The next contribution to our knowledge of the anatomy of _Sigillaria_ was made by Renault and Grand’Eury[519] who described the structure of _Sigillaria spinulosa_ Germar[520], a species now recognised as the Leiodermarian condition of _S. Brardi_, and probably, therefore, not specially distinct from the specimen described by Brongniart in 1839 as _S. elegans_. In Brongniart’s fossil the leaf-cushions are in contact (Clathrarian form of _S. Brardi_: fig. 203, upper part) whereas in the specimen now under consideration the leaf-scars are further apart (Leiodermarian form of _S. Brardi_, fig. 203, lower part, and fig. 196, C). It may be, as Scott suggests, that these two specimens are not specifically identical but closely allied, an opinion based on certain anatomical differences[521]; we may, however, include both under the comprehensive name _S. Brardi_. The primary xylem (fig. 200, B, _x_), is in some regions separated into distinct strands, in others it forms a continuous band equal in length to several of the separate groups. This type of stele, in which the primary xylem consists in part of separate strands and in part of a continuous cylinder, forms a transition between that represented in fig. 200, A, and the steles of _Sigillaria elegans_ (fig. 202, A) and most species of _Lepidodendron_. The tendency of the primary xylem strands to become united laterally, forming broader bands, was first described by Solms-Laubach[522] in a French specimen of _Sigillaria spinulosa_ in the Williamson collection. The leaf-traces arise from the middle of the concave outer face of the primary xylem groups. The inner cortex is composed of small parenchymatous cells as in _Lepidodendron_, and it is noteworthy that traces of partially disorganised tissue, described as large canals, in the region external to the secondary wood, bear a resemblance[523] to the secretory tissue of _Lepidodendron_. Other interesting features are presented by the structure of the outer cortex and the parichnos. The outer cortex in the leaf-scar region is composed of parenchyma, but for the most part it consists of radially elongated groups of thin-walled parenchyma enclosed in a framework of thicker-walled and elongated elements (fig. 200, B, _c_³). This type of cortex, to which Brongniart applied the name _Dictyoxylon_, would produce a cast in the case of a partially decorticated stem characterised by a surface formed of irregularly oval and raised areas bounded by narrow grooves; the greater prominence of the former being due to the more rapid decay of the softer tissue, which would produce depressions on the exposed face of the dead stem. Casts of this type are not uncommon in Carboniferous rocks, and while some may belong to the Pteridosperm _Lyginodendron_, others may be those of Sigillarian stems. [Illustration: FIG. 202.