This Wealden species, represented in the North German flora and in beds of approximately the same age at Quedlinburg, has been discovered by Dr Marcus Gunn in Upper Jurassic rocks on the north-east coast of Scotland. The lamina (12 cm. or more in length) is divided into five to seven linear segments and bears a close superficial resemblance to leaves of _Baiera_ and to recent species of _Schizaea_ (fig. 222, p. 287). Each segment contains one or two main ribs (fig. 288, A). A similar form is described by Bartholin[974] and by Moeller[975] as _H. Forchammeri_ from Jurassic rocks of Bornholm. _Hausmannia Kohlmanni_, Richt. Fig. 278, F. In this species, instituted by Richter from material obtained from the Lower Cretaceous beds of Strohberg[976], the comparatively slender rhizome bears fronds with petioles reaching a length in extreme cases of 25 cm. but usually of about 10 cm. The lamina (1–7 cm. long and 1–10 cm. broad) is described as leathery, obcordate, and divided into two symmetrical halves by a median sinus which, though occasionally extending more than half-way through the lamina, is usually shallow. The venation consists of two main branches which diverge from the summit of the petiole (fig. 278, F) and subdivide into dichotomously branched ribs; finer veins (not shown in the drawing) are given off from these at right angles and form more or less rectangular meshes as in other members of the Dipteridinae and in such recent ferns as _Polypodium quercifolium_ (fig. 231, D, p. 297). The imperfect lamina represented in fig. 289 may belong to _Hausmannia Richteri_ or may be a distinct species; it shows some of the finer veins connecting the shorter forked ribs, which formed part of the reticulate ramifying system in the mesophyll. This specimen was obtained from the plant-beds of Culgower on the Sutherlandshire coast, which have been placed by some geologists in the Kimmeridgian series. The smaller type represented in fig. 278, E, is referred by Richter to a distinct species, _Hausmannia Sewardi_[977], founded on a few specimens from the Lower Cretaceous strata of Strohberg. This species is characterised by a stouter rhizome bearing smaller leaves consisting of a short petiole (3–4 cm. long) and an obovate lamina (1–2 cm. long and broad). There are usually two opposite leaflets on each leaf-stalk, and these may be equivalent to the two halves of a single deeply dissected lamina. [Illustration: FIG. 289. _Hausmannia sp._ Upper Jurassic, near Helmsdale, Scotland. From a specimen in the British Museum. (Nat. size.)] It is interesting to compare these different forms of _Hausmannia_ with the fronds of recent species of _Dipteris_ represented in fig. 231. The more deeply dissected type, such as _H. dichotoma_, closely resembles _D. Lobbiana_ or _D. quinquefurcata_, while the more or less entire fossil leaves (fig. 278, E, F and fig. 289) are very like the somewhat unusual form of _Dipteris conjugata_ shown in fig. 231, B, p. 297.