23 
kindness of C. W. Peach, Esq., F.G.S., the President of the Royal Physical 
Society of Edinburgh, to obtain some specimens of an organism peculiar, 
so far as is known at present, to Arthur's seat, and only discovered in 1868. 
It is an Entomostracon of the G-enus Estheria, and occurs in a nodular bed 
about two inches thick among the calciferous sandstones. The Nodules 
are hard and brown inside, but weather to a soft mass of a yellow colour, 
and crumble down to an ochrey powder under the touch. It has been 
named by Prof. T. Rupert Jones after its discoverer, E. Peachii.* 
The volcanic agency which toward the close of the Old Red Sandstone 
period had sunk to temporary repose had evidently broken out again 
during the deposition of these lowest strata of the carboniferous system. 
Beds of volcanic ash occur containing rounded crystals of felspar in a 
dark purplish porphyritic paste, and masses of almost basaltic trap 
with crystals of black augite. 
The lower carboniferous series in the neighbourhood of Bristol is 
completed by about 400 feet of light coloured shales and limestone bands, 
in which space occurs the well known palate-bed. But in the Scottish 
area instead of these we find, first, — a considerable thickness of dark 
shales celebrated for the abundance of fish-remains which they have 
yielded, consisting of at least nine species : 
Amblypterus nemopterus. Palseoniscus carinatus. 
"With them are found the usual accompaniments of Sphenopteris, 
Lepidodendron, &c. Several of the above species also occur in the 
Coalfield of Lorraine, near the now notorious town of Saarbriick. 
Next in ascending order comes an immense thickness of white, clean, 
thick-bedded sandstone, Scottish freestone, easily worked and withstanding 
exposure well. Of this the city of EcLinburgh has been built, and in 
perhaps the largest quarry opened for that purpose, the now classical 
Craigleith, was exposed in 1830 the fossil tree figured by Lyell on page 
* Prof. T. R. Jones, F.Gr.S., has kindly furnished the writer with the 
following specific description: — " It is of a subquadrate form, boldly ridged, 
concentrically. Its sculpture is not preserved, and indeed only mere films 
of the shell itself. Its form however is sufficiently distinct to authorize 
us to regard it as a new species 'Estheria Peachii."' Several of the 
specimens exhibited are now in the Museum of the Philosophical 
Institution. 
punctatus. 
striatus. 
Eurynotus fimbriatus. 
crenatus. 
Acanthodes sulcatus. 
Wardii. 
Rhizodus Hibberti. 
