156 Camhridge Philosophical Society : — 



fore to be the base of those rocks which, in the north of England, 

 represent the Wenlock and Ludlow groups of Siluria. 5. A coarse 

 slate, often much contorted. 6. A bed of impure limestone, which 

 may be traced from Tottlebank Fell towards the north-east for about 

 two miles, after which it thins out and does not again appear further 

 northward. 7. A coarse and often contorted state. When No. 6 

 is wanting. No. 5 and No. 7 may be considered as one group (now 

 called Banisdale Slate), which is widely spread, and gradually passes 

 into more coarse and gritty masses, that link themselves to the next 

 superior group. 8. Grit, slate, and tilestone, expanded between 

 Kendal and Kirkby Lonsdale. This is followed by unconformable 

 masses of Old Red Sandstone and carboniferous limestone. Of the 

 above groups, Nos. 5, 6, and 7 approximately represent the Wenlock 

 series, and No. 8 abounds in characteristic Ludlow fossils. 



In the range of these groups from Shap Fell to Tottlebank Fell 

 (which is about two miles south-west of Coniston Waterfoot) there 

 seems to be no ambiguity ; but to the south of Tottlebank Fell the 

 groups have, through the intervention of great faults, been thrown 

 into such abnormal positions that their relations have often been 

 misunderstood. Thus, (in 1822) when the author first attempted 

 to map this part of Lancashire, he was led, by the line of strike as 

 •well as by the whole physical characters of the country, to identify 

 the Tottlebank Limestone with a calcareous band a few miles further 

 south, which ranges (on the east side of the Duddon estuary) from 

 the hills above Bunk House, through Meer Beck, towards the vil- 

 lage of Ireleth, and which from thence by an enovmons fault {upcast 

 towards the south) is thrown into the ridge of High Haume, near 

 Dalton, from which it is continued nearly in the same strike till it is 

 covered by the Old Red Sandstone and Mountain Limestone. This 

 identification was however erroneous ; for the limestone-beds above 

 mentioned, ranging on the east side of Duddon Sands, are altogether 

 unconnected with the Tottlebank Limestone, and are in mineral type 

 and fossils absolutely identical with that portion of the Coniston 

 Limestone which appears, as is well known, on the other side of 

 Duddon Sands in the south-western extremity of Cumberland. 



The above mistake (made in like manner by several subsequent 

 observers) was partially corrected by the author in 1845 ; when, on 

 good physical and fossil evidence, he placed the High Haume Lime- 

 stone on the same parallel with that of Coniston. Not having any 

 fossils from the limestone quarries north of the village of Ireleth, and 

 not having found a single characteristic fossil from the slate-rocks 

 between Ulverston Sands and Duddon Sands, he was in 1845 unable 

 to carry his correction any farther; but even then he remarked again 

 and again that the calcareous beds north of the village of Ireleth in 

 structure resembled the Coniston Limestone, which is seen on the 

 north-west side of the Duddon, much more nearly than they resem- 

 bled the calcareous beds of Tottlebank. 



In the autumn of 1856 the author, accompanied by his friends 

 (Mr. Gough of Reston Hall, and Mr. John Ruthven of Kendal), saw 

 for the first time the excellent local collection formed during the 



