288 LAMPLUGII : GLACIAL SECTIONS NEAR BRIDLINGTON. 
ordinary diversity. Besides fragments from nearly every stratified 
formation, there are innumerable igneous and metamorpliic rocks 
whicli the skilled petrologist alone can determine. I made a large 
collection of these boulders from the present section and from that 
illustrated in Part 11., and a list of the rocks identified within this 
limited area is given at the end of this paper (Appendix B). The list 
might have been almost indefinitely lengthened if it were possible for 
me to define accurately minor differences in the igneous rocks. 
Fortunately through the kindness of Mr. A. Harker, M.A., 
F.G.S., Fellow of St. John's, Cambridge, I have been able to place a 
few of the most interesting specimens into thoroughly qualified hands: 
and in Mr. Harker' s valuable notes which are appended to my paper 
(Appendix c), will be found exhaustive petrological descriptions of 
some of the selected fragments which have been sliced and examined 
microscopically. Mr. Harker indicates, as have all previous observers, 
a widely diverse origin for the pebbles, and thinks that, though not 
many of the rocks can be precisely localised, there are amongst them 
some probably from Scandinavia, others from the Cheviots, and 
others from the South and even perhaps from the West of Scotland. 
But as I shall presently show, these smaller pebbles though very 
interesting, are not safe guides to the actual direction of the ice-flow, 
and 1 think that the study of the larger boulders of the drifts on 
which I am at present engaged, and in which also I have received 
promises of invaluable aid from Mr. Harker, is more likely to yield 
information on this point. An instalment of this work will be found 
in the present volume of the Proceedings of this Society. 
It remains now to give, as on former occasions, some inferences 
with regard to the Basement Clay to which I have been led by the 
study of the sections. 
Notes and Inferences. — Nothing could be clearer than that the 
scrapings of a sea-bottom have been incorporated in the Basement 
Clay ; and in these sections one may study almost every process in 
its manufacture. It is easy to recognize in the curved and contorted 
fragments of beds, which the Basement Clay contains, the raw 
material that went to the making of it, and one finds this material 
in every stage, from that on which its original structure and organic 
