10 FEBNS OF THE LAKE COUNTRY 



Sori round or roundish, springing from 



the backs of the veins, having a special indusium : 



two genera Polysticlium, Lastrea. 

 ASPLENIE^E Sori oblong, or elongated, springing from 



the sides of the veins, having a special indusium : 



four genera Athyrium, Asplenium, Scolopendrium, 



Cetarach. 

 LOMARIEJE Sori forming longitudinal lines between 



the midrib and margins of the leaflets, or divisions, 



of the fronds, with a special indusium : one genus 



Blechnum. 

 PTERIDE.E Sori borne upon the frond-margins, which 



are changed, continuously or interruptedly, into 



special indusia : one genus Pteris. 

 * ADIANTEJE Sori in patches on the reflexed lobes of 



the frond-margins, which form indusia : one genus 



Adiantum. 

 CYSTOPTERLDE^: Sori with special oval indusia affixed 



behind and bent hood-like over them : one genus 



Cystopteris. 



PERANEME^; Sori roundish and springing from the 

 backs of the veins, with special involucriform or 



semi-involucriform indusia : one genus Woodsia. 



TRICHOMANINE^E fructification marginal, that 

 is, having the spore-cases on the edges of the frond; sori 

 produced around the ends of veins projecting from 

 the frond-margins, and surrounded by urn-shaped mem- 

 branes, expansions of the frond : two geneva * Tricho- 

 Hymenoplitjllum. 



* * See note at page 9. 



