553 
of the south of Ireland. Hence, though excellent examples of a group 
of upper ‘fossiliferous slates, they do not offer any help as to the 
number and order of the natural groups into which the great in- 
fra-carboniferous series may be conveniently divided. He then points 
out that the grouping of the older strata in the south of Ireland, now 
given by Mr. Griffith, is not only sanctioned by the sections, but 
gets rid of a great supposed anomaly,—-viz. the re-appearance of the 
carboniferous fossils at different levels on a general descending: sec- 
tion of the older rocks of Ireland. 
The author then briefly notices the fossils in the true Silurian rocks 
in the north of Ireland, in progress of publication by Captain Port- 
lock. They form an admirable series, but the sections do not appear 
to connect the group of rocks containing them with the older forma- 
tions, so as to lend much help in their subdivisions or grouping. 
Mourne mountains, Galloway chain, &e.—After a few details re- 
specting the mineral structure, strike, altered rocks, granite veins, 
&c., of Downshire, the author proceeds to notice the Galloway chain 
(which extends from the Mull of Galloway to St. Abb’s Head). Its 
prevailing strike, like that of the Mourne mountains, is about N.E. 
by E.; and this is sometimes persistent, even in the neighbourhood 
of protruded masses of granite. It is generally made up of beds of 
a hard arenaceous greywacke, sometimes of a very coarse structure, 
sometimes finer, and occasionally passing into a good roofing slate, 
—generally it is without fossils; but the Graptolites foliaceus (first 
noticed by Mr. Carrick Moore) occurs, though rarely, among the 
finer slates. In these respects the chain is analogous to that in 
Pembrokeshire, where the same fossil occurs in the slates below the 
Lower Silurian rocks of Mr. Murchison. 
He then notices a ridge of rocks visited by Mr. Carrick Moore 
and himself, which breaks out from under the carboniferous basin of 
Girvan-water in Ayrshire. It contains many fossils, among which 
Mr. Sowerby finds three or four new species of Orthis, Tentaculites, 
Atrypa, and one or two species of Terebratula. Near it, and probably 
forming a part of it, is a small mass of limestone, with many corals 
and some Trilobites, the latter unfortunately lost by the author. 
Mr. Lonsdale states that the corals are difficult’ and obscure, but 
there is a true Favosites fibrosa, probably also a Favosites spongites ; 
and there are, among the specimens, several small hemispherical 
corals which may be young Stromatopora concentrica. From this 
evidence he would be inclined to refer the limestone to an Upper 
Silurian or Devonian group. From the number of Orthidia, Mr. 
Sowerby would refer the fossiliferous slates to the Lower Silurian ; 
but the whole mass, including slates and limestone, is of small extent, 
and seems to form but one group, which may be considered as 
Silurian. 
‘ ‘To show the position of these beds, the saghon gives a transverse 
section from the Solway Firth over the Galloway chain to the fossil 
group above mentioned. The groups on the section appear in the 
following order, beginning at the south end :—1. Old red sandstone. 
‘2. Greywacke of the Galloway chain. 3. Granite. 4. Greywacke 
