Sori forming chainlike rows parallel to the 
* midrib or central vein of the pinnules. 
Leaves uniform, pinnate- pinna tif id. 
12. Anchistka. 
Leaves of two kinds, fertile leaves pinnate 
pinnae linear ; sterile leaves deeply pin- 
natifid. 13. Lokinseiua. 
Sori linear or oblong, along the veins orscat- 
tered. 
Leaves various, veins free. 
Sori straight. 14. Aspt.knium. 
Sori sometimes curved ; leaves 2-pinna- 
tifid to 2- pinnate. 15. Athyhium. 
Leaves simple, veins united ; sori scattered. 
16. Camptosorus. 
Sori orbicular. 
Indusia superior; plants robust. 
Indusium peltate ; leaves pinnate. 
17. Polys ricHUM. 
Indusium reniform ; leaves 2-3-pinnate. 
18., Dryoptekis. 
Indusium partly superior ; leaves 2- 3- 
pinnate ; plants delicate. 19. Filix. 
Indusium inferior ; leaves 2 - pinnate, 
glandular pubescent : pinnae distant, 
divaricate. 20. Woodsia. 
Indusium cupshaped ; leaves 3 - pinna- 
tifid. 21. Dennstaedtia. 
Leaves of two kinds ; sporophylls 3-7 dm. high, 
pinnate, segments closely rolled together. 
Sterile leaves 2- pinnatifid, 6- 20 dm. high. 
22. Mateuccia. 
Sterile leaves triangular, pinnatifid. 
23. Oxocr.EA. 
7 
