349 CHARACTERS OF TRIBES AND GENERA. 
of a definite number of sporangia and the ring being hori- 
zontal, its mode of growth is, however, very different from 
Gleichenia, the caudex being woody, erect, and branching, 
bearing tufts of fronds in many respects similar to Oleandra 
neriiformis, but differs in having pinnatifidly pinnate fronds, 
much resembling the larger forms of Jamesonia. 
The above character is drawn up from description and 
from notes communicated to me by Mr. Baker. 
Sp. S. moniliformis, Mett., in Ann. Soc. Nat., 1861, p. 
84, t. 3. 
Sect. 2.-—Sori (sporangia) in marginal bilabiate cysts, 
opening exteriorly. 
Tribe 95.—HYMENOPHYLLEUE. (Plate 25.) 
(Hymenophyllacee, Pr.). 
Fronds membranous, generally pellucid, entire, or vari- 
ously compound, from less than an inch to a foot or more 
in length. Sporangia sessile, compactly seated round a ` E 
columnar terminal receptacle, which is formed by a free 
prolongation of the venule, included within a bilabiate or 
urceolate usually vertical cyst, open exteriorly. 
Oss.—This is an extensive and very distinct tribe of 
Ferns, differing from all others by the extremely delicate 
and in general thin pellucid texture of the fronds, and also 
by the form and attachment of the sporangia. The fronds 
vary much in form and size, some being simple entire, - : : ^ 
forked or flabelliform, not more than half an inch in lengtb, — — 
while others are more or less compound, or multifidly 
divided into fine hair-like segments, and vary from a few n x 
inches to 1 or 13 feet in length. 
The distinct habit and peculiar structure of the sporan- 
gium led some Pteridologists to characterise Breme 
