THE TUNBRIDGE FILM FEI 
Fronds smooth, pellucid-membranaceous, minutely cellular, dee metimes brightish green, 
ar or five inches long, varying in outline, usually ovate, lanceolate-ovate, or oblong, mo 
at the b the larger fronds, a narrow entire wing to the rachis ; distich 
mboid in circumscription ; fureately bipinnatitid, that is to say, twice 
ions alternating, and so placed 
divided with the ramifications on dichotomous or forked plan, the di 
nterior side from the medial or axial vein (which 
Ultimate segments Vinear-obtuee, spinulosely serrate. 
may be recognised), curving upwards. 
Venation consisting of a series of dichotomous ramifications (two or three-times repeated) of the 
ne of these 
nately from the main rachis, each ultimate segment having 
wiry ribs which branch alt 
x. Thus the fronds might be said to 
divisions along its centre, and not quite reaching to its a 
тей with a delicately cellular pellucid: 
consist of slender branching wiry ribs everywhere I 
menibranaceous margin, 
fi two valved 
Fructification usually produced in the upper half of the 
exterior, Sort consisting of 
outwards fe ening bo 
clustered around the receptacle, Receptacle formed of the altered apex of the 
west anterior vein of the pin 
а, spongy, oblong-clavate ; free, central and shorter than the valves of the 
involucre, therefore included. Znrofueres sessile, supra-axillary, i. е, borne in the axils of the pinnas or 
imewhat inflated, cuneate and more or less sunk in the 
primary divisions, short, с 
apre 
segment; the anterior part two-valved, the valves semiorbicular, flatish, spinulosely serrate at the upper 
margin. Spore-cases sessile, affixed obliquely, vertically compressed, thus lenticular, with a transverso 
ring. Spores minute, irregularly oblong, or triangular. Normally the lower anterior branch of the 
pinn only is fertile, b nes one or more others are also soriferous, 
аге also perennial, growing up in the course of 
Duration. "The rhizome is perennial. The frond: 
the summer, attaining their fall growth during the season, but enduring two or three years under 
favourable eireumstancen 
‘The two British Mymenophyllums, may be known from other Ferns by the matted growth of their 
thread-like rhizomes, by the small size, the pellucid, and finely cellular texture of their fronds, whose 
fications, They may be 
segments have each only a central rib, and by the two-valved marginal fruct 
involueres and of their valves ; for although they may 
best known from each other by the form of 
1 by a practised eye by their peculiarities of growth, yet these latter are 
probably always bo recogni: 
not features to be generally depended on, In Z7. tunbridgense the valves of the involucre are roundish 
nnd flattish, and the upper margin is spinulosely-serrate, like the margin of the segments of the pinna: 
aterale the valves are ovate and convex, and the margin is quito even. In the former 
whilst in Ж. uni 
the involueres are usually sessile and erect ; in the latter stalked and deflexed in an opposite direction 
ments. No varieties of importance have been observed in the British Hymenophyllums. 
to the 
