360 PLEISTOCENE GEOLOGY OF THE THAMES VALLEY.
mild winters, for the ivy is extremely sensitive to winter cold.
Both the character of the flora and the position of the deposit
suggest correlation with the temperate plant beds at Hoxne,
which lie between the Boulder Clay and the deposit with Arctic
species. The Ivy and the Poplar have not previously been
recorded as British fossils."
We sent some samples of the Blue Clay (No. 10) of the
Orsett Road Section to Mr. C. Reid who says of these that they
yielded remains of mosses, but of indeterminable species. It is
of interest to note Mr. Reid's conclusion as to the character of
the climate of the Brickearth stage as it exactly corresponds
with our own, arrived at from a study of the lithological and
the other Palaeontological characters of the beds.
PALAEONTOLOGICAL SUMMARY OF THE PLEISTO-
CENE DEPOSITS OF GRAYS.
VI. PHYSIOGRAPHY.
The physiography of the Grays Thurrock Area presents
certain features of great interest, which features are likewise of a
somewhat complicated nature. In the present section of this
communication we propose to describe one of the physiographical
features of the eastern portion of the district, and this description
will embody the results of our observations on the structure and
formation of several valleys which intersect and diversify the
plateau formed by the High Terrace Drift.
The valleys referred to may be likened to wide, shallow
grooves of about thirty feet in depth, varying from a quarter to
half a mile in breadth and about three-fourths of a mile to one mile