XXXV] MTTSOCARPTJS 361 



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^ as Polyptero- 

 carpus, 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 wotdd seem to be more than two, but this appearance is 

 regarded by Nathorst as misleading and he beheves that except 

 at the apex there are only two wings. 



Musocarpus. Brongniart. 



Brongniart^ proposed this name for two species, M. prismaticus 

 and M. difformis, from French Coal Measures, but gave no descrip- 

 tion of the specimens. The type-species, described from the Loire 

 by Grand'Eury as Musocarpus prismaticus^, is an ovate seed 

 nearly 3 cm. long with six longitudinal ribs, three being more 

 prominent than the others, and characterised by a ribbed pro- 

 longation of the base of imiform 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 

 Westphahan beds in Lanarkshire are closely allied to or perhaps 

 identical with M. prismaticus. In the presence of a distinct 

 basal region Musocarpus resembles Codonospermum*, 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. 



Holcospermuin. Nathorst. 



Holcospermum sulcatum (Sternberg). The cast reproduced in 

 fig. 506, A, affords a good example of a form of seed recorded 



1 Grand'Eury (77) A. PL xvi. figs. 2 — i. 



2 Brongniart (28) A. p. 137. 



- Grand'Euiy (77) A. p. 184, Pi. XV. fig. 3. « See page 330. 



