1919] Weatherby,— Nomenclature of Gray's Manual Ferns — 175 
group more primitive than the true Aspleniums and standing between 
them and Thelypteris in the evolutionary sequence, as we now con- 
struct it. The section Athyrium, then, of the Manual becomes a 
genus to which the last three species under Asplenium are to be trans- 
ferred. Butters! has recently pointed out that (as in many similar ` 
cases) it is the lady fern of western America, heretofore generally 
known as Athyrium or Asplenium cyclosorum, not that of the eastern 
states, which is really conspecific with the original A: Filiz-femina of 
Europe and should bear that name; and that our northeastern plants 
comprise two species, A. angustum and A. asplenioides, distinct from 
it and from each other and long ago recognized and named by Willde- 
now and Michaux. He also points out that Asplenium angustifolium 
and A. acrostichoides of the Manual belong rather with the tropical 
group Diplazium than with typical Athyrium (the lady ferns); but 
since there is doubt if Diplazium, though rather generally accepted, 
ought to be separated as a genus, it seems best to leave them, for the 
present at least, under the older name Athyrium. 
Dicksonia.— The pasture fern and its congeners were long referred 
to Dicksonia because of a similarity in the structure of the indusium. 
They differ widely from it, however, in habit and, what is more im- 
portant, in the structure of the sporangia, which is altogether that of 
the Polypodiaceae, not of the Cyatheaceae to which the true Dicksonias 
belong. Our fern should bear the name Dennstaedtia given it more 
than a century ago by Bernhardi. 
Onoclea.— The two sections of Onoclea, as pem in the Manual, 
are now regarded by most authors as genera. The present writer 
confesses to some doubt as to the propriety of this segregation; but 
the weight of.opinion is for it. The name Onoclea remains with O. 
sensibilis. The earliest generic name for the ostrich ferns, Struthiop- 
. teris Willd. (1809) is invalid because of an earlier Struthiopteris Scop. 
(1760). Nieuwland? has recently pointed out that the name usually 
taken up, Matteuccia Todaro (1866), is also long antedated by the 
obscurely published Pteretis Raf. which is the correct name for the 
genus. Fernald è has shown that the American ostrich fern is speci- 
fically distinct from the European and should bear the specific name 
nodulosa, given it by Michaux. Pteretis nodulosa (Michx.) Nieuwl. 
becomes the name for our ostrich fern. 
1 Raopona, xix. 178ff. (1917). 
? Am. Midland Nat. iii. 194ff. (1914). 
3 Ruopora, xvii. 161ff. (1915). 
