10 



into vast clusters of several tons weight, resembling masses of sta- 

 lactite, the component portions being nearly parallel to each other. 

 Mr. Strickland supposes that currents of water (or possibly of wind, 

 operating during ebb tide), flowing in a certain direction, may have 

 disposed the sand in ridges parallel to that direction, and the car- 

 bonate of lime may have afterwards been attracted into these ridges 

 in preference to the intermediate portions. This view is confirmed 

 by the fact, that these concretions have frequently a pebble attached 

 to the larger end, as though it had protected a portion of sand from 

 the current, and caused it to accumulate in a ridge on the lee side, 

 a circumstance which may frequently be observed where sand is 

 drifted by the wind or water. 



Nov. 30. — William Baker, Esq. of Bridgewater, Andrew Roos- 

 malecoeg, Esq. of King's College, Dr. Lyon Playfair of Primrose, 

 near Blackburn, Lancashire, and John Buckman, Esq. of Pittville 

 Street, Cheltenham, were elected Fellows of this Society. 



" On the Bala Limestone." By Daniel Sharpe, F.G.S. 



Before entering upon his own views, the author quotes the opinions 

 published by others upon the age of the limestones of Bala and Coni- 

 ston ; previous to the labours of Professor Sedgwick and Mr. Mur- 

 chison, these two calcareous bands were thought to be of the same 

 age, and to be nearly the oldest fossiliferous beds in this country ; 

 but the first definite arrangement of them was made by Professor 

 Sedgwick, whose views will be found in our Proceedings (vol. ii. p. 

 675), placing both these limestones in the Upper Cambrian system, 

 which he stated to lie below the Silurian system of Mr. Murchison, 

 and above the Lower Cambrian system, or old slate series of Car- 

 narvonshire, Cumberland, &c., a view adopted by Mr. Murchison in 

 his work upon the Silurian system, upon the authority of Professor 

 Sedgwick. 



In 1839 Mr. James Marshall classed the Coniston limestone 

 with the Caradoc sandstone, upon the evidence of fossils examined 

 by Mr. J. Sowerby, and pointed out that it rested upon the Lower 

 Cambrian rocks ; thus omitting the Upper Cambrian system in the 

 North of England (Reports of the British Association, vol. viii. p. 67.) 



The second edition of Mr. Greenough's Map adopts Mr. Marshall's 

 view of the age of the Coniston limestone, and omits the Upper 

 Cambrians in the district of the Lakes ; but retains them in North 

 Wales, under the name of Upper division of the lower Killas, in 

 which is included the Bala limestone, thus placed in a diiFerent system 

 from the limestone of Coniston. 



Professor Sedgwick's memoir of November 1841 follows the same 

 view (Proceedings, vol. iii. p. 545) ; and in a note, p. 551, that author 

 removes all doubt as to his opinions by apologizing for having for- 

 merly placed the Bala and Coniston limestones on the same parallel. 



Notwithstanding the agreement of our best geologists in placing 

 the Bala limestone in the Upper Cambrian system, Mr. Sharpe was 

 induced to doubt the accuracy of this classification, by observing that 



