98 HIGH-LEVEL GRAVEL. [1855-56. 



J. Prestwich to Sir Charles Lyell. MARK LANE, 12th July 1855. 



MY DEAR SIR CHARLES, Unless business calls me out of 

 town, any alteration of the days will be immaterial to me. 



I think you will certainly find work for more than one day at 

 Pulborough. On Wednesday, the 18th, I am engaged. Thurs- 

 day and Friday will do for Flower's and Ilford. When we go to 

 Ilford, I should like to take you to Havering-Atte-Bower, 

 Chigwell, and Hainault Forest, so that you may see the relation 

 of the Ilford deposit to the surrounding drifts, which I think 

 always essential. 



No mammalian remains have ever been found in the high- 

 level gravel, nor I believe in the mid-level, though the oppor- 

 tunities for finding them are almost equally good as in the valley 

 gravel. The bones brought by Mr Lubbock from the valley 

 gravel of Maidenhead prove to belong to the musk-ox, the first 

 found in this country, a capital fact. 



A newspaper paragraph which I have not yet seen announces 

 the discovery also of bones and tusks in some gravel beds near 

 Kingston. 



The correction of my Correlation paper reminds me of some 

 questions I had to ask you. 



You give a list of shells from beds of sandstone in your section 

 of Cassel Hill (Q. J. Geol. Soc., vol. viii. p. 331). May not these 

 beds belong to the Nummulites planulatus series ? Although this 

 fossil is not found at Cassel, M. D'Archiac alludes to fossiliferous 

 beds of that age at Cassel. I have ventured to refer to that list 

 (p. 3) as possibly belonging to the Lits Coquilliers zone. Can 

 you now furnish me with a more complete list of the shells of 

 the N. planulatus series than you possessed in 1852 ? Have you 

 also increased your list of fossils of the N. Icevigatus (Calcaire 

 Gfrossier) series of Belgium ? 



If you can give me any information on these points I shall feel 

 much obliged, and remain, dear Sir Charles, yours very truly, 



J. PRESTWICH. 



I should much like to see Forbes's MS. about the 

 gravels. He has, I see, adopted my term of high- and low-level 

 gravels, and I believe agreed in several of my views. How 



