XXIV COMPENDnm. 



GENUS 24, LUERSSENIA. Indusium oblong, ± 3 X 

 as long as broad. Fronds simple, not articulate 

 to the rhizome; veins anastomosing copiously. 



GENUS 28. ASPIDIUM. Indusium round or reniform, 

 rarely nearly 2 X as long as broad. Fronds 

 simple or divided, not articulate to the rhizome; 

 veins anastomosing copiously ; included free veinlets 

 wanting or present, but then not as in genus 26, 

 if excurrent then solitary in the areolae. 



GENUS 26. CYRTOMIUM. Indusium round. Fronds 

 as in genus 25, but only simply pinnate: included 

 free veinlets excurrent, 2 — 3 to each areola. 



Tribe III. Davallieae. Sori roundish, oblong or linear, if 

 roundish or longitudinally elongated then solitary and 

 terminal on the veins (dorsal in genus 27), if transver- 

 sally oblong or linear then uniting the apices of 2 or 

 more veinlets. Indusium + of the same shape as and a 

 at the inner side of the sorus, opening outwardly. 



GENUS 27. CYSTOPTERIS. Sori roundish, dorsal on 

 the veins. 



GENUS 28. ODONTOSORIA. Sori roundish or trans- 

 versally oblong, terminal on the cuneate, ultimate 

 segments. 



GENUS 29. LINDSAYA. Sori roundish, transversally 

 oblong or linear, submarginal. Fronds divided; 

 leaflets dimidiate, i.e. the half on the lower side 

 of the midrib cut away. 



GENUS 30. SCHIZOLOMA. Sori transversally oblong 

 or linear, submarginal. Fronds simple or divided; 

 leaflets not dimidiate. 



GENUS 51a. SACCOLOMA. Sori roundish, submarginal, 

 immersed in conspicuously cucuUate lobes, covered 



