SPECIES AND VARIETIES OP BRITISH PERNS. 63 
POLYPODIACEiE § PTERIDEjE. 
Genus 11. PTERIS, Linnaeus. 
1. P. aquilina, Linnams. —The only British species. Plate 
XVII. fig. 1. 
POLYPODIACEiE § AdIANTE^I. 
Genus 12. ADIANTUM, Linnaeus. 
1. A. Capillus-Veneris, Linnaeus. —The only British spe¬ 
cies. Plate XVI. fig. 1. 
i POLYPODIACEiE § CYSTOPTERIDE^. 
Genus 13. CYSTOPTERIS, Bernhardi . 
1. C. fragilis, Bernhardi. —Fronds lanceolate, bipinnate, 
pinnules ovate, acute, toothed or lobed; sori central. 
Plate X. fig. 1. 
mr. angustata.—Pinnules ovate, deeply pinnatifid, the 
lobes with narrow acute teeth ; sori central. 
mr. dentata.—Pinnules ovate, obtuse, bluntly-toothed, 
distinct; sori marginal. 
mr. Dickieana.—Pinnules broad, obtuse, slightly blunt¬ 
toothed, overlapping; sori marginal. 
2. C. regia, Brest. —Fronds lanceolate, subtripinnate, seg¬ 
ments linear, Plate X. fio*. 2. 
