THE COMMON HART'S-TONGUE FERN. 175 
and sublaciniate, the apex attenuate; the margin irregularly cre- 
nate-lobate, somewhat undulated. They are submarginate beneath, 
and submuricate towards the margin above, the face of the frond 
being uneven, hollowed out here and there into cavities, bounded 
by raised lines and points, so as to become almost interruptedly 
supralineate. The fronds are less affected in the lower half, being 
there only slightly crenate; they are abundantly fertile, and some- 
what suprasoriferous. It was found in Ireland, in 1853, by Dr. 
Allchin, and is a singular and rare as well as handsome variety. 
82. bimarginatum (Woll.). This is one of the most curious 
varieties yet known, and forms a very handsome plant. The fronds 
are sometimes narrow, from abouta quarter to half an inch wide, 
and about six inches long excluding the scaly stipes ; others are threc- 
quarters of an inch wide, and from six to nine inches long. The 
base of the fronds is truncate, often broken up into a few 
separate lobes; the apex is either simple or multifid ; the edges are 
laciniate-toothed or broken up into narrow shallow truncate lobes, 
which are bifid or toothed; and the surface both above and below 
is marginate, the fronds thus becoming bimarginate. The excurrent 
membrane forming the margination, appears on the under side, as 
in other marginate forms; but on the upper surface, the cuticle is 
very irregularly broken up, the membranes being gathered and 
puckered so as to form cavities and excrescences, while the 
few lower separate lobes not unfrequently spread into small calyci- 
form or trumpet-shaped bodies tapered to a stalk-like base. The 
tip of the frond whether simple or divided, is generally somewhat 
less obviously marginate, and sometimes a little broader. The 
autumnal fronds are broader and irregular on the margin. It 
seems a somewhat tender variety, and does not perfect its spores 
so freely as many other kinds. The original plant was found near 
Rotherham, in Yorkshire, by Mr. H. Hayling, gardener to the Rev. 
W. Hudson, of St. Catherine’s, Regent’s-park ; and this form is not 
unfrequently multifid. Others having the same general characters 
have been found by Mr. J. R. Cobb, on a bridge near Brecon; and 
by Mr. Hadwin at Ulverstone: the latter being a finely multifid- 
lobate plant, apparently constant. Mr. Elworthy has raised the 
same form from spores. l 

