_Palaeostachya vera_ sp. nov. Fig. 98. In 1869 Williamson[714] described a fragment of a strobilus which showed certain anatomical features indicative of a close relationship or even identity with _Calamites_. Some years later[715] a much more perfect example was obtained from the Coal-Measures of Lancashire, and the additional evidence which it afforded definitely confirmed the earlier views of Williamson. The cone was more fully described by Williamson in 1888, as “the true fruit of _Calamites_.” It is clearly a form of Weiss’ genus _Palaeostachya_; Williamson and Scott[716] refer to it in their Memoir as _Calamites pedunculatus_. It is preferable, however, to retain the generic designation _Palaeostachya_ for cones of this type. As the name _P. pedunculata_ has previously been adopted by Weiss[717] for a cone figured by Williamson[718] in 1874, and afterwards referred to by that author in writing as _P. pedunculata_, it is proposed to substitute the specific name _vera_; this specific name being chosen with a view to put on record the fact that it was this type of cone that Williamson first proved to be the _true_ fructification of the Calamite. The axis of _P. vera_ is practically identical in structure with a Calamitean twig. There is a hollow pith in the centre of the stele surrounded by a ring of 16–20 collateral bundles, each of which is accompanied by a carinal canal as in a vegetative shoot. As the pedicel of the strobilus passes into the cone proper it undergoes some modification in structure, but retains the characteristic features of a Calamite. The diagrammatic longitudinal section of fig. 98, which is copied from a drawing by Williamson[719], shows the broadening of the vascular strands at the nodes, and here and there a carinal canal is seen internal to the wood. The axis of the cone bears whorls of bracts at right angles to the central column. Each whorl consists of about 30–40 segments coherent basally into a disc of prosenchymatous and parenchymatous tissue. The free linear bracts curve sharply upwards from the periphery of the disc, approximately parallel to the axis of the cone. From each of these sterile whorls there are given off 16–20 long and slender obliquely-inclined sporangiophores, _sp_, which arise from the upper surface of the disc close to the axis. Each sporangiophore no doubt bore four sporangia, _S_, containing spores of one size,—about ·075 mm. in diameter. The specimens of _Palaeostachya vera_ so far obtained do not show the actual manner of attachment of the sporangia, but more complete examples of other species of _Palaeostachya_[720] enable us to assume with certainty that the sporangiophores terminated in a distal peltate expansion bearing four sporangia on its inner face. [Illustration: FIG. 98. Diagrammatic longitudinal section of _Palaeostachya vera_, sp. nov. _S_, _S_, _S_, sporangia; _x_, xylem; _sp_, sporangiophore. (After Williamson.)]