920 Comparative Studies upon the Glaciation of { November, 
+ seemed to be the principal source of the glaciers which became 
confluent to form the great ice-sheet. In its advance this ice- 
sheet probably met and amalgamated with a number of already 
existing local ‘glacial systems, and it was suggested that there 
was no necessity for assuming either an extraordinary thickness 
of ice at the pole or great and unequal elevations and depressions 
of land. 
Detailed studies made by the author in Ireland, in 1885, had 
shown remarkably similar glacial phenomena. 
The large ice-sheet which covered the greater part of Ireland 
was composed of confluent glaciers, while distinct and local gla- 
cial systems occurred in the non-glaciated area. The principal _ 
ice-sheet resembled that of America in having for its center a 
_ great inland depression surrounded by a rim of mountains. 
_ These appear to have given rise to the first glaciers, which after 
uniting poured outwards in all directions. Great lobes from this | i 
Tak ice-sheet flowed westward out uf the Shannon and out of Galway, 7 
= Clew, Sligo and Donegal bays, northward out of Loughs Swilly f 
< -and Foyle, and south-eastward out of Dundalk and Dublin bays, ~ 
-while to the south the ice-sheet abutted against the M ullaghareirk, _ | 
_ Galty and Wicklow mountains or died out in the plains. _ i 
~ Whether it stopped among the mountains or in the lowlands 
its edge was approximately outlined by unusual accumulations of 
drift and boulders, representing the terminal moraines. As in 
- America, this outer moraine was least distinct in the lowlands, 
and pn often bordered by an outer fringe of drift several miles 
‘ in wid ; 
ic cus of an east and west line extending from Tralee to Wex- 
word i is a non-glaciated zone free from drift. Several local sys- 
tems of glaciers occur in the south of Ireland, of which by fat 
the most important is that radiating from the Killarney mountains, 
covering an area of 2000 aS miles, ies entitled to be called 
lc ice-sheet 
ied by its own moraine. 
> nce of any great marine submergence was 
auth as had noe the eee part of 
sco 
Ireland 20 
