Parr II. Sxcr. iv. § 2.] CARBONIFEROUS. , 747 
southern side lie the lower Devonian beds, below which the Carbon- 
iferous Limestone, and even Coal-measures are made to plunge. Bores 
and pits near Liége at the one end, and in the Boulonnais at the other, 
have reached workable coal, after piercing the inverted Devonian rocks. 
By continuing the boring the same coals are found at lower levels in 
their normal positions. Besides this dominant dislocation many minor 
faults and plications have taken place in the Carboniferous area, some 
of the coal-seams being folded zig-zag, so that at Mons a bed may be 
perforated six times in succession by the same vertical shaft, in a depth 
of 350 yards. At Charleroi a series of strata, which in their original 
horizontal position occupied a breadth of 84 miles, have been compressed 
into rather less than half that space by being plicated into twenty-two 
zig-zagz folds. 
Southwards the area of crystalline rocks in Central France is dotted 
with numerous small Carboniferous basins which contain only portions 
of the Coal-measures. It would appear, however, that some of the 
surrounding schists are really altered representatives of the lower parts 
of this system, for undoubted Carboniferous limestone fossils have been 
found in them between Roanne and Lyons, and near Vichy. Even as 
far south as Montpellier, beds of limestone full of Productus giganteus 
and other characteristic fossils are covered bya series of workable coals. 
The Carboniferous limestone is well developed westward in the 
Cantabrian mountains in the north of Spain, where it likewise is 
surmounted by coal-bearing strata. Grand’Hury, from a consideration 
of the fossils, regards the coal-basins of the Roannais, and lower part of 
the basin of the Loire, as belonging to the age of the “culm and upper 
greywacke,” or of strata immediately underlying the true Coal-measures. 
But the numerous isolated coal basins of the centre and south of France 
he refers to a much later age. He regards these as containing the most 
complete development of the upper coal, properly so called, enclosing a 
remarkably rich, and still little known, flora, which serves to fill up the 
paleontological gap between the Carboniferous and Permian periods.! 
Some of these small isolated coal basins are remarkable for the extra- 
ordinary thickness of their coal-seams. In the most important of their 
number, that of St. Etienne, from 15 to 18 beds of coal occur, with a 
united thickness of 112 feet, in a total depth of 2500 feet of strata. In 
this basin near Chalons and Autun the main coal averages 40, but 
occasionally swells out to 130 feet, and the Coal-measures are covered, 
apparently conformably, by the Permian rocks, from which so remark- 
able a series of saurian remains has recently been obtained. 
Germany.’—Tracing the extension of the Carboniferous system, we 
find the upper, or Coal-measures, portion extending in detached basins 
north-eastwards from Central France into Germany. One of the most 
important of these, the basin of Pfalz-Saarbriicken, lying unconformably on 
Devonian rocks, contains a mass of Coal-measures believed to reach a maxi- 
mum thickness of not less than 20,000 feet, and divided into two groups : 
2. Upper or Ottweiler beds, from 6500 to 11,700 feet thick, consisting of red 
sandstones at the top, and of sandstones and shales, containing 20 feet of 
coal in various seams, Pecopteris arborescens, Odontopteris obtusa, Anthra- 
cosia, Estheria, Leaia ; fish remains. 
1 Grand’Eury, “ Flore Carbonifeére.” 
2 Geinitz, “ Die Steinkohlen Deutschlands,” Munich, 1865, 
