on British Ferns. 
xxvn 
Genus. — Woodsia, II. Br. 
Mid-vein of ultimate divisions indistinct, lateral veins 
branched, free : involucre seated near the extremity of each 
branch, its base inclosing the base of the capsules, its mar- 
gin split into capillary segments, which mingle with the 
capsules. 
Woodsia Ilvensis. 
? Acrostichum Ilvense, Linn. Sp. PI. 1528. 
Acrostichum Ilvense, Huds. FI. Ang. 451 ; Bolt. Fil. Brit. 
14, t. 9. 
Polypodium arvonicum, With. Arr. 774. 
Woodsia Ilvensis, R. Br. Tr. Linn. Soc. xi. 173 ; Sm. E. F. 
iv. 322, E. B. S. 2616; Neiom. N. A. 13, F. 137; 
Hook, and Am. 567. 
Woodsia Ilvensis, Bab. 409, ad partem. 
Ehizoma tufted ; stipes sometimes as long as the frond, 
but generally shorter, distinctly articulated towards the 
base ; frond erect, lanceolate, pinnate ; pinnae oblong, sub- 
opposite, lobed or pinnatifid, scal} r . 
A very small and rare fern. Found on rocks in Caer- 
narvonshire by Mr. W. Wilson ; in Durham by Mr. Back- 
house ; in Forfarshire by Mr. Watson and Mr. Wilson. 
Woodsia alpina. 
Polypodium fontanum, Herb. Linn, certe. 
1776. Acrostichum Ilvense, With. Arr. 649. 
1790. Acrostichum alpinum, Bolt. Fil. Brit. 76, t. 42. 
1793. Acrostichum liyperboreum, Liljeblad, St. Tr. 201, t. 8. 
Woodsia liyperborea, R. Br. Tr. Linn. Soc. xi. 173; Sm. 
E. F. iv. 323, ? E. B. 2023 ; Hook, and Am. 567. 
Woodsia Ilvensis, Bah. 409, ad partem. 
Woodsia alpina, Neivm. N. A. 13, F. 143. 
Ehizoma tufted ; stipes shorter than the frond, articu- 
lated ; frond narrow, linear, pinnate ; pinnae distant, del- 
toid, blunt, lobed. 
A very small and rare fern. Found on rocks in Caer- 
narvonshire and Perthshire by Mr. W. W ilson. 
