INTRODUCTION TO VOLUME II 



applies to the Gleicheniaceae : but the reference of Oligocarpia to this family 

 may be held as doubtful. Seward sums up the case thus {I.e. p. 352): 

 " Despite an agreement between Oligocarpia and Gleichenia as regards the 

 form of the sori and the number of sporangia, it is not certain that the 

 existence of a typical Gleicheniaceous annulus has been proved to occur in 

 any Palaeozoic sporangia." But in Triassic and Jurassic times their presence 

 is proved, and they survive in the modern Gleicheniaceae. 



Fig. 310. Boweria schlatzlarensis Kidston. Sporangia enlarged about 

 50 times. ^, from Clifton, Lancashire; B, C, from Monckton Main 

 Colliery, near Barnsley. (After Kidston.) 



The Schizaeaceae are also early Ferns in geological time. But according 

 to Seward (J.c. p. 347), the first confident recognition of the Family is in the 

 older Jurassic Rocks. It is true that earlier records have been quoted: in 

 particular Senftenbergia elegans described by Corda from the Carboniferous 

 of Bohemia was referred to this Family, But it seems now more probable 

 that this and other early fossils, while bearing a resemblance to Schizaeaceae, 

 are really generalised types foreshadowing lines of evolution rather than 

 already representing the actually differentiated Family. 



The Matonineae were undoubtedly represented in Mesozoic times by 

 Laccopteris and Matonidium: and the type survives to the present day in 

 Matonia. 



The Dipteridinae also appear represented by numerous fossil t}-pes in the 



Mesozoic Age, while the family still exists in the 



genus Dipteris, and 



it is probably represented also in a large number of those Polypodiaceae 

 which may be looked upon as Dipterid-derivatives. 



With regard to the Cyatheaceae (incl. Dicksonieae) Seward remarks that 

 "we have as yet no satisfactory evidence of the existence of the Cyatheaceae 

 in Palaeozoic Floras. It is not until we reach the Jurassic Period that 

 trustworthy data are obtained" {I.e. p. 366). But then they appear to have 

 been fairly well represented, and the type has survived in a large number of 

 living species. 



Certain early fossils have been referred to the Hymenophyllaceae, in par- 

 ticular Hymenophyllum weissii from the Coal Measures of Saarbriicken, and 

 Hymenopliyllites quadridaetylites Gutbier from the French Coal Measures. 



