1865..
WHITAKEE BXrCKlNGHAM CHALK,
399
I cannot give the thickness with accuraC3\ I will now give a short
account of each, beginning with the lowest.
(g). Chalk-marl. — A
rather brownish-white,
slightly sandy, clayey
chalk, fissile, with stony
layers here and there, and
often with fossils (notably
fish-scales). This is per-
haps 80 feet thick, and
mostly causes a rise of the
ground above the sloping
plain of the Upper Green-
sand.
(/). Totfernlioe Stone.-
At the top of the Chalk-
marl in this district there
are generally two layers
of rathersandy limestone,
separated by a little marl,
and which are more dis-
tinct further north-east-
ward (in Bedfordshire),
where they are each about
3 feet thick. One bed is
always here present, but
I did not always see the
two. This stone mostly
yields fossils, amongst
which Ammonites vai'ians
and an Inoceramus are
abundant, and small,
hard,dark-brown nodules,
most likely coprolitic : it
is harder and darker than
common chalk, and con-
tains many small dark
grains ; and was once
largely quarried, for build-
ing, at Totternhoe, where
there are plentiful traces
of the workings. Most
of the old churches of the
neighbourhood were built
in great part of this pe-
rishable stone, but I be-
lieve that its use has been
long discontinued.
Details of the occur-
rence of this bed will be
given in the ' Gcolo-
2 E 2