2n6 154 



3. Veins all free or Ihe lower 1 — 3 pairs united and sending an 

 excurrenl vein towards the sinus; in some species the lowermost 

 pair (rarely the two lower pairs) is nieniscioid, i. e. the excurrent 

 branch being interrupted before reaching the next pair of ana- 

 stomosing veins. 



4. Indusium persistent. Lower veins connivent to sinus, rarely 

 truly united. Lower pinnæ mostly with a cuneate base 

 {D. bifonuata excepted). 

 5. Sori near the margin. 



6. Lamina coriaceous, glabrous; pinnæ scarcely incised '/.■!. 

 Indusium reniform, whitish, glabrous. 



251. 1). paucipinnata (Donn. Smith) Maxon. 

 K. Lamina thinly membranous, hairy on the ribs; pinnæ 

 incised about '/j. Indusia reniform, athyrioid or asple- 

 nioid in the same pinna oi- even segment. 



254. D.Schaffneri (Fée) C. Chr. 

 5. Sori medial. 



(i. Basal pinnæ not cuneate at base; fertile pinna- antl 



segments contracted 239. D. hiformald Ros. 



f). Basal pinnæ with a long cuneate, entire base; fertile 

 pinnæ and segments not contracted. 

 7. Indusium small, .setose. Veins 12—14. Andes. 



249. D.tristis (Kze.) O. Kl/.e. 

 7. Indusium large, nearly glabrous. Veins 9 — 11. South 



Brazil 253. Ü. ciineata n. sp. 



4. Indusium none or minute, rarely found. 



5. Under surface without minute stellate hairs on costulæ 

 and lea {'-tissue. 



(5. Lower 2 — 4 pairs of veins connivent to sinus, only oc- 

 casionally the lowermost pair is united. 

 7. Smaller plant; pinnæ 2—4 to each side, serrulate. 



densely warted on both surfaces 258. D.juruensis u. sp. 



7. Larger with about 10 pairs of pinnæ, not or incon- 

 spicuously warted, more deeply cut. 

 8. Lower pinnæ with a long cuneate, entire base, 

 incised about halfway down; 2 pairs of veins 

 connivent to sinus. Sori medial . . 249. D. tristis (Kze) O. Ktze. 

 <S. Lower pinnæ lobed to the very base, scarcely 

 incised to the middle; 3 — 4 pairs of veins con- 

 nivent to sinus. Sori inframedial or about medial. 

 9. Rachis upwards and costæ beneath densely 



tomentose; upperside strigose. 243. D. lugtibriforinis Eos. 

 9. Rachis and costæ beneaht glabrous or nearly so. 

 10. Leaf papyraceous, light-green; costæ and 

 costules prominent, stramineous. Lower 

 pinnæ not retlexed. 



11. Pinnæ 2 cm broad, crenate or slightly 

 lobed; veins 3 — 5 jugate. Rachis gem- 

 miferous, glabrous. 256. D. straminea {Bi\k.)C. Chr. 

 11. Pinnæ 3 cm broad, lobed halfway 

 down, veins 12 — 18 to a side. Rachis 

 minutely pubescent, not gemmiferous. 



250. Ü. nicaragiiensis (Fourn.) (>. Chr. 



