150 "> Tp Bey, MAXWELL H, Choss, ~ 
It is very remarkable that the above-mentioned conglomerates 
near’ Rush and near Baldungan contain pebbles: of Carboni- 
ferous limestone. In other places the limestone is thickly 
interspersed with small, angular fragments of older. beds of 
the same ‘formation ; these are very visible when they are of a 
different shade of colour from the matrix. These facts seem to 
imply that there were minor, pretty even, upheavals and sub- 
sidences during the deposition of the Carboniferous Limestone: 
and that older beds were uplifted from the sea, and had acquired 
considerable hardness when later beds were being formed partly 
from their angular and rolled debris, The phenomenon of lenticu- 
lar bedding, often to be observed in the Limestone, indicates that 
there were irregular changes of condition connected with the 
deposition of the strata. 
Upper Shules—A remnant strip of this formation extends 
from Baldungan towards the Naul, as indicated near the northern 
extremity of the map. Its length is nearly ten miles, its mean 
width about one and a half. The rocks consist of hard, splintery 
shales, interstratified, in some places, with thin grits and flag- 
stones. They used to be called'Coal Measures, that term veing 
applied, in a wide sense, to include, not only the Coal Measures 
proper, but all the strata between them and the top of the Car- 
boniferous Limestone. They are to be correlated with the 
Yoredale beds. Only the lower part of the group remains,. the 
thickness being about 500 feet. The overlap above mentioned, 
still continues into this formation, as can be seen near the Bog 
of the Ring, where these Upper Shales evidently extend beyond 
the Limestone, so as to come directly upon the Lower Silurian. 
Though this formation is properly described as conformable with 
the Limestone, yet, occasionally, local unconformabilities: have 
been noticed between the contiguous beds of the two:series. This 
is What might have been expected, as the great general subsi 
dence during the Carboniferous age must have been, not only 
interrupted, but temporarily reversed at the end of the Limestone 
period. As already mentioned, a similar temporary reversal 
seems to have taken place during the deposition of the Limestone 
itself; this being apparently necessary to explain the presence of 
fragments of earlier beds in the later beds of that formation. ~ 
The Upper Shales in this district contain a very characteristic 
assemblage of fossils. There is a very interesting coast section 
