605 
the author is imduced to infer, from eleven of the twenty-five 
species found in the bottom beds of Herefordshire occurrmg also 
in the upper Ludlow rocks of that district, and from seven of the 
remaining fourteen species occurring low in the Ludlow rocks of 
Westmoreland, that the beds which have been considered to form 
the bottom of the old red sandstone ought to be included in the Silu- 
rian system. A further argument in support of this arrangement is 
drawn from the fact, that where the old red sandstone rests on the 
Windermere rocks these doubtful beds are wanting, the shells bemg 
found only where the Ludlow rock occurs. 
A list of thirty-four species of fossils is given m the paper, con- 
sisting almost solely of Ludlow Testacea figured in Mr. Murchison’s 
work, but the author does not state positively to what portion of 
the Ludlow series the Westmoreland beds ought to be assigned. 
5. Old Red Sandstone.—The following distinct districts, composed 
of old red sandstone, occur within the area described by the author : 
(a.) that in the valley of the Lune and the neighbourhood of Kirkby 
Lonsdale; (4.) those near Kendal and in the valleys of the Kent, 
Sprint, and Mint; and (c.) that near Shap and Tebay. 
5a. To the old red of the valley of the Lune, above Kirkby Lons- 
dale, the author assigns the bed of loose conglomerate and red clay, 
which he says dips under the scar limestone of Casterton, the lime- 
stone being inclined to the south-east at an angle of 30°, and the 
conglomerate to the east by north at an angle of 25°. The want of 
conformity is stated to be more manifest to the westward ; for where 
the limestone bends round by Kirkby Lonsdale bridge it dips 25° or 
30° to the south-south-east ; at Catshole quarry the strata are arched 
with a north-west strike; at Hollin Hall quarry the dip is south-west 
30°, and at Teamside 40° south-east; but the old red sandstone dips 
throughout, as far as the beds can be seen, to the east. At Caster- 
ton the loose conglomerate is 100 feet thick, and passes downwards 
into red marl, occasionally mottled blue, and estimated to be fifty feet 
thick. This marl rests on alternating beds of red marl and red sand- 
stone, beneath which is a considerable deposit of dark red tilestone 
and light-coloured sandstone, forming the passage beds into the Lud- 
low rocks. The total thickness is estimated at 1000 feet. To the 
north of the Casterton fault, the lower beds of the old red sandstone 
are stated to be raised up and exposed, far to the eastward of their 
position below Casterton ; and above this spot the right bank of the 
river is said to be composed of the lowest beds of the tilestones and 
the passage beds into the Ludlow rock, but the left bank to consist 
of tilestones and red sandstones. ‘The dip is east, at an angle of 25°. 
Mr. Sharpe also assigns to the old red sandstone, but not definitive- 
ly, the bed of brown gravel, or of brown clay full of pebbles, which 
covers the whole of the valley of the Lune to its junction with the 
Rathay, and up that valley nearly to Sedbergh. It forms a line of 
low hills on each side of the Lune, resting on the northern edge of 
the tilestones above Barbon Beck, and conceals the junction of the 
Ludlow rocks on the right of the Lune with the Windermere rocks 
on the left of that river. 
