XXl] SCHIZAEACEAE 347 



Schizaeaceae, though normally one row deep, may consist in 

 part at least of two rows. Zeiller* examined specimens of 

 Corda's species and decided in favour of a Schizaeaceous 

 affinity ; he describes the sporangia as 0'85 — 095 mm. in length, 

 with ?i to 5 and occasionally only two rows of cells in the apical 

 annul us. Zeiller's figures (fig. 270, A) confirm the impression 

 that Corda's drawings are more beautiful than accurate. Stur^ 

 on the other hand, who first pointed out that the type-specimens 

 of Senftenhergia came from the Radnitz beds of Bohemia and 

 not from the Coal-Measures, convinced himself that the 

 sporangia have no true annulus (fig. 270, E). He describes them 

 as characterised by a comparatively strong wall and by the 

 presence of a band of narrow vertical cells marking the line of 

 dehiscence, features which lead him to assign the plant to the 

 Marattiales, a group which seems to have exercised a dominating 

 influence over his judgment. In a later publication Zeiller' 

 replies to Stur's criticism but adheres to his original opinion. 

 Solms-Laubach^, while expressing himself in favour of Marat- 

 tiaceous affinity, recognises that Zeiller's arguments cannot be 

 set aside. 



The question must remain open until further evidence is 

 forthcoming ; but it would seem that this Carboniferous type, 

 not as yet recognised in Britain, possessed sporangia having a 

 distinct resemblance to those of the Schizaeaceae, though this 

 similarity does not amount to proof of the existence of the 

 family in the Palaeozoic era. 



Palaeozoic floras may be described as rich in generalised 

 types, types foreshadowing lines of evolution, which in the 

 course of ages led to a sorting and a redistribution of characters. 

 It may be that Senftenhergia is one of these generalised types. 



It is not until we ascend the geological series as far as the 

 older Jurassic rocks that we meet with a type which can with 

 confidence be classed with the Schizaeaceae, as least so far as 

 sporangial characters are concerned. The species Klukia exilis 



1 Zeiller (83) p. 188, PI.- x. figs. 1—5. " gtur (85) A. p. 64. 



=• Zeiller (88) A. p. 50. ■• Solms-Laubach (91) A. p. 147. 



