Brongniart[1047] proposed this name for two species, _M. prismaticus_ and _M. difformis_, from French Coal Measures, but gave no description of the specimens. The type-species, described from the Loire by Grand’Eury as _Musocarpus prismaticus_[1048], is an ovate seed nearly 3 cm. long with six longitudinal ribs, three being more prominent than the others, and characterised by a ribbed prolongation of the base of uniform diameter spoken of as a carpophore, which was apparently articulated to the lower part of the seed-proper from which it was easily detached by a natural absciss-layer. Nothing is known of the structure or of the affinity of the genus. Some specimens in Dr Kidston’s collection from Westphalian beds in Lanarkshire are closely allied to or perhaps identical with _M. prismaticus_. In the presence of a distinct basal region _Musocarpus_ resembles _Codonospermum_[1049], though without any knowledge of the anatomy of the former type it is impossible to say whether or not this resemblance has any morphological importance. =Holcospermum.= Nathorst. _Holcospermum sulcatum_ (Sternberg). The cast reproduced in fig. 506, A, affords a good example of a form of seed recorded under several generic names and not uncommon in Upper Palaeozoic rocks in Europe and North America, which in most cases cannot be assigned to a genus implying the possession of certain anatomical characters. This type was figured by Sternberg[1050] from the Coal Measures of Radnitz as _Carpolites sulcatus_. Some ‘fruits’ collected on the beach near Newhaven, Midlothian, from the Calciferous Sandstone series, are figured by Lindley and Hutton[1051] as _Carpolithes sulcata_, but as already stated these have been transferred[1052] to the genus _Rhynchogonium_. Several authors have referred specimens of the type now included in _Holcospermum_ to _Rhabdocarpus_, but that genus, as stated on a previous page, is restricted to seeds agreeing in form with _R. tunicatus_. Renault[1053] instituted the genus _Colpospermum_ for a partially petrified seed from Commentry agreeing externally with _Carpolites sulcatus_ Sternb. and regarded by him as specifically identical, characterised by longitudinal ribs which represent folds of the testa, the intervening grooves being occupied by an irregular reticulum formed by occasionally anastomosing smaller ribs. The generic name _Colpospermum_ should therefore be reserved for ribbed seeds showing the anatomical features described by Renault and Zeiller: its application to Sternberg’s species is inadvisable on the ground that we have no information with regard to the morphological nature of the ribbing. More recently Arber[1054] has proposed the name _Platyspermum_, a name previously applied to a Cruciferous plant, for Stephanian and Permian seeds formerly assigned to Berger’s genus _Rhabdocarpus_, which are symmetrical in two planes. In this genus he includes _Platyspermum sulcatum_ and among other species _P.