28 



end of Rather Heath and a little south of Cowan Head, and also in 

 Lambrigg Park ; it is usually accompanied by Attypa affinis, Spirifer 

 octoplicatus, Leptana lata and depressa, Orthis lunata, and Terehratula 

 nucula : the T. navicula seems to have died out suddenly, as it is not 

 found in the Upper Ludlow beds. 



The same division of the Ludlow rocks may be obtained by attend- " 

 ing to the direction and dip of the beds ; the lower series partakes 

 of the north-east strike, which runs through the older Silurian rocks 

 in these counties, and is traversed by many of the same faults as 

 those formations, but the Upper Ludlow beds are thrown up in anti- 

 clinal ridges with a different direction. 



Mr. Sharpe gives a list of the organic remains found in each divi- 

 sion of the formation, which includes forty-four of the species de- 

 scribed in Mr. Murchison's work from the old red sandstone and 

 Upper Ludlow, fourteen of those from the Aymestry limestone, and 

 twenty-two of those from the Lower Ludlow beds. Of the species 

 of shells placed by Mr. Murchison in the old red sandstone*, all 

 but two have now been found low in the Ludlow beds, proving that 

 the red beds containing these species in Herefordshire must be classed 

 with the Upper Ludlow formation. 



Old Red Sandstone, — The only addition to the former paper which 

 relates to this formation, is in mapping it in the upper valley of the 

 Lune, where the tile-stones reach above the hamlet of Langdale, 

 dipping N.N.E. 10°. 



The age of the large masses of gravel of a brown or red colour 

 noticed in the valley of the Lune between Sedberg and Casterton, 

 and of the Kent and Sprint, was before left uncertain ; the author 

 now regards them as a modern surface drift. 



Mountain Limestone. — The description of this formation did not 

 enter into Mr. Sharpe's plan, but he examined the portion of it which 

 occurs in Low Furness, to ascertain the geological position of the 

 Ulverston iron ore. 



The ore occurs in veins usually perpendicular, and bearing 

 W.N.W., which cut through the limestone, but are not continued 

 into the Silurian rocks. The following veins are mentioned : — 

 Plumpton Hall ; now abandoned. 



Lindal Moor vein ; an exception to the usual condition, as it runs 

 between the mountain limestone and the Windermere grits, striking 

 north-west and dipping south-west 45° ; it is the principal and most 

 profitable vein of the district. 



Stainton ; three veins separated by a few yards of clay, spar, and 

 limestone, perpendicular, and bearing W.N.W. 



Lindal Court ; several perpendicular veins near together, bearing 

 W.N.W. 



Crosthwaite ; a poor vein bearing W.N.W., thought to be the 

 continuation of that at Stainton. 



Wet Flat ; the rocks near are much disturbed, and the vein, after 

 running W.N.W., turns down a fault in the limestone to N.N.W., 

 but soon thins out. 



* Silurian System, p. 603. and t. 3. 



