Other Palaeozoic species of _Equisetites_ have been recorded, but with one exception these need not be dealt with, as they do not add anything to our knowledge of botanical importance. The specimen described in the _Flore de Commentry_ as _Equisetites Monyi_, by Renault and Zeiller[506], differs from most of the other Palaeozoic species of _Equisetites_, in the fact that we have a stem with short internodes bearing a leaf-sheath at each node divided into comparatively long and distinct teeth. This species presents a close agreement with specimens of _Calamitina_, but Renault and Zeiller consider that it is generically distinct. They suggest that the English species, originally described and figured by Lindley and Hutton[507] as _Hippurites gigantea_, and now usually spoken of as _Calamitina_, should be named _Equisetites_. It would probably be better to adopt the name _Calamitina_ for the French species. The type-specimen of this species is in the Natural History Museum, Paris. [Sidenote: EQUISETITES PLATYODON.] [Illustration: FIG. 59. _Equisetites platyodon_ Brongn. (After Schoenlein, slightly reduced.)] When we pass from the Permian to the Triassic period, we find large casts of very modern-looking Equisetaceous stems which must clearly be referred to the genus _Equisetites_. The portion of a stem represented in fig. 59 known as _Equisetites platyodon_ Brongn.[508] affords an example of a Triassic Equisetaceous stem with a clearly preserved leaf-sheath. The stem measures about 6 cm. in diameter. One of the oldest known Triassic species is _Equisetites Mougeoti_[509] (Brongn.) from the Bunter series of the Vosges. The Keuper species _E. arenaceus_ is, however, more completely known. The specimens referred to this species are very striking fossils; they agree in all external characters with recent Horse-tails but greatly exceed them in dimensions. 4. _Equisetites arenaceus_ Bronn. This plant has been found in the Triassic rocks of various parts of Germany and France; it occurs in the Lettenkohl group (Lower Keuper), as well as in the Middle Keuper of Stuttgart and elsewhere. The species may be defined as follows:— Rhizome from 8–14 cm. in diameter, with short internodes, bearing lateral ovate tubers. Aerial shoots from 4–12 cm. in diameter, bearing whorls of branches, and leaf-sheaths made up of 110–120 coherent uni-nerved linear segments terminating in an apical lanceolate tooth. Strobili oval, consisting of crowded sporangiophores with pentagonal and hexagonal peltate terminations.