e Tllust. Hook. jen Bauer. Gen. Fil, t 1.49 A; Ms Ind, ; 
Fil., p. 85 B ; J. Sm. Ferns Brit. and For., fig. 133. d 
—.—. Osgs.—The Gëss) habit of the species of this genus Si 
agree in every respect with Cyathea, and are only dis- ` 
tinguished by the technical character, which consists in the 
indusia of Alsophila being either absent, small, scale-like, or 
- forming a nearly complete cup. 
In my Genera of Ferns, 1841, I arranged the species of 
Alsophila under two sections, the first Hymenostegia, including 
_those having a membraneous indusium, very small in some, 
„but in others forming a nearly complete cup, differing from 
Cyathea only by not completely surrounding the base of the 
receptacle, there being always an open sinus on the exterior 
side; and the second, Trichostegia, those in which the mem- 
braneous indusium is entirely absent, the sporangia being 
more or less covered with articulate hairs. 
Although thirty years have elapsed since that mode of ` 
. arrangement was published, and having observed much ` 
during that period, I find I can make little or no alteration ` 
in it, except by amalgamating the genus Gymmosphera, of —— 
- Blume, with Alsophila, of the species of which I now form ` E 
a third section, characterised by the sori being destitute of ` — 
8 membrane and of hairs, in that respect not technically : 
= distinct, except in the arborescent habit, from Phegopteris, 
to which it is otherwise related through the genus Lopho- 
soria, 
In the “Species Filicum” sixty-three species are described, : 
_ of which about a dozen are marked dubious, the “ Synopsis,” 
_ however, enumerates ninety species including the Appendix. ` 
: Ee are widely dispersed over both hemispheres. . 
