188 ` CHARACTERS OF TRIBES AND GENERA. 
Tilust. Hook. and Bauer, Gen. Fil, t. 37; Hook. Gard. 
Ferns, t. 50; Moore Ind. Fil., p. 48; J. Sm. Ferns, 
Brit. and For., fig. 50; Hook. Syn. Fil., t. 6, fig. 92, À.' 
Oss.— This genus as here restricted, includes a consider- 
able number of species varying greatly in size and circum- 
scription of the fronds, but all agreeing in having the 
sporangia produced on forked free veins, forming linear, 
naked sori, examples of the extreme sizes being represented 
on the one hand by G. leptophylla, an annual a few inches 
high, and the magnificent species, G. javanica and G. pro- 
cera (Ooniogramma, Fée), which have fronds 2 to 5 feet 
high, with broad pinnæ. 
These differences have induced some authors to cha- 
racterise the different groups as distinct genera, of which 
Professor Link has five, and with some alterations M. Fée 
makes ten, the whole including about forty species. Sir 
William Hooker, in his “Species Filicum,” goes much 
beyond this; he includes all Ferns with oblong, linear, 
oblique, naked sori, thus including species with both free 
and anastomosing venation, under which he describes 
seventy-five species, thus making it a more unnatural 
genus than when it was in its original state; he, however, 
divides them into six sections, the last inclading the genus 
Selliguea of Bory, which belongs to the division Eremobrya, 
and therefore has no natural relationship with Gymno- 
gramma, With regard to true Gymnogramma, I consider it 
best to adopt, so far as I find convenient, Link and Fée’s 
generic names as sectional names only. 
1. Fronds simple, entire, reniform, smooth (Pterozonium, Fée). 
G. reniformis, Mart. ; Hook. Second Cent. of Ferns, t. 9. 
2. Fronds simple, entire, linear lanceolate, smooth (Asple- 
nitis, J. Sm.). 
G. marginata, Mett. 
