1. _Marchantites erectus_ (Leckenby). Fig. 49. This species may be described as follows: The thalloid body is divided into spreading dichotomously branched segments, obtusely pointed apically. The slightly wrinkled surface shows a distinct and comparatively broad darker and shorter median band, with lighter coloured and thinner margins. [Illustration: FIG. 49. _Marchantites erectus_ (Leck.). From the type-specimen in the Woodwardian Museum. Nat. size.] In 1864 Leckenby described this plant from the Lower Oolite beds of the Yorkshire coast near Scarborough, as _Fucoides erectus_, regarding it as a fossil alga. I recently pointed out that the general appearance and mode of occurrence of the specimens suggest a liverwort rather than an alga, and proposed the substitution of the genus _Marchantites_[460]. It would, however, be unwise to speak with any great confidence as to the real affinities of the fossil. The example shown in the figure is the type-specimen of Leckenby[461]: the breadth of the branches is about 3 mm. Under a low magnifying power the surface shows distinct and somewhat oblique wrinklings, the general appearance being very similar to that of some recent forms of the genus _Marchantia_. A closely allied species has recently been described from the Wealden beds of Ecclesbourne, near Hastings, on the Sussex coast, as _Marchantites Zeilleri_ Sew.[462]. In a recent monograph on Jurassic plants from Poland, apparently containing much that is of the greatest value, but which is unfortunately written in the Polish language, Raciborski[463] describes a new species of thalloid Liverwort under the name of _Paleohepatica Rostafinski_. The specimens are barren plants larger than any Jurassic species hitherto described; they agree closely in habit with Saporta’s Tertiary species _Marchantites Sezannensis_. 2. _Marchantites Sezannensis Saporta._ Fig. 50. The body is broadly linear and dichotomously branched, with a somewhat undulating margin. Midrib on the dorsal surface depressed, but more prominent on the ventral surface. The upper surface is divided into hexagonal areas, in each of which occurs a central pore. There are two rows of scales along the median line on the lower surface. Stalked male receptacles. Brongniart[464] first mentioned this fossil hepatic, which was found in the calcareous travertine of Sézanne of Oligocene age in the Province of Marne. The specimens figured by Saporta[465] show very clearly the characters of one of the _Marchantiaceae_, and in this case we have the additional evidence of the characteristic male receptacles which are given off from a point towards the apex of the lobes, and arise from a slight median depression. In one of Saporta’s figures (reproduced in fig. 50 _A_) there are represented some median scars which may mark the position of cups similar to those which occur on recent species of _Marchantia_, and in which gemmæ or bulbils are produced.