In 1899 Zeiller[298] instituted the name _Potoniea_ for some peculiar fertile leaves found in the Coal Measures of Heraclea consisting of a branched axis with cuneate segments, 7–10 × 6–8 mm., bearing numerous fusiform bodies, 1–1·5 mm. long, at the upper edge (fig. 421, A). These marginal bodies he regarded as sporangia and expressed the opinion that _Potoniea_ may be the fructification of some form of _Neuropteris_, _Mariopteris_ or _Alethopteris_. Carpentier[299] afterwards described similar though rather larger examples from the Pas-de-Calais coal-field as microsporophyll fragments of some Pteridosperm: he stated that similar specimens had been found by Kidston in England. In a later work Carpentier[300] described the sporangia as crowded in groups (fig. 421, B) in the substance of the thick lamina of _Potoniea_, and he connected the fertile segments with _Neuropteris gigantea_, _N. pseudogigantea_ Pot. and _Linopteris obliqua_ (Bunb.). Similar specimens are said to have been found in Holland and Silesia. Bertrand[301] also records the association of _Potoniea_ with _Neuropteris gigantea_ and _N. pseudogigantea_: he describes some specimens as belonging to _N. gigantea_ Sternb. while others, distinguished only by small differences, he attributes to _N. pseudogigantea_. Kidston[302] has recently drawn attention to the inconstancy of the characters mentioned by Potonié as distinguishing features of _N. pseudogigantea_, and he shows good cause for referring the examples so named to _N. gigantea_. The fertile lamina is almost orbicular in surface-view and attached to a slightly excentric pedicel; the microsporangia are borne on the lower surface and probably in groups as described by Carpentier. _Neuropteris Carpentieri_ Kidston. Kidston[303] has recently described some fertile leaflets under this name from the Westphalian series of South Staffordshire which he identifies with French examples referred by Carpentier[304] to _Potoniea adiantiformis_ Zeill. The fertile pinnules are thick and sub-cyclopteroid in form; the upper surface bears densely packed, narrow and long, microsporangia, 4 × 0·5 mm., containing more or less spherical microspores 45–60μ in diameter; the ventral face of the lamina on the removal of the spores shows several strong veins. With these are associated sterile pinnules of the Neuropteroid type, and examples are described intermediate between the sterile and fertile leaflets. Kidston believes the specimens to be microsporophylls of some species of _Neuropteris_, but as the material does not suffice for identification with any known species a new name is proposed. It is pointed out that in some states of preservation the leaflets resemble Goeppert’s Permian species _Dictyothalamus Schrollianus_[305]. _Alethopteris. Linopteris._