86 
which have chiefly afforded the plants to be described 
below; and it is exclusively in these areas that we 
find underclays with roots, or true fossil soils. Most 
of the localities of fossil plants in the districts above 
mentioned have been visited, and their plants studied 7 s7tu 
by the writer. The Gaspé sandstones were first studied 
and carefully measured and mapped by Sir W. E, 
Logan. The Devonian beds of St. John’s, New Bruns- 
wick, have been thoroughly examined and illustrated by 
Prof. Hartt and Mr. Matthews, and those of Perry by 
Prof. Jackson, Prof. Rogers, and Mr. Hitchcock. Prof. 
Hall, of the Survey of New York, has kindly communi- 
Fic. 1.—Psilophyton princeps—the oldest known plant of America, restored. 
(a), Fruit, natural size ; (4), Stem, natural size ; (0, Scalariform tissue 
of the axis, highly magnified. In the restoration one side is repre- 
sented in vernation, and the other in fruit. 
cated to me the plants found in that State, and Prof. 
Newberry has contributed some facts and specimens illus- 
trative of those of Ohio. 
In the Sandstone cliffs of Gaspé Bay, Sir W. E. Logan 
recognised in 1843 the presence of great numbers of ap- 
parent roots in some of the shales and fine sandstones. 
These roots had evidently penetrated the beds in a living 
state, so that the root-beds were true fossil soils, which, 
after supporting vegetation, became submerged and 
covered with new beds of sediment. This must have 
occurred again and again in the process of the formation 
of the 4,000 feet of Gaspé sandstone. The true nature of 
the plants of these fossil soils 1 had subsequently good 
opportunities of investigating, and the most important 
results, in the discovery of the plants of my genus Psz/ophy- 
Zon, are embodied in the restoration of ?.Arzuceps in Fig. 1. 
This remarkable plant, the oldest land plant known in 
America, since itextends through the Upper Silurian aswell 
NATURE 
[ une 2, 1870 
as the Devonian, presents a creeping horizontal rhizome 
or root-stock, from the upper side of which were given 
off slender branching stems, sometimes bearing rudi- 
mentary leaves, and crowned, when mature, with groups 
of gracefully nodding oval spore-cases. The root-stocks 
must in many cases have matted the soils in which they 
grew into a dense mass of vegetable matter, and in some 
places they accumulated to a sufficient extent to form 
layers of coaly matter, one of which on the south side of* 
Gaspé Bay is as much as three inches in thickness, and 
is the oldest coal known in America. More usually the 
root-beds consist of hardened clay or fine sandstone filled 
with a complicated net-work or with parallel bands of 
rhizomes more or less flattened and in various states of 
preservation. In all probability these beds were originally 
swampy soils. From the surface of such a root-bed 
there arose into the air countless numbers of slender but 
somewhat woody stems, forming a dense mass of vegeta- 
tion three or four fect in height. The stems, when young 
or barren, were more or less sparsely clothed with thick, 
short, pointed leaves, which, from the manner in which they 
penetrate the stone, must have been very rigid. At their 
extremities the stems were divided into slender branches, 
and these when young were curled in a crosier-like or 
circinate manner. When mature they bore at the ends 
of small branchlets pairs of oval sacs or spore-cases. 
The rhizomes when well preserved show minute mark- 
ings, apparently indicating hairs or scales, and also round 
areoles with central spots, like those of Stigmaria, but 
Fic. 2.—Lefptophleum rhombicum—a Lycopodiaceous tree of the Devonian. 
not regularly arranged. These curious plants are un- 
like anything in the actual world. I have compared their 
fructification with that of the Pilularize or Pillworts, a com- 
parison which has also occurred to Dr. Hooker. On the 
other hand, this fructification is borne in a totally different 
manner from that of Pilularia, and in this respect rather 
resembles some ferns ; and the young stems by themselves 
would be referred without hesitation to Lycopodiacez. 
In short, Psilophyton is a generalised plant, presenting 
characters not combined in the modern world, and, per- 
haps illustrating what seems to be a general law of 
creation, that in the earlier periods low forms assumed 
characteristics subsequently confined to higher grades 
of being. 
A second species of Psilophyton (P. vodbustius), also 
abundant at Gaspé, shows stouter stems than the former, 
more abundantly branching and with smaller leaves, often 
quite rudimentary. Its spore-cases are also of different 
form and borne in dense clusters on the sides of the 
stem. Masses of very slender branching filaments ap- 
pear to indicate a third species (P. elegans) which is 
also found in the Devonian of St. John, New Brunswick. 
These species of Psilophyton occur both in the lower and 
middle Devonian, and, as will be mentioned in the sequel, 
they extend also into the Upper Silurian. 
Decorticated and flattened stems of Psilophyton cannot 
be readily recognised, and except when their internal 
structure has been preserved, might be mistaken for algae, 
a mistake which I believe has in some instances been 
