The anatomical structure of a specimen referred to _Annularia stellata_ has been described by Renault[671]. The cortex consists of parenchyma traversed by lacunae and limited peripherally by a denser hypodermal tissue. In the stele Renault describes 14 xylem strands, each with a large carinal canal. The pith was apparently large and hollow. The same author describes an _Annularia_ strobilus in which the lower sporangiophores bear macrosporangia, and the upper microsporangia. [Illustration: FIG. 89. _Annularia sphenophylloides_ (Zenk.). _A._ Strobilus (_Stachannularia calathifera_, Weiss). ⅔ nat. size. _B._ Vegetative shoot. ⅘ nat. size. From specimens in the Collection of Mr R. Kidston. Upper Coal-Measures, Radstock.] The references in the footnote should be consulted for figures of this species of _Annularia_; it is from the examination of such specimens as are referred to in the note that the above diagnosis has been compiled[672]. _Annularia sphenophylloides_ (Zenk.). Fig. 89. 1833. _Galium sphenophylloides_, Zenker[673]. 1865. _Annularia brevifolia_, Heer[674], Strobilus. 1876. _Calamostachys_ (_Stachannularia_) _calathifera_, Weiss[675]. Principal branches 8–12 mm. wide, with internodes 8–10 cm. in length, giving off two opposite branches at the nodes; from the secondary branches arise smaller branches in opposite pairs. The leaf-verticils and branches are all in one plane. Each verticil consists of 12–18 spathulate segments, 3–10 mm. long, cuneiform at the base and broader above, with an acuminate tip; the lateral segments are slightly longer than the upper and lower members of a whorl. The small and crowded leaf-whorls give to this species a characteristic appearance, which readily distinguishes it from the larger-leaved forms such as _Annularia stellata_. A fossil figured by Lhwyd[676] in 1699 as _Rubeola mineralis_ is no doubt an example of _Annularia sphenophylloides_.