ; and this mode of dentition may 

 explain why many of the fossil grinders, in other respects per- 

 fect, have their roots very much shortened. 



The head of the elephant before mentioned, found near 

 Cromer, had suffered little from mechanical action when first 

 discovered ; and it is scarcely possible to believe that this 

 head with its tusks had been drifted very far from the place 

 where the animal perished : if this be admitted, it will render 

 a similar inference probable respecting the other mammalian 

 remains in its vicinity. 



Hampstead, December 12. 1835. 



Art. XV. A Description of the Geological Conditions of the 

 Chalk, and Argillaceous Beds, at Ballingdon Hill, Essex, with 

 Inferences. By John Brown, Esq. 



The observation of your intelligent correspondent [Mr. 

 Hunter] in speaking, in VIII. 597., of the limestone quarries 

 and petrifying spring of Pounceford, Sussex ; and in his 

 allusion to what Dr. Fitton says, that no opportunity should 

 be omitted of examining and measuring strata in highly cul- 

 tivated districts, is perhaps as applicable to the spot under 

 review as the locality which he has so ably illustrated, although 

 it be another portion of the field of geological inquiry; as, in 

 both localities, agricultural pursuits are carried out to their 

 full extent : and, perchance, another reason will avail us here, 

 for briefly noticing the geology of this interesting locality, 

 namely, the level and unbroken surface, and the generally 

 monotonous character of the Essex strata. These are some of 

 the reasons why I communicate an observation or two that oc- 

 curred to me during a brief survey of this part of our county. 



A favourable opportunity has been offered, during the last 

 spring and summer, for ascertaining the geological structure 

 and the mineral contents of one of the highest hills in this 

 part of the county of Essex, by removing the upper part of 

 Ballingdon Hill for about 30 ft., in a vertical direction from 

 the top, and for a considerable way down ; and carrying the 

 earth to the lower part to improve the London road. 



