67 
Microlepia is Tindofinable because generalized. Leucostegia may also be 
primitive, or it is possibly heterogeneous but it is as natural a group as 
is made by combining it with Ilumafa, and its union witli Davallia' scorns 
to mc still less proper. 
My reasons for believing that the nearest affinity of Olcandm is to 
Ilwmata have already been published/''^ These do not constitute good 
proof, but they are the best evidence we have as to the aflPinities of 
Oleandra; but Oleandra would appear from its distribution to be the 
older group. 
+ 
The mutual affinity of the otlier genera treated as Dmmlliem is still 
more dubious. Arthropleris seems to me to be very near Lcusinea, in 
which group its first species was described. Our seaudent Lastrwa (No. 
1712) shares with Arlkropteris the articulate stipe and the terminally 
placed sori. In spite of the very striking retieinl)lance between their 
fronds, comparing, for instance, Arlhropieris ramosa witJi NepJuvIcpis 
Lauterbachii or Neplirolepis cordifolia, the affinity of these two genera is 
by no means above doubt, and if one is descended from the other, it is 
not a proven fact that Arlliropteris, in spite of its apparently much closer 
affinity to Lastrwa^ is the parent, for Neplirolepis is shown by its distribu- 
tion, and still more by its conspicuous morphological isolation, and by 
the diversity of its fructification, to be a very ancient genus. 
Nephrolepis acutifolia is like Scliizoloma iu two conspicuous characters, 
the articulate pinnfe and the unbroken marginal sori, but this is probably 
only a coincidence. The latter genus is an unmistakable relative of 
Lindsaya, and, less intimately, of Odontosona^ but the common ancestry 
of the group is\loubtful. Of the three, Odontosona seems tlic nearer 
to Microlepia. The group is certainly terrestrial in origin. 
M onacliosorvm is, as Dicls says, "ha])itiu'll an Davallia erinnerndes, 
but the suggestion of Leucostegia is stronger; and this is due almost 
exclusively to their common share in the aspect of Acrophorus and various 
species of Lastrcea', that is, Monachosorum is more like the generalized 
ferns than like the more highly developed ferns of any tribe, and its 
assignment to any tribe, by our present knowledge, is purely arbitrary. 
The most primitive genus of the Aspleniece is unquestionably AUnj- 
rium. It is a generalized group, sharing, on tlie one hand, tlie characters 
of Diplazium and Asplenlum, and merging into both, and on the other, 
beine: indistinguishable from Ladnva. Atlnjninn cyclosonim "Rupr., of 
?? 
Asia and western North America, usually regarded as a form of A, filix- 
fcemina^ is Lastraeoid in its indusia. I have recently described a new 
^PolypodiacoiT of tlie Philippines, Oovt. hah. PuhL (1905) 28: 48. "The 
reseiubliiuce to * * * the aimplo species of Humoffi — the cropping, sealy 
rliizome, the articulate stipe, the free, forked, closely parall.l veinH, the shape, 
attachment, and texture of the indusiutn, and its oi>ening ol»li(|uely toward the 
apex of the frond — nil these can not well be constrxied otherwise tlian as evidences 
of real affinity." 
