In the memoir in which the genus was founded Williamson described two species from the Lower Coal Measures of Lancashire, _Lagenostoma ovoides_ and _L. physoides_[168]. The seeds described under the latter name had previously been assigned by him to another new genus, _Physostoma_, and named _P. elegans_[169]. _Lagenostoma physoides_ was afterwards figured by Butterworth[170] who recognised some new features. For this species Prof. Oliver[171] has adopted Williamson’s earlier name, _Physostoma elegans_. The former species, which has recently received exhaustive treatment by Miss Prankerd[172], agrees generally in its morphological characters with _L. Lomaxi_, but differs in the structure of the surface-tissue of the integument and in some anatomical features. Moreover no cupules have been found and there is ‘very little trace of a layer of separation’ such as occurs in _L. Lomaxi_. Over the surface of the integument is a layer of prismatic cells, much shorter and less palisade-like than those in _L. Lomaxi_, and there are none of the pegs which are a constant feature in that species. There are, however, indications that mucilage was poured out by the rupture of the distended cells. Some microspores were found in the pollen-chamber with an average size of 72 × 53μ; they may be as much as 90μ long. None were observed with sperm-like contents like those described by Dr Benson. Miss Prankerd discusses the morphology of the integument in relation to that of cycadean seeds and makes an instructive comparison between the lagenostome (that is the modified nucellar apex) and such fern sporangia as those of _Angiopteris_, _Osmunda_, and _Schizaea_, but especially the sporangia of _Senftenbergia_[173] with their multiseriate annulus. An interesting feature is shown in the longitudinal section reproduced in fig. 493, A (p. 311). The apex of the nucellar cone appears to be composed of thick-walled, dark cells and it is suggested that this may have served as a stopper blocking up the circular orifice of the pollen-chamber (seen below the apex between the nucellar cone and the thick surface-layer of the nucellus) and serving as a protection to the embryo. A comparable closing-up of the micropyle occurs in the seeds of _Gnetum Gnemon_[174] and in the beak of cycadean seeds. At the time of pollination, when the pollen-chamber must have extended to the apex of the lagenostome, the tip of the nucellar cone may have secreted some sticky substance to which the microspores would adhere.