THE BROAD PRICKLY-TOOTHED BUCKLER FERN. 239 
with any other form, is probably a small state of the var. alpina; as 
also, a similar dwarf form, found on Loch-na-gar in Aberdeenshire 
by Mr. W. Sutherland. 
10. nana (Newm.). This form proves to be a permanent variety, 
and not an immature condition of the species, as might be supposed. 
It differs most obviously from the usual and commoner forms of the 
Species in its constantly smaller size; the extreme length of the 
fronds, including the stipites, varying from two to four inches in the 
smallest forms, to eight or ten inches or a foot in the largest forms 
of the variety. This small size and dwarfness is a permanent 
characteristic, the variety having been observed for the last twenty 
years, by Mr. J. Tatham, growing near Settle, in Yorkshire, without 
change, and in company with the ordinary forms of the species three 
feet in height; and even when freely manured, these plants though 
attaining about fifteen inches high, did not lose the dwarfish aspect of 
the natural specimens. The Rev. J. M. Chanter has also observed 
the same fact of constancy for a series of years in plants which we 
think belong to this variety, occurring near Ilfracombe, in Devon- 
shire; and cultivation in a greenhouse was not found to add to the 
size of the Devonshire plants, which assume slight variations of form 
among themselves. The Settle plant is the typical form of the 
variety. The fronds of this are ovate broadest at the base, or oblong- 
ovate, bipinnate. The stipites and rachides, as well as the under side 
of the veins, are sparingly clothed with short-stalked glands; and the 
stipes moreover, which forms nearly half the entire height, is clothed 
thickly at the base, more sparingly upwards, with lanceolate scales 
having the usual dark central mark. The pinne are spreading and 
somewhat acuminate, the lowest pair unequal-sided, but the rest 
nearly equal. The basal pinnules are distinctly stalked, the next 
decurrently stalked, and the upper ones adnate, somewhat convex, 
the larger ones deeply, the rest shallowly lobed, the lobes being 
serrated; the smaller ones are merely serrate; the teeth all acute 
and mucronate. The sori are often most copious in the upper part 
though frequently occupying the whole of the frond, and form a line 
on each side the midvein of the pinnules nearer the rib than the 
margin; they are rather small, and are each covered by a delicate, 
somewhat glandular-margined indusium, which soon shrivels and 

