NOTES ON NEUROSORIA PTEROIDES. 53 



soria from Allosorus, he says, of the former, "margo 

 segmentorum vix revolutus," and, of the latter, "margo 

 segmentorum ultimorum fertilium manifeste revolutus." 

 The contradiction is perhaps more apparent than real. As 

 distinguished from the ferns formerly assigned to Allosorus 

 (now included in Pellcea, Cryptogramma, etc.), in which 

 the indusium-like margin is widely bent back over the sori, 

 the margin of Neurosoria may be regarded as, compara- 

 tively, "vix revolutus"; but Brown's original description 

 {vide supra) cannot be ignored, nor the testimony of Ben- 

 tham and Bailey. Judging from the material I have seen, 

 the facts are as follows : — 



(a) When specimens are dry, the opposite edges of a 

 pinnule bend under to such an extent that, often, they 

 nearly, sometimes quite, toucli one another, almost com- 

 pletely hiding the sori. Moreover, when moistened, the 

 pinnules are flattened out with difficulty. 



(b) In addition to this bending back of the opposite edges 

 of the pinnules, there is often visible a narrow recurving 

 of the attenuated margin. It does not at all approach the 

 strong, indusium-like, recurved margin of Pellcea, but the 

 modified recurved margin is certainly present; and Ben- 

 tham's "a very narrow margin recurved over the young 

 sori," must be accepted. For the removal of any remain- 

 ing doubt, it is much to be desired that living plants should 

 be examined. 



(c) A point overlooked by Kuhn must be noted. The 

 attenuated margin is crenulated, as will be seen from Plate 

 IV a, d; but the crenulations do not exhibit any regularity 

 in structure, nor do they appear to stand in any definite 

 relation to the ends of the nerve-branches. 



4. The nerve-structure is of great importance in this 

 fern. First of all, Kuhn's "costa tenera, proeminens" 

 accurately describes one of the striking features of the 



