ity of the plant that, unlike the brake, it threw off,
ere the main divisions of its rachis took place, two pinnae placed in the
alternate order, and of comparatively small size. The frond of
_Sphenopteris bifida_ was of a more simple form than that of its larger
congener, and not a little resembled a living fern of New Zealand,
_Coenopteris vivipara_. It was tripinnate; its secondary stems were
placed directly opposite on the midrib, but its tertiary ones in the
alternate arrangement; and its leaflets which were also alternate, were
as rectilinear and slim as mere veins, or as the thread-like leaflets of
asparagus. Like the fronds of Coenopteris when not in seed, it must
have presented the appearance of the mere macerated framework of a fern.
I need scarce remark that, independently of the scientific interest
which must attach to restorations of these early plants, they speak
powerfully to the imagination, and supply it with materials from which
to construct the vanished landscapes of the Carboniferous ages. From one
such restored fern as the two now submitted to the Association, it is
not difficult to pass in fancy to the dank slopes of the ancient land of
the Lower Coal Measures, when they waved as thickly with graceful
Sphenopteres as our existing hill sides with the common brake; and when
every breeze that rustled through the old forests bent in mimic waves
their slim flexible stems and light and graceful foliage.

In 1844, when Professor Nicol, of Marischal College, Aberdeen, appended
to his interesting "Guide to the Geology of Scotland," a list of the
Scottish fossils known at the time, he enumerated only two vegetable
species of the Scotch Oolitic system,--_Equisetum columnare_ and
_Pinites_ or _Peuce Eiggensis_; the former one of the early discoveries
of our distinguished President, Sir Roderick Murchison; the latter, of
the late Mr. William Nicol of Edinburgh. Chiefly from researches in the
Lias of Eathie, near Cromarty, and in the Oolites of Sutherland and the
Hebrides, I have been enabled to increase the list from two to rather
more than fifty species,--not a great number, certainly, regarded as the
sole representative of a flora; and yet it may be deemed comparatively
not a very small one by such as may remember, that in 1837, when Dr.
Buckland published the second edition of his "Bridgewater Treatise,"
Adolphe Brogniart had enumerated only seventy species of plants as
occurring in all the Secondary formatio