Fune 2, 1870] 
made. Specimens of the barren stems (var. ornatum) 
might readily be referred to the genius Lycopodites. 
Another genus of generalised type is that named by 
Haughton Cyclostigma. As found at Gaspé it presents 
slender stems with rounded scars, placed either spirally 
or in transverse rows, and giving origin to long rigid 
leaves. It had a slender axis of scalariform vessels, 
and fructification of the form of elongated spikes or 
strobiles is found with it. In many respects these plants 
resembled Psilophyton, and their affinities were distinctly 
Lycopodiaceous. Specimens from Ireland, in the Museum 
of the Geological Society, kindly shown to me by Mr. 
Etheridge, appear to show that in that country these plants 
attained the dimensions of trees, and had roots of the 
nature of Stigmaria. Mr. Carruthers has even suggested 
that they may be allied to Syringodendron, a group of 
Carboniferous trees connected with the Szgz/ari@. 
The genus Lycofodites is represented by a trailing 
species, bearing numerous oval strobiles (Z. Richardson), a 
species quite close to many modern club-mosses (ZL. Mat- 
thewi), and a remakable pinnate form (Z. Vanuxemii), 
which, though provisionally placed here, has been vari- 
ously conjectured to resemble Ferns, Cycads, Algee, and 
Graptolites. But the most remarkable Lycopodiaceous 
plants are the gigantic arboreal Lefzdodendra, plants 
the 
Fic. 3.—Cyclopteris (Archeopteris) Facksoni—a Devonian Fern, 
American representative of C. Hibernicus. 
which, while they begin in the Middle Devonian, become 
eminently expanded in numbers and magnitude in the 
Carboniferous. The common species in Eastern America 
(Z. Gaspianum) was of slender and delicate form, very 
elegant, but probably not of large size. In the same 
family I would place my new genus Lep/ophleum, a portion 
of whose curiously-marked bark is represented in Fig. 2. 
The Calamites, afterwards so largely developed in the 
Carboniferous, and to be replaced by true Equiseta in 
the Trias, make their first appearance in a large species 
(C. znornatum) in the Lower Devonian, and are represented 
in the middle and upper parts of the system by two other 
species, which extend upward into the Carboniferous. 
They are also represented in the Devonian of Germany 
_ and of Devonshire. The peculiar type indicated by the 
internal casts known as Calamodendron is likewise found 
in the Devonian. 
More beautiful plants were the Asterophyllites, with 
more slender and widely branching stems, and broader 
leaves borne in whorls upon their branches. These plants 
have been confounded with leaves of Calamites, from 
which, however, they differ in form and nervation, and in 
the want of the oblique interrupted lines common to the 
true leaves of Calamites and to the branchlets of Equise- 
tum. The Asterophyllites, and with them a species of 
Sphenophyllum, appear in the Middle Devonian, 
NATURE 
87 
No plants of the modern world are more beautiful in 
point of foliage than the Ferns, and of these a great number 
of species occur in the Middle and Upper Devonian. I 
must refer for details to my more full memoirs on the sub- 
ject, and in the present paper shall content myself with a 
few general statements. Some of the generic forms of 
the Devonian, and perhaps a few of the species, 
extend into the Carboniferous ; others are peculiar 
to the Devonian; and among these, forms allied to 
the modern Hymenophyllum and Trichomanes appear 
to prevail. One remarkable type, Cyclopteris (Arch@o- 
pleris) Hibernicus, with its American allies, C. Zacksoni, 
&c., extends in the Upper Devonian over both continents, 
yet is wanting in the Carboniferous. Tree ferns also 
existed in the Devonian. ‘Two species have been found by 
Dr. Newberry in Ohio, and remarkable erect trunks have 
been obtained by Professor Hall from Gilboa, in the State 
of New York. The latter are surrounded by aerial roots, 
and thus belong to the genus Psaronius, a genus which, 
however, must be artificial, since in modern tree ferns 
aerial roots often clothe the lower part of the stems while 
absent from the upper part. The only indication as yet 
of a tree fern in the Old World is the Cawlopteris Peachii, 
of Salter, from the Old Red of Scotland. It is further 
remarkable that the ferns of the genus Archopteris are 
much more large and luxuriant in Irelandthan in America, 
and that in both regions they characterise the upper 
member of the system. 
Fic. 4.—Prototaxites Logani—the oldest known tree. 
trunk, much reduced.) 
(Fragment of the 
Of the plants of the Paleozoic world, none are more 
mysterious than those known to us by the name Szgz/- 
larie, and distinguished by the arrangement of their 
leaves in vertical series, on stems and branches often 
ribbed longitudinally, and by the possession of those 
remarkable roots furnished with rootlets regularly arti- 
culated and spirally arranged, the Stigmarie. It seems 
evident that this group of plants included numerousspecies, 
differing from each other both in form and structure. Still, 
as a whole, they present very characteristic forms dissi- 
milar from those of their contemporaries, and still more 
unlike anything now living. I believe that many of them 
were Gymnosperms, or at the least, Acrogens with stems 
as complicated as those of Gymnosperms. In the Car- 
boniferous period these plants have a close connection 
with the occurrence of coal. Nearly every bed of this 
mineral has under it a “Stigmaria underclay,” which 
is a fossil soil on which a forest of Sigillariz has 
grown, and the remains of these trees are very abundant 
in the coal and the accompanying beds. Hence the Sigil- 
lariz of the coal-period are regarded as the plants most 
important in the accumulation of coal. In the Devonian, 
as far as we yet know, they did not attain to this utility, 
and in the lower part of the system at least, the rhizo- 
mata of Psilophyton seem to have occupied the place after- 
wards held by the Stigmariz. In connection with this, 
it is to be remarked that the Sigillariz of the Erian 
