1856. _Pecopteris Huttoniana_, Zigno, Flor. foss. Oolit. Vol. I. p. 133. 1867. _Acrostichites Goeppertianus_, Schenk, Foss. Flor. Grenzsch. p. 44, Pl. V. fig. 5, Pl. VII. fig. 2. 1883. _A. linnaeaefolius_, Fontaine, Older Mesoz. Flora Virginia, p. 25, Pls. VI.–IX. — _A. rhombifolius_, _ibid_. Pls. VIII. XI.–XIV. 1885. _Todea Williamsonis_, Schenk, Palaeont. Vol. XXXI. p. 168, Pl. III. fig. 3. 1889. _Cladophlebis virginiensis_, Fontaine, Potomac Flora, p. 70, Pl. III. figs. 3–8; Pl. IV. figs. 1, 4. [Illustration: FIG. 256. A. _Cladophlebis denticulata._ B, B′. _Todites Williamsoni_ (fertile). C. _T. Williamsoni_ (sterile pinna). D. _Discopteris Rallii._ E, E′. _Kidstonia heracleensis._ F. _Todeopsis primaeva._ G. _Todites Williamsoni_ (sporangium). [B, C, from specimens (13491; 39234) in the British Museum (B, very slightly reduced; C, ½ nat. size); D, E, after Zeiller; F, after Renault; G, after Raciborski.]] It is hopeless to attempt to arrive at satisfactory conclusions in regard to the applicability of the name _Todites Williamsoni_ to the numerous fronds from Jurassic and Rhaetic rocks, agreeing more or less closely with Brongniart’s type-specimen. Specimens from the Rhaetic may not be specifically identical with those from the Jurassic; the main point is that, whether actually identical or not, both sets of fossils clearly represent the same general type of Osmundaceous fern[798] and may for present purposes be included under the same designation. The above synonymy, though by no means complete[799], serves to illustrate the confusion which has existed in regard to this widely spread type of Mesozoic fern. _Todites Williamsoni_ may be briefly described as follows:— Frond bipinnate; long linear pinnae (20–30 cm.) of uniform breadth arise at an acute angle, or in the lower part of a frond, almost at right angles, from a stout rachis. Closely set pinnules attached by a broad base; slightly falcate, the side towards the rachis strongly convex and the outer margin straight or concave and bulged outwards towards the base of each segment, margin usually entire, or it may be slightly lobed. Fertile pinnules similar to the sterile; sporangia of the Osmundaceous type and often scattered over the whole lower surface of the lamina (fig. 256, B, B′, G). Venation of the _Cladophlebis_ type (cf. fig. 256, A).