56 
THE ESSEX NATURALIST. 
iacture, and such places are described as Neolithic sites in this 
paper. Such sites occur frequently in connection with the gravel 
terraces or outcrops, but are by no means confined to^:such local¬ 
ities. Human artifacts become fewer on the margin of the 
Boulder Clay and are usually absent at any considerable distance 
from the Chalk outcrop. The Chiswick Hall site is, however, 
well within the Boulder Clay and isolated examples of worked 
flint may occur on any part of the area. 
THE TYPE OF ARTIFACTS FOUND IN THE CAM 
VALLEY. 
The implements found in this area are mainly referable to 
one culture type, the same forms recurring again and again on 
the different sites, with occasional exceptions which will be 
mentioned later. Among the numerous records of the remains 
of Neolithic man in Britain there are several well-marked series, 
e.g., the Pebble Industry of the shores, the Microlithic or Pigmy 
Industry, the Cissbury and Grimes Graves type, and so forth, 
but their chronological sequence is still doubtful. It may, 
however, be possible to make some comparison of the material 
from the Cam Valley with that obtained from other sources. 
Mr. Hazzledine Warren, in a paper on “ The Classification 
of Pre-historic Remains in Eastern Essex ” (6), has recognized 
two series of Neolithic remains in that area, an earlier series 
possibly extending from Pre-Robenhausian to Robenhausian 
times and a later series from Robenhausian well into the early 
Bronze period. In the scheme of sequence-dates that accom¬ 
panies this article, he gives the place of (9)40 ? to (9)50 to the 
earlier series and (9)50 to (9)58 to the later series. 
Mr. Warren’s earlier series appears in many ways to present 
affinities with the culture exhibited by the Cam Valley artifacts, 
thus the presence of implements allied in form to the grattoir 
tarte, the rudeness of the axe forms, the presence of re-worked 
polished specimens, and the character of the flakes are points in 
common. On the other hand the rarity of arrow heads, and the 
presence of abundant examples of prismatic cores in the Cam 
Valley, seem to point to a difference in culture which may, 
however, be of local significance only. From the examples 
illustrated in this article and in the Essex Naturalist (6-7), 
and a few specimens from the East of Essex that the writer has 
