72 Geological Society. 
A paper was next read, “ On the recent discovery of Fossil Fishes 
( Palgoniscus catopterus, Agassiz,) in the new red sandstone of T yrone, 
Ireland ;"’ by Roderick Impey Murchison, Esq., V.P.G.S. 
A Sinall specimen of new red purtachenved presenting the first im- 
pressions of fishes found in this formation in the British Isles, having 
been exhibited before the Geological Section of the British Association 
at the late meeting in Dublin, Mr. Murchison, in company with Prof. 
Sedgwick, Lord Cole, and Mr. Griffith, visited the spot where it had 
been obtained. 
The quarry is at Rhone Hill, in the parish of Killyman, about three 
miles east of Dungannon. ‘The new red sandstone in which it is ex- 
cavated is a prolongation of the deposit which occupies large tracts 
in the county of Antrim, and extends into this part of Tyrone, where 
it surrounds a small, slightly productive coal-field, but reposes for the 
greater part upon mountain Jimestone. The eastern flank of the di- 
strict is covered by a vast thickness of clay, containing lignite, the 
exact age of which is not known; and the surface generally is very 
much overlaid by loose detritus, consisting of sand and gravel, derived 
from the adjacent formations. Large blocks of syenite and green- 
stone, referrible to a northern origin (Antrim), are scattered here and 
there. 
The beds of new red sandstone exposed in the quarry dip about 15° 
to the N.N.E., and consist, in the upper part, of red and green marls, 
passing down into a dark red, thickly bedded, siliceous sandstone, 
with a few irregular, highly micaceous way-boards of a deep purple. 
colour. The surface of some of the beds exhibits ripple-marks. The 
quarry, which is the property of Mr. Greer, is from 25 to 30 feet deep, 
and the fishes are found only in the bottom beds, but are in great 
abundance *, 
Dr. Agassiz afterwards gave a systematic enumeration of the fos- 
sil fishes which he has found in English collections. He commenced by 
detailing the general results of his researches, from which it appears, 
that the discovery in England of three hundred new species has 
corroborated the laws of development which he had previously de- 
termined in the succession of these animals during the different 
changes which our globe has undergone, with the exception of the 
discovery in the chalk of two species belonging to two genera which 
he had before observed only in the oolitic series, and of a species of 
one of those genera in the lower tertiary strata. 
The secondary systems (terrains) of England are the richest in fos- 
sil fishes ; and Dr. Agassiz stated that the number of specimens which 
he has seen in English collections is astonishing. The species which 
he has determined are about 400; but the specimens too imperfect 
to be described, at present, announce the existence of a still greater 
number. 
Their geological distribution presents the following details: 
In the Silurian system of Mr. Murchison there are five or six spe- 
cies which exhibit the first appearance and organization of this long 
* A slab, presented to the Geological Society by Mr. Greer, exhibits, on 
a surface not exceeding two feet square, above 250 fishes. 
