1823.] the principal Mountain Chains of Europe. 213 



3. In the Hebrides, that portion of the sandstone which is 

 closely associated with the gryphite limestone is probably refer- 

 able to this series. 



4. It is generally believed that the sandstones of the lowlands 

 are partly to be ascribed to the old red sandstone ; viz. where 

 they skirt the Grampian chain, and partly to the coal sandstones, 

 the present series not occurring in that tract. 



6. On the south of the southern Or transition chain of Scotland, 

 however, the sandstones of the present series certainly occur in 

 the valley of the Tweed, and in the shores of the Firth of Sol- 

 way, in Dumfrieshire, being in the latter district connected with 

 the mass of the same formations stretching into the north of 

 Cumberland. 



6. In Ireland, the saliferous sandstones underlie the basalt of 

 the Ulster district, but are confined to a narrow zone encompass- 

 ing that area. 



7. In England, the saliferous sandstone mantling round the 

 south and south-west of the penine chain (see the account of 

 the coal districts) occupies the central counties, sending a branch 

 north-west to the point where the Cumbrian chains inosculate 

 with the former, and in the opposite direction, forming a band 

 between the lias and the coal and transition series, through 

 Warwickshire, Worcestershire, and Gloucestershire. In South 

 Gloucester, Somerset, and the south of Monmouth and Glamor- 

 gan, these formations have a very irregular outline, since they 

 form upfillings through which the elder rocks of the coal series 

 protrude in all the loftier ranges ; in Devonshire they are simi- 

 larly disposed among the transition chains. 



In all these places the lowest members appear to abound in 

 conglomerates ; those of Devonshire, which are associated with 

 amygdaloid, have every feature of the German rothetodte, but 

 the magnesian limestone is here wanting, and the variegated 

 sandstone lies immediately on those conglomerates. 



I have, in the preceding number, suggested the inquiry, whe- 

 ther the rock distinguished in Smith's Yorkshire as the Ponte- 

 fract rock may not possess similar analogies. 



The magnesian limestone forms a continuous band from the 

 south of Durham through Yorkshire and Nottinghamshire. 



Mr. Smith, in his geological map of Yorkshire, subdivides the 

 magnesian limestone, or, as he calls it, red-land limestone, thus : 



1. A hard bluish-white thin bedded stone which at Kinnersley, 

 Knottingly, and Brotherston, makes the lime celebrated for 

 agricultural purposes. 



2. Red and blue clay and gypsum. 



3. A soft yellowish calcareous freestone or magnesian lime- 

 stone. 



These beds are separated from the superior red marl by a thick 

 conglomerate. 



Mr. Buckland has observed in Yorkshire, beds closely resem- 



