SPEOIES AND VARIETIES OP BRITISH FERNS. 63 
POLTPODIACEiE § PTERIDEiE. 
Genus 11. PTERIS, Linnaeus. 
1. P. aquilina, Linnwus, — The only British species. Plate 
XVII. fig. 1. 
POLYPODIACEiE § AdIANTE.®. 
Genm 12. ADIANTUM, Linnaeus. 
1. A. Capillus-Veneris, Linnaeus. — The only British spe- 
cies. Plate XVI. fig. 1. 
POLYPODIACEJE § CySTOPTERIDE^. 
Genus 13. CYSTOPTERIS, Bernhardi. 
1. C. firagilis, 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. re^a, Pm^. — Fronds lanceolate, subtripinnate, seg- 
ments linear. Plate X. fig. 2. 
