Many species of Mollusca, and especially Brachiopoda, appear in the Permian seas of this age, Spirifera and Producta being the most characteristic.

Other shells now occur, which have not been observed in strata newer than the Permian. Strophalosia (Fig. 73) is abundantly represented in the Permian rocks of Germany, Russia, and England, and much more sparingly in the yellow magnesian limestone, accompanied by Spirifera undulata, &c. S. Schlotheimii is widely disseminated both in England, Germany, and Russia, with Lingula Credneri, and other Palæozoic Brachiopoda. Here also we note the first appearance of the Oyster, but still in small numbers. Fenestella represents the Polyzoa. Schizodus has been found by Mr. Binney in the Upper Red Permian Marls of Manchester; but no shells of any kind have hitherto been met with in the Rothliegende of Lancashire, or in the Vale of Eden.

The brecciated limestone (No. 2) and the concretionary masses (No. i) overlying it (although Professor King has attempted

Fig. 73.— Strophalosia Morrlslana. Fig. 74. — Cyrtoceras depressum.

to separate them) are considered by Professor Sedgwick as different forms of the same rock. They contain no foreign elements, but seem to be composed of fragments of the underlying limestone, No. 3. Some of the angular masses at Tynemouth cliff are two feet in diameter, and none of them are water-worn. The crystalline or concretionary limestone (No. I ) formation is seen upon the coast of Durham and Yorkshire, between the Wear and the Tees; and Mr. King thinks that the character of the shells and the absence of corals indicate a deposit formed in shallow water. The plants also found in some of the Permian strata indicate the neighbourhood of land. These are land species, and chiefly of genera common in the Coal-measures. Fragments of supposed coniferous wood (generally silicified) are occasionally met with in the Permian red beds of many parts of England. Among the Ferns characteristic of the period

may be mentioned Sphc?wpteris dichotonia and ^S*. Artemisicefolia J Pccopteris lonchitica and Neuropteris

Fig. -Wakhia gtgantea^ figured on pp. 143, 144. " If we are, ^chiotheimii, says Lyell, " to draw a line between the Secondary

PERMIAN ■RO'CKS. IJJ

and Primary fossiliferous strata, it must be run through the middle of what was once called the ' New Red.' The inferior half of this group will rank as Primary or Palaeozoic, while its upper member will form the base of the Secondary or Mesozoic series."* Among the Equiseta of the Permian formation of Saxony,. Colonel Von Gutbier found Calamites gigas and sixty species of fossil plants, most of them Ferns, forty of which have not been found elsewhere. Among these are several species of Walchia, a genus of Conifers, of which anIn theirexamplestems,is leaves,given andin Fig.cones,75. i'^ig- 76.-Trigouocarpum Noggerathii. they bear some resemblance to the Araucarias^ which have been introduced from North America into our pleasure-grounds during the last half-century. Among the genera enumerated by Colonel Von Gutbier are some fruits called Cardiocarpon^ and Asterophyllites and Ajmuiaria, so characteristic of the Carboniferous age. The Lepidodendron is also common to the Permian rocks of Saxony, Russia, and Thuringia; also the Noggerathia, a family of large trees, intermediate

between Cycads (P'ig. 72) and the Conifers. The fruit of one of these is represented in Fig 76.

Permian Rocks. — We now give a sketch of the physiognomy of the earth in Permian times. Of what do the beds consist? what is the extent, and what is the mineralogical constitution of the rocks -deposited in the seas of the period? The Permian formation consists of three members, which are in descending order —

I. Upper Permian sandstone, or Gres des Vosges; 2. Magnesian Limestone, or Zechstein; 3. Lower Red Sandstone, Marl-slate or Kupferschiefer, and Rothliegende.

The grh dcs Vosges, usually of a red colour, and from 300 to 450 feet thick, composes all the southern part of the Vosges Mountains, where it forms frequent level summits, which are evidences of an ancient plain that has been acted on by running water. It only contains a few vegetable remains.

The Mag7iesian Limestone, Pierre de mine, or Zechstein, so called in consequence of the numerous metalliferous deposits met with in its diverse beds, presents in France only a few insignificant fragments; but in Germany and England it attains the thickness of 450 feet

*' Elements of Geology," p. 456.

It is composed of a diversified mass of Magnesian Limestone, generally of a yellow colour, but sometimes red and brown, and bituminous clay, the last black and fetid. The subordinate rocks consist of marl, gypsum, and inflammable bituminous schists. The beds of marl slate are remarkable for the numbers of peculiar fossil fishes which they contain \ and from the occurrence of small proportions of argentiferous grey copper-ore, met with in the bituminous shales which are worked in the district of Mansfeld, in Thuringia — the latter are called Kupfej'schiefer in Germany.

The Lower Rea Sandstone^ which attains a thickness of from 300 to 600 feet, is found over great part of Germany, in the Vosges, and in England. Its fossil remains are few and rare; they include silicified trunks of Conifers, some impressions of Ferns, and Calamites.

In England the Permian strata, to a great extent, consist of red sandstones and marls; and the Magnesian Limestone of the northern counties is also, though to a less degree, associated with red marls.

In Lancashire thin beds of Magnesian Limestone are interstratified with red marls in the upper Permian strata, beneath which there are soft Red Sandstones, estimated by Mr. Hull to be about 1,500 feet thick. These are supposed to represent the Rothliegende, and no shells of any kind have been found in them. The upper Permian beds, however, contain a few Magnesian Limestone species, such as Gervillia antiqua, Pleiirophorus costatiis, Schizodus obsairus, and some others, but all small and dwarfed.

