KIDSTON : THE FLORA OF THE CARBONIFEROUS PERIOD. 363 
Gymnosperms. 
We now pass to the Gymnosperms, of which we shall briefly con- 
sider the Cordaitece, Coniferce, Ginkgoacece. Of the Cijcadacece there 
is no evidence of their occurrence in British Carboniferous rocks. 
CORDAITE.5:. 
In the Cordaitece are placed the genus Cordaites and certain 
genera of fossil fruits, some of which belong to Cordaites, but which, 
owing to our ignorance of the species of Cordaites to which they 
belong, necessitates their being placed in separate genera until their 
parentage has been ascertained. It is possible, however, that some 
seeds at present included in the Cordaitece may not belong to that 
group, but may be the seeds of other plants, which, with the excep- 
tion of the fruit, may be quite unknown to us. 
Cordaites linger. This genus occupies a very prominent and 
important place amongst the plants of the Carboniferous Period, for 
though Cordaites extends into the Permian Formation it is essentially 
a Carboniferous genus, for the plant-bearing beds near St. John, 
New Brunswick, from which the late Sir William Dawson recorded 
Cordaites as Devonian, are, there is very strong reason to believe, 
really Carboniferous. 
Cordaites had thick stems two feet or more in diameter, and which 
attained a height of 100 feet and terminated in an irregular, much- 
branched, dense, leafy head. 
The branches bore long, lanceolate, spathulate, or linear leaves, 
which in some cases must have been two feet or more in length. The 
leaves have parallel veins {Cordaites principalis Germar. sp., Plate 
LXIV., fig. 3, base of leaf, and Plate LVIL, fig. 2, apex of leaf), 
which increase in number in the leaf by dichotomous division. In 
some species the veins are equally strongly marked on the surface ; 
in others, lying between the veins are one or more finer parallel 
threads, which appear to represent bands of sclerenchyma rather 
than weaker veins. 
The leaves are spirally arranged, and when shed leave a trans- 
versely oval scar on the stem {Cordaites principalis Germar. sp., 
Plate LIIL, fig. 1). Well-preserved stems show on the leaf scars 
