each megasporangium, are identical in size with those of another Culm form, _Lepidodendron rhodumnense_. Some of these have retained traces of prothallus tissue, and in one spore Renault figures what he regards as an archegonium: the drawing is by no means convincing. 2. _Lepidodendron rhodumnense_, Renault[321]. The species from the Culm of Combres (Loire) agrees in its solid xylem cylinder and in the differentiation of the secondary cortex, as also in the association of two kinds of spore, with _Lepidodendron esnostense_. A comparison of the leaves of the two types reveals certain differences which may be of specific rank, but, apart from minor differences, these Culm species may be classed under one anatomical type. 3. _Lepidodendron saalfeldense_, Solms-Laubach[322]. This Devonian species was founded on a specimen 3 × 2·5 cm. broad at the base, which shows the stumps of four branches recalling the dichotomously branched arms of _Stigmaria_ and _Pleuromeia_. If these are in reality the remains of Stigmaria-like horizontal branches the species affords an interesting example of a Lepidodendron axis with a subterranean rhizome of the type which has been found in several Sigillarian stems. In the upper end of the axis the stele consists of a solid strand of xylem which is not sufficiently well preserved to show the position of the protoxylem groups. A transverse section taken near the base reveals a type of stele differing from that at the upper end in being composed of radially disposed tracheids and in its resemblance to the stele of _Stigmaria_. 4. _Lepidodendron fuliginosum_, Williamson. Figs. 162–172, 179, E. 1871. _Lepidodendron Harcourtii_, Binney, Palæont. Soc., p. 48, Pl. VII. fig. 6. 1872. _Halonia regularis_, Binney, Palæont. Soc., p. 89, Pl. XV. 1881. _Lepidodendron Harcourtii_, Williamson, Phil. Trans. Roy. Soc., Vol. 172, p. 288, Pls. XLIX–LII. 1887. _Lepidodendron fuliginosum_, Williamson, Proc. Roy. Soc., Vol. XLII. p. 6. 1891. _Lepidodendron Williamsoni_, Solms-Laubach, Fossil Botany, p. 226. 1893. _Lepidophloios fuliginosus_, Kidston, Trans. Roy. Soc. Edinburgh, Vol. XXXVIII. p. 548.