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the undulation of the margin, and the marginal teeth are fre- 
quently deeper and more evident. This form is of continental 
origin, but a similar one, quite constant, and very ornamental in 
character, has been found in Guernsey by Mr. James of Vauvert. 
23. fissum (M.). A vigorous and handsome form, somewhat 
resembling polyschides (21) and macrosorum (22). The fronds are, 
however, larger and broader, being from a foot to eighteen inches 
long, and from an inch and half to two inches wide, oblong, the 
base subcordate, the apex usually blunt, and the margin irregular, 
deeply incised, and somewhat undulate, so that the incisions are not 
very apparent, the whole being crenately toothed: the veins are 
slightly netted; and the sori grow in oval-oblong, irregularly- 
disposed masses. It is quite permanent, and was several years since 
found at St. Decuman's, near Nettlecombe in Somersetshire, by Sir 
W. C. Trevelyan, Bart. Similar forms have been gathered near 
Denbigh by Mr. J. W. Griffith ; near Torquay and Dunchideock by 
Mr. R. J. Gray; and in Guernsey by Mr. C. Jackson. 
24. imperfectum (Woll.). This variety was remarkable in the 
wild state for the unfinished appearance of the margin of the narrow 
frond, which appeared as though cut away as far in as the sori. 
The cultivated fronds become broader and lobed as in polyschides (21) ; 
they are eight or ten inches high, and an inch and three-quarters 
broad, truncate or subeordate at the base, abrupt and sometimes 
sub-cornute at the apex; the margin irregularly wavy, here and 
there obscurely erenate-lobed, or sometimes deeply lobed, as in 
polyschides, especially towards the top, the rest nearly entire. 
The sori are linear, unequal, many of them extending to the margin. 
It was found, in 1855, by Mr. G. B. Wollaston, on Whitbarrow 
in Westmorland, and a similar form has since been gathered at 
Barnstaple, Devonshire, by Mr. H. F. Dempster. 
25. fisso-lobatum (M.). This is a very handsome form, resem- 
bling fissum (23) in its habit and in its broadish fronds, which are 
lobate on the margin, and split into numerous narrowish lacini, 
or teeth; but the apex, which is similarly toothed, is multifidly 
lobed. The fronds are contracted below the apex, irregularly 
reticulated, and freely fertile, as well as suprasoriferous. It was found 
near Nettlecombe, Somersetshire, by Mr. C. Elworthy. 

