210 J. 8S. GARDNER—DESCRIPTION AND 
which the Bracklesham beds can be divided. His description of 
Highcliff stopped short E. of Christchurch Harbour; but it is of value 
in connexion with the present subject, since he shows that a pebble- 
bed at the top of the white sand at Highcliff is the equivalent of one 
of the higher beds of the Bracklesham series. Assuming the correct- 
ness of this determination, we have a defined horizon to start from ; 
and as it can be shown that the sequence across the valley is unin- 
terrupted and the dip regular, it seems to me that the position of the 
rest of the beds can be fixed with great accuracy. 
The views I venture to put forward diverge from those of Prof. 
Prestwich. Although beds on the headland and on the coast almost 
immediately to the east of it both contain septaria, I believe them 
to be on different horizons, the former belonging to a separate 
series unrepresented elsewhere on the coast except at Alum Bay. 
Again, the slight throw-in of Barton Clay west of the promontory is, 
for me, only the most easterly of numerous and identically similar 
patches of the Bournemouth beds. : 
My views also differ slightly from those of Mr. Fisher. I think 
that the lower 123 feet of strata included by him in the Brackles- 
ham series at Whitecliff may probably represent in time the Lower 
Bagshot beds. The Bracklesham beds are supposed by him to thin 
to only 43 feet at Alum Bay, and 35 feet at Highcliff. Even if, as 
he says, the 35 feet of sandy clay and the pebble-bed at Highcliff 
represent the whole uppermost strata of the series 130 feet thick at 
Whitecliff Bay, and we deduct the 123 feet placed in the Lower 
Bagshot, there are still some 400 feet unaccounted for. These 400 feet 
are, I think, not only well represented at Christchurch Head, where 
the strata are mapped as Bracklesham by the Survey, but also by 
the marine beds thence to and even beyond Boscombe, and at Alum 
Bay as well. I also find myself at variance with the Geological 
Survey, since I believe that the so-called Upper Bagshot beds of the 
London basin do not belong to that series, but are the equivalents 
of beds which I shall refer to as the Boscombe Sands. These 
Boscombe Sands and the marine Bournemouth beds are, I believe, 
the western equivalents or extreme shore-conditions of the Brackles- 
ham sea. 
My especial object in bringing this paper before the Society is, how- 
ever, to prove that the Bournemouth leaf-beds immediately underlie 
Fig. 1.—Restored Section between Highcliff and Hengistbury Head. 
Hengist- Hip = 
bury Head. Cliff end. cliff, 
1. Hengistbury-Head beds of the Middle Bracklesham. 
2. White Sands at the base of Highcliff and capping Hengistbury Head. 
3. Barton and Upper Bracklesham beds. 
