Charleswokth — Glacial Geology of North- West of Ireland. 177 



of 1866/ and though his meaning is in places somewhat obscure, I have failed 

 to discover any passage which could be allowed this interpretation. One is 

 indeed forcibly struck with the fact that this pioneer of Irish glacial geology 

 recognised with true insight the extreme complexity of the ice movements. 



A line of dispersion traversing south Donegal was noted by J. E. Kilroe, 

 who imagined it as a " spur or projection from the central snow field. "- 

 The same view was expressed by E. Hull.^ 



J. R. Kilroe {oj^.cif., p. 831) added to this glaciation from the "Central Show- 

 field," an earlier glaciation by an ice-sheet which, proceeding from Scotland, 

 flowed across N"orth Ireland from the east coast to the Atlantic seaboard. 

 He writes : " Hence the ice-sheet which off the Wigton and Ayrshire coast 

 flowed on to Irish soil, and urged its way across the country, bearing previous 

 accumulations before it, to escape on the western coast by the various bays 

 of Donegal, Sligo, Mayo, and Galway, and over mountain groups which were 

 unable to command an independent glacial system sufficient to obstruct or 

 divert its flow." 



In a paper published at a much later date, Kilroe * states he has " found 

 it necessary to add another important ice-flow " intermediate in time between 

 the Scottish glaciation and the later period of the " Central Snowfield," and 

 which moved " southwards over parts of Ulster .... from an ice centre 

 situated over the area of the Inner Hebrides." To the evidence upon which 

 this intermediate glaciation is based it will be necessary to return at a later 

 page. 



J. E. Portlock, in the " Eeport on the Geology of Tyrone and Londonderry " 

 of 1843, has several allusions to the glaciation of these parts of Ireland, to 

 which reference will be made in the proper places. 



H. Carvill Lewis, in his " Glacial Geology of Great Britain and Ireland," did 

 not propound any large views of the glaciation of North Ireland : his sojourns 

 in this pai't of the country were too brief. Yet this keen observer made many 

 very apposite remarks on individual glacial occurrences, to whicli reference 

 will be made as occasion arises. He would appear to have been strongly 

 impressed with the idea of an ice-sheet in the interior of Ireland, which 

 radiated in all directions to the coast. He started, however, with quite 

 different views, based on the general association of glaciers with highland 

 regions ; these ideas, as it will be shown in this paper, approximated more 



' Notes on the General Glaciation of Ireland, Journ. Roy. Geol. See. Ireland, vol. i, 



p. 207. 



- Oj}. cit., p. 832. ' Op. cit., p. 272. 



* Outlines of Geological Observations in North-east Londonderry, Belfast Nat. Field 

 Club, Ser. ii, Vol. vi, Part iv, pp. 634-663. 



