168 PTERIDOSPERMS [CH. 



sporangia. Some seed-bearing specimens in Dr Kidston's collec- 

 tion show cups, like those figured by Sterzel, on pinnules from 

 which the seeds have fallen, and it is not improbable that they 

 are the scars of seeds. In 1905 Grand' Eury published a description 

 and photographs of specimens of P. Pluckeneti from the St Stienne 

 coal-field showing hundreds of well-preserved seeds, many of 

 them attached to pinnules characterised by a very slightly reduced 

 lamina. Some fronds were found to be entirely fertile, while 

 others bore both sterile and fertile pinnae. The smallest seeds, 

 5 mm. long and 3 mm. broad, were found at the tips of unexpanded 

 leaves: the mature seeds, only slightly larger, agree in their 

 broadly oval form and narrow marginal ' wing ' with small examples 

 of Samaropsis 1 . The seeds were figured by Grand' Eury 2 in an 

 earlier work as Carpolithes granulatus. They are believed to have 

 hung free from the lamina, a conclusion based on the position of 

 the seeds relative to the plane of the pinnule in well-preserved 

 examples. Prof. Zeiller informs me that he is by no means 

 certain that Grand' Eury's seed-bearing fronds should not be 

 referred to Pecopteris Sterzeli ; but as that species and P. Pluckeneti 

 are very closely allied forms and may well have borne the same 

 general type of fructification, the question of specific difference 

 does not affect the significance of Grand'Eury's discovery. A 

 statement was made in vol. II. 3 , quoted from Grand'Eury, that 

 the fronds of P. Sterzeli were borne on a Psaronius stem, but 

 Prof. Zeiller told me that in his opinion the fronds and stem are 

 merely in association and not in organic contact. It is probable 

 that the Psaronius stem bore fronds of some species of Pecopteris 

 with sori of the Asterotheca or Scolecopteris type and not seeds. 

 Pecopteris Pluckeneti and P. Sterzeli are no doubt the fronds 

 of a Pteridosperm 4 , but apart from the seed-impressions there is 

 no evidence as to the nature of the reproductive organs or stem. 

 The form of the seeds with a fairly thick sarcotesta, which gives 

 them a winged appearance, suggests a member of the Medulloseae 

 rather than a plant with seeds like those of Lyginopteris and 

 Heterangium. 



1 See also Zeiller (05) B. p. 725. 



2 Grand'Eury (77) A. PI. xxxm. fig. 7. 3 Vol. n. p. 419, fig. 297. 

 4 Zeiller (06) B. p. 63. 



