ve BRITISH FERNS. 
in which case the lobes are slightly notched; the 
upper surface of the frond appears smooth to the 
naked eye, but under a lens of high power a few long 
bristle-like scales are observable, all of them pointing 
outwards; the under surface is pubescent, and, with 
the aid of a lens, this pubescence is found to consist, 
Jirst, of very long, pointed, narrow scales, which are 
more particularly abundant about the midrib; secondly, 
of glittering and jointed hairs, which are scattered 
over nearly the entire surface; and, thirdly, of the 
capillary segments of the inyolucres, which are also 
_ glittering and jointed. The seeds are placed in 
circular clusters near the margins of the lobes or 
pinnules; they are frequently concealed by the pu- 
bescence already described. The length of frond is 
generally less than four inches, 
rarest British ferns. I am only acquainted with one 
English locality, namely, at the foot of basaltic rocks 
on the Durham side of the river Tees, about two 
hundred yards below Caldron Snout, One Welsh 
county, Caernarvonshire, has also produced it; it 
grows on rocks near a little lake called Llyn-y-Cwn, 
@ethe Dog’s Lake, on the ascent of Glyder Vawr: as 
many as a hundred plants still exist here, but are 
- Inaecessible without a ladder: there are also a few 
Plants on rocks of a peculiar character resembling 
