22 
FERNS. 
[ Grammitis . 
f f EVIDENTLY INDUSIATE. 
Indusium distinct from the Frond. 
Sori round. Indusium cleft into hair-like segments . Woodsia. 
Sori round. Indusium hood- or bladder-shaped . Cystopteris. 
Sori round. Indusium shield-like, either round or 1 . 
kidney-shaped |Aspidium. 
Sori linear or oblong, transverse, solitary. Indusium from 1 . 
lateral veins, opening towards the midrib . . J Asplenitjm. 
Sori linear, transverse. Indusia splitting down the middle, 1 „ 
and turning back to each side ^ . . j- S colopendrium. 
Sori linear, longitudinal, close to the midrib. Indusia] R 
separating next the midrib, and turning outwards / Blechnum - 
Indusium apparen tly part of the Frond itself reflexed. 
Sori linear, continued around the margin of the leaflets ; 1 p 
reflexed margin membranous . . . j * TERIS> 
Sori on transverse veins, near to the margin ; reflexed ] n 
margin unaltered . . . j- Cryptogramma. 
Sori in distinct spots, attached to the cover itself; re-1 
flexed margin membranous . . . . j Adiantum. 
* * Thecce in marginal receptacles. 
Thecae in deeply cup-shaped receptacles . . . Trichomanes. 
Thecae in compressed, two-valved receptacles . . IIymenophyllum. 
* * * Theca on divisions of the leaf destitute of parenchyma. 
Thecae stalked, reticulated, terminating a bipinnate leaf . Osmunda. 
Thecae sessile, smooth, in a separate compound spike . Botrychitjm. 
1 heccc sessile, smooth, in a separate simple spike , Ophioglossum. 
**** Thecae in catkins, terminating a hollow, jointed, 1 r 
and apparently leafless stem . . f- iiaciSETUM. 
***** Thecae imbedded in the base of radical leaves . Isoetes. 
****** Thecae in the axils of the ordinary leaves, or of 1 T 
scales gathered into terminal catkins . . j Lycopodium. 
** : **** Thecae in sporanges, stalked upon the creeping 1 
stem, near the bases of the leaves . . . j * il ulari a. 
GRAMMITIS. Swz. GRAMMITIS. 
(r papya, a line ; alluding to the linear fructification.) 
A shows the under surface of the leaf of Grammitis ceterach. B, the veins 
according to Newman.* C, the veins according to Presl. I), position of the fruit. 
E, un unopened theca. F, a theca scattering its spores. G, the spores. II, a 
scale. I, epidermis and stomata. J, transverse section of the leaf-stalk. 
* Inaccurately copied. — Ed. 
