130 
SILURIA. 
[Chap. VII. 
of Ludlow rocks, as in the ridges of Mary Knoll and Brindgwood Chase j 
west of Ludlow, — and in the hills extending from the View Edge and 
Norton Camp, where it forms a conspicuous band parallel to, and loftier f 
than, the Wenlock Edge (see woodcut, p. 124). 
At Aymestry the limestone occupies both banks in the gorge of the : 
River Lugg ; but, as above said, it rapidly thins out to the south-west, j 
On the whole it has much less of a concretionary structure than the sub- 
jacent Wenlock limestone, and partakes more of the flat-bedded character j 
which is observable in the ' pendle ' beneath and distinguishes, indeed, all j 
parts of the Ludlow formation. 
In the old quarries at Aymestry it is conspicuously marked by the lines 
of cavities whence its numerous Corals have been weathered out. 
In the Woolhope valley of elevation, the Aymestry rock (see section, 
p. 110) assumes precisely the same external or physical features as on the 
flanks of the Ludlow promontory, having from its hardness resisted denu- 
dation better than other portions of the deposit. It thus forms the crest |; 
of the external and encircling ridge, and is prominent in the hills of 
Marden, Seager, and Backbury. Although it differs in being a less pure 
limestone than that near Ludlow, it contains many of the same fossils, 
even the Pentamerus Xnightii, its most characteristic shell (PI. XXI. 
f. 10), having been found in the Woolhope district since the ' Silurian 
System ' was published. 
On the outermost western slopes of the Malvern Hills, and on the sides 
and summits of their northern prolongation the Abberley Hills, the 
Aymestry rock, though containing less calcareous matter than in Shrop- 
shire, is still the well-defined central portion of the Ludlow formation. 
In some of these tracts (as near the Hundred House) it might be used for 
lime, if the "Wenlock limestone, of such superior quality, were not in close 
proximity. In the districts of May Hill, Usk, &c. this limestone is simply 
represented by the harder and slightly calcareous central part of the 
Ludlow rocks. 
At Sedgeley, in Staffordshire, the rock becomes once more a useful lime- 
stone, in which the predominant Aymestry fossil, Pentamerus Xnightii, 
abounds. There it is known as the 4 black limestone,' in contradistinction 
to that of Dudley, on which, with some intermediate shale or ' bavin/ it 
reposes*. 
The fossils which pervade the Aymestry limestone, in addition to Pen- 
tamerus Xnightii, are Bhynchonella Wilsoni, Lingula Lewisii, Stropho- 
mena euglypha, and large specimens of Atrypa reticularis, Bellerophon 
dilatatus, Pterinea Sowerbyi, &c, and many of the same Shells, Corals, and 
Trilobites which are common in the subjacent "Wenlock limestone. In- 
deed, except in the less number of species, and the occurrence of some of 
* See ' Silurian System,' sections, p. 481 et seq. The Eev. T. T. Lewis first called my attention to the 
fact of the Sedgeley limestone being the equivalent of the Aymestry rock. 
