478 
ON LEPIDOPHLOIOS AND LEPIDODENDRON. 
BY WM. CASH, F.G.S., F.L.S., F.R.M.S., AND JAS. LOMAX. 
The genus Lepidophloios appears to have been established by 
Sternberg at a time when our knowledge of Carboniferous plants was 
based, for the most part, upon merely superficial characters and not 
upon the anatomical structure of the plants themselves. The two 
genera, Lepidodendron and Lepidophloios, though long known to hold 
close affinities, are clearly separated by well-marked characters. 
In Lepidodendron the leaf-cushions are fusiform or quadrate, 
varying much in form, even in the same species, according to their 
position on the .stem and conditions of growth. Situated on the 
cushions and generally above the centre is the leaf-scar proper, whose 
upper and lower boundary lines are usually more or less convex and 
unite in lateral angles. Within the leaf-scar are three punctiform 
cicatricules, the central of which is alone connected with the vascular 
system, the two lateral being probably glandular. The cones in some 
species are borne at the terminations of the branches, and in others 
in two opposite vertical rows (Ulodendron, L. and H., in part). 
In Lepidophloios the leaf-cushions are rhomboidal (as in L. lari- 
cinmi) or elongated-truncate (as in L. scoticum), and the leaf-scar is 
situated at the extremity of the cushion, having three punctiform 
cicatricules as in Lepidodendron. The cones are borne on specially 
modified branches and are arranged in spirals {Halonia, L. and H.) 
The two genera are therefore very distinct in the position of the 
leaf-scar on the cushion, as also in the mode of fructification. The 
knowledge obtained of the structure of Lepidophloios since Sternberg's 
time, and especially that acquired in recent years, has confirmed the 
view of its close affinity with Lepidodendron. 
Williamson has described the twigs, branches, stems, and fruits 
of Lepidophloios hrevifolimn from Burntisland, and has shown that, 
fundamentally, these have the structure of the same parts of Lepido- 
dendron. 
Solms-Laubach, in his ' Einleitung in die Palaephytologie,' states 
that Corda's Lomatophloios crassicaule has a structure similar to that 
of the true Lepidodendron Harcoiirtii. 
