in the Lyginodendrece. 159 



This was the genus Medullosa, in which Mr Kidston* has shown 

 that the seeds were borne on ordinary fronds identical with 

 the sterile foliage. Since then two new discoveries have been 

 announced, and in both cases the seeds are borne on fronds. 

 Mr David White f has described the seeds of a species of Aneimites 

 (= Adiantites), an important genus occurring in Lower Carboniferous 

 and Upper Devonian rocks, which are borne on fronds with reduced 

 lamina just as in the case of the new seeds described here. 



Still more recently M. Grand'Eury j has made a most interesting 

 discovery, affecting a genus of Palaeozoic plants almost universally 

 regarded as true ferns. The genus Pecopteris, especially charac- 

 teristic of the higher beds of the Upper Carboniferous, and of the 

 Permian, contains a large number of species, among which one, 

 Pecopteris (Dicksoniites) Pluckeneti SchL, not perhaps a very typical 

 member, has been shown by M. Grand'Eury to be a seed-bearing 

 plant. In this case the seeds are borne on fronds hardly differing 

 at all from the sterile fronds. 



Thus in the four groups or genera, Medulloseae, Lyginodendreae, 

 Adiantites, and some Pecopterids, in which the seed-bearing habit 

 is known, the seeds are in all cases borne on fronds, which are 

 either little modified and similar to the sterile foliage, or fronds 

 with reduced lamina. In lax arrangement of the fructification, 

 the habit of these Fern-like spermaphytes must have presented 

 a striking contrast to most of the other great Palaeozoic groups in 

 which strobili or cones were dominant and conspicuous types of 

 sporangial aggregation. 



* Kidston, Phil. Trans. R. Soc, Ser. B, Vol. 197, p. 1, 1904. 



t White, Smithsonian Miscell. Collections, Vol. 47, Pt. 3, p. 322, Dec. 1904. 



X Grand'Eury, Compt. Rend. Acad. Set., Vol. 140, p. 920, April 3, 1905. 



