Vol. 62.] THE CLAY-WITH-FLINTS. 135 



at the bottom of p. 283 (op. tit.), where he speaks of ' the unworn 

 and often unbroken character of the flints' as being against the 

 theory of transport. It is true that both kinds of flints are 

 unworn, but there is a great difference between entire flint-nodules 

 (as they occur in the Chalk) and angular pieces of broken-up 

 flints. 



I have not had a sufficiently-wide experience of Clay-with-Flints 

 in the South of England to be able to assert that angular flint- 

 fragments are everywhere abundant in it. I can only testify to their 

 occurrence in the counties of Hertford, Bedford, and Buckingham, 

 and again in Dorset. Mr. H. J. Osborne White, however, who has 

 special acquaintance with the deposits overlying the Chalk in 

 the counties of Buckingham, Oxford, and Berkshire, informs me 

 that he considers the angular flints to be generally more 

 numerous than the unbroken flint-nodules, and that he knows of 

 exposures where the latter are rarely found and where all the 

 flints usually to be seen are angular. Lastly, Mr. Clement Reid, 

 writing of the country around Salisbury, 1 describes the clay as 

 containing ' unworn or shattered flints/ by which I suppose he 

 means unbroken and broken flints. 



Charles Darwin, when describing the Clay-with-Flints near Down 

 in Kent, 2 remarks that the flints are often broken though not rolled 

 or abraded, and that the elongate flints are commonly found 

 ' standing nearly or quite upright in the red clay,' a position which 

 he ascribes to the downward movement of the mass from higher to 

 lower levels. He also incidentally mentions that the flints in the 

 clay ' form almost half its bulk.' 



"With regard to the unbroken flints, which have mostly been 

 derived directly from the Chalk, Mr. Osborne White tells me 

 that, in his experience, they seldom occur in any number, except 

 in the bottom-layer of the clay at its junction with the Chalk, and 

 in pipes or funnels which penetrate into the Chalk. Their greater 

 abundance in such hollows is not surprising, since these are evidently 

 spots where solution has taken place more extensively than else- 

 where. 



Another point requiring notice is the frequent occurrence of 

 green-coated flints, derived from the base of the Reading Beds. On 

 this matter Mr. White writes : 



' I feel sure that green-eoated flints are quite as common in the Clay-with- 

 Mints as one would expect them to be.' 



It is moreover possible that the black-coated flints, which are also 

 common where the clay is black, may be such flints coated or 

 stained black by oxide of manganese. 



Mr. Clement Reid, describing the Clay-with-Fiints^ in Sussex, 3 

 says that it consists of Eocene material mixed with a certain 



1 Expl. of Sheet 298, Mem. Geol. Surv. 1903, p. 64. 



2 'The Formation of Vegetable Mould, &c.' 1881, pp. 138-39. 



3 'Geology of Eastbourne' 1898, p. 10, and 'Geology of Chichester' 1903, 

 p. 38, both memoirs of the Geological Survey. 



