Chap. XII.] 
NOETHUMBEIAN AND SCOTTISH COAL. 
291 
I repeat, with their representatives in Derbyshire, the north of England, and 
particularly in Scotland, where they swell out into a vastly thicker series. In 
Pembrokeshire, also, these Lower Carboniferous rocks expand to some extent 
and begin to assume the Irish type. They contain Fishes (Palseoniscus, Psam- 
modus, &c.), with marine Shells, at their base. In the north-western parts of 
Lancashire and Yorkshire, also, as described by Prof. J. Phillips, those strata 
consist, in ascending order, of the Great Scar Limestone, estimated to vary in 
thickness from 500 to 1000 feet, — followed, in the west of Yorkshire, by consider- 
able alternations of shale and limestone, called by Professor Phillips the Yore- 
dale Series,' and considered by him to be about 1000 feet thick ; while the whole 
is surmounted by 800 feet of Millstone-grit *. 
North- Northumbrian and Scottish Coal. — Besides its grand protrusions of basalt 
and greenstone, the coast of Northumberland and South Berwickshire exhibits 
these Lower Carboniferous Limestones, much intruded upon by igneous green- 
stones and basalts, and opening out into different courses and interlaced by copious 
masses of schist and several coal-seams. One of the calcareous bands, near 
the centre of the group, is especially characterized by the Posidonomya Becheri 
of Bronn. Now it is to be specially noticed that it is through this striking spe- 
cies (which occurs also in the ' Calp ' of Ireland) that the thin beds of black 
Culm Limestone in Devonshire, wherein it also occurs, are known to be of this 
age (see section, p. 272). This fossil is, further, of frequent occurrence in the 
schists and 1 Kiesel-Schiefer ' of the Rhenish Provinces of Prussia, both with and 
without limestone, and is therefore a good type of the Lower Carboniferous age. 
It was by such proofs, and by the order of the strata, that Professor Sedgwick 
and myself showed how the Rhenish schists with Posidonomyse were the exact 
equivalents of the British Carboniferous or Culm Limestone of Devon, and 
how the sandstone which overlies them (the 1 Jiingere Grauwacke,' or ( Flotz- 
leerer Sandstein ' of the Germans) is the representative of the British Millstone- 
grit f. 
Ascending from the uppermost Old Red (occasionally a yellowish sandstone 
characterized by the Holoptychius Andersoni and Pterichthys hydrocephalus of 
Agassiz), the Lowest Carboniferous beds, as seen in the counties of Haddington, 
Edinburgh, and Fife, consist of a very thick series of sandstones and shale (laden 
with the remains of Plants), and occasional courses of limestone, to the lower 
mass of which that sound geologist Mr. Charles Maclaren % assigned the general 
name of 'Calciferous Sandstones.' In the environs of the Scottish metropolis, 
the Lowest Carboniferous zone ranges from near Portobello, on the east, to Lin- 
lithgow, on the west, the city of Edinburgh being entirely built of its excellent 
freestone. It also contains thin layers of coal, though the mineral is rarely of 
sufficient value to be worked. The upper portion of this lowest member, par- 
ticularly in Edinburghshire and Fifeshire, exhibits those courses of limestone 
(one of the thickest masses known being at Burdie House) the beds of which 
are charged with numerous fossil Fishes, such as Holoptychius Hibberti, Pa- 
lseoniscus Robisoni, Pygopterus Bucklandi, Eurynotus crenatus, Megalichthys 
Hibberti, &c. Some fossils of this band, including the Unio-like shells called 
Anthracosia, with dwarf Leperditiae, indicate the deposit as having been formed 
* See the memoirs of Professor Sedgwick, ' On account of the Yoredale rocks and Millstone-grit 
the General Structure of the Cumbrian Moun- of North Staffordshire, Derbyshire, Cheshire, and 
tains,' and ' On the Carboniferous Chain from Lancashire the student is referred to Messrs. 
Penyghent to Kirkby Stephen' (Trans. Geol. Hull and Green's memoir in the Quart. Journ. 
Soc, n. s., vol. iy. pp. 47 et seq.) ; also Phillips, Geol. Soc. vol. xx. p. 242. 
Geology of Yorkshire, vol. ii., a most valuable mo- t See Trans. Geol. Soc, n. s., vol. vi. p. 228 et seq. 
nograph of the native county of the distinguished J Geology of Fife and the Lothians, 1839. 
author. For a most instructive and trustworthy 
v 2 
