HUGHES : INGLEBOROUGH. 
49 
Limestone. Below this comes the Fairy Gill Shale, which passes 
down into the Coniston Shale with Strophomena and Trinucleus 
fairly abundant in it. The Fairy Gill Shale also breaks up 
into prismatic fragments which are larger and larger as we 
descend, until they are more than a foot in length. 
In this lower series there is also a fossiliferous calcareous 
gritty band, which is the bed referred to by Harkness (Q.J.G.S., 
xxiv., 1868, p. 301) where he quotes me for the occurrence of 
Bala fossils in calcareous shales. Those fossils were not found 
in the calcareous beds in the Graptolitic Mudstone but in the 
calcareous band shown in the section (Plate VI.) in the upper 
Bala or Fairy Gill Shale. 
The other section is that seen in Whinny Gill which runs 
down into Cross Haw Beck, Sedbergh. This section traverses 
the same beds as those seen in Spengill, but the rocks are faulted 
and folded to such an extent that it would be impossible to 
work out the succession from what is there seen. 
The Spengill section, however, has fortunately escaped this 
tangle of faults and folds, and gives us a sequence by reference 
to which, notwithstanding differences in thickness, &c., we may 
fit the beds seen on the south side of Ingleborough into their 
proper place. 
The Graptolitic Mudstone or Stockdale Shale. 
The Graptolithic or Graptolitic Mudstone was first cut 
off from the top of the Bala Beds by Harkness and Nicholson,* 
but it is olear from their lists of fossils that they had collected 
from beds far below what was afterwards included in the Grapto- 
Utic Mudstone, as well as from beds in what is now recognised 
as the lower part of the Silurian. Therefore the next step in 
the history was the limitation of the Graptolitic Mudstone. 
The lower beds, which are stratigraphically and palseontologically 
tied to the Bala, were called Fairj^ Gill or Ashgill Shale, while 
Mr. Aveline proposed the name Stockdale Shale for the upper 
part. The Graptolitic Mudstone or Stockdale Shale consists of 
very soft black shale wdth thin subordinate harder beds of cal- 
careous sandstone or limestone. The series, therefore, yields very 
* Q.J.G.S., xxiv., 1868, p. 299; xxxiii., 1877, p. 461. 
D 
