the integument accompanied by some large cells (aqueous tissue). The elongated epidermal cells at the apices of the lobes of the integument form the frill, _f_, and at a lower level the cells of the same layer are much smaller and papillate (_e_): the outer integument, _c_, forms the so-called cupule. The transverse section shown in fig. 414, B, is taken at the level of the roof of the pollen-chamber and of the nucellar cap; it illustrates the contrast between the ‘multiseriate annulus’ and the central column of small parenchyma. _Sphaerostoma_ differs from _Lagenostoma_ in the whorl of crests around the micropyle, in the nearly hemispherical form of the lagenostome and in the relatively wider pollen-chamber with its peculiar form of dehiscence. Miss Benson, while regarding _Sphaerostoma_ as similar to _Lagenostoma_ in general plan, believes the distinguishing features of the former to be such as are consistent with a more primitive form. An important argument in support of connecting this seed with _Heterangium_ is derived from the juxtaposition of some seeds and portions of _Heterangium_ petioles, a juxtaposition that is believed to demonstrate original continuity. Grand’Eury[224] has recorded the association of two species of leaves, _Sphenopteris elegans_ and _S. dissecta_, with small seeds compared by him with _Lagenostoma_. In the absence of petrified specimens it would be practically impossible to distinguish between _Lagenostoma_ and _Conostoma_ or _Sphaerostoma_. Carpentier[225] has described some impressions from French Westphalian beds as _Conostoma_ and he records cupules without seeds on fronds of _Sphenopteris obtusifolia_ which he speaks of as having transverse striations like those of _Heterangium_. Dr Kidston pointed out to me that the surface-features of the _Sphenopteris_ rachis are probably due to ramental scales and not to the presence of horizontal sclerous bands. Carpentier’s seeds may be compared with _Lagenospermum Sinclairi_. _Heterangium tiliaeoides_ Williamson, Phil. Trans. R. Soc. Vol. 178, p. 289.