400 CXLTII. FILTCES. 



nate sori, is not represented in South Africa, nor are any of the groups with 

 anastomosing venation. Some of the species vary remarkably in the 

 cutting of the frond. 



Tribe 8. Aspidie^. 



Sori globose or oblong, placed on the back of the segments 

 Avitli an involucre of tlie same shape covering them, of which 

 the edges are free nearly or quite all round. 



20. DIDYMOCHL^NA, Desv. 



Sori elliptical, terminal on the veinlets ; the involucre 

 cmarginate at the base, attached to the linear receptacle, free 

 all round the edge. — Pappe and Bawson, p. 15 ; Hook, and 

 Baker, Syn. Fil. p. 248. 



A single cosmopolitan tropical species, which extends into Natal. 



21. ASPIDIUM, Swartz (in part), E. Br. 



Sori subglobose. Involucre orbicular, fixed by the centre. 

 — Hook, and Baker, Si/n. Fil. p. 248. Polystichum and Cyr- 

 tomium, Pappe and Bawson, pp. 14, 15. 



5 Cape species, 4 belongmg to sect. Polystichum, with ample 2- or 3- 

 pinnate, coriaceous fronds and free venation ; and 1 to sect. Cyrtomium, 

 with simply pinnate fronds and veins uniting slightly towards the edge. 



22. NEPHRODIUM, Eich. 



Sori subglobose ; the involucre cordate-reniform, attached 

 by the sinus. — Hook, and Baker, Syn. Fil. p. 259. Lastrea 

 and Nephrodium, Pappe and Bawson, pp. 12 and 14. 



Texture of the frond herbaceous ; the pinnae pinnatifid or still more di- 

 vided, not jointed at the base. — 5 Cape species, belonging to sect. Lastrea, 

 which has the veins free ; and 2 to EunepJirocUum, in which the lower 

 veinlets of the contiguous regularly-pinnated groups join at their points. 



23. NEPHROLEPIS, Schott. 



Sori globose, on the apex of an upper branch of a vein, 

 generally near the edge of the frond. Involucre reniform or 

 suborbicular. Pinnae simple, articulated at the base, marked 

 on the upper surface with white, chalk-like dots. — Hook, and 

 Baker, Syn. Fil. p. 300. 



A single common cosmopolitan tropical species reaches Natal. 



24. OLEANDBA, Cavan. 



Sori globose, inserted in a row near the base or below the 

 centre of the compact, free veinlets. Pronds quite simple, 

 the rhizomes wide-trailing and stems jointed. — Pappe and 

 Bawson, p). 13; Hook, and Baker, Syn. Fil. j^- 302. 



1 tropical African species reaches Natal. 



