THE SPLEENWORTS. 
429 
influence of the sea air. The true habitat of 
the Sea Spleenwort is the open sea coast; some¬ 
times on the outside face of the rocks, and some¬ 
times within shadowy caverns. It not only grows 
in crevices in the rock, but on the rock itself, 
into which it insinuates its roots. Sometimes it 
grows on the roofs and at the sides of dripping 
caverns; and in such situations it will often 
spread its roots like a web over the damp, stony 
surfaces. 
Its fronds are leathery in texture ; and of so 
bright, fresh, and shining a green colour, that it 
is positively refreshing to look upon them. 
Average specimens are six or eight inches long; 
but in dripping sea caves they sometimes hang 
pendant from the roofs, and reach a length of as 
much as eighteen inches. The shape of the frond 
of the Sea Spleenwort is narrowly oblong, 
broadest about the centre, narrowing slightly to¬ 
wards the base, tapering upwards, and blunt- 
pointed. On each side of the rachis is a simple 
row of leaflets. These are arranged in pairs near 
the bottom of the frond, but become alternated 
towards the top. Immediately contiguous to, and 
