Under this specific name are included strobili from Upper Carboniferous rocks which, in spite of minor differences, may be considered as one type. The cylindrical cones vary considerably in size, some reaching a length of 50 cm. or more. The sporophylls are attached by a pedicel, 4–8 mm. long, at right angles to the axis, while the distal portion forms an oval lanceolate limb 10–20 mm. in length. The sporangia are 4–8 mm. long. The branched example figured by Lindley and Hutton[419] as a variety (L. _ornatus_ var. _didymus_) illustrates a phenomenon not uncommon in both Palaeozoic and recent lycopodiaceous strobili. [Illustration: FIG. 191. _Lepidostrobus._ A–D. _L. oldhamius._ B, C, D. From sections in the Binney Collection, Cambridge. E. Megaspore. (After Kidston.) F. Megaspore (Coal-Measures, Halifax). (After Williamson.) G. Megaspore of _Lepidostrobus foliaceus_. (After Mrs Scott.) H. Tangential section of sporangium. (After Bower.) I. Part of sporangium wall, _Sm_, of the cone of _Lepidodendron Veltheimianum_, enclosing two megaspores. (Cambridge Botany School.)] ii. _Lepidostrobus oldhamius_ Williamson[420]. Fig. 191, A–D. Williamson[421] instituted this term for strobili previously described by Binney[422], without adequate evidence, as the cones of _Lepidodendron Harcourtii_. In shape and in the main morphological features this type resembles _L. variabilis_, which is however known only in the form of casts and impressions. A cone of _L. oldhamius_, 2–3 cm. in diameter, possesses a medullated stele consisting of a ring of primary xylem (fig. 191, D, _x_) with exarch protoxylem and no secondary elements. Maslen found several short tracheae at the periphery of the xylem and states that these led him to compare the cone with the vegetative shoots of _Lepidodendron vasculare_, but the common occurrence of such elements in different types of shoot renders them of little or no specific value. The inner cortex is like that of vegetative shoots of _Lepidodendron_ and the middle cortex, which was no doubt of the type described in _Lepidostrobus Brownii_, is represented by a gap in the sections, beyond which is the stronger outer cortex (fig. 191, D) passing into the horizontal pedicels of the sporophylls. The section of the axis reproduced in fig. 191, D, was figured by Binney[423] as _Lepidodendron vasculare_. The leaf-traces, several of which are seen in the middle cortical region in fig. D, _lt_, consist of a strand of scalariform tracheae, with a mesarch protoxylem, succeeded by a few parenchymatous cells; beyond these there is usually a small gap which was originally occupied by a strand of thin-walled cells. It is important to note that in one sporophyll-trace figured by Maslen[424] there is a strand of thin-walled elongated elements abutting on the xylem, which he describes as phloem. This tissue is certainly more like true phloem than any which has hitherto