lamplugh: buried cliff at sewerby. 
385 
scattering of flint pebbles among the chaUy shingle ; but all the 
flints we found had come from the Yorkshire chalk, and among them 
there were none of the foreign red and black flints, such as occur 
plentifully in our boulder-clays, so that the pebbles have no doubt 
drifted along the coast from the north side of the headland, or have 
been brought by fresh water down the Boynton valley. Foreign 
pebbles were not, however, absent, for at rare intervals we 
threw out worn fragments of sandstones, quartzites and basalts ; but 
these erratics were very scarce, forming only an infinitesimally small 
proportion of the w^hole, and the largest was no larger than a child's 
clenched hand. Fragments of a black carbonaceous shale, such as 
occurs in some of the estuarine beds of the Oolite, were rather more 
plentiful, and we rarely passed a day w^ithout finding three or four 
pieces of it ; this, being very light, may have drifted along the coast. 
B. The Old Land-surface. 
Resting on the old beach was an irregularly stratified mass of 
marly clay, with sub-angular lumps of chalk and thin streaks of 
sand, evidently talus and rain-wash from the impending clifi". 
This indicates that the sea no longer reached the cliff, the change 
having been very gradually brought about, as w^as shown by the way 
in which the lower part of the rain-wash intercalated with the old 
beach Bones were rarer in this deposit than in the beds below, but 
occurred here and there in the clayey layers, along with numerous 
small land-shells and obscure traces of vegetation. Remains of fish 
were of course absent, but we found a tooth of a small rodent, 
probably the vole, and several birds' bones, besides the remains of 
the larger mammals. 
The thickness of this bed close to the old cliff was from four 
to six feet, but it thinned rapidly as it left the cliff, and, at a distance 
of from 5 to 10 yards, generally disappeared by dovetailing into the 
blown sand, into which it also passed gradually upwards. It has 
evidently accumulated in the sheltered hollow between the sand- 
dunes and the cliff, and is of peculiar interest as affording us the 
only land-surface yet known in our Yorkshire coast-sections. 