The coal-fields of North and South Staffordshire, Tamworth, Coal-brook Dale, and of the Forest of Wyre, are partly bordered by Permian rocks, which lie unconformably on the Coal-measures; as is the case, also, in the immediate neighbourhood of Manchester,

where they skirt the borders of the main coal-field, and consist of"the Lower Red Sandstone, resting unconformably on different parts of the Coal-measures, and overlaid by the pebble-beds of the Trias.

At Stockport the Permian strata are stated by Mr. Hull to be more than 1,500 feet thick.

In Yorkshire, Nottinghamshire, and Derbyshire, the Permian strata are stated by Mr. Aveline to be divided into two chief groups: the Roth-liegende, of no great thickness, and the Magnesian Limestone series; the latter being the largest and most important member of the Permian series in the northern counties of England. The Magnesian Limestone consists there of two great bands, separated by marls and sandstone, and quarried for building and for lime. In Derbyshire and Yorkshii'e the magnesian limestone, under the name of Dolomite, forms an excellent building-stone, which has been used in the con- ;5truction of the Houses of Parliament.

PERMIAN ROCKS. I79

In the midland coiftities and on the borders of Wales, the Permian section is different from that of Nottinghamshire and the North of England. The Magnesian Limestones are absent, and the rocks consist principally of dark-red marl, brown and red sandstones, and calcareous conglomerates and breccias, which are almost entirely unfossiliferous. In Warwickshire, where they rest conformably on the Coal-measures, they occupy a very considerable tract of country, and are of very great thickness, being estimated by Mr. Howell to be 2,000 feet thick. In the east of England the Magnesian Limestone contains a numerous marine fauna, but much restricted when compared with that of the Carboniferous period. The shells of the former are all small and dwarfed in size when compared with their congeners of Carboniferous times, when such there are, and in this respect, and the small number of genera, they resemble the living mollusca of the still less numerous fauna of the Caspian Sea.

Besides the poverty and small size of the mollusca, the later strata of the true Magnesian Limestone seem to afford strong indications that they may have been deposited in a great inland salt-lake subject to evaporation. 1 he absence of fossils in much of the formation may be partly accounted for by its deposition in great measure from solution, and the uncongenial nature of the waters of a salt-lake may account for the poverty-stricken character of the whole molluscan fauna.

The red colouring-matter of the Permian sandstones and marls is considered, by Professor Ramsay, to be due to carbonate of iron introduced into the waters, and afterwards precipitated as peroxide through the oxidising action of the air and the escape of the carbonic adid which held it in solution. This circumstance of the red colour of the Permian beds affords an indication that the red Permian strata

were deposited in inland waters unconnected with the main ocean, ^ which waters may have been salt or fresh as the case may be. " The Magnesian Limestone series of the east of England may, possibly, have been connected directly with an open sea at the commencement ofthe deposition of these strata, whatever its subsequent history may have been; for the fish of the marl strata have generically strong affinities with those of Carboniferous age, some of which were truly marine, while others certainly penetrated shallow lagoons bordered by peaty flats."*

"On the Red Rocks of England," by A. C. Ramsay. Quart Jour. GcoL Soc.f vol. xxvii., p. 246. M 2

l80 THE WORLD BEFORE THE DELUGE.

There is indisputable evidence that the Permian ocean covered an immense area of the globe. In the Permian period this ocean extended from Ireland to the Ural mountains, and probably to Spitzbergen, with its northern boundary defined by the Carboniferous, Devonian, Silurian, and Igneous regions of Scotland, Scandinavia, and Northern Russia; and its southern boundaries apparently stretching far into the south of Europe (King). The chain of the Vosges, stretching across Rhenish Bavaria, the Grand Duchy of Baden, as far as Saxony and Silesia, would be under water. They would communicate with the ocean, which covered all the midland and western counties of England and part of Russia. In other parts of Europe the continent has varied very litle since the preceding Devonian and Carboniferous ages. In France the central plateaux would form a great island, which extended towards the south, probably as far as the foot of the Pyrenees; another island would •consist of the mass of Brittany. In Russia the continent would have extended itself considerably towards the east; finally, it is probable that, at the end of the Carboniferous period, the Belgian continent would stretch from the Departments of the Pas-de-Calais and Du' Nord, in France, and would extend up to and beyond the Rhine.

In England, the Silurian archipelago, now filled up and occupied iDy deposits of the Devonian and Carboniferous systems, would be •covered with carboniferous vegetation; dry land would now extend, .almost without interruption, from Cape Wrath to the Land's End; but, on its eastern shore, the great mass of the region now lying less than three degrees west of Greenwich would, in a general sense, be under water, or form islands rising out of the sea. Alphonse Esquiros thus eloquently closes the chapter of his work in which he treats of this formation in England: " We have seen seas, vast watery deserts, become populated; we have seen the birth of the first land and its increase; ages succeeding each other, and Nature in its progress advancing among ruins; the ancient inhabitants of the sea, or at least their spoils, have been raised to the summit of lofty mountains. In the midst of these vast cemeteries of the primitive world we have met with the remains of millions of beings; entire species sacrificed to the development of life. Here terminates the first mass of facts •constituting the infancy of the British Islands. But great changes are still to produce themselves on this portion of the earth's surface."

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