Proceedings of the Geological Society. 187 
carboniferous scries and the old red-sandstone of one colour ; and by 
confounding, along a considerable part of the country bordering on 
the north shore of the Solway Firth, the new with the old red-sand- 
stone. 
Old Red-Sandstone.—The extraordinary irregularity of this for- 
mation in the British Isles is first noticed; the old red conglome- 
rates of Cumberland are then compared with those on both sides of 
the Galloway chain; and the sections in the south of Treland, con- 
necting the old red-sandstone with the carboniferous series, and con- 
stituting a good passage, are next described. The lower carbonifer- 
ous shales there pass into roofing slates, resembling the black slates 
at the base of the Devonshire culm-measure ; and the great coal-field 
in the west of Ireland overlying the mountain-limestone assumes 
the characters of the same culm-measures. These facts, the author 
says, remove the difficulty in classification presented by the mineral 
structure of the Devonshire culm-series. From the details connected 
with the above statements, Mr Sedowick draws the inference, that 
no new formation can be interpolated between the old red-sandstone 
and the carboniferous series, the sequence of strata being complete ; 
and as the sections in the silurian country described by Mr Murchi- 
son, shew that no member is wanting between the old red-sandstone 
and the Ludlow rocks, there is consequently one continuous unbroken 
succession from the lower division of the new red-sandstone down to 
the Llandeilo Flagstone ; and, therefore, that the argument for the 
true place of the Devonian system is complete. For any formation 
with fossils intermediate between the carboniferous and silurian sys- 
tems must have an intermediate position,—must, therefore, be on the 
parallel of some part of the old red-sandstone which fills that whole 
intermediate position. 
Sections of North Wales.—The author, after referring to his 
former description of the great masses of North Wales, states that 
his Snowdonian fossils have been found to be identical with Silurian 
species ; and that the same result has been obtained from an exami- 
nation of the organic remains of the Berwyns. Hence, he concludes, 
that in the great section of North Wales, there is no positive zoolo- 
gical distinction in the successive descending groups, the only differ- 
ence being the gradual disappearance of species which occur in the 
higher beds. 
Cumbrian Groups.—The groups exhibited in a section from Kes- 
wick, through Kendal, Kirby-Lonsdale, are, 1st, that by Skiddaw 
Forest ; 2d, a group essentially composed of quartzoze and chloritic 
roofing-slates, associated with innumerable igneous rocks, and bound- 
ed by caleareous slates, which extend from the south of Cumber- 
