290 STUDIES IN FOSSIL BOTANY 



Palaeozoic times of Ferns allied to Gleicheniaceae. As 

 Professor Bower has pointed out, " the type of sorus " 

 in Gleichenia " is that of the Marattiaceae." l Hence, 

 on soral characters alone, it, would not be possible to 

 distinguish between a fossil fructification of this family 

 and one of the Marattiaceae with free sporangia 

 arranged circularly. The genus Oligocarpia of Goppert, 

 with Sphenopteroid foliage, bore such sori, which in 

 surface view certainly look wonderfully like those of a 

 Gleichenia (see Fig. 109, E). Each sporangium shows 

 a transverse, or somewhat oblique annulus, just as in 

 that genus ; though some authors have denied that the 

 apparent annulus is really distinct from the rest of the 

 sporangial wall, the inspection of the specimens, especially 

 those of O. robustior, Stur, leaves no doubt that the 

 former interpretation is correct. Zeiller, who supports 

 the Gleicheniaceous affinities of this genus, further cites 

 certain isolated sporangia, which have been found in 

 the Quartz of Autun, as having unmistakably the 

 characters of that family. 



Sporangia with a transverse annulus, much like 

 that of the Hymenophyllaceae, have been observed on 

 the fronds of some Sphenopteroid Ferns from the Coal- 

 measures (Hymenophyllites quadridactylites), but the 

 evidence as to their position on the leaf is not sufficient 

 to place the affinities of these fossils beyond doubt. 

 The Devonian genus Archaeopteris or Palaeopteris, the 

 type-species of which, the famous A. kibernica,\s charac- 

 teristic of the Old Red Sandstone of Ireland, was once 

 referred by some authors to the Hymenophyllaceae, by 



1 "Studies in Morphology of Spore-producing Members," Part iv., 

 Phil. Trans. Roy. Soc. vol. 192, B, p. 38, 1899. 



