HALLE, ON THE SPORANGIA OF SOME MESOZOIC FERNS. 15 



scribed in some detail, opinions still diverge regarding the sys- 

 tematic position of the genus. 



The first important contribution to the knowledge of the 

 sporangia and the affinities of the genus was given by GÖP- 

 PERT (1841, Lief. 1 — 2, p. 2) in his description of the species 

 Thauinatopteris Münsteri Göpp., which was later transferred 

 to Dictyophyllum by Nathorst (1876, p. 24 and foil.). Göp- 

 pert's own words may be quoted: »Die Sporangien sind gros- 

 ser, als ich sie irgend bei den Polypodiaceen der Jetztwelt 

 gesehen habe und nähern sich in dieser Beziehung den Cya- 

 theaceen, mit den sie auch rücksichtlich des completten Ringes 

 verwandt erscheinen». Göppeet's figure (pl. 2, fig. 6) in- 

 deed shows a very distinct complete annulus in several of 

 the sporangia figured, but the figure gives the impression 

 of being somewhat diagrammatic. 



The idea of a close relationship to the Cyatheaceae was 

 favoured also by Schenk (1867, p. 71), who states that the 

 type is more closely related to the Cyatheaceae than to the 

 »Acrostichaceae ». In his »Fossile Pflanzenreste», however, 

 Schenk (1888, p. 37) speaks of Dictyophyllum and allied 

 genera as occupying an intermediate position between the 

 Gleicheniaceae and the Cyatheaceae and also remarks on the 

 resemblance to Matonia. Potonié in his »Lehrbuch» (1899, 

 p. 88) refers Dictyophyllum and allied genera to the Cyathea- 

 ceae, but remarks that this genus and some others allied to 

 it are perhaps better treated as a separate group intermediate 

 between the Cyatheaceae and the Gleicheniaceae in accordance 

 with the opinion already expressed by Schenk. In his treat- 

 ment of the fossil ferns in Engler & Prantl's »Natürhche 

 Pflanzenfamilien», however, Potonié (1902, p. 349) ranges 

 Dictyophyllum, Clathropteris and Camptopteris as well as Lac- 

 copter is under the Matoniaceae. 



As early as 1828, Brongniart (1828, p. 62) remarked 

 on the resemblance to the Polypodiaceae shown by the closely 

 related Clathropteris, and several of the following wiiters 

 expressed similar opinions regarding Dictyophyllum. Saporta 

 brought these and other related genera to a separate group, 

 which he called the »Proto-Poly^odiées » (Saporta & Marion, 

 1881, p. 167). 



Zeiller in 1882 (p. 17) drew attention to the resemblance 

 of the allied genus Clathropteris to Dipteris, which was at that 



