418 99. FiLiCES. 



10. ScoLOPENDRiuM. Clusters long, straight, 2 together. 

 Indusia of each pair opening towards each other. 



11. Cbtbrach. Lateral veins anastomosing, clusters attached 

 to their middle on the side next the midrib, except in the 

 lowest. Indusium (?) a narrow nearly erect membrane on 

 the back of the vein. Whole back of the frond covered 

 with chaify scales. 



[12. Gymnogramma. Clusters oblong or linear on both 

 branches of the forked vein, becoming confluent and cover- 

 ing the back of the frond. Indusium wanting.] 



Tr. IV. ADIANTE^. Capsules covered by a marginal or sub- 

 marginal elongated part of the frond, or by a separated por- 

 tion of the cuticle resembhng an indusium. 



13. Blechnum. Capsules in a continuous line parallel to 

 the midrib upon a longitudinal anastomosing part of the 

 transverse veins, covered by a continuous scarious indu- 

 sium. 



14. Ptbris. Capsules in a continuous marginal line covered 

 by a continuous indusium formed of the reflexed margin. 



15. Adiantum. Capsules marginal, oblong or roundish, 

 covered by distinct reflexed portions of the margin of the 

 frond. 



Suborder II. HYMENOPHYLLACE^. 



Capsules opening irregularly ; ring oblique, excentric, trans- 

 verse, complete ; receptacle terminating a vein at the margin of 

 the frond. 



Tr. V. HYMENOPHYLLE^. 



16. Trichomanes. Capsules on a long filiform receptacle 

 within a cupshaped involucre of the same texture with the 

 frond. 



17. Hymenophyllum. Capsules on a narrow subclavate 

 receptacle within a two-valved involucre of the same texture 

 with the frond. 



** Capsules without an elastic ring. 



Suborder III. OSMUNDACE^. 



Vernation circinate. Rachis woody. Capsules regularly 2- 

 valved, stalked, in clusters at the extremity of the frond. 



