116 PROCEEDINGS OF THE GEOLOGieAL SOCIETY. [Jail.?, 



Nor is this the only difficulty. From the absence of the calca- 

 reous band (4? /3), all the subordinate groups are packed in one mass ; 

 and the impress of slaty cleavage, notwithstanding the extraordi- 

 nary contortions and dislocations, affects them all. These cleavage 

 planes strike, in almost undeviating lines, through all the compli- 

 cated curves and broken masses, in a direction on the averagQ 

 within a point of magnetic east and west. In the Ireleth ridge the 

 cleavage planes hang toward magnetic south ; but further north, the 

 same planes (nearly with the same strike) hang within a point of 

 magnetic north, generally inclining towards true north. I think these 

 phaenomena theoretically important, and I hope to return to them in 

 a future communication. 



These reasons are sufficient, mineralogically, for grouping to- 

 gether all these slaty masses over the hard grits (No. 3). Neither 

 do the fossils indicate the expediency of any further subdivision 

 under the name of Windermere rock, or any other local name. 

 The more slaty masses out of which roofing-slate is extracted, may 

 in a general way follow particular zones, but they are not continu- 

 ous, and I believe they often shift their parallels. This is the case 

 in the older Cumbrian slates, and also, I believe, in the group I am 

 describing (No. 4 y). Still we may in an approximate way follow 

 on the strike the lower slates (4 a), and the higher (4 y). The 

 latter I would place near the foot of Coniston Water, and thence 

 across Hawkshead valley to the shore of Windermere, a little below 

 the Ferry. This is, I think, nearly the range given in Mr. Sharpens 

 last abstract. But if this be true it follows that the slaty beds 

 extending to Latterbarrow must represent the group (4 a). 



/. Section from Skelwith Common to Windeemere. 

 N.N.W. E.S.E. 



Skelwith Windermere 



Common. Brathay. Latter barrow. Ferry. 



Now in this group we have fossils ; and in some bands on the right- 

 hand of the road from the Ferry-house to Hawkshead, we find 

 several species of fossils, and the Terebratula navicula in vast 

 abundance. I do not contend that the bands with T. navicula 

 exactly represent (4 /3) or upper limestone ; neither would I bring 

 them into exact comparison with the Aymestry limestone of Siluria. 

 The comparison would be too wiredrawn to be of any use ; and, by 

 like reasoning, we might prove the existence of three or four bands 

 of Aymestry limestone on different geological parallels. Following 

 the several groups along the line of strike over Coniston Water and 

 Windermere, and thence through an undulating country of singu- 

 larly contorted strata into the valleys of Kentraere and Long Sled- 



