130
PEOF. J. PEESTWICH ON A PECULIAE
4 teeth of Bison, and some undeterminable fragments.- There are
no traces of gnawing on any of the bones.
When I first visited the cutting the drift- exposure was at its
deepest, extending to the base of the cutting, a depth of 28 feet,
and just reaching the chalk beneath. The section it here presented
is as under (fig. 4).
Fig. 4. — Section in Catting near the village of Chilton, at B,fig. 1,
enlarged.
.0
1 "1 L_*h-^ \ -- i Chalk.
1 v
feet.
1. Surface soil (reddish loam with a few flints) £ to 1.
a. Cream-coloured fine chalk- and flint-rubble, showing a deeply
festooned or waved surface 6 to 10.
b. Soft white marl (reconstructed chalk) with shells 4 to 6.
c. Very light yellow chalk- and flint-rubble (with an occasional
black band) 2 to 5.
d. Dark brown clay (almost black in places), forming a line of
separation between the lighter beds above and the darker
yellow and brownish beds beneath

two specimens of Pupa
marginata 2 to 4.
e. Light-yellow flint- and chalk-rubble, fine

one Pupa 3 to 6.
/. Coarser flint- and chalk-rubble

bone of Bison 5 to 10.
In the lower half of the drift there were found irregularly dis-
persed in various parts of the cutting a few blocks of very hard and
compact Sarsen stone (Lower Tertiary Sandstone). Two of the
largest measured 2 ft. x 10 in. x 9 in. and 1 ft. 9 in. x 1 ft. 6 in.
X 10 in. The angles were rounded

but otherwise they were not
much worn.
In the beds c and / were some grains of glauconite, derived pro-
bably from Lower Tertiary sands

and the clay of bed d may be
derived from some of the Tertiary clays. The black band in c is
caused by the admixture of a sooty manganese peroxide.
The fragments of chalk mostly vary from the size of a pea to that
of a bean. Some, which consist of soft chalk, are worn and rounded

but others, which consist of a very hard chalk, are flat and