196 Mr. 8. V. Wood on the Red Crag 
they repose on the Chalk, while in the south-eastern area they 
repose, in the condition of gravels, on the London Clay. The 
southern boundary of this formation may be indicated in some 
parts with such precision that it can with certainty be averred 
that this was the shore in this direction of the bay of the period. 
Along the coast south of the Stour, the denudation has in many 
places removed this formation, leaving the London Clay to form 
the coast-line—the lower Drift appearing a few miles inland, 
and furnishing outliers occasionally nearer the coast. Ranging 
south as far as Chelmsford, its southern edge may be traced 
crossing the railway-cutting a few furlongs south of Chelmsford 
Station, from which place it extends eastward to Danbury Hill, 
where it forms an outlier, apparently nearly 100 feet in thickness, 
resting on London Clay. Between those two points it occurs at 
the villages of Badow and Sandon. West of Chelmsford, it passes 
by Writtle, and, a mile north-west of that place, is lost under the 
Boulder-clay, a deep section being exposed at that place about a 
furlong only from its disappearance under the overlying Clay 
Drift. From that point to Badow, the margin of the bay depo- 
siting the beds may be indicated with certainty; but east of 
Badow its boundary-line has been destroyed by the great denu- 
dation that has removed the Bagshot gravels and the upper beds 
of the London Clay. The precise margin alluded to is shown 
in this way. At intervals over Southern Essex, the Bagshot 
sands and gravels, that originally extended, for a thickness of 
about 50 feet, continuously over the London Clay, now remain 
as outliers on the summits of the higher hills, as at Raleigh, 
Galleywood, Langdon, Stock, Margaretting, Warley, Shenfield, 
South Weald, Epping Forest, &c., uncovered by any Drift-beds, 
the upper or Clay Drift having been removed from them, while 
the tablelands that range from Brentwood towards Epping on 
the one hand, and towards Ongar and the Rothings on the other, 
are capped by these Bagshot beds, covered with patches of the 
upper or Clay Drift, without the faintest trace of anything re- 
sembling the lower-Drift deposit between them. 
These Bagshot beds possess so uniform a character, both in 
their constituent material and thickness, and are so evenly and 
uniformly covered by the Drift clay in immediate contact with 
them, where that remains undenuded, that the idea of any ex- 
tension of the lower Drift over this area, during the interval 
between the two formations, is precluded. In addition to this, 
the lower Drift, wherever it occurs, has invariably eroded the 
whole of the Bagshot beds, so that it rests on the London Clay 
only. This process is conspicuous near Chelmsford: there the 
Drift gravels may be seep resting on the London Clay, while, 
within the distance of a mile, the complete beds of the Bagshot 
