The seed figured by Nathorst[1041] from the Culm of Spitzbergen as _Lagenospermum? glandiforme_ agrees closely with _Rhynchogonium_ and _Boroviczia_, and it is impossible to decide whether the lobed appearance is due to the presence of a cupule or to the divisions of an integument. =Boroviczia.= Zalessky. The specimens from Lower Carboniferous beds in Russia[1042] on which this genus was founded are perhaps unnecessarily separated from _Rhynchogonium_; they are ovate and beaked, 10 mm. long with a maximum breadth of 6 mm. The type-species, _Boroviczia Karpinskii_ (fig. 506, I), is represented both by specimens in which the cast is complete and by others in which the apical snout of the integument is split into separate lobes identical in form and apparently in number with those of _Rhynchogonium_. Nathorst[1043], who retains the generic name and describes two additional species from Spitzbergen, points out that in Boroviczia the tapered apex is more sharply differentiated from the broader basal portion, a difference hardly worthy of generic recognition. If _Boroviczia_ is retained as a genus distinct from _Rhynchogonium_ it should include the seeds described by Young as _Trigonocarpum gloagianum_. =Diplopterotesta.= Nathorst. _Diplopterotesta spitzbergensis_ (Heer). Heer[1044] included in _Samaropsis_ some seeds, described as _Samaropsis spitzbergensis_, from Lower Carboniferous strata in Spitzbergen which differ considerably from typical examples of the genus. These have recently been made the type of a new genus _Diplopterotesta_[1045]: they are platyspermic seeds nearly twice as long as broad, 6–9 × 3·5–5 mm., characterised by a thin sclerotesta expanded throughout the length of the seed into two prominent transversely striated wing-like ribs or flanges (fig. 506, D). At the apex, which is broad in contrast to the pointed basal end of the seed, the sclerotesta forms a crown of eight lobes about the flat summit of the seed-body. As Nathorst points out, this species closely resembles the Carboniferous seeds figured by Grand’Eury[1046] as _Polypterocarpus_, but in the latter type there are more than two wings. Nathorst’s figures, one of which is reproduced in fig. 506, D, suggest a difficulty in determining the number of the flanges, which would seem to be more than two, but this appearance is regarded by Nathorst as misleading and he believes that except at the apex there are only two wings. =Musocarpus.= Brongniart.