Vol. 62.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. CXXXV 



2. * The Crag of Iceland — an Intercalation *in the Basalt- 

 Formation.' By Dr. Helgi Pjetursson. (Communicated by 

 Prof. W. "W. Watts, M.A., M.Sc, F.R.S., Sec.G.S.) 



Mr. George Abbott, in exhibiting specimens and photo- 

 graphs of limestones showing band- and ball-structure, 

 remarked that, at Fulwell-Hill Quarries, near Sunderland, some of 

 the uppermost beds of the Magnesian Limestone presented this 

 peculiarity. In places, the limestone contained as much as 97 per 

 cent, of calcium-carbonate. The solid bands of limestone were from 

 1 to 7 inches thick, but the ball-layers were seldom more than 

 1 inch wide. This was a form of parallel banding that had no 

 regular relation to the bedding, being sometimes at right angles 

 thereto, and might even be seen passing uninterruptedly through 

 several underlying bedding-planes. The speaker considered the 

 structure to be the result of segregation after the formation of a 

 mass of balls. 



In addition to the exhibit mentioned above, the following 

 specimen and lantern-slides were exhibited : — 



Quartzose gravel from the upper part of the Reading Beds, Lane 

 End (Buckinghamshire), exhibited by H. J. 0. White, F.G.S. 



Lantern- slides exhibited by Prof. W. J. Sollas, Sc.D., LL.D., 

 F.R.S., F.G.S., in illustration of his paper. 



June 27th, 1906. 



Sir Archibald Geikie, D.C.L., Sc.D., Sec.R.S., President, 

 in the Chair. 



The List of Donations to the Library was read. 



The Names of certain Fellows of the Society were read out for 

 the second time, in conformity with the Bye-Laws, Sect. YI, Art. 5, 

 in consequence of the Non-Payment of the Arrears of their 

 Contributions. 



The President announced that the Foreign Secretary had, on 

 behalf of the Officers and Council, addressed a letter of con- 

 gratulation to Commendatore Prof. Arturo Issel, For.Corr.G.S., 

 on the occasion of the fortieth anniversary of his professorate. 



The following communications were read : — 



1. ' Interference -Phenomena in the Alps.' By Mrs. Maria 

 M. Ogilvie Gordon, D.Sc, Ph.D., F.L.S. (Communicated by 

 Sir Archibald Geikie, D.C.L., Sc.D., Sec.R.S., P.G.S.) 



2. ' The Influence of Pressure and Porosity on the Motion of 

 Sub-Surface Water.' By William Ralph Baldwin-Wiseman, M.Sc, 

 Assoc.M.Inst.C.E., F.G.S. 



