The transverse section represented in fig. 146, G, shows in the left-hand cushion, _a_, the exit of the two parichnos arms and the leaf-trace between them: it illustrates also the various forms assumed by lepidodendroid leaf-cushions when cut across at different levels. iv. _The Anatomy_ of Lepidodendron vasculare _Binney_[260]. Figs. 148–155, 168, A. In the earlier literature dealing with the anatomy of _Lepidodendron_ and _Sigillaria_ the presence or absence of secondary vascular tissue was made the criterion of generic distinction and the distinguishing feature between the classes Pteridophytes and Gymnosperms, _Lepidodendron_ being relegated to the former class because it was supposed to have no power of forming secondary wood, while _Sigillaria_, characterised by a considerable development of such tissue, was classed by Brongniart and afterwards by Renault as a Gymnosperm. Binney[261] in 1865 recognised that the two types of stem pass into one another, but it was Williamson[262] who provided complete demonstration of the fallacy of the Brongniartian view. These two undoubted Pteridophytes agree very closely in anatomical structure and both are now recognised as arborescent genera of Lycopodiaceous plants. In a paper published by Lomax and Weiss in 1905[263] a specimen is described from the Coal-Measures of Huddersfield, in which a decorticated stem with the anatomical characters of Binney’s _Sigillaria vascularis_ gives off a branch having the anatomical structure which it has been customary to associate with the species _Lepidodendron selaginoides_, so-called by Sternberg and founded by him on impressions showing well-preserved external characters. In 1862 Binney[264] described petrified specimens of vegetative shoots from the Lower Coal-Measures of Lancashire under the names _Sigillaria vascularis_ and _Lepidodendron vasculare_. These were afterwards recognised as different states of the same species. A few years after the publication of Binney’s paper Carruthers[265] identified Binney’s species _Lepidodendron vasculare_ with Sternberg’s _L. selaginoides_. The evidence on which this identification rests has not been stated, but many writers have retained this specific designation for the well-defined type of anatomical structure first described by Binney as _L. vasculare_. The use of the specific name _selaginoides_ is, however, open to objection. The species _Lepidodendron selaginoides_, as pointed out by Kidston[266], is probably identical with the plant which Brongniart had named _L. Sternbergii_ before the institution of Sternberg’s species, and we are not in possession of convincing evidence as to the connection of _L. Sternbergii_ (= _L. selaginoides_) with specimens possessing the anatomy of Binney’s type. Binney’s designation is therefore retained for the anatomical type described in the following pages[267].