108 VII. LASTKEA. 
habit, and grows three to four feet high. The fronds, 
which are distinctly bipinnate, are lance-shaped in out- 
line, and do not, as is frequent in the normal plant, 
abruptly contract into an acuminate apex. The pinnules 
are also less crowded ; those near the base of the pinnae 
being narrowed where they are connected with the rachis, 
frequently but not always considerably so ; in form they 
are more elongate, and narrowed into a somewhat acute 
apex, the margins more or less deeply inciso -lobate, with 
the lobes cut into from two to five serratures. The ve- 
nules are more numerous, several being developed from each 
vein, one of these extending up the centre of each lobe, 
those near the base of the pinnule producing the most nu- 
merous venoles. The sori however, are, notwithstanding 
the more compound venation, produced only by the lower 
anterior branch, so that they here also form a single line 
on each side the midrib, only they are commonly extended 
further up the pinnule and often reach almost to its apex. 
The indusium is convex, without any marginal glands, and 
is often met with smaller and less persistent, than in the 
form we have considered the normal plant Irregular and 
monstrous developments of this variety seem to constitute 
the Aspidium depaatum of Schkuhr, of which the fronds are 
broader, with large deeply lobed oblong pinnules occurring 
along with smaller deformed ones. The variety incisa 
is probably equally common with the type form. We 
have seen specimens from the counties of Devon, Somerset, 
Wilts, Dorset, Kent, Surrey, Hertford, Northampton, 
Hereford, Derby, and Cumberland, in England ; and from 
those of Lanark, Perth, and Kincardine hi Scotland. 
The variety abbreviata is a dwarf plant not exceeding 
a foot in height, and it is remarkable in having the pinna-. 
curved backwards so that the upper surface of the frond 
is concave. The stipes is very short. The outline is 
narrow lanceolate ; the pinnae one and a half to two 
inches long and bluntish at the apex. The pinnules, 
which are all connected at the base, one or two of the 
