_Diplotesta Grand’Euryana_ Brongniart. The generic name _Diplotesta_, suggested by Grand’Eury, was given by Brongniart[972] to a Grand’ Croix seed which he compared with that of the Conifer _Cephalotaxus_. The type-specimen is elliptical and platyspermic (fig. 495, H, p. 322), and differs from _Taxospermum_ in the cordate form of the seed-cavity, also in the more restricted union of nucellus and testa. The testa is differentiated into a sarcotesta (_sa_) and sclerotesta, and the latter forms two feebly developed keels in the principal plane: a characteristic feature shared with _Mitrospermum_ is the splitting of the shell into two equal valves (fig. 495, F). Fig. 495, H, shows the contracted cylindrical nucellus and the pollen-chamber: the sarcotesta (_sa_) is only partially preserved. _Diplotesta_ differs from _Cardiocarpus_ in the course of the integumental vascular bundles which are of the type illustrated by _Rhabdospermum_, _Taxospermum_, and _Cyclocarpus_, but from these genera it is distinguished by the dehiscence of the shell, also by its form and certain anatomical features as described by Brongniart and Bertrand[973]. In this genus Bertrand includes Brongniart’s species _Sarcotaxus avellana_ (fig. 495, F), a correlation suggested by the latter author. =Leptocaryon.= Brongniart. Brongniart[974] founded this genus for a single species, _Leptocaryon avellana_, represented by a Grand’ Croix specimen 12 × 10 mm., which he believed to be related to _Taxus_. _Leptocaryon_ differs from _Taxospermum_ in the structure of the testa, but resembles it in external features. Bertrand[975] in his revision and extension of Brongniart’s account says that the sections throw no light on the nature of the vascular supply, and it is therefore impossible to form a satisfactory opinion as to the relationships of the genus. Renault[976] referred this genus to the Cordaitales, but we have no evidence as to the parent-plant. =Taxospermum.= Brongniart.