THE FOSSILIFEROUS DEPOSITS OF SCOTLAND. 379 
that we need warmly congratulate ourselves on the fact,— but 
certainly a fact it is,— that the geologic section of our Society 
is in no danger of exhausting its work at home for a very consid- 
erable time tocome. We have still much to do in acquainting 
ourselves with the extinct productions of our country in those 
remote pre-Adamic periods of its history when it existed, now 
as a group of Pleistocene islands,— now as a land covered by 
the Oolitic forests, and washed by seas tenanted by the ammo- 
nite and the nautilus,— now, ere yet its existing mountains had 
arisen from the abyss, as a series of dark plains and steaming 
morasses, brown with the rank and dusky vegetation of the 
Carboniferous period,— now as an extended sea-bottom, muddy 
or arenaceous, swum over by the strange ganoids of the Old - 
Red Sandstone, and with here and there a minute island, green 
with, so far as it is yet known, the earliest ferns and the oldest 
trees,— and now as the bottom of a sea profounder still,—a 
sea without visible shore, inhabited by the minute brachipods 
and unique crustaceans of the earlier Silurian ages. That 
history of Scotland which, omitting the human period as too 
modern, stretches backwards from the recent shells of the old- 
coast line to the olenus and lingula beds of Girvan, and which 
is still unwritten, save in the rocks, will give our younger 
members work enough thoroughly to decipher and transcribe 
for perhaps a quarter of a century to come. 
On first setting myself, about fourteen years ago, to add to 
my collection a set of Silurian fossils, I had to content myself 
with specimens derived chiefly from England and America. 
All the organisms detected at that time in the great Silurian 
deposits of Scotland,— though Sir James Hall had found shells 
in the Wrae Hill limestone nearly half a century previous, and 
Mr. Charles Maclaren in the Silurians of the Pentlands at 
least six years previous;— would scarce have half-filled a 
single shelf. Now, however, our old obstinate Grauwackes 
