438 



THE GEOLOGIST. 



the same time its characteristic fossils, but he also correlated it, and its under- 

 lying beds, with the Zechstein, Kupferschiefer, and Rothe-todte-liegende, of 

 Germany. But whilst this is the true order in both countries, there is this 

 considerable difference in England, that along the zone where the Magnesian 

 Limestone exists as a mass, and where Sedgwick described it, the inferior 

 member of the group 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 con- 

 trary, and notably in Thuringia and Silesia, the same lower band, with a few 

 intercalated courses of limestone, swells out into enormous thicknesses and 

 even constitutes lofty ridges. _ 



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

 There the calcareous bands, containing the very same species of shells as the 

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

 sandstones, marls, and copper-ores, so that, although the same lithological order 

 does not prevail as in the Saxon or typical Permian country of the elder Ger- 

 man geologists, the group is, through its fossil types, unquestionably the same. 

 It was from the observation of this fact, and from seeing that these deposits, 

 so mixed up, yet so clearly correlated by their animal and vegetable relics, and 

 all superposed to the Carboniferous system, occupied a region twice as large as 

 the British Tsles, in which the varieties of structure are best seen in the 

 government of Perm, that I proposed in 1841, that the whole group should 

 have the name of " Permian." 



Of late years 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 the Penine chain ; and recently Mr. Kirkby has produced a carefully 

 written and well-considered memoir, showing the relations of the whole group, 

 by comparing its structure and palseontological contents in Durham with those 

 in South Yorkshire. Whilst, in addition, my associates of the Geological 

 Survey, particularly Mr. Aveline, have been carefully delineating the area of 

 these beds in their northern range from Nottingham through Yorkshire, much 

 yet remains to be done in correlating the Permian rocks lying to the west 

 of the Penine ridge, or where we are now assembled, with their eastern 

 equivalents. 



Already, however, great strides have been made towards this desirable end. 

 Thus, Mr. Binney has indicated the succession in the neighbourhood of Man- 

 chester, and has shown us that there some of the characteristic fossils of the 

 eastern magnesian limestone exist in red marl and limestones subordinate there- 

 to, and that these are clearly underlaid by other red sandstones, shales, and 

 limestones, which he terms Lower Permian. He has further followed these 

 Lower Permian beds to the west and north-west, and finds them expanding 

 into considerable thicknesses at Astley, Scarisbrick, and other places where 

 they overlie the coal-measures, and he has also traced them into Westmoreland, 

 Cumberland, and Dumfries-shire. In the last case he went far to prove that 

 which I suggested many years ago, that the red sandstones of Dumfries-shire 

 containing the large footprints of chelonians, as described by Sir W. Jardine, 

 are of Lower Permian age. 



This view of the relations of the Permian rocks of the north-west has been 

 also taken by Professor Harkness, and this summer he has successfully worked 

 it out, and has definitely applied the Permian classification to large tracts in 

 Cumberland, as explained in a letter to myself. He finds that the breccias and 

 sandstones of Kirby- Stephen and Appleby, which at the latter place have a 

 thickness of three thousand feet, extend northward on the west side of the 

 Eden (the breccia being replaced by false-bedded sandstones with footprints), 

 ami attain near Carlisle the enormous thickness of about five thousand feet. 

 These beds he classes unhesitatingly as Lower Permian, because he finds them 



