Sternberg[548] figured some leaves of _Cordaites_ from Carboniferous rocks in Bohemia under the generic name _Flabellaria_ in the belief that they belonged to a Palm. Brongniart substituted a new name _Pycnophyllum_[549] on the ground that Corda had disproved the supposed relationship with Monocotyledons. The name _Cordaites_ was instituted by Unger[550], his definition being based on leaf-form as well as on stem-anatomy. It has recently been proposed to revive the forgotten designation _Pycnophyllum_[551], but the reasons given are hardly likely to induce botanists to discard the familiar generic name which perpetuates the memory of Corda. As already pointed out, the name _Cordaites_, even though employed in what has always been regarded a legitimate sense, is no doubt often given to specimens of some other allied member of the Cordaitales which can only be recognised as such in the case of more completely preserved material. The naming of wood of the Cordaitean type, but which may equally well belong to another genus, raises a difficult question: if there is satisfactory evidence from collateral sources that the wood is that of a _Cordaites_ Grand’Eury’s name _Cordaixylon_[552] or Schenk’s form _Cordaioxylon_[553] may be used, though there seems to be no adequate reason against the use of the name _Cordaites_. If there is no confirmatory evidence available and it is impossible to say whether the wood is that of a Conifer or a _Cordaites_, or some other plant with the same type of secondary xylem, Endlicher’s term _Dadoxylon_[554] is most conveniently employed. The confusion liable to follow from the use of the two generic names _Dadoxylon_ and _Araucarioxylon_ for wood of the same type differing only in geological age is an argument in favour of extending _Dadoxylon_ to all specimens having certain anatomical characters, which cannot be certainly assigned either to the Araucarineae or the Cordaitales, irrespective of geological age. The term _Cordaicladus_ sometimes applied to branches is hardly necessary, but the subgeneric names _Eu-Cordaites_, _Dory-Cordaites_, and _Poa-Cordaites_, instituted by Grand’Eury for different forms of leaf, are frequently employed and serve a useful purpose as descriptive terms though the characters which they connote are of small importance and by no means always well defined or constant. For inflorescences it is customary to adopt the name _Cordaianthus_ suggested by Grand’Eury as a substitute for _Antholithus_ and some other terms. The same author uses _Rhizo-Cordaites_ for roots.