XKVI COMPEBBIUM. 



Tribe IV. Pterideae. Sori roundish, oblong or linear, if 

 roiindish or longitudinally elongated then solitary and 

 terminal on the veins, but not rarely laterally confluent 

 into a subniarginal line, if transversally oblong or linear 

 then uniting the apices of several veinlels. Indusium ± 



the shape of the sorus, marginal, i.e. consisting of the re- 

 flexed, modified margin of the frond, opening invf ardly. 



GENUS 57. ADIANTUM. Differs from the following 

 genera by the indusium bearing the capsules on 

 its inner surface. 



GENUS 38. HYPOLEPIS. Sori roundish, distant, con- 

 fined to the tops_(angles) of the ultimate sinuses, 

 1 to each sinus. Indusium roundish, small, hardly 

 covering the sorus at full maturity. 



GENUS 39. CHEILANTHES. Sori roundish or oblong, 

 solitary and terminal on the veins, soon confluent 

 into a submarginal line. Indusium roundish, trans- 

 versally oblong or linear. Vein tips thickened. 

 Stipes not as in genus 40. Fronds uniform. 



GENUS 40. PLAGI06YRIA Sori as in genus 39. 

 Indusium linear. Vein tips not or hardly thickened. 

 Stipes abruptly thickened at the base and gene- 

 rally purveyed there with ± 2 — 12 spongy 

 glands or tubercles on the outer side. Fronds 

 dimorphous, the fertile segments contracted, nar- 

 rowly linear. 



GENUS 41. PELLAEA. Sori linear, or round to oblong, 

 but then soon confluent into a submarginal line. 

 Ipdusium linear. Fronds divided, the leaflets ± 

 stalked, articulate j^atUhe base. 



GENUS 42a. DORYOPTERIS. Sori and indusia as in 



