CLVI. FILICES. 1931 



Tribe IV. XymenopliylleeB.— Spore-cases depressed, teith a transverse ring, sessile or 

 nearly so on a cohimnar receptacle ivithin a cup-sfmped er 2-lobed indusium, embedded in or 

 protruding from the margin of the frond. Fronds of a thin membranous half-pellucid texture. 



Indusium cup-sbaped or tubular, with an entire or shortly 2-lobed 



margin Receptacle often exserted 12. Teichomanes. 



Indusium divided to below the middle into 2 valves. Eeceptacle usually 



included .13. Hymenophylldm. 



Tribe V. Cyatheeae.— Tress. Fronds large, comiwund. Spm-e-cases small, with a 

 more or less oblique ring, sessile an a slightly raised receptacle, in globular sori on the under 

 surface of the fronds. 



Indusium at first globular enclosing the sorus, at length cup-shaped 



under it 14. Cyathea. 



No indusium ..:....... . . 15. Alsophila. 



Tbibe VI. Polypodlese. — Habit various. Spore-cases small, with a longitudinal or 

 scarcely oblique ring, numerous and stipitate in sori or patches on the urider-side .oi rarely the 

 margins of the frond. 



A. Sort covered at least when young %oith an indusium. 



Sori globular or slightly . oblong. Ini3.u3ium cup-shaped or globular 

 and 2-valved. 

 Sori close to the niargin. Indusium adnate on the uppet side, opening 



in 2 valves or leaving a complete ring . ... 16. Dicksonia. 



Sori close to or near the margin. Indusium adnate at the base only 

 or along the sides forming with the frond a complete cup . . . . I7. Davallia. 

 Sori linear, marginal. Indusium linear, openini; from the margin 



Inwards. ' ' •,.■■','■■ ^ 



Frond simple, linear.' Indusium of the texture of the frond, the sorns i . ■ i 

 apparently embedded in a double margiii ..... . . . 18. TiTiAliiAi 



Frond pinnate or bipinnate. Indusium membranous . . ... . .,19. LiNDs.a:A. 



Sori marginal. Indusium continuous with the margin and opening , 



from the under edge outwards. 

 Fronds pinnate or compound. Veins of the pinnules forked or 



dichotomons, radiating from the petiole . 20. Adiantum. 



Fronds compound. Pinnules penninerved Sori short. Indusium 



a small scale recurved over them r • ■ 21. Hypolepis. 



Fronds compound, with sniall lobed segments. Sori short or globular. 



Indusiuni the slightly altered margins of the loljes curved over them 22. Cheilanthes. 

 Fronds various. Sori and indusia linear, usually long and continuous 23. Pteris. 

 Sori in a continuous line along the midrib. 

 Sori on both sides of the midrib, the indusium opening froni the 

 nflidrib outwards. , 

 Soi'i at length covering the under surface of the fertile fronds . 24. Lomabia. 



Sori at length confluent over the midrib but distant from the 



niargin .25. BLECHNnm. 



Sori in h single line along the midrib, in a groove of which the • • 

 edges form the indusium. Frond small,, single ...... 26. Monogbamme. 



Sori and jndij^ia oblong; or shortly linear, parallel to the midrib, on 



veinlets connecting'ihe forked veins ...,,.. 27. Doodia. 



Sori and indusia oblbiig or linear, on veins diverging from the midrib . 28. Asplenium. 

 Sori orbicular, usually small, as in Potypoditim, biit with an indusium. 

 Indusium attached within the sorus, peltate or orbioular-reniform . 29. Aspieium. 



B. No'indvsimn. 



Sori orbicular,' usually small, variously arranged on the under surface . 30. Polypodium. 

 Sori marginal as in Vhielanthes but the margin undltered inconsistence 



though often curved over the young sorus ....... . . 31. Nothol.ena. 



Sori linear or oblong, on veins diverging from the midrib, sometimes 



crowded in an intramarginal line . 32. Gbammatis; 



Sori oblong or linear or sometimes orbicular and geminate, arising from 



the transverse connivent veinlets ...... . . . , . . , 33. Meniscium. 



Sori long, linear, on the longitudinal anastomosing veins of a siinple 



frond '.,... ■ . . • • 34. Anteophyum. 



Sori confluent, at length completely covering the under surface of the 



fertile fronds or pinnules . .35. Acbostichcm. 



Spore-cases innumerable in large patches at the ends of the lobes or at 



the first, Sinus of the fertile fronds 36. Platyoerium. 



