For a fuller synonymy reference should be made to Kidston’s account of this species[1017], from which the above list is compiled. The large fronds of this species are tri- or quadripinnate. The pinnules vary much in shape and size and in degree of lobing, according to their position on the frond (fig. 293). The primary pinnae are subtended by two Aphlebiae (fig. 293, A) appressed to the rachis, like the delicate leaves of the recent fern _Teratophyllum aculeatum_ (see page 301). The sporangia (0·5–0·65) are oval and exannulate and are attached parallel to the lateral veins; they may occupy the whole of the space between the midrib and the edge of the pinnules. This species occurs in the Upper, Middle, and Lower Coal-Measures of Britain, reaching its maximum in the Upper Coal-Measures. The aphlebiae undoubtedly served to protect the young fronds, as shown by a specimen figured by Kidston (fig. 293, B); they may also have served other purposes, as suggested by the above comparison with _Teratophyllum_, in the mature frond. Lindley and Hutton regarded the aphlebiae as leaves of a fern climbing up the rachis; which they named _Schizopteris adnascens_, a confusion similar to that already mentioned in the description of _Hemitelia capensis_ (see p. 304). [Illustration: FIG. 292. _Dactylotheca plumosa._ (After Kidston. Slightly reduced.)] [Illustration: FIG. 293. _Dactylotheca plumosa_: A. Rachis with Aphlebiae. B, _a_, young pinnae circinately folded. (After Kidston. A, B, ⅘ nat. size.)] _Renaultia._ This name was proposed by Zeiller[1018] for Upper Carboniferous fertile pinnae of the Sphenopteroid type, bearing ovoid sporangia either singly or in marginal groups of 2 to 5 at the ends of the veins. The appearance of the apical cells occasionally suggests the presence of a rudimentary annulus. Kidston has recorded this type of fructification in Britain[1019]. Stur describes fertile pinnules of the same type under the generic name _Hapalopteris_[1020]. _Zeilleria._ This genus was founded by Kidston[1021] for fertile pinnae of a very delicate fern, _Zeilleria delicatula_ (Sternb.) characterised by filiform ultimate segments bearing an indusium-like body, spherical when immature and splitting at maturity into four small valves. Kidston, in his earlier paper, compared the species with recent Hymenophyllaceae. In the same genus he includes _Z. avoldensis_[1022] (Stur) assigned by Stur to _Calymmatotheca_, a genus described by some authors as characterised by groups of radially elongated sporangia at the tips of the pinnules; these supposed sporangia are now known to be the valves of an indusium-like organ or cupule, as Stur asserted. There can be little doubt that the fertile fronds placed in _Calymmatotheca_ and in _Zeilleria_ were borne by Pteridosperms. _Urnatopteris._