

284 THE BRITISH FERNS. 
which is terminal and adherent to the caudex, as well as sparingly 
furnished with pale membranaceous hair-scales. Rachis slightly 
coloured, and bearing a few pale narrow deciduous hair-scales. 
Fronds from two to six inches long, linear in outline, membra- 
naceo-herbaceous, tender green, pinnate. Pinne not rarely sub- 
opposite, more frequently alternate, triangular-ovate, obtuse, sessile 
or very shortly stalked, pinnatifid, the lower ones distant; the latter 
separated about three-eighths of an inch in the smaller plants and 
three-fourths of an inch in the more vigorous ones, the pinne being 
about one-fourth of an inch long in medium-sized specimens, up to 
about half an inch in the larger ones; the upper pinn® are more 
closely placed, and all are set on nearly horizontal. Lobes five to 
seven, roundish obovate, largest at the base, the lowermost some- 
times divided nearly to the midvein, the upper ones more confluent, 
and the apex, in the most vigorous specimens, notched so as to 
indicate an additional pair of lobes; they are entire or obscurely 
crenate on the margins, furnished with a few scattered tubular 
jointed hairs and hair-seales, which also occur here and there on 
both the upper and the under surface. 
Venation of the lobes consisting of a flexuous indistinct costa or 
midvein, from which proceed alternate veins; the lower veins are 
forked, but seldom more than once, and the upper ones are undi- 
vided; both veins and venules terminate within the margin in a 
slightly thickened point. The anterior venules of the forked veins, 
and some or all of the simple veins bear sori. 
Fructification produced over the whole back of the frond, but 
somewhat more copiously in the upper part. Sori situated below 
the apex of the venules, hence medial, and often at length confluent 
over the lobes; circular, seated within, that is above, a small mem- 
branaceous scale whose margin is fringed with jointed hairs curving 
inwards so as to enclose the spore-cases: hence the sori are involu- 
erate.  Spore-cases roundish obovate. Spores brown, round or 
roundish-oblong, the surface granulated or tuberculate. j 
Duration. The caudex is perennial. The fronds are annual, 
growing up in spring, and perishing late in autumn. 
The above deseription of this very rare species has been drawn 

