XXIIJ URNATOPTERIS, ETC. 407 



Zeilleria. 



This genus was founded by Kidston' for fertile pinnae of a 

 very delicate fern, Zeilleria delicatula (Stemb.) characterised 

 by filiform ultimate segments bearing an indusium-like body, 

 spherical when immature and splitting at maturity into four 

 small valves. Kidston, in his earlier paper, compared the 

 species with recent Hymenophyllaceae. In the same genus he 

 includes^. ai;oMensis''(Stur) assigned by Stur to Calymmatotheca, 

 a genus described by some authors as characterised by groups of 

 radially elongated sporangia at the tips of the pinnules ; these 

 supposed sporangia are now known to be the valves of an 

 indusium-like organ or cupule, as Stur asserted. There can be 

 little doubt that the fertile fronds placed in Calymmatotheca 

 and in Zeilleria were borne by Pteridosperms. 



Urnatopteris. 



The Upper Carboniferous fronds of a delicate Sphenopteris 

 habit, to which this name was assigned by Kidston*, were 

 described by him as Musphenopteris tenella (Brongn.)* and 

 compared with Hymenophyllaceae; subsequently Kidston ex- 

 pressed the opinion that Urnatopteris may be a Marattiaceous 

 fern, as Williamson^ believed ; he has since suggested that 

 the sporangia are the microsporangia of a Pteridosperm' The 

 sterile and fertile pinnae differ in the absence of a lamina in 

 the latter. The sporangia (or microsporangia) are characterised 

 by a poricidal dehiscence. 



The records from strata higher in the geological series than 

 the Permian, disregarding many of doubtful value, afford ample 

 testimony to the existence of Marat tiaceae in Upper Triassic 

 and Rhaetic floras. 



Marattiopsis. 



The generic name Danaeopsis was applied by Heer' to an 

 Upper Triassic fern, previously described by Presl as Taeni- 



1 Kidston (842). 2 Kidston (87). 



3 Kidston (82) p. 32. ■• Kidston (84^) p. 594. 



5 Williamson (83) A. « Kidston (06). 



' Heer (76) A. p. 71, PI. xxiv. fig. 1. 



