i68 SCHIZAEACEAE [CH. 



opposite (A E). In the other genera the sporangia are more or less curved, 

 so as to be dorsiventral : this curvature is slight in Anemia and Schizaea 

 (A, B, F, G), but very marked in Lygodium {C). 



Certain fossils which have been referred to this affinity stamp the antiquity 

 of these characters, and help towards an understanding of the living forms. 

 The earliest of these is Senftenbergia from 

 the Upper Carboniferous, of which the ^ 

 sporangia were described by Corda as of 

 Schizaeaceous character, and disposed on a ~;;\i. 

 Pecopterid leaf, apparently just as are those tj\ 

 oi Anemia (Fig. 452). A detailed examina- si' 

 tion by P. Bertrand of a slab from the Coal 

 Basin of Northern France {^Ann. Soc. Geo!. 

 du Nord, Ixi, 191 2J, bearing a fossil de- 

 scribed as Pecopteris pennaeformis Brongn., Fig 452. Senftenbergia (Pecopteris) 



(. , ■ . . r 1 £ J i.1 elemns Corda. ^ = a small piece of 



confirms this comparison : for he finds the sp.^rophyll ( x 4). i? = a sporangium 

 isolated sporangia orientated as in Anemia, (x 3.^)- (After Zeiller. from Englerand 

 but larger, and having what he describes as 



a "plaque elastique" at the tip, consisting of two to three rows of cells, 

 while narrow and elongated cells represent a stomium. A terminal "plate" of 

 thin- walled cells, or "distal face" as described above for the living Schizaea- 

 ceae, has not been seen. But, as Zeiller has pointed out, these are not 

 absolute differences from living forms, for various species of Lygodium, 

 a genus which has itself been traced back to Cretaceous times, have a 

 partially double series of cells of the annulus (Fig. 454, A\ while the "plate" 

 in living forms is often so ill defined that it might well escape detection in 

 a fossil (Zeiller, i)W/. Soc. Bot. de France, xliv, p. 217). The facts appear to 

 establish the Schizaeoid nature of the sporangia of the new French specimen, 

 and that they were borne on a leaf described as Pecopteris pennaeformis 

 Brongn. (P. Bertrand, Ann. Soc. Geol. du Nord, Ixi, p. 222, 191 2). 



Whether or not these Carboniferous fossils are really to be included in the 

 Family, there can be little doubt of the correctness of the reference of Khikia 

 to the Schizaeaceae. It represents the fructification of a Pecopterid from 

 the Jurassic, and several species have been described b}- Raciborski (Engler's 

 Jahrb. xiii, p. I, Taf l). Here the arrangement of the sporangia, and their 

 structure down to the single series of cells of the annulus and the line of 

 dehiscence, are as in Schizaea (Fig. 453). In both of the genera of fossils above 

 mentioned the sporangia appear as though intra-marginal,on the lower surface 

 of the pinnule; but there is no distinction of fertile from sterile pinnules, nor 

 any special indusial protection. From such comparisons it appears that the 

 Schizaeaceous type is an ancient one, and that a Pecopterid foliage in early 

 days bore its characteristic sporangia. Probably in their development these 



