280 THE BRITISH FERNS. 
or subulate, pale brown. Fibres dark brown, wiry, branched, 
slightly hairy. 
Vernation circinate, the young fronds becoming bent like a 
shepherd's crook. 
Stipes pale reddish brown, from one to two inches long, articulated 
above the base, which is terminal and adherent to the caudex; and 
as well as the rachis crinite, with numerous pallid subulate scales. 
Fronds from two to four or six inches long, lanceolate oblong, 
herbaceous dull deep green, more or less rusty beneath from the 
abundant reddish scales, pinnate. Pinne opposite or alternate, ovate- 
oblong, deeply pinnatifid, sessile or very shortly stalked, more distant 
below, all spreading or nearly horizontal; the larger ones about an 
inch, the smaller half an inch, in length. Lobes eight to twelve, 
oblong obtuse, the basal ones largest, their margins obscurely erenate, 
and as well as the upper surface furnished with coarse scattered hairs, 
in addition to which on the under surface are numerous long subulate 
scales on the rachides and veins. 
Venation of the lobes consisting of a flexuous and not very distinct 
costa or midvein, from which arise alternate veins ; the lower of these 
are usually forked some distance from their base, and the venules 
extend quite free nearly to the margin, and bear the sori near to but 
below the apex ; the upper veins, which are also fertile, are simple. 
Fructification on the back of the frond, scattered nearly equally 
over the whole surface, sometimes copious and becoming confluent, 
situated below the apex of the veins and venules. Sori circular, 
consisting of few spore-cases, seated within, that is above, a small 
membranaceous scale, whose margin is fringed with jointed shining 
hairs, which curve inwards, involving the spore-cases ; hence they 
are involucrate.  Spore-cases roundish-obovate. Spores oblong, 
roundish, or irregularly three-cornered, muriculate. 
Duration. The caudex is perennial. The fronds are annual, 
growing up in spring, about March, and perishing in autumn. 
The chief peculiarity of the genus to which this species is referred, 
is found in the peculiar investing membrane which covers the sorus, 
and which is not easy of examination without careful manipulation. 
This membrane or involucre consists of a small concave scale, resting 

