on British Ferns. 
xi 
Obs. — This genus has a very great similarity, in general habit, to 
that which immediately follows ; a similarity also extending more or 
less to several genera of the following family : it is comprised in the 
genus Aspidium of Smith : it is now almost universally regarded as 
comprising but a single species, the Polypodium Filix-femina of Lin- 
neus, and the following synonymes are those of the genus. 
Polypodium Filix-femina, Linn. Sp. PI. 1551 ; Light f. FI. 
Scot. 673 ; Huds. FI. Ang. 458 ; With. Arr. 778. 
Polipodium Filix-femina, Bolt. Fil. Brit. 46, t. 25. 
Aspidium Filix-femina (Swartz), and Aspidium irriguum, 
Sm. E. F. xv. 295, 6, E. B. 1459 and E. B. S. 2199. 
Asplenium Filix-femina (Bernh.), Mack. FI. Hib. 342 ; 
Hook, and Am. 574. 
Athyrium Filix-femina (Both), Newm. F. 420 ; Bab. 413. 
* Frond deltoid. (No ascertained British species). 
(Athyrium deltoideum. 
Aspidium crenatum, Sommerf. in Vet. Ac. Handlung. 104. 
Cystopteris crenata, Fries, Nov. FI. Suec. 165 ; Hook. Sp. 
Fil. i. 200. 
Stipes as long as the frond, pretty thickly clothed to- 
wards the base with dark brown lanceolate scales; frond 
deltoid, resembling that of Eupteris aquilina, hut of small- 
er size, pinnate ; pin me stipitate, lanceolate, pinnate ; hi 
the first pair of pinnae the pinnules on the lower are longer 
than those on the upper side ; pinnules pinnate, their lobes 
distant, but united at the base by the winged midrib of the 
pinnule, blunt, slightly lohed on the upper margin ; clus- 
ters of capsules confined to the upper portion of the frond, 
rather scattered in an oblique series on each side of the 
midrib, and rather near it ; involucre nearly linear, at- 
tached to the side of the capsuliferous vein, and opening 
towards the midrib, its free margin ragged. 
North of Europe, in thick woods. Found by Mr. R. B. 
Bowman, in the Pass of Ivringelen, in Norway. 
Obs. — There exist a Polypodium crenatum, an Aspidium crenatum, 
and an Athyrium Filix-femina, var. crenatum ; under these circum- 
stances, a change of name will, I hope, be allowed. The plant is here 
