102 
BRITISH FERNS. 
3. A. Rut a-mur aria. Fronds bipinnate; pinnules wedge- 
shaped at the base,, lobed ; involucre jagged. 
4. A . viride. Fronds linear, pinnate; rachis green. 
5. A. Trichomanes. Fronds linear, pinnate; rachis 
black. 
a. var. incisum . Pinnse larger, deeply cut and 
serrated. 
6. A . marinum . Fronds pinnate ; rachis winged. 
7. A . lanceolatwn . Fronds bipinnate, lanceolate ; rachis 
not winged. 
8. A. Adiantum-nigrum . Frond bipinnate or tripinnate, 
triangular ; involucres firm. • 
a . var. obtusum . Fronds short, blunted. 
&. var. acutum . Fronds long, outspread, tapering. 
9. .4. fontanum. Fronds bipinnate, narrow-lanceolate ; 
rachis winged. 
10. ^4. Filix-fcemina . Fronds bipinnate, lanceolate; 
pinnae lanceolate, pointed ; pinnules flat, linear- 
oblong. 
var. multifidwrn. Pinnae divided at the ends. 
b . var. crispum. Fronds curled and puckered in 
every part. 
c. var. incisum . Fronds feathery ; pinnules very 
deeply cut. 
d. var. convexum. Pinnules narrow, distinct, 
linear, convex. 
e. var. latifolium. Pinnules broadly ovate, crowded, 
irregularly lobed. 
/. var. mode. Fronds smaller; tapering leaflets 
oblong, winged. 
g\ var. marinum . Fronds small, horizontal, ele- 
gantly tapering; leaflets oblong, bluntly 
toothed. 
