Grand’Eury[1027] adopted this generic name for seeds from St Étienne characterised by the presence of three, six, or more deep wings or flanges. The term _Pterospermum_ has recently been proposed by Arber[1028] for a seed from the Coal Measures of Staffordshire, which he names _P. anglicum_: the type-species of the genus has three deep wings, one from each angle. For the same seed Kidston[1029] proposed the name _Tripterospermum ellipticum_, but as Arber’s account was published first his specific name has priority. _Pterospermum_ had, however, been previously used for a genus of Sterculiaceae, and partly on this account but mainly because Grand’Eury’s genus _Polypterocarpus_ is available the latter designation is adopted. In _Polypterocarpus anglicus_ (fig. 496, B) the flanges project slightly beyond the apex of the seed and there is a small notch at the base; the nucule is 5 cm. long and 1 cm. broad. While it is not improbable that this seed is generically identical with Brongniart’s _Tripterospermum_[1030], it is safer, in the absence of structural details, to employ the less committal term. There is no information with regard to the nature of the parent-plants of species of _Polypterocarpus_. The English seed from the Middle Coal Measures of Derbyshire and the Staffordshire coalfield described by Arber[1031] as _Radiospermum ornatum_ and by Kidston[1032] as _Polypterospermum ornatum_ affords another example of _Polypterocarpus_ as the generic name is here employed. =Rhynchogonium.= Heer.