Mr Gordon has recently described in a preliminary note a new type of stem stele under the name _Zygopteris pettycurensis_ from the Lower Carboniferous plant bed of Pettycur[1140]: he regards the petioles attached to the stem as identical with _Zygopteris Roemeri_ Solms-Laubach[1141]. This species, founded by Solms-Laubach on petioles only, is placed by Bertrand[1142] in the genus _Diplolabis_ and regarded as identical with _D. esnostensis_ Ren. The stele found by Mr Gordon may therefore be assigned to the genus _Diplolabis_: it includes two regions composed exclusively of tracheae and is cylindrical in transverse section. The inner xylem zone consists of short, square-ended, reticulately pitted elements and the outer zone is composed of long and pointed conducting tracheae. The scalariform protoxylem elements are situated between the two metaxylem zones. As Mr Gordon says: this type of stem occupies a position “in the Zygopteroid alliance” corresponding to that which _Thamnopteris Schlechtendalii_ (p. 329) occupies in the Osmundaceous series. The discovery of this stem supplies another link between the two fern groups, Osmundaceae and Coenopterideae. Pelourde[1143] has described an imperfectly preserved vascular strand from a locality near Autun as the type of a new genus _Flicheia esnostensis_. Mr Gordon has pointed out to me that this is a partially rotted petiole of _Diplolabis esnostensis_ (= _Zygopteris Roemeri_). In their recent account of fossil Osmundaceous genera, Kidston and Gwynne-Vaughan[1144] speak of the central parenchyma of the existing medullated stele as being derived from tracheal tissue. They add that if the Zygopteroid line of descent is at all close to the Osmundaceous, we must be prepared for the existence of a _Zygopteris_ with a solid xylem like that of _Thamnopteris_: “such a discovery, in fact, we hopefully anticipate[1145].” The new Pettycur stem amply justifies this prophecy. It is noteworthy that Mr Gordon’s stem affords an instance of the occurrence of a type of stele, similar in its cylindrical form and in the absence of parenchyma to that of _Botryopteris_, in a plant bearing leaves characterised by the _Zygopteris_ type of vascular strand. _Metaclepsydropsis duplex_ (Will.) fig. 310, A[1146]. [= _Rachiopteris duplex_, Williamson 1874. _Asterochlaena_ (_Clepsydropsis_) _duplex_, Stenzel 1889. _Clepsydropsis_, Renault 1896.]