54 
HUGHES : INGLEBOROUGH. 
direction. The beds of tough sandstone, thus formed, resisted 
earth movements and denudation more than the flags, and 
consequently everywhere stand out in bold relief, and by their 
obtrusiveness give an impression that there is a larger proportion 
of beds of coarser texture than is really the case. They were 
called grits both in North Wales and in the North of England 
by the early geologists, who always spoke of Coniston Flags 
and Grits, or Denbigh Grits and Flags. 
Anyone who had worked chiefly among the Carboniferous 
rocks would be surprised at this use of the v/ord grit by Silurian 
geologists. The Coniston Grit and the Denbigh Grit are gener- 
ally very fine sandstones, although in some locahties, as at 
Caer Drewyn, near Corwen, for instance, or at a higher horizon, 
in the case of the Winder Grit, near Sedbergh, the rock is made 
up of quartzose fragments so large that no one would quarrel 
with the name grit as applied to them ; but these are beds of very 
Umited extent. It is perhaps the toughness of the rock, and its 
rough feel, that caused the name grit to be extended further than 
the texture would suggest. If the name trachyte had not been 
appropriated for an igneous rock it would be very applicable 
to our Silurian grit. The matter has been discussed on several 
occasions. In 1866 (see Geol. Mag., vol. iii., p. 207, footnote) 
I used " Greywacke " as a lithological term for the rough, tough 
sandstones so common in the palaeozoic rocks, as grit was re- 
quired for the coarse-grained rock intermediate between sand- 
stone and conglomerate, e.g.. Millstone Grit, and in 1867 Mr. 
David Forbes urged that the old word, Greywacke, which was 
no longer employed with its original stratigraphical signification, 
should be transferred and applied as a lithological term to rocks 
of the character of the Coniston grit, but the proposal was not 
generally accepted (Geol. Mag., vol. iv., 1867, p. 229, footnote). 
The characteristic fossil is Monograptus vomerinus Nich., 
which was detected by Miss EUes on the western slope of the 
valley near Sowerthwaite. I had found it long ago about 170 yards 
north of Sowerthwaite, but in those days it was not distinguished 
from G. priodon, or when it was, was called G. Sedgwickii. 
These beds are the equivalent of the Lower Coniston Flags, 
and of the Penyglog Flags in North Wales. 
