As we pass upwards to Wealden and more recent rocks it becomes clear that the Gleicheniaceae were prominent members of late Mesozoic floras in north Europe and reached as far north as Disco Island. In English Wealden beds portions of sterile fronds have been found which were assigned to a new genus _Leckenbya_[861], but it is probable that these specimens would be more correctly referred to _Gleichenites_. Similarly fragments of Gleichenia-like pinnae with very small rounded pinnules occur in the Wealden rocks of Bernissart, Belgium[862], in north Germany[863], and elsewhere. Conclusive evidence has been obtained by Prof. Bommer of the existence of _Gleichenites_ in Wealden beds near Brussels, where many plant remains have been found in a wonderful state of preservation. The specimens, which I had an opportunity of seeing some years ago, might easily be mistaken for rather old and brown pieces of recent plants. Some of the Belgian fragments, of which Prof. Bommer has kindly sent me drawings and photographs, are characterised by an arrangement of vascular tissue identical with that in the petioles and rhizomes of some protostelic Gleichenias. The stele of one of the Belgian rhizomes appears to be identical with that of _Gleichenia dicarpa_ (fig. 237, C. p. 310). [Illustration: FIG. 262. A. _Gleichenites longipennis_ Heer. B. _G. delicatula_ Heer. C. _G. Nordenskioldi_ Heer. D. _G. Zippei_. (Corda.) (After Heer; A, B, D, very slightly reduced.)] _Gleichenites Zippei_ (Corda). Fig. 262, D. This species, originally described by Corda as _Pecopteris Zippei_[864] and afterwards figured by Heer[865] as _Gleichenia Zippei_ (fig. 262, D) from Urgonian rocks of Greenland, affords a striking example of a Mesozoic member of the _Gleicheniaceae_. It is characterised by the dichotomous branching of the frond and by the occurrence of arrested buds in the forks. The long and slender pinnae, reaching a length of 9 cm. and a breadth of 6–8 mm., bear small crowded pinnules occasionally with circular sori which are described by Heer as consisting of a small number of sporangia (cf. fig. 262, C). Several other Lower Cretaceous species are recorded by Heer from Greenland, some of which are probably unnecessarily separated from _Gleichenites Zippei_. Examples of these are represented in fig. 262, A, B, C. A Gleicheniaceous species described by Debey and Ettingshausen from Lower Cretaceous rocks of Aix-la-Chapelle as _Didymosorus comptonifolius_[866] is very similar in habit to some of Heer’s Greenland species: this should probably be referred to the genus _Gleichenites_. _Gleichenites hantonensis_, Wank. Fig. 263.