140
ON A DEEP CHANNEL OF DRIFT
E. roseana. Common on Slopes. The larvae are abundant in
teazle-heads ; often in those tenanted also by P. gentiana.
Xanthosetia zoegana and X. hamana. Slopes, &c.
Chrosis alcella. Sea-wall; common and variable.
Lobesia reliquana. Eastwood 5 common.
Argyrolepia hartmanniana. Eastwood; rare in swampy
places.
A. zephyrana. Slopes, Sea-wall and River-wall; very common.
A. aeneana. Slopes; rare.
Conchylis dipoltella. Sea-wall; rare.
C. francillana. Slopes, Sea-wall and River-wall; common.
C. dilucidana. Potteries.
C. smeathmanniana. Slopes; rare.
C. straminana. Slopes and Sea-wall, and in lanes.
ON A DEEP CHANNEL OF DRIFT IN THE
VALLEY OF THE CAM, ESSEX.
By WILLIAM WHITAKER, B.A., F.R.S., F.G.S., of the Geological Survey of England
and Wales.
[The following is an abstract of a paper (read before the British
Association, at the Newcastle meeting) which Mr. Whitaker intends to
submit to the Geological Society. Some of the facts have already
been given in Mr. Whitaker's paper, "Some Essex Well-sections
(Part II.)," in the Essex Naturalist. This abstract is published
by kind permission of the author.—Ed.]
Well-sections have given us much information as to the deep-
seated geology of the London Basin and of the rising up of older
beds beneath the Cretaceous beds. We have now like evidence of an
occurrence of the opposite kind, the deep sinking down of Drift beds.
In Scotland and in northern England, long and deep channels
filled with Drift have been noticed, but not in southern England.
There are, however, evidences of some such occurrences in Western
Norfolk, though not to the depth of the channel now in question.
For some years, one deep well-section has been known which
showed a most unexpected thickness of Glacial Drift in the higher
part of the valley of the Cam, where that Drift occurs mostly on the
higher grounds and is of no very great thickness. Lately further
evidence has come to hand, showing that the occurrence in question
is not confined to one spot, but extends for some miles. Details of