Maryland Geological Survey 215 



still earlier ferns as have been supposed to exhibit aflfinities with the 

 Schizaeacese, as, for example, the Paleozoic genus Senftenbergia, are too 

 obscure and indefinite to be of much value, and it seems certain that the 

 older Mesozoic and Paleozoic ferns, at least the Leptosporangiate ones, 

 were too generalized to admit of their being referred to the accepted 

 families, based as the latter are to such a large extent, upon existing 

 species. There is, however, abundant collateral evidence for the view 

 that by the dawn of the Cretaceous the main lines of cleavage which 

 separate the fern-families, as we now know them, were rather clearly de- 

 fined. In addition to the 8cliiz(jea-V\k.e. species here described, the Schizsea- 

 cese were represented in the Lower Cretaceous rocks of both Europe and 

 America by several species referred to the genus Bujfordia, which, in the 

 character of its sterile and fertile fronds, resembles the modem genus 

 Aneimia. 



There is also the well-authenticated Jurassic genus Kluhia of Eaci- 

 borski,^ which seems to fall within this family, and Professor Zeiller'' 

 has recently called attention to certain fern remains from the Wealden 

 of Peru, which have annulate sporangia of the Schizece type. Finally, 

 Stopes and Fujii^ have described structural material from the Upper 

 Cretaceous of Hokkaido, Japan, sufficiently preserved to show some of 

 the soral characters and to warrant the restoration of the sporangium 

 of what they call ScJiizcBopteris mesozoica. 



"While the present genus is thus far confined to the eastern United 

 States, the genus Acrostichopteris, which so closely resembles it in vege- 

 tative habit and geological position, has been found in the Kootanie 

 formation of Montana and in the Wealden of England, and closely allied, 

 if not identical, forms have been described by Saporta from the Lower 

 Cretaceous rocks of Portugal as various species of Sphenopteris. 



iRaciborski, Engler's Bot. Jahrb., Band xiii, 1891, p. 1. 

 " Zeiller, Comptes rendus, tome cl, 1910, p. 1488. 



^ Stopes and Fujii, Phil. Trans. Roy. Soc. Lond., vol. cci B, 1910, p. 6, tf. 1-3, 

 pi. il, fig. 1. 



