826 Dr. G. Ogilvie on the Vascular 
Lastrea cristata. 
The petiole has two large lateral fasciculi, and three smaller 
intermediate, the latter running into one upwards ; all with dark 
sheaths. 
Lastrea Thelypteris. 
The petiole has two flattened and plaited fasciculi, somewhat 
resembling those of Athyrium Filia femina, but with dark sheaths. 
They unite above into one of a horseshoe section, as in Poly- 
podium alpestre. 
The rhizome is long, and creeps horizontally. The fasciculi 
of the vascular cylinder which lie towards the upper surface are 
thicker than those on the lower. The substance is of pale tissue, 
with a brown cuticular layer. 
Athyrium Filia foemina. 
The petiole tapers from a swelling near the base to its point 
of connexion with the rhizome; it has two fasciculi, without 
dark sheaths, which acquire the form of fluted bands, in the 
dilated portion of the petiole. 
The rhizome is indented as in Polystichum aculeatum, and is 
formed of pale but dense and thick-walled cells, with a cuticular 
layer of brown tissue. 
Athyrium fontanum. 
The petiole has two fasciculi running on into the midrib of 
the frond, without dark sheaths. 
The rhizome has no dark deposit in the parenchyma, but the 
scalariform vessels have a decided brown tint. 
Asplenium marinum. 
The petiole has a single central fasciculus, without a dark 
sheath. 
The rhizome is of pale tissue, except the cuticular layer. 
Asplenium Adiantum nigrum. 
Petiole and rhizome as in the last species, except that the 
former has two fasciculi at the base, which coalesce as they 
ascend towards the frond. 
Asplenium lanceolatum. 
The petiole has two (or sometimes three) fasciculi, uniting 
above, as in the last species, without dark sheaths, but with the 
vessels themselves and the cambium-layer of a brown colour, 
most decided at the base of the petiole, and disappearing up- 
wards. 
The rhizome is of pale tissue, as in the last species, except 
