great difference had begun to arise, which has increased immensely up to the present time. The climate must have been not only more equable, but warmer, as is shown by the coral-banks which were formed at that time in Spitzbergen, as well as by the enormous tree- like Cryptogams and the large-leaved ferns which Bear Island produced.
Appendix.
On Cyclostigma, Lepidodendron, and Knorria, from Kiltorkan. By Prof. Oswald Heer, F.M.G.S.
[Plate IV.]
(Read January, 10, 1872*.)
1. CYCLOSTIGMA KILTORKENSE, Haught. Ann. & Mag. Nat. Hist. ser. 3, vol. v. p. 444.
Stem clothed with a finely wrinkled bark. It is covered with numerous and very close striae ; and these very fine striae pass away into spiral lines, and are in some places joined together. When the outer bark is wanting we have only these fine striae. Such a specimen I received as C Griffithii, Haught.
On the bark there stand in regular rows small round warts, which have a circular depression at the top. These are surrounded by a projecting rim, which is often striated with fine cross lines. Some- times these warts look like small hollows having a smooth middle part. The warts are about 2 millims. in diameter. They are from 8 to 13 millims. apart, and form highly oblique transverse rows. Pl. IV. fig. 5a is a piece of a stem ; 5 b a portion with the wart, magnified.
Branches. — These agree entirely with the stems in the formation of the bark and in the warts. The bark is also wrinkled and covered with very fine and close striae. The warts are from 6 to 8 millims. apart, and in a branch 13 millims. broad there are two or three in the oblique row (fig. 4, and, a portion enlarged, fig. 4 b).
As remains of fruit-cones, which Schimper has described as Lepidostrobus Bailyanus (Traite de Paleontologie Veget. ii. p. 71), are often found near the stems of this species, they probably belong to it. In support of this view is the fact that in Bear Island also the cone-scales have been found near the fragments of the stem (see my Fossil Flora of Bear Island,' pl. xi. fig. 3 c). These cones differ from those of Lepidodendron in their firm and almost woody base, which is marked with a longitudinal furrow, and in the remarkably long bristle-like front portion.
2. CYCLOSTIGMA MINUTUM, Haught. ibid. p. 444.
Lepidodendron minutum, Haught. Journ. Geol. Soc. Dublin, vol. i. p. 235.
Lepidodendron, sp., Lyell, Elements of Geol. ed. 6, p. 521, fig. 585.
- See p. 85 of the present volume.
