OF THE Synopsis FILicumM 623 
with Wotholaena, Monogramma, Antrophyum, Vittaria, Hemionitis, 
and several smaller genera, associated in this tribe by the posses- 
sion of sporangia arranged in lines not covered by an indusium. 
In this way the most variable and ephemeral of all the structures 
possessed by the ferns, namely the membranous indusium which 
as a peripheral structure, a mere flattened trichome, more subject 
to variation than any other single structure, is made the artificial 
character by which genera are united into tribes and by which the 
individual genera are characterized, to the exclusion of real char- 
acters based on more fundamental portions of the plant anatomy 
or on habit relations which so often are real guides to blood rela- 
tionship. Notholaena is simply a non-indusiate complex of the 
Pterideae, in part related to Cheilanthes and in part related to Pe/- 
laea; Vittaria is properly the type of a tribe in which some of 
the smaller genera will associate themselves; while Gymmo- 
gramme as represented by the ninety-eight species described in 
Synopsis Filicum is the most unaccountable and unnatural collec- 
tion of misfits that ever figured in the pages of a treatise on syste- 
matic botany. With the possible exception of Hemuonitis, no part 
of Gymnogramme as here treated has any natural relation to the 
other genera with which it is associated, and the removal of its 
broken fragments almost bodily to the tribe Pterideae by Diels 
‘in his treatment of the family in Die natiirlichen Pflanzenfamilien 
give them no more secure a resting-place, for the diverse sections 
of the genus are related some to one tribal alliance and some to 
another, while some may have to form a tribe by themselves with 
No very close relations to any other known forms. 
The genus Gymnogramma was established by Desvaux * in 
1811 based on thirteen species in the order named below: 
Sec. 1. Frondibus pinnatis. 
I. G. RUFA ( Preris ruffa L., Acrostichum rufum L.). 
2. G. TOMENTOSA (Asplenium tomentosum Lam. ). 
3- G. ACROSTICHOIDES ( Hemienitis acrostichoides Sw. ). 
Sec. 2. Frondibus bipinnatifidis. 
4. G. FILIPENDULAEFOLIA (Asplenium filipendulacfolium Aubert). 
5. G. TRIFOLIATA (Acrostichum trifoliatum L.). 
Sec. 3. Frondibus bipinnatis. 
6. G. Japonica (Hemionitis Japonica Thunb. ). 
* Desvaux, Berl. Mag. 5: 304. 1811. (Copy in the New York Public Library. ) 
