92 LAMFLU(;iI : land-shells in INKHA-CLACIAL C II ALK-KriJULH. 
laiid-sliells occurred plentifully in this earth. Tlie chalk-rub})le 
on tlie foreshore in which these sliells were found was about 
30 yards from the base of the present cliff, and extended in a 
stri]) from three to five yards wide for about 150 yards, dis- 
appearing soutliward beneath l)oulder-clay wliich was exposed 
for about 50 yards fiutlier. I had not before seen so good an 
exposure on this part of the shoie. 
In the clift" just opposite tlie middle ])ortion of the exposure, 
the chalk-rubble is well seen in section, liaving a thickness there 
of ten feet. In this section it is immediately covered by boulder- 
clay, tlie junction-plane being sharp and definite. After finding 
the shells in the shore-exposure I was able to detect them also 
in an earthy seam in the rubble near the base of this cliff 
(Fig.,, p. 94). 
The shells are in a very fragile state, and at })resent only 
one species has been recognised : — Pupa muscorurn.^ But a 
small Hdix is probably also present, though not identifiable in 
the material submitted to palseontological examination at the 
Museum of the Geological Survey. 
Samples of the shelly earth were washed and sifted in the hope 
that it might yield other organic remains ; but with the exception 
of one small carbonaceous fragment, which may have been of 
vegetable origin, no other fossils were found. 
The chalk-rubble is almost wholly composed of small an- 
gular fragments of chalk ranging from one-eighth to half an inch 
in diameter, firmly set in a matrix of yellow silty clay which 
may represent the residue from decomposed chalk. Occasion- 
ally there are seams of larger fragments of chalk, up to one to 
two inches in diameter, but these are comparatively rare, and 
it is singular how comparatively regular and even has been 
the trituration of the hard rock which has gone to form the 
bed. The chalk-rubble appears to be unlike any superficial 
deposit which is at present being accumulated from the waste 
of chalk surfaces, and it probably represents the weathering 
of the chalk slopes under peculiar climatal conditions which 
* [ am indebted to Mr. E. T. Xewton, F.R.S., for this determination. 
