TRANSACTIONS OF THE SECTIONS. 103 



latious between jungles and the sea; and lastly, by the extensive growth of large 

 plants in shallow seas. /-,.,• 



The Geological Map of Edinburghshire, prepared by MM. Howell and Geikie, and 

 recently published, with its lucid explanations, affords indeed the clearest proofe 

 of the frequent alternations of beds of purely marine limestone charged with Pro- 

 ducti and bauds of coal, and is in du-ect analogy with the coal-fields of the Donetz 

 iu Southern Russia*. 



In sinking through the extensive coal-tracts around Manchester (at Dukinfield), 

 where one oi the shafts already exceeds in depth the deepest of the Durham mines, 

 rigorous attention will, I hope, be paid to the discovery of the fossils which cha- 

 racterize each bed passed through,— not merely to bring about a correctly matm-ed 

 view of the whole history of these interesting accimiulations, formed when the 

 siu'face of our planet was first fiu-nished with abundant vegetation, but also for the 

 practical advantage of the proprietor and miner, who, in certain limited areas, may 

 thus learn where iron-ores and beds of coal are most likely to be persistent. In 

 carrying out his siurvey-work through the north-western coal-tracts of Lancashu'e, 

 to which the large or six-inch Ordnance Map has been applied, one of the Secreta- 

 ries of this Section, Mr. Hull, has done good service in accurately defining the 

 tracts wherein the elevated coal-deposits are covered by drift only, in contradi- 

 stinction to those which are still sm-mounted by red rocks of Permian and Triassic 

 ago. In seeing that these are eagerly bought by the public, and in recog-nizing the 

 gi-eat use which the six-inch survey "has proved in the hands of the geological sur- 

 veyors in Scotland, oiu: friends in and ai-omid Manchester may be led to insist on 

 having that large scale of sm-vey extended to their own important district. By 

 refei-ring to the detailed delineations of the outcrops of all the Cai-bonrferous strata 

 in the counties of Edinbui-gh, Hadding-ton, Fife, and Linlithgow, as noted by 

 Professor Ramsay and MM. Howell and Geikie, the coal-propriotors of England 

 will doubtless recognize the gi-eat value of such determinations. 



Concenaing the Permian rocks, which were formed towards the close of the 

 long palffiozolc era, and constitute a natural sequel to the old Carboniferous depo- 

 sits, it is to be hoped that we shall here receive apposite illustrations from some of 

 our associates. 



When Professor Sedgwick, thirty-fom- years ago, gave to geologists his excellent 

 Memoir on the Mag-nesian Limestone of our country, as it ranges fi-om Durham, 

 through Yorkshire, into Nottinghamshfre, ho not only described the numerous 

 varieties of mineral structiu-e which that rock exhibits, noting at the same time its 

 characteristic fossils, but he also correlated it, and its imderlying beds, with the 

 Zechstein, Kupferschiefer, and Rothe-todte-liegende of Germany. But whilst this 

 is the true order in both coimteies, there is this considerable diflerence in England, 

 that along the zone where the Magnesian Limestone exists as a mass, and where 

 Sedg-wick described it, the inferior member of the gi-oup is a thin band of sandstone, 

 usually of a yellow colour (the Pontefract rock of William Smith), which in its 

 southern extremity, near Nottingham, is almost evanescent. In many parts of 

 Germany, on the contrary, and notably in Thuringia and Silesia, the same lower 

 band, with a few intercalated com-ses of limestone, swells out into enormous thick- 

 nesses and even constitutes lofty ridges. 



In Russia the series of this age puts on a very different mineral aiTangement. 

 There the calcareous bands, containing the veij same species of shells as the mag- 

 nesian limestone of Germany and Britain, are intercalated with pebble-beds, sand- 

 stones, marls, and copper ores, so that, although the same lithological order does 

 not prevail as in the Saxon or t^'pical Permian coimtiy of the elder German geolo- 

 gists, the group is, through its fossil types, unquestionably the same. It was from 

 the observation of this fact, and fi-om seeing that these deposits, so mixed up, yet 

 so clearly con-elated by then- animal and vegetable relics, and all superposed to the 

 Carboniferous system, occupied a region twice as large as the British Isles, in 

 which the varieties of structm-e are best seen in the government of Perm, that I 

 proposed in 1841 that the wliole group should have the name of ' Permian.' 



Of late yeai-s various British authors, including King, Howse, and others, have 

 ably described the fossil shells of this deposit as it exists on the eastern side of 



* See ' Eussia in Europe and the Ural Mountains,' vol. i. 



