48 
FERNS AND FERNERIES. 
Asplenie.e. 
Having spore-cases with special indusia of an oblong form springing from 
the sides of the veins (fig. 4). m 
Blechne^e. 
Sori, having special indusia forming linear growth between the midrib and 
margins of the divisions of the frond (fig. 5). 
PTERIDEiE. 
In this case the margin of the frond is continuously or interruptedly changed 
into a kind of indusium (fig. 6). 
Adiante^e. 
The margin of the fronds bear reflexed lobes, changed into indusia, under 
which are the spores (fig. 7). 
Cystopterideje. 
Having special ovate and hoodlike indusia affixed behind and covering the 
sori (fig. 8). 
WOODSIEAL 
Sori generally covered by an indusium having hairlike bodies attached to 
its margin (fig. 2, 9). 
Hymenophylle^e. 
Sori are generally produced around the end of veins which project from the 
frond ; these are either urn-shaped or consist of a two-valved membranous sac 
(fig. 2, 10, a, b). 
OSMUNDACE 4 E. 
Chief characteristic : Young leaves circinate ; the spore-eases are also desti¬ 
tute of an elastic ring or annulus (fig. 3). 
OPHIOGLOSSACEA 2 . 
This group is chiefly remarkable for having the leaves folding straight; spore- 
cases generally in a spike, without an elastic ring, and two-valved (fig. 4). 
MUIR, PATERSON, AND BRODIE, PRINTERS, EDINBURGH. 
1 SMOV.1321 
