CL. XXIV.] CRYPTOGAMIA FERNS. 389 



rib and margins ; stalk scaly at the base. Fronds two feet high, 



erect, narrow below, yellowish-green, with longish stalks. Pe- 

 rennial : bears fruit in August : grows on boggy heaths in England : 

 rare. Eng. Bot. vol. xxx. pi. 2125. Eng. Fl. vol. iv. p. 289. 1474. 



6. A. aculedtum. Common Prickly Shield-fern. Frond twice pin- 

 nate ; leaflets egg-shaped, pointed, stalked, somewhat crescent- 

 shaped, fringed with prickly serratures ; stalk and central ribs scaly. 

 Fronds about two fee't high, lance -shaped, dark-green. Pe- 

 rennial : bears fruit in July : grows in woods and shady places : 

 common. Eng. Bot. vol. xxii. pi. 1562. Eng. Fl. vol. iv. p. 290. 1475. 



7. A.anguldre. Angular-leaved Shield-fern. Frond twice pinnate ; 

 leaflets egg-shaped, bluntish, stalked, fringed with bristly serra- 

 tures, each leaflet with a lateral lobe at the base, the lowermost 



elongated ; stalks and ribs scaly. Perennial : bears fruit in July : 



grows in woods and shady places. Eng. Fl. vol. iv. p. 291. 1476. 



8. A. lobdtum. Close-leaved Prickly Shield-fern. Frond twice 

 pinnate ; leaflets elliptical, pointed, decurrent, somewhat serrate ; 



stalk and shaft scaly. Perennial : bears fruit in July : grows 



on shady hedge-banks : common. Eng. Bot. vol. xxii. pi. 1563. 

 Eng. Fl.\o\. iv. p. 291. 1477. 



9. A. spinutisum. Prickly -toothed Shield-fern. Frond somewhat 

 triangular, smooth, twice pinnate ; leaflets decurrent, elliptical, 

 deeply serrate, with prickly teeth, their central rib undulated; 



stalk elongated, scaly at the base. Fronds about a foot high, 



smooth, light-green. Perennial : bears fruit in June and July : 

 grows in marshy places : found by Withering on Birmingham 

 heath, and in Devonshire. Eng. Bot. vol. xxi. pi. 1460. Eng. Fl. 

 vol. iv. p. 292. A variety with the lower primary leaflets, twice 

 pinnate, and not pinnate, is the A. dilatdtum, Broad Sharp-toothed 

 Shield-fern. Eng. Bot. vol.xxi.pl. 1461. .%. J7.vol.iv.p.293. 1478. 



10. A.f'dix-f&mina. Female Shield-fern. Frond twice pinnate ; 

 leaflets between oblong and linear, pinnatifid, serrate, pointless ; 

 stalk smooth ; sori oblong. Fronds about two feet high, lance- 

 shaped, deep-green. Perennial : bears fruit in June and July : 

 grows in moist shady places: common. Eng. Bot. vol. xxi. pi. 

 1459. Eng. Fl. vol. iv. p. 295. A small variety has been described 

 as distinct, under the name of A. irrigium, Brook Shield-fern. Eng. 

 Bot. pi. 2199. Eng. Fl. vol. iv. p. 296. 1479. 



CYSTE'A, BLADDER- FERN. 



Sori round, convex, variously scattered over the back of the 

 frond, between the central rib of each leaflet or lobe and the 

 margin. Cover white, round, concave, fixed by a narrow 

 point at the side of each sorus beneath. ^Capsules several, glo- 

 bular, on short stalks, each one-celled, two-valved, bound by 

 a jointed ring. Seeds numerous, roundish, very minute. 

 Name from ciste, a little box. 464. 



1. C. frdgilis. Brittle Bladder-fern. Frond between oblong 

 and lance-shaped, twice pinnate ; leaflets egg-shaped, pinnatifid, 

 the lobes toothed or serrate ; partial stalks bordered ; sori crowded. 

 Fronds from four to ten inches high, smooth, bright- green ; 



