THE BRITTLE BLADDER FERN. / 267 
6. furcans (M.). In this form the apices of the pinnœ are more 
orless uniformly forked, with the points spread apart; sometimes 
they are twice forked, and usually there is a slight irregularity 
in the development of the pinnules; in some of the pinn® the apex 
is spread out into five points. The general character of the fronds 
otherwise resembles dentata. This plant was found at Killin in 
Perthshire by Mr. S. O. Gray; and a similar form communicated 
by Messrs. Stansfield of Todmorden, hàs been found in the Clova 
Mountains. 
7. interrupta (Woll.). This is a curious monstrous form, and quite 
permanent. The fronds are dissimilar, but from the altered or inter- 
rupted or contracted state of the pinne, they are all more or less nar- 
rowed, and are very frequently nearly linear throughout, or for the 
greater part of their length. The pinne where normal resemble den- 
tata, but are usually shorter and more confluent; they are however 
sometimes reduced to small fan-shaped or three-lobed bodies, and 
where this occurs in a continuous manner along the rachis, the frond 
becomes narrow-linear. Sometimes the pinne consist of two to four or 
six very unequal and irregular pinnules, which are often fan-shaped, 
and then the fronds have a narrow but irregular contracted outline. 
The pinnules in the interrupted portions are variously truncated lacin- 
iated or depauperated, or sometimes bifid or multifid. It was found 
in Westmoreland by Mr. I. Hudhart, and was distributed by Mr. 
F. Clowes. [Plate CII E.—Folio ed. t. XLVI A. fig. 7. ] 
(8.) sempervirens (M.). There is another form reputed to have 
been found both in Devonshire and Kent, which has several distinc- 
tive features, namely :—the fronds are of evergreen character under 
shelter, the plants kept in a cold greenhouse continuing to grow in 
succession through the whole winter, when all other forms. of 
Cystopteris known in cultivation are quite dormant ; the stipites are 
stout, pallid, not brittle but tough, so much so that they are not easily 
broken asunder; the anterior basal pinnules are larger than the 
posterior ones; and the surface of the indusium is clothed with 
glandular hairs, which are conspicuous in the fresh plant. This 
evergreen species, for such we believe it to be, has, in addition, a 
short creeping rhizome, vigorous fronds of narrow lanceolate outline, 

