224 
THE GEOLOGIST. 
bonlferous limestone is seen to dip couformably to, and rest upon, these 
very strata. Much of the picturesque scenery of the road from Eoss 
past Penyard Castle to Hope Mansell is due to highly inclined strata, 
forming headlands of these upper beds, the average mean dip of which, 
however, is not more than 25° towards the coal-field. As a rule, 
fossils are very rare, excepting in one seam of blue argillaceous shale, 
about the middle of the series, and a bed of coarse-grained yellowish 
sandstone near the top, where the remains of plants are tolerably 
numerous ; there are also some impressions of shells in a thin bed of 
sandstone, about a foot in thickness, which immediately subtends the 
limestone-group. 
These upper beds rest upon the conglomerate -beds, which make up a 
thickness of some 200 feet or more of coarse-grained sandstone, much 
charged with per-oxidc of iron, and containing dispersed quartz and 
other pebbles, marl-partings, and thin bands of small pebbles, the 
whole iutcrstratified in irregular, lenticular-shaped drifts, affording 
lozenge and diacaond-shaped sections, several of which may be seen 
on the road across the Wye Valley, from Wilton to Ross. Many other 
sections, equally characteristic, are to be obtained between Eoss and 
Monmouth. 
The high grounds round the Monmouthshire side of the Forest abound 
with gigantic blocks and solitary tors, composed of the conglomerate, 
which forms the outlier known as the " Buck-stone," which is usually 
mistaken for, and mis-stated to be, a Druidical monument, besides 
having a host of other mythic legends and stories connected with its 
suppositious historj\ 
The cornstoncs, and some members of the Old Eed Sandstone, call for 
no notice in this place, since I have merely introduced the description, 
already given, of the superior beds of Old Red, from the circumstance of 
that deposit forming the base, as it were, of the basin, and, in conjunction 
with the account, next following, of the Carboniferous limestone and of 
the Coal-measures, making a connected sketch of the general geology 
of the district. 
II. Caeboniferous Lijiestoxe. 
The Carboniferous limestone would mark a continuous band round 
the Forest of Dean, flanking and underlying the Coal-measures, but 
that it is cut off on the south-cast by a down-throw fault, commencing 
