GENERA OF FERNS. 429 
Species. L. Cunninghamii, R. Br. (Davallia dealbata, A 
Cunn. MSS. 
Ilust. Comp. to Bot. Mag. t. 33, 32. Hook. et Bauer Gen. 
Fil. t. 15. 
Obs. The habit and apparent view of the sori of this re- 
 markable fern are similar to several species of Davallia, but 
from which it differs by the sporangia being produced in an 
imbricate manner round a vertical columnar exserted recep- 
tacle, which may be viewed as formed by the union of the 
base of the pedicels, and which structure forms a transition 
from Davallia to Trichomanes, and also agreeing with the 
latter genus, in the ring being oblique. 
Sect. III. TRICHOMANES, J. Sm. 
Sporangia sessile, compactly seated round a columnar ter- 
minal receptacle, (which is formed by. a free prolongation of 
the venule,) included within a bilabiate or urceolate, usually 
vertical cyst, that is formed by the connivence of the in- 
dusium with the margin of the frond. 
109. TRICHOMANES, Linn. 
(Feea, Bory.) 
Veins simple or forked, direct ; sori vertically oblong, ter- 
minal; indusium urceolate, or calyciform; sporangia sessile, 
Seated round a columnar receptacle, which is filiform and ex- 
serted. 
Fronds from an inch to 1 or 9 feet high, produced from a 
creeping or cespitose rhizoma, varying from simple to de- 
compound multifid, the fertile part, or sometimes the whole 
frond contracted and spiciform, membranous and pellucid, 
smooth, or furnished with simple, forked, or stellated hairs ; 
Sporangia compressed; ring more or less oblique or trans- 
verse, 
Examp. |. T. reniforme, Forst. 9. T. membranaceum, 
Linn. 3. T. sinuosum, Rich. 4. T. floribundum, Humb. 
5. T. crispum, Linn. 6. T. alatum, Sw. 7. T. spicatum, 
R. Hedw. | 8. 'T. trichoideum, Sw. 
