406 MESSES. H. W. MONCKTON Al^D R. S. HERRIES 



shows about fifteen feet of yellow sands, with lines of clay, and a 

 small" pebble-bed near the base, resting on about six feet of yellow^ 

 very clayey sand. The surface of the ground at the top of the 

 cutting is covered with rolled pebbles. Mr. Irving considers the 

 pebble-bed in the cutting to be the base of the Upper Bagshot, and 

 the loamy bed below to belong to the Middle Bagshot ; but a serious 

 objection to that hypothesis is that he has to place the surface 

 pebble-bed about fifteen feet above the base of the Upper Bagshot, 

 in which series the occurrence of pebbles is most unusual. If, on 

 the other hand, he were to place the upper pebble-bed at the base 

 of the Upper Bagshot, he would have over twenty feet of Middle* 

 Bagshot without green sand, which is also very uncommon. We 

 believe the whole cutting, so far as we have seen it, including the 

 lower pebble-bed, to belong to the Lower Bagshot ; and we do not 

 see that any satisfactory evidence has been given to prove that the 

 dark, black and green clay, of which four feet are said to be 

 exposed at the bottom of the cutting (bed "a" of Mr. Irving's 

 section), is not the London Clay, which occurs unmistakably in the 

 cutting on the opposite or west side of the station. If this be so, 

 the section would agree well with that described in the brickfield of 

 Wick Hill, and with the bottom beds of the Lower Bagshot as 

 observed in other places, as, for instance, Aldershot. 



The pebble-bed at the top of Wick Hill, which is described as in 

 the Upper Bagshot by Mr. Irving, is about twenty-five feet above the 

 London Clay. It is not easy to say whether it is really a Bagshot 

 pebble-bed in situ or not ; but as we have shown that at St. Ann's 

 Hill the Lower Bagshot is found with masses of pebbles resting on 

 and running into it, the presence of this mass of pebbles is no suffi- 

 cient reason for saying that the underlying beds are not Lower 

 Bagshot. The small pebble-bed at a lower level must, if we are 

 right, be Lower Bagshot. 



The so-called pebble- beds at the surface, both in the outlier and 

 the adjoining portions of the main mass of the Bagshot sands, are 

 proved by the presence of angular flints to have been re-arranged in 

 post-Bagshot times. This observation applies to the bed described 

 as a pebble-bed by Mr. Irving at Easthampstead Church (Proc. Geol. 

 Assoc, vol. ix. p. 223), for it contains numerous angular flints. 



South-west of Bracknell we find the Middle Bagshot green sand 

 cropping out at several points between Caesar's Camp and Wel- 

 lington-College Station. It is seen on the South-Eastern liailway^ 

 a little north of that place, and the section there was described 

 by one of the authors in 1883 (Q. J. G. S. -vol. xxxix. p. 351), since 

 which time it has been twice figured by Mr. Irving (Proc. Geol. 

 Assoc, vol. viii. p. 150 ; and Q. J. G. S. vol. xH. p. 498). We now 

 insert a continuation of our original figure, extending from the 

 station at Wellington College to the Mne-mile Bide, drawn to the 

 same scale as Mr. Irving's ; and a comparison of the two will 

 show that, though we agree with him as to the outcrop of the green - 

 sand bed north of the station, we differ from him in our reading of 

 the country north of this point (fig. 1). According to Mr. Irving, a 



