38
THE ESSEX NATURALIST.
the temperate species were displaced by the tundra vegetation,
and by the reindeer, even in the south of France ; the same con-
ditions being represented in this country by the Ponder's End
stage.
It is, therefore, not really surprising to find some anomalies
of association when such vast biological changes were in pro-
gress. I think the existence of species which cannot live through
the frosts of the present day is significant. More northern plants
might surely thrive in a milder climate much more easily, if
other conditions were suitable.
The Flint Industry.
This is of special interest, as it is now believed that it con-
stitutes one of the best series of the Mesvinian industry yet recog-
nised. Examples were collected by the Rev. J. W. Kenworthy,
who may have been the first to discover it, and some of his speci-
mens are in our Stratford Museum, which also contains casts
of some of the best selected and most typical specimens, from
my own collection.
The style of the flint work is very primitive, and it has no
typological affinity with either the Chellean or the Acheulean
groups. This is the more remarkable as in point of date the
Clacton industry must come in either at the very end of the
Chellean, or more probably during the early part of the succeeding
Acheulean.
In the later part of the Acheulean, Elephas antiquus was
giving place to E. primigenius, and at the time of the following.
Mousterian period this replacement was complete. That fixes
our Clacton bed as being pre-Upper Acheulean in date.
The Clacton industry does not include any of the "classical"
forms of pointed or ovate implements of the River Drift. It is
characterized above all by the strength and freedom of the
flaking. There are scrapers and trimmed flakes which present
much resemblance to the Mousterian types, only they are more
primitive. There are discoidal forms, together with various
crude implements, but the most notable among these are rude
side choppers with a zig-zag segmental edge and a thick and
heavy back for grasping in the hand. There is a similar object,
probably of the same date, in the British Museum from North-
fleet.