435 
of the fossil contents. The cover was a strong clay mixed 
with numerous boulders of sandstone and limestone, on one 
of which were numerous scratches. I procured two speci- 
mens of the rocks, which I left with Mr. Ord, at Whitfield, 
and even on these small pieces the polished surface and 
grooving were conspicuous. This example clearly shows 
that these peculiar features exist in the North of England, 
and I doubt not that when attention is more generally given 
to the subject, many more will be discovered. 
If these features are entirely due to glacial action, it 
would seem natural to conclude that the hardest rocks and 
the highest altitudes would afford the best opportunities of 
observation. With this view it was thought by Dr. Buck- 
land that the slate rocks and elevated valleys of Snowdonia 
in North Wales would present great facilities of observation, 
and I accompanied him in an examination of that district in 
October last. 
Until I had an actual inspection of the rocks in various 
parts of North Wales, I had no idea of the close resem- 
blance they bear to the forms which Agassiz has figured in 
his plates, and the impression produced on my own mind was, 
that this form could only be derived from the slow movement 
of solid masses of vast momentum. The weather was unfa- 
vourable for the general examination of the surface as regards 
mounds of earth, or the structure of supposed moraines, 
inasmuch as the ground was saturated by heavy and almost 
incessant rain; but on the other hand this very circumstance 
was peculiarly favourable for examining the rocks, the con- 
stant washing of which presented a clearer view of their 
features than would have been seen if they had been perfectly 
dry, and to this cause Dr. Buckland attributed the discovery 
of several phenomena which had escaped the attention of 
previous observers. 
After examining the district near Ellesmere, which consists 
