THE BRITISH FERNS. 
namely, the hippocrepiform sori, and as its short sori, which might 
appear to connect it with $ Allantodia, have not the vaulted indusia 
of that group, we leave it among the short-fruited Euaspleniums. 
The generic name is a latinized form of the Greek asplenon, 
which signifies Spleenwort, and comes from a, privative, and splen, 
the spleen. The English name Spleenwort is generally adopted. 

SYNOPSIS OF THE SPECIES. 
$ Euasplenium.—Sori oblong or linear ; veins simple or Jorked, 
and divergent at an obtusish angle from a central costa. 
* Fronds bi-tri-pinnate, rarely sub-bipinnate. 
+ Fronds lanceolate ; sori short, 4. e. oblong. 
1. A. fontanum : fronds small (3-8 in.) narrow, linear-lanceolate, bipinnate ; 
rachis smooth, narrowly winged. 
2. A, lanceolatum: fronds larger (6-18 in.) broader lanceolate, bipinnate ; 
rachis minutely scaly, margined in front, not winged. 
var. microdon: fronds linear, scarcely lanceolate, pinne sub-pinnate 
or lobed only at the base, the pinnules mostly confluent, wavy. 
++ Fronds ovate or deltoid ; sori linear elongate. 
3. A. Adiantum-nigrum: fronds bi-tri-pinnate ; segments oblong-wedge-shaped 
or sub-trapezoid, shallowly lobed or toothed, teeth acute; fronds and 
pinne acute or acuminate. 
var. acutum: fronds tripinnate ; segments narrow-lanceolate, inciso- 
pinnatifid, the lobes linear erect acute ; fronds and pinne caudate. 
var. obtusatum: fronds bipinnate ; pinne bluntish ; pinnules ovate, their 
blunt apices toothed. 
« 
var. microdon: fronds sub-bipinnate, pyramidal or elongate-deltoid ; lower 
pinne hastate, stalked, the rest sub-hastate more or less con- 
fluent; the upper ones confluent; sori often scolopendrioid. 
** Fronds pinnate, (sub-bipinnate in A. marinum, v. sub-bipinnatum). 
+ Rachis winged. 
4, A. marinum: fronds coriaceous, pinnate; pinne oblong, truncate-auricled 
at the upper, cuneate at the lower base, obtuse, crenated or toothed. 
var, trapeziforme: pinn® shorter, less auricled, trapeziform, crenately 
toothed, the lower ones deflexed. 
. incisum: pinne small, blunt, unequally inciso-pinnatifid, the lobes 
obscurely crenate. 
. ramosum: pinn® obliquely ovate or triangular, the margin lobate ; 
stipites usually two-branched, or united in pairs at or near the base. 
r. acutum: pinne elongate linear-oblong, truncate-auricled, tapered to an 
acute point, crenate. 

