288 Reports and Proceedings : 
and the Lower Carboniferous rocks; and on their western margin 
they have usually the Pennine Fault bringing against them the 
Upper Permian strata. The greatest breadth of the Lower Silurian 
rocks, as exposed in the NE. of Westmorland and the SE. of Cum- 
berland, does not exceed 14 miles. 
The contour of the country occupied by rocks of this age presents 
a strong contrast with the areas where the newer paleozoic rocks 
occur, being composed of hills possessing a conical outline, of which 
the Pikes, Knock, Dufton, and Murton, are fine examples; whilst the 
newer paleozoic strata presenta regular outline as seen in the Pennine 
Chain, or an undulating aspect as exhibited by the Permian group. 
The Lower Silurian rocks of this part of the North of England 
have an ENE. and WSW. strike ; and their prevailing dips are to- 
wards the SSE. In their more northerly extension, these rocks show 
strata belonging to the Skiddaw Slates; and several bands of rocks 
of this age are exposed by flexures and denudations in this Lower 
Silurian area. These Skiddaw Slates have the mineral nature and cha- 
racteristic fossils of this series as represented in the Lake-ccuntry. 
To these succeed a thick mass, composed of greenstones, porphyries, 
and ash-beds, which have also their equivalents in the rocks over- 
lying the Skiddaw Slates, and which are known as the greenstones, 
porphyries, and ashes of the typical Lake-country. ‘They are well 
seen in the NE. of Westmorland, in Knock and Dufton Pikes. Im- 
mediately south of Dufton Pike a totally different group of rocks makes 
its appearance. This consists of black flaggy shales full of fossils ; 
and these flaggy shales are of such a nature as to mark them as the 
equivalents of rocks of the same nature, which are seen interbedded 
between porphyries and greenstones in the Arens and Arenigs in 
Wales, and also in the Snowdonian group. Upon these fossiliferous 
black shales, greenstones, porphyries, and ashes are also seen; and to 
the latter there succeeds a mass of dark-coloured limestone, which is 
worked at Keisley. The Keisley limestones are also fossiliferous ; 
and their position and fossil contents show their analogy to the Bala 
or Coniston Limestone. 
Immediately S. of the limestone at Keisley, the Skiddaw Slates 
are again seen, dipping NNW. or directly opposite to the Keisley 
limestone. They here form Murton Pike. ‘The occurrence of a 
ereat W. and E. fault, probably of 10,000 feet throw, brings these 
lower rocks against the Coniston Limestones here. 
Another fault, having a NNW. and SSE. direction, also intersects 
the Lower Silurian of this part of the North of England, throwing 
them down towards the W. ‘This, however, is comparatively slight ; 
but it detaches a small area of Carboniferous strata, which in one 
locality lie on the west side of the older paleozoic series from the 
great mass of limestone of the Pennine escarpment. 
On some New Forms or OLENoi Tritopirrs From THE LowrER FosstLirERous 
Rocxs or Wass. By J. W. Savrer, Esq., A.L.S., F.G.S. 
HE erey rocks and black shales at the base of the Lower 
Lingula-flags, in which Mr. Salter discovered, two years ago, 
the great Paradoxides Davidis, are being fully explored (with the 
