450 HIXD : CARBONIFEROUS ROCKS OF THE PENNINE SYSTEM. 
the Pennine system, in Nortli Wales, the Carboniferous series 
consists of 1,700 feet of limestone, with 250 feet of cherty sandstone, 
Holywell shale, 100 feet, the latter containing the fauna of the 
Pendleside series. No Yoredale phase, therefore, occurred in that 
area, and it was altogether outside the influence of the mud and 
sandbearing waters of the north. 
Similarly the sequence in the Isle of Man shows an absence of 
intercalated beds of detrital sediment, 
Poolvash, Posidonomya shales : Pendleside series. 
Poolvash Limestone, massive, shelly, and very fossiliferous. 
Well-bedded Limestones of Scarlet and Ballasalla. 
And, as has been mentioned above (page 438), while in south Furness 
the Limestone is almost undivided by shales, as it passes north, on the 
west of the inlier of the older rocks constituting the Lake District, 
between Egremont and Penrith, masses of shale divide the limestone 
into well-marked beds, showing an approach to the Yoredale phase, 
which characterises the whole of the Carboniferous rocks from 
Ingleborough to the centre of Scotland. 
Probably, therefore, in point of time, the thick mass of limestone 
in the Midlands corresponds to the Calciferous Sandstone series and 
Carboniferous Limestone series of Scotland, the Tuedian, Carbon- 
aceous, and Calcareous divisions of Northumberland, and the Great 
Scar Limestone, plus Y^oredales, of Wensleydale. The change of type 
in the stratification is only what might have been naturally expected 
to obtain in a marine firea liable to be affected by detrital material, 
and the two types of rocks are essentially part of one and the same 
story, and require no hypothetical barriers or curious contemporary 
earth movements to explain them. 
The Pendleside Series. 
In the north Midlands the thick and undivided Massif of Lime- 
stone is overlaid by a series of dark shales with thin black and cherty 
limestones. These limestones gradually become obsolete higher 
in the series, and fine quartzose or gannister-like sandstones, with 
plant remains, and an occasional marine band, occur in the shales. 
This series varies from a few to 1,500 feet in thickness, and 
formed the main subject of the paper by Mr. Howe and myself 
