248 Proceedings of the Royal Physical Society. 
and the Broxburn and Dunnet Shales. The remains of less persistent and 
less extensive outbursts occur at several horizons within the Oil-Shale group. 
The lowest of these occurs within the Wardie Shales. A second forms an 
ash bed at the horizon of the Pumpherston Shales, a third is in connection 
with the Burdiehouse Limestone at Carlops, a fourth gives rise to the 
Barracks-ash lying between the oil-shale and the limestone of that name 
on the Dunnet horizon. As already stated there is evidence of volcanic 
ashes in connection with the Houston Marl. The agglomerate overlying 
the two-foot coal has been already mentioned, while near Linlithgow the 
place of the Mungles and Raeburn Shales must be occupied by lavas and 
ashes of the Bathgate Hills, where the volcanoes were active at intervals 
till well on into Carboniferous Limestone times. 
This succession of local outbursts of vulcanicity within the area suggests 
the idea that it had some connection with the intermittent step-like settling 
of the ground. Whether that were so or not, there appears to be some 
association of these manifestations with horizons where crowds of exceptionally 
well-preserved higher crustacean and whole fish remains occur, viz, the 
Wardie Shales, the Pumpherston “shrimp bed,” the Gullane fish and 
crustacean bed, which is a thin bed of black Carbonaceous Limestone in 
an impure oil-shale, from which complete specimens of Tealliocaris and 
fishes have been obtained. 
On other horizons, the remains of fishes and crustacea are generally much 
broken up, and it is exceptional to find a whole fish, while there is usually 
evidence that the crustacea had been preyed upon. In the cases above 
mentioned it looks as if all the animals, captors and prey alike, had been 
suddenly killed, as if all had shared in the same catastrophe, Both the 
crustaceans and the fishes are fossilised in constrained attitudes suggesting 
that they met with a violent death. May this not have been caused by 
volcanic exhalations or poisonous waters impregnated with solutions derived 
from the soluble or unstable minerals of the ash showers or lava flows ? 
The frequent association of ashes with the dark shales—impure oil-shales— 
gives colour to such a supposition. Moreover, such solutions would have a 
preservative action and help to mineralise the remains. 
THe Prerrycur Poot. 
There is one clear case where the most delicate structures of plants have 
been preserved by such mineralisation. It has been long known that a 
limestone occurred among the volcanic rocks exposed on the shore between 
Pettycur and Burntisland, in which plant remains are so well preserved as to 
show their minute structures. The late Mr David Grieve, a former president 
