Chap. VII.] 
UPPEE LUDLOW EOCKS. 
135 
range from Shropshire, through Herefordshire, Eadnor, Brecon, and Car- 
marthen, where they are often of red and yellowish colours, they are 
charged with Orthoceras bullatum, Chonetes lata, Spirifer elevatus, Orthis 
lunata, Rhynchonella nucula, Cucullella? ovata, Bellerophon trilobatus, B. 
expansus, Platychisma helicites, Holopella obsoleta (see PL XXXIY.), and 
the minute bivalved Crustacean, Beyrichia Klcedeni (Foss. 64. f. 4). All 
of these are common fossils of the Upper Ludlow rock ; and a few of them 
are found as low even as the Upper Llandovery rock beneath the Wenlock 
shale. 
If we include the Downton Castle building-stone, this transition-band 
contains the oldest casts of recognizable terrestrial vegetation yet found in 
England and Wales*. The specimens hitherto collected are usually small, 
and little more than carbonized fragments. At the bottom of the detached 
basin of Old Eed Sandstone of Clun Forest in Shropshire, I detected thin 
layers of matted and broken vegetables (frequently carbonized) in the 
'tilestone' and 'firestone' beds of that tract (Sil. Syst. p. 191). Since 
then our acquaintance with them has been enlarged ; and the Museum in 
Jermyn Street contains many more specimens from this stratum, among 
which are the minute globular bodies, PL XXXY. f. 30, called ' Bufonites ' 
in the ' Silurian System,' but which, as will presently be explained, are 
now known to be of vegetable origin. 
Though not everywhere divisible into the portions above described, the 
Upper Ludlow rock maintains, on the whole, a decisive aspect in its range 
through Shropshire, Hereford, and Badnor into Brecknock and Carmar- 
thenshire, until last seen in the cliffs of Marloes Bay, Pembrokeshire. 
Frequently somewhat calcareous, the deposit is in these districts for 
the most part a harder and more sandy stone, partaking in a greater 
degree of the character of the Italian ' Macigno,' as before said, than any 
other rock of the Silurian system. Sometimes it is even a hard siliceous 
rock. 
On the eastward slopes of Bradnor and Hergest Hills, near Kington, and 
particularly in the ridges extending thence by Gladestry and Pains Castle 
to the Trewerne Hills on the Wye, this formation is often admirably ex- 
posed in slightly inclined masses replete with fossils. In the escarpment 
of the Trewerne and Begwm Hills f , and in many other places, it is stri- 
kingly exhibited as a grey, shelly, thin-bedded rock, dipping under the 
bottom beds of the Old Bed Sandstone, as in the woodcuts, pp. 110, 124, 
137. 
Along the outer or western edge of the Malvern Hills, the section of the 
Upper and Lower Silurian rocks, as illustrated at p. 95, exhibits, in like 
manner, Upper Ludlow rocks dipping under the Old Bed. Descriptions 
of this subformation, as occurring at many places, from Ledbury northwards, 
* Some traces of large Plants, possibly of land t This was my first Silurian section, 1831, in 
growth, occur in the Upper Silurian rocks of the passing from the knmvn Old Eed to the then mi- 
Eastern Harz, near Magdesprung. knoivn Ludlow rocks, Sil. Syst. pp. 5, 312. 
