62 Proceedings of Royal Society of Edinburgh. [sess. 
small local coal-basin of tbe Laggan, near Campbelltown. This is 
the only coal-basin remaining in Scotland on the west coast, north 
of the Firth of Clyde. Richly fossiliferous beds of the Carboniferous 
limestone crop out from underneath it to the south ; and under these 
beds again the Old Red Sandstones are seen to dip along the same 
southern boundary of the coal-field. The metamorphic series, there- 
fore, in Kintyre are there exhibited immediately underlying the 
Old Red, which again is seen immediately underlying the Carboni- 
ferous series and the Coal Measures. There is no reason, so far as 
I know, to separate the metamorphic slates of Kintyre from those 
of the more northern areas of the county, of which the peninsula 
of Kintyre seems to be a mere prolongation. Instead, therefore, of 
seeking to identify the local quartzite of Inveraray as Silurian 
because of its annelid remains, I should be disposed to identify those 
remains as due to annelids, because of the clear stratigraphical evi- 
dence that these quartzites are Silurian. When we find that in the 
Northern Silurians these silicious beds have preserved their organic 
remains far better and far more generally than the calcareous beds, 
we have good reason to expect as probable the same result in the 
South-Western Silurian series. It is the obliteration, and not the 
preservation, of annelid markings, which needs explanation in our 
Argyllshire quartzites, such as those of Jura and Islay. It is, of 
course, quite easy to understand that such markings should be 
squeezed out under enormous pressures. But, on the other hand, it 
is only the fulfilment of a natural and reasonable expectation when 
we do find certain beds in the south that have preserved the traces 
of the particular form of life which seems to ha^e been so abundant 
when the northern Silurian quartzites were deposited. The compara- 
tively thin beds in which the annelid tubes are found at Inveraray 
are by no means the lowest in our series. They are underlaid 
and overlaid by a great number of beds both slaty and silicious. 
But the great mass is slaty, with a highly-developed micaceous 
character. The correlated development of mica in the quartzite 
bed itself, where the annelids have selected and segregated the 
argillaceous particles, seems to throw an important light on this 
product of metamorphism. 
There is, however, another question connected with geological 
science which is of high importance, and on which the appearances 
