S8 DAVALLIOID FERNS [CH. 



(iii) NeJ>/iro/£'ps {Schott., iST)4) ... ... 17 species. 



Leaves once pinnate, with continued apical growth. Venation 

 free. Sori marginal or variously intra-marginal: marginal 

 coenosori in some species: where intra-marginal the inner 

 indusium kidney-shaped, with free margins. 



II. Individuality of the sori retained: position intra-marginal. 

 Inner indusium partially or completely abortive. 



(iv) yir///r^//^;7i- (J. Smith, 1854) ... ... 4 species. 



Dermal scales and habit as in Hiimata, of which it may be 

 held as an ex-indusiate type. 



III. Distinguished by relatively condensed leaf-structure, culminat- 

 ing in simple blades. Dermal scales. Venation mostly open, 

 but reticulate in'the most condensed types. Sori marginal, 

 fused in varying degree to form coenosori. 



(v) Tapeinidium (Presl, 1849) C. Chr. 1906 ... 4 species. 



Leaves simply pinnate. Sori slightly intra-marginal, often 

 fused. 



(vi) Z?zV//z'(^ (Brackenridge, 1854) ... ... 7 species. 



Leaves simply or repeatedly pinnate. Occasional fusion of sori. 



(vii) 0<3'<7;//(7J-^rm (Presl, 1836) Fee, 1850 ... 19 species. 



Leaves repeatedly pinnate. Sori variously fused. 



(viji) Lindsaya (Dryander, 1793) (reduced) ... 90 species. 



Leaves variously pinnate, or even simple: pinnae unilateral, 

 veins free or sometimes anastomosing. Sori marginal or sub- 

 marginal, variously fused. 



(ix) DictyoxipJiiiii>i (Hooker, 1840) ... ... i species. 



Leaves simple, venation reticulate. Coenosorus marginal, 

 continuous, but with upper indusium obsolete. 



Genus incertae sedis. 



Oleandra {Q^.va.x\\\\q'&, 1799) ... ... 10 species. 



For a discussion of the affinity of Deparia, Cystopteris and Prosaptia, 

 see Chapter XLViii. 



The grouping given above must not be taken as any detailed exposition 

 of the phyletic relationships of the Davallieae. It is based upon the recog- 

 nition of methods of evolutionary advance, any one of which may be carried 

 out homoplastically in a plurality of phyla. For instance, Section III includes 

 genera which have in common a probable condensation of leaf-structure from 

 some more complicated primitive branching. This may naturally bring with 



