155 207 



10. Leaf thinner, dark-green; costæ and coslules 

 not stramineous. Pinnæ in very distant, op- 

 posite pairs, the basal ones reflexed. 



252. D. Fraseri (Metl.) O. Ktze. 

 B. Basal pair of veins normally united ; in most species the 

 next 2—3 pairs of veins are connivent to sinus and 

 often alternately anastomosing into a flexuose common- 

 branch, which runs to sinus. 



7. Pinnæ entire, serrulate or lobed but never cut '/:i 

 to the costa. Basal veins upcurved and anastomosing 

 under acute angles, the following pair as a rule also 

 anastomosing. 



8. Leaf praclicallv glabrous; in some species the 

 rachis and costæ beneath are minutely pube- 

 rulous. Sporangia glabrous, or (in I), obliterata) 

 deciduouslv setose. 

 9. Both surfaces densely warted. Pinnæ 2—4 to 



^ j.j(je 258. D. juruensis n. sp. 



9. Surfaces not warted. Several pairs of pinnæ. 

 10. Pinnæ entire or very shallowly serru- 

 late. Basal veins spring out from the 

 costule 1 mm above the costa. 



255. D. vivipara (Raddi) C. Chr. 

 10. Pinnæ broadly serrate or lobed ' i or a 



little more. Basal veins spring out from 

 the base of the costule or the posterior 

 one from the costa. 



11. Only the lowermost pair of veins ana- 

 stomosing, or all free. Rachis gemmi- 

 ferous. 



12. Veins 4— B jugate, the two basal 

 one as a rule not united and not 

 reaching the sinus. 



256. D.slraminea (Bak.l C. Chr. 

 12. Veins 8—9 jugate, those of the 



basal pair united 257. U. CöhUi n. sp. 



11. At least 2 pairs of anastomosing veins. 

 Rachis rarely gemmiferous. 

 12. Terminal pinna small, often abort- 

 ive. Pinnæ few, wrinkled, 5—8 

 cm long. Veins 4— 5-jugate. 



260. D. nigrescentia (Jenm.) C. Chr. 

 13. Terminal pinna confluent 

 with the upper lateral ones. 



227. D. hastata (Fée) Urb. 

 13. Terminal pinna distinct. 



259. D. obliterata (Sw.) C. Chr. 

 8. Lamina rather densely pubescent throughout 



beneath. Sporangia densely setose. 261. D. Rolandii n. sp. 

 7. Pinnæ incised to the middle or deeper. Only the 

 basal pair of veins anastomosing under broad angles. 

 8. Costæ beneath puberulous by stellate hairs. 



240. D. eijiiitans (Christ) C. Chr. 



27* 



