A new type of _Physostoma_ has been briefly described by Gordon[830], without a specific designation, from the Lower Carboniferous beds of Pettycur (Fife): it was found in association with _Heterangium_ and _Sphaerostoma ovale_. We have no knowledge of the plant to which _Physostoma_ belonged, but the general plan of organisation of the seed points to a near relationship to _Lagenostoma_ and presumably, as regards the parent-plant, to a genus related to _Lyginopteris_. =Conostoma.= Williamson. This name[831], suggested by the funnel-like pollen-chamber or lagenostome, was applied by Williamson[832] to some seeds from the Lower Coal Measures of Lancashire and Yorkshire and from the Lower Carboniferous beds of Burntisland. The Burntisland seeds, referred by Williamson to two species, have recently been united and described by Miss Benson as _Sphaerostoma ovale_[833]. The English species has been thoroughly investigated by Oliver and Salisbury[834] who have also described a second species, _C. anglo-germanicum_, from the Coal Measures of Lancashire and Germany. _Conostoma oblongum_ Williamson. This rare type is represented by approximately cylindrical seeds with an average length of 5 mm. and a maximum breadth of 2·3 mm. borne on a relatively stout stalk and tapering to a blunt apex characterised by a canopy of six short lobes (fig. 494, B, C) in marked contrast to the long tentacles of _Physostoma_. In the basal region the integument has six prominent ribs which soon die out when traced upwards: a transverse section through the body of the seed is hexagonal (fig. 494, D), the angles corresponding to the basal ribs, and there is a slight tendency to platyspermy. The testa has an epidermal mucilaginous layer which becomes exfoliated through the lifting-up of the cuticle by the underlying mucilage: below this, at the apex of the seed, is a cap of fleshy tissue (fig. 494, B, _sa_) which, it is suggested, may have had a secretory function in connexion with a drop-mechanism in pollination like that in recent Conifers. No microspores have been found in the pollen-chamber. The epidermis, called by Oliver and Salisbury the blow-off layer (fig. 494, B, _m_), together with the cap of soft tissue constitute a feebly developed sarcotesta. A sclerotesta consisting of a palisade-layer and a fibrous hypoderm extends over the main body of the seed below the epidermis; it forms the basal ribs and increases considerably in breadth at the apical region to form a sclerous cone penetrated by six strands of parenchyma enclosing vascular bundles (fig. 494, D) which pass up from the conducting tissue immediately external to the nucellus. The nucellus is coalescent with the integument, as in _Physostoma_, as far as the level of the domical free apex of the nucellus where the tapetal tissue that lines the seed-cavity passes across the almost flat top of the central region originally occupied by the megaspore. In some sections