136 Correspondence. 
the New Red Sandstone plain of Cheshire to those of North Wales. 
But more than that, I take it that the patch of Carboniferous Lime- 
stone near Corwen, together with the Flintshire escarpments, makes 
it almost certain that the whole Carboniferous formation spread 
formerly over the greater part of North Wales, with just a few 
island-peaks of older rocks, perhaps, rising up through it. In short, 
I believe that, with the possible exception of a few isolated points 
there and elsewhere, as in Cumberland and about the Southern 
Highlands of Scotland, the whole of the Southern half of Scotland 
and all England and Wales were, at the close of the Carboniferous 
period, covered by level and continuous sheets of Coal-measures. 
Local thinnings and thickening of the beds there were, doubtless, 
in all directions. 
As to Ireland, I have long taught in my lectures, and I believe 
demonstrated, that, with the exception of a few small isolated peaks 
of the Older Paleozoic rocks, it also was at the same period one 
great plain of Coal-measures, whether above or under water. 
How far the Carboniferous Limestone of the Isle of Man proves 
that the English and Irish Carboniferous formations were then 
connected across what is now the Irish Sea, I forbear to decide. 
My own private opinion is that they were more or less connected, 
just as at a later period the Red Marls and Lias of Antrim were 
continuous with those of Cheshire, Worcestershire, and Gloucester. 
I almost fear that I am writing what to many persons will appear 
mere common-place truisms; but the expressions of your Reviewer 
have induced me to run the risk of that imputation rather than that 
any persons should retain what I believe to be erroneous and narrow 
views in our science. 
The portions of the Paleozoic rocks still left in our islands are only 
the mere ruined fragments and foundations of those that once existed. 
The hole in the Chalk that occurs in the Wealden district excites 
attention because, from its comparatively slight extent, people can 
see that it is a hole, while the far more extensive destruction of the 
older rocks has been so great that the former continuity of their 
fragments is ignored or discredited.—Yours, &c., 
J. BEETE JUKES. 
Dupuy: Feb. 6, 1868. 
2. CARBONIFEROUS SANDSTONE WITH SURFACE-MARKS. 
[Plate IV.] 
To the Editor of the GEOLOGICAL MAGAZINE. 
Sir,— Having lately obtained a slab of one of the Carboniferous 
sandstones (a few feet below the ‘ Yard-seam’ and above the ‘ Five- 
quarter-seam’ at Bowden-close, in the Bishop-Auckland Coal-field, 
Co. Durham), which bears about fifty impressed hoof-shaped marks, 
and not being aware that any such markings, usually supposed to be 
foot-prints of some-animal, have been found lower down than the 
