








176 THE BRITISH FERNS. 
83. bimarginato-muricatum (M.). A singular and exceedingly 
beautiful form, combining the characters of bimarginatum (82) and 
muricatum (85). "The fronds are a foot long, of two kinds; the 
narrower and more decidedly bimarginate ones are irregular in 
outline like the forms of sinuatum, that is, there are here and there 
larger projecting lobes or portions of frond, the rest being con- 
tracted to about half an inch in width. In the example before us 
there is one cordate basal lobe, and the extreme apex is nearly 
normal, but the rest is nearly all contracted and bimarginate; 
the lobes of the margin are in several places carried quite down to 
the excurrent membrane, which is very near the costa, and being 
set some distance apart, the frond has an interrupted character ; these 
separate lobes form little marginal eup-like cavities. When the 
surface is broader, it is striately furrowed as in muricatum (85); 
the contracted parts being, however, like bimarginatum. The 
broader fronds are about an inch wide, cordate below, the margin 
unequally lobed and irregular, and the surface striately-furrowed. 
It was found in Guernsey, by Mr. James. 
84. bimarginato-cordatum (M.). A. very beautiful and perfectly 
constant form, apparently of dwarfish habit. It resembles bimargina- 
tum (83) in structure, but is a trifle broader, and it produces a 
pair of broad equal cordate basal lobes. It was raised by Mr. 
Elworthy, from spores of a very good form of muricatum (85). 
The following varieties referred to other groups, are also more or 
less marginate :—compositum (14), marginato-cornutum (20), fisso- 
lobatum (25), curtum (88), pocilliferum (44), resectum (51), retiner- 
vium (52), scalpturatum (87), multiforme (125), lacerato-marginatum 
(149), marginato-laceratum (150), ramo-submarginatum ( 153), ramo- 
marginatum (154). 
Muricatum Series. 
85. muricatum (M.). This variety may be taken as the type of 
another kind of variation, in which parallel strise or ridges or pro- 
jecting points are developed on the upper surface of the frond. The 
fronds are normal in size, coriaceous, cordate at the base, attenuate at 
the apex, the margin somewhat crenately-lobed or sinuous, here and 

