ique tree cast root and flourish,
when the extinct genera Pterichthys and Coccosteus were enjoying life by
millions in the surrounding seas, long ere the flora or fauna of the
Coal Measures had begun to be?

I may be here permitted to mention, that in a little volume, written in
reply to a widely known and very ingenious work on the Development
hypothesis, I described and figured this unequivocally genuine lignite,
in order to show that a true wood takes its place among the earliest
terrestrial plants known to the geologist. I at the same time
mentioned,--desirous, of course, that the facts of the question should
be fairly stated, whatever their bearing,--that the nodule in which it
occurred had been partially washed out of the fish bed in which I found
it, by the action of the surf; and my opponent, fixing on the
circumstance, insinuated, in the answer with which he honored me, that
it had _not_ belonged to the bed at all, but had been derived from some
other formation of later date. He ought, however, to have taken into
account my further statement, namely, that the same nodule which
enclosed the lignite contained part of another fossil, the well marked
scales of _Diplacanthus striatus_, an ichthyolite restricted, like the
Coccosteus (a specimen of which occurred in a neighboring nodule), to
the Lower Old Red Sandstone exclusively. If there be any value whatever
in palaeontological evidence, this Cromarty lignite must have been
deposited in a sea inhabited by the Coccosteus and Diplacanthus. It is
demonstrable that, while yet in the recent state, a Diplacanthus lay
down and died beside it; and the evidence in the case is unequivocally
this, that in the oldest portion of the oldest terrestrial flora yet
known, there occurs the fragment of a tree quite as high in the scale as
the stately Norfolk Island pine, or the noble cedar of Lebanon.

[I have failed hitherto in finding any remains of terrestrial
plant-covered surfaces in the Old Red Sandstone of Scotland, though
decided traces of desiccated sub-aerial ones are not rare. Shallows and
banks seem to have been numerous during the period of at least the Lower
formation. The flagstones of Caithness and Orkney, and the argillaceous
fish beds of Cromarty and Ross, not only abound in the ripple-marked
surfaces of a shallow sea, but also in cracked and flawed planes that
must have dried and split into polygonal partings in the air and the
sun. The appearance of these in the