Geological Society. 311 



of that line, which are generally at right angles to each other, and 

 are frequently seen upon the same rock-surface. The direction of 

 one of these is N. by W. in Antrim and Londonderry ; N.W. over 

 the highlands of Fermanagh ; and X.E., 1ST., and N. by W. in 

 Donegal £c. That of the second set is "W. 25° S., swinging round 

 to W. in Donegal and S.W. towards Galway Bay, and is strikingly 

 persistent throughout. Besides these, a very few striations occur 

 which do not conform to these directions, and are attributable to 

 local ice-flows. 



The second set of striations was referred to the ice of the Scottish 

 Glacial System, and evidence was cited from the researches of Messrs. 

 Syines and M c Henry, Dr. Geikie, and others in support of this 

 view, which is confirmed by the relative positions of the boulders 

 and their parent rocks. Striae bearing westward have been ob- 

 served at a height of 1 100 feet in co. Mayo. 



The effects of the Irish Glacial System have been considered by 

 the Rev. TT. Close, Mr. G. EL Kinahan, and Prof. Hull. Striations 

 occur up to 1340 feet in Donegal. The ice of this system flowed 

 in a general S.E. direction to the S. of the axis. 



With regard to the relative age of the two sets of striae, it is 

 observable that those bearing northward are by far the most nume- 

 rous ; so that although it is reasonable to suppose that a considerable 

 accumulation of snow and ice obtained in the Irish area whilst the 

 Scotch system was gathering its maximum strength, the striations 

 produced by this gathering would be largely effaced by the west- 

 ward-flowing Scotch ice ; and that, after the decline of the latter, 

 an independent Irish Iter de glace flowed northward and southward, 

 finding its axis of movement in the great central snow-field. 



3. "Evidence of Ice-Action in Carboniferous Times." By John 

 Spencer, Esq., F.G.S. 



The author combated the notion that there is any a priori im- 

 probability in the action of ice during the period in question. In 

 the case under consideration, of the two agents, land-ice or floating- 

 ice, he was inclined to adopt the latter, as having been the cause of 

 the phenomena he described. The bed affected is the Haslingden 

 Flag-rock, a member of the Millstone-Grit series, which is directly 

 covered by a shale of the same series. The surface of this Flag-rock is 

 largely striated, the striae having a N.E. and S.W. direction, and being 

 nearly parallel. The area exposed is 200 square feet. The Flag-rock 

 dips to the east at an angle of 30° ; but there seems no possibility 

 of these striae having been produced by landslips or local disturbance. 

 A quarry on the same horizon, near Rochdale, exhibits similar phe- 

 nomena. As collateral evidence of ice- action, he alluded to the 

 boulders frequently found in the coal-seams. 



4. " The Greensand Bed at the Base of the Thanet Sand." By 

 Miss Margaret I. Gardiner, Bathurst Student, Newnham College, 

 Cambridge. 



This bed may be seen between Pegwell Bay on the east, and Chisle- 

 hurst on the west, and a somewhat similar bed occurs at Sudbury, 



