Correspondence — Mr. Alfred Rarker. 565 



Farther east the fossiliferous beds of Dinas Bran appear to lie 

 considerably above the Leintwardiuensis Slates. 



On comparison with other areas it is found that this succession 

 is almost identical with that in the Long Mountain, in North 

 Denbighshire, and in the Lake District. It is also inferred that 

 the Lehitwardinensis Slates represent the Leintwardine Flags of 

 Herefordshire, and that the Dinas Bran beds correspond with a 

 part of the Upper Ludlow. 



3. "On some Points in the Geology of the Harlech Area." By 

 the Eev. J. F. Blake, M.A., F.G.S. 



In testing the conclusions arrived at in regard to the Llanberis 

 and Penrhyn area by an examination of that of Harlech, two 

 questions are raised concerning the latter: — (1) Can a succession be 

 traced below the Purple Slates similar to that which the author has 

 described as occurring in Caernarvonshire ? and (2) Where is the 

 most natural break in the series, and does it show an unconformity ? 



With reference to the first question, the author gives his reasons 

 for concluding that, as far as the succession is seen in the Harlech 

 area, it is similar to that of Caernarvonshire. A group of Purple 

 Slates is described which so closely resemble the Llanberis and 

 Penrhyn Slates, that he considers that he is justified in definitely 

 correlating them with those slates. Below these are slaty grey- 

 wackes, which, if not identical with those of Caernarvonshire, bear 

 a greater resemblance to them than any other part of the series does. 

 No older beds are seen. Above the Purple Slates are the Harlech 

 Grits proper. 



In discussing the second question, the author describes con- 

 glomeratic beds occurring some distance above the base of these 

 Harlech Grits; but at Pont Llyn-y-Crom the junction between them 

 and the underlying Purple Slates shows features recalling what is 

 seen at Bronllwyd. He discusses the possible existence of an 

 unconformity at the base of these grits, and concludes that on the 

 w^hole the phenomena point, though not very strongly, to an 

 unconformity of no great importance. 



The concluding part of the paper is occupied with a consideration 

 of the question of classification of the Cambrian strata and those in 

 juxtaposition with them. 



COI^iaiESIPOlNr ID IE n::TCE. 



SIR H. HOWOETH ON THE HOLDERNESS BOULDERS. 

 Sir, — The title and some of the paragraphs of Sir Henry 

 Howorth's latest contribution have been penned under a singular 

 misapprehension. I have written not a word " on the Scandinavian 

 Ice-sheet," nor offered any opinion as to the mode of transport of 

 those very damaging boulders. I have, indeed, my own views on 

 these questions, but have kept them to myself with the modesty 

 which your correspondent recommends. This reserve I propose 

 to maintain, despite Sir Henry's somewhat inconsistent challenge 



