106 Vol. XLin., Art. l.-K. Yendo: 



ones at wide intervals, but middle and upper ones approximate 

 and regularly disposed, adding new ones successively upwards, 

 long linear, 5-20 cm. in length, w^ith well-defined cylindrical 

 petioles ; base of sporophyll acute or obtuse, very often asym- 

 metrical ; tip, when entirely soriferous, attenuate with obtuse apex, 

 and when partially soriferous the upper sterile part often abruptly 

 expanded wdth round margin. Sorus generally formed in a con- 

 tinuous patch on both surfaces of each sporophyll, occupying the 

 entire surface except a narrow border along the margin, resulting 

 in a considerable thickness of the sporophyll ; or often leaving 

 a sterile portion at the upper part of the sporophyll. In the latter 

 case, the upper limitation of the sori is gradual and faint. 



Remarks on the limit of variations. The species is characterized 

 by having unrivalled thick sporophylls when tlicy become fully 

 matured. Miya.be states, 1. c, p. 54, that the margins of immature 

 sporophylls are finely serrated. But this statement is resulted from 

 a false observation of the fine crispation of the sterile margins 

 frequently met with, certainly due to the greater growth of the 

 marginal parts than the soriferous area (Plate X). 



In the mode of attachment of sporophylls to the stipe, the 

 present species agrees exactly with A. esculcnta Grev. While the 

 sporophylls have not yet matured and the peculiarity of the species 

 is not conspicuously manifested, both species are hardly separable 

 one from the other. 



Specimens from the type locality have generally the matured 

 sporophylls enormously thickened and frequently entirely free 

 from the sterile portion, as illustrated by Kjellman. Very often, 

 however, the upper part of some sporophyll is broadened and 

 remains sterile and membranaceous for the wdiole life. This aber- 

 rancy grows greater and greater as we trace the species towards 



