of the _Lagenostoma_ type in close association with impressions of _Sphenopteris Dubuissonis_ and other leaves of similar habit. A seed of _Lagenostoma Lomaxi_ reaches a length of 5·5 mm. with a maximum diameter of 4·4 mm.; it is broadly oval or barrel-like (fig. 408, C) and when immature was invested by a loose irregularly lobed glandular envelope (fig. 408, B) from which the seed eventually freed itself by a natural process of abscission. The central body or nucellus, except in the apical region, is concrescent with a fairly stout integument or testa (fig. 408, C, _f_) the outer portion of which is characterised by regular longitudinal rows of palisade-like cells comparable with the broad palisade-layer in the sporocarp of _Pilularia_. On the exposed surface of this palisade-tissue are small dark structureless pegs[148], possibly the remains of a mucilaginous layer such as occurs on the seed-coats of some recent Flowering plants. At the base of the nucellus the chalazal region, fig. 408, C, _ch_, is provided with sclerous elements and forms a hard investment to the axial vascular strand from the pedicel. It is at the base of this chalazal region that the seed is eventually cut off by an absciss-layer. The integument is supplied throughout its length by nine vascular bundles of endarch, or approximately endarch, structure. The free portion of the integument seen from the outside (fig. 408, B) has the form of a fluted cone with a circular opening at its summit. The greater part of this domical apex, as seen in longitudinal section in fig. 408, C, appears to be hollow, but in the living state the dome, or canopy as Williamson called it, was filled with parenchyma in which the vascular bundles were embedded and, as shown in the transverse section in fig. 409, the canopy is divided into compartments by radial septa which in its basal region are replaced by regular and deep furrows on the inner face. Enclosed by the canopy, with its outer surface fluted as the result of the partial collapse of the outer wall of each compartment due to the decay of the filling tissue, is the flask-shaped apex of the nucellus; between the apical cone of nucellar parenchyma and the superficial layer is an annular cavity which Williamson[149] called the lagenostome. The parenchymatous core tapers to a narrow summit which slightly overtops the integument and is constricted at the broad base (fig. 493, A, B; page 311). The bottle-shaped apical tissue is separated by an annular space, _c_, fig. 493, B, from the limiting layer of the nucellus: this space is the pollen-chamber formed in the living seed by the disorganisation of the subepidermal cells of the nucellar apex. The pollen-chamber is a feature characteristic of recent cycadean ovules (see p. 6). In _Lagenostoma_ the annular form of the pollen-chamber is a peculiarity distinguishing this type of seed from those of recent Gymnosperms and most other Palaeozoic seeds. As Oliver