12 
feet in total thickness. To the north-west of the Bela section, 
the Marls repose, sometimes on one horizon of the Magnesian 
Limestone series, sometimes upon another; or they may lie 
upon any part of the Plant Beds. In the Midland Railway cutting, 
a few hundred yards on the Appleby side of Newbiggin station, 
the Marls were seen to lie with a sharp junction across the edges 
of the Plant Beds, which had evidently undergone a certain 
amount of erosion before the newer strata were laid down upon 
them. Again, in the gypsum quarries at Kirkby Thore the marls 
lie in some parts upon a remnant of the Plant Beds, while in other 
parts of the same workings the Plant Beds, as well, of course, as 
the Magnesian Limestone, are absent, and the Marls he directly 
upon the Penrith Sandstone. Facts of much the same kind are 
observable in West Cumberland. 
Now, if we were dealing, in this connection, with the relation of 
the upper beds to the Magnesian Limestone alone, a very obvious 
explanation of the facts would be that, the Magnesian Limestone, 
being a deposit more or less of a chemical origin, might be expected 
to be variable in regard to thickness—its absence at any given spot 
being simply due to its never having been deposited there. But 
with the Plant Beds the case is different. These consist of alter- 
nations of fine-grained sandstones of a prevalent ochreous tint, and 
usually more or less dolomitic in composition, with grey clays, 
reddish clays and shales, beds of lignite, here and there a film of 
veritable coal, and thin seams of argillaceous, arenaceous, or 
bituminous dolomite. The plant remains, such as they are, occur 
chiefly in the sandstones, where, doubtless, their preservation 
is due to the conditions of lesser salinity that prevailed when these 
rocks were formed. ‘They consist of carbonized fragments of 
drifted vegetation, hardly ever in a sufficiently good state of 
preservation to be identified. The Plant Beds are therefore un- 
mistakeably of sedimentary origin, and their general aspect would 
lead one to expect that they had been laid down with comparative 
uniformity over large areas. The absence of true sedimentary 
beds such as the Plant Beds at any given spot below the Bunter 
Marls may therefore be taken as good evidence of their removal 
