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CLASS Th 
CELLULARES. 
SUB-CLASS III. 
ACOTYLEDONES, OR CRYPTOGAMIC PLANTS. 
ORDER CII. FILICES.—Juss. 
Leafy plants, producing a rhizoma, which creeps below or upon the 
surface of the ground, or rises into the air like the trunk of a tree, 
cylindrical, soft and cellular within, hard and fibrous externally, 
which is like a rind, and is formed by the united basis of the leaves. 
Leaves or fronds coiled up (circinate) in vernation, with annular 
ducts in the vascular tissue of their petioles, entire, lobed, or much 
divided, the veins dichotomous, occasionally furnished with ducts, and 
the cuticle with stomates. ructificution consisting of theca, or 
semi-transparent cases, arising from the veins upon the under surface 
of the leaves or from the margin, and called sori. Thece either ° 
pedicellated, with the pedicle passing round them in the form of an 
elastic ring, or sessile, and without a ring, either springing from be- 
neath the cuticle, which they then force up in the form of a mem- 
brane, called an indusium, or from the actual surface of the leaf, and 
are naked. Syporules mostly triangular, arranged without order 
within the thece, very numerous. Sometimes the leaves are con- 
tracted about the thece, so as to assume the appearance of forming a 
part of the reproductive organs, and sometimes the place of the thece 
is supplied by the depauperated lobes of the leaves. 
TRIBES. 
Thece furnished with an elastic ring. 
Thece attached in clusters to the back 
Of the frond’ vsrsecs:..s.ccestsesveccsass Lo OLYPODIAGEEE. 
Thece attached in a receptacle on the 
margin of the frond .................. 2. GLEICHENIACER. 
Thece two valved, without an elastic 
ring. 
Thece reticulated and striated. Frond 
Circinate In Vernation ........ceceee- 3. OSMUNDACER. 
Thece not reticulated or striated. 
Fronds straight in vernation ...... 2. OPHTOGLOSSACEZ. 
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