C. _Schizoneura._ The plants included under this genus were originally designated by Brongniart[574] _Convallarites_ and classed as Monocotyledons. Some years later Schimper and Mougeot[575] had the opportunity of examining more perfect material from the Bunter beds of the Vosges, and proposed the new name _Schizoneura_ in place of Brongniart’s term, on the grounds that the specimens were in all probability portions of Equisetaceous stems, and not Monocotyledons. Our knowledge of this genus is very limited, but the characteristics are on the whole better defined than in the case of _Phyllotheca_. The following diagnosis illustrates the chief features of _Schizoneura_. Hollow stems with nodes and internodes as in _Equisetum_; the surface of the internodes is traversed by regular ridges and grooves, which are continuous and not alternate in their course from one internode to the next. The leaf-sheaths are large and consist of several coherent segments; the sheaths are usually split into two or more elongate ovate lobes, and each lobe contains more than one vein. Fertile shoots are unknown. Two of the best known and most satisfactory species are _Schizoneura gondwanensis_ Feist. and _S. paradoxa_ Schimp. and Moug. _Schizoneura gondwanensis_ Feist. Fig. 69, A and B. This species is represented by numerous specimens from the Lower Gondwana rocks of India[576]; it is characterised by narrow articulated stems which bear large leaf-sheaths at the nodes. The sheaths may have the form of two large and spreading elongate-oval lobes, each of which is traversed by several veins (fig. 69, B), or the lobes may be further dissected into long linear single-veined segments, as in fig. 69, A. It is supposed that in the young condition each node bears a leaf-sheath consisting of laterally coherent segments which, as development proceeds, split into two or more lobes. Feistmantel records this species from the Talchir, Damuda and Panchet divisions of the Lower Gondwana series of India; these divisions are regarded as equivalent to the Permo-Carboniferous and Triassic rocks of Europe. The two specimens shown in fig. 69 are from the Lower Gondwana rocks of the Raniganj Coal-field, India. As already pointed out[577], some of the specimens of flat and broader stems referred by Feistmantel to _Schizoneura_ are identical in appearance with stems which have been described from India and elsewhere as species of _Phyllotheca_. [Illustration: FIG. 69. _Schizoneura gondwanensis_ Feist. (After Feistmantel; slightly reduced.)] There are a few specimens of _S. gondwanensis_ in the British Museum, but the genus is poorly represented in European collections.