= 
Notices of Memoirs—Papers at British Association. 469 
of New York, but in Ohio, Indiana, and Illinois occasionally leaving 
moraines only a little north of the 39th parallel of latitude. Of these 
relics my first-hand knowledge is very small, but the admirably 
illustrated reports and other writings of American geologists indicate 
that, if we make due allowance for the differences in environment, the 
tills and associated deposits on their continent are similar in character 
to those of the Alps. 
In our own country and in corresponding parts of Northern Europe 
we must take into account the possible co-operation of the sea. In 
these, however, geologists agree that, for at least a portion of the Ice 
Age, glaciers occupied the mountain districts. Here ice-worn rocks, 
moraines and perched blocks, tarns in corries, and perhaps lakelets in 
valleys, demonstrate the former presence of a mantle of snow and ice. 
Glaciers radiated outwards from more than one focus in Ireland, Scot- 
land, the English Lake District, and Wales, and trespassed, at the 
time of their greatest development, upon the adjacent lowlands. 
They are generally believed to have advanced and retreated more than 
once, and their movements have been correlated by Professor J. Geikie 
with those already mentioned in the Alps. Into that very difficult 
question I must not enter ; for my present purpose it is enough to say 
that in early Pleistocene times glaciers undoubtedly existed in the 
mountain districts of Britain and even formed piedmont ice-sheets on 
the lowlands. On the west side of England, smoothed and striated 
rocks have been observed near Liverpool, which can hardly be due to 
the movements of shore-ice. . . . On the eastern side of England 
similar markings have been found down to the coast of Durham, but 
a more southern extension of land ice cannot be taken for granted. 
In this direction, however, so far as the tidal valley of the Thames, 
and in corresponding parts of the central and western lowlands, 
certain deposits occur which, though to a great extent of glacial 
origin, are in many respects different from those left by land ice in the 
Alpine regions and in Northern America. 
They present us with problems the nature of which may be inferred 
from a brief statement of the facts.! 
(To be concluded in our next Number.) 
II.—Bririsa AssocratTion FoR THE ADVANCEMENT OF ScrtencE, E1gHTIETH 
AnnuaL MEETING, HELD AT SHEFFIELD, SEPTEMBER 1-7, 1910. 
List oF Tirtes oF Papers READ IN SeEction C (GEOLOGY) AND IN 
OTHER SECTIONS BEARING UPON GEOLOGY. 
Presidential Address by Dr. A. P. Coleman, F.R.S. 
Cosmo Johns.—The Yoredale Series and its equivalents elsewhere. 
Dr. J. &. Marr, .RS., & W. G, Fearnsides, U.A.—The Paleozoic 
Rocks of Cautley (Sedbergh). 
Miss G. R. Watney & Miss EL. G. Welch.—The Graptolitic Zones of 
the Salopian Rocks of the Cautley Area (Sedbergh). 
Professor J. Joly, D.Sc., F.R.S.—Pleochroic Halos. 
1 See footnote on p. 463, at the commencement of the President’s Address, 
