Xivii. 



lines of spore-cases become confluent. Veins reduced to the 

 eosta, and the intramarginal receptacles parallel with it. 



Fronds crowded, simple, narrow, erect. Ehizome short, creep- 

 ing. This fern has been placed by its author near to 'Elechnwm. 

 The fructification, however, as indicated in the admirable figure 

 above quoted, does not appear to us to have any affinity with 

 Blechrwm. The spore-cases lie in two deep oblique furrows, one 

 on each side the costa and open towards it ; but the upper valve 

 of this furrow is thick and herbaceous and not of the nature of 

 an indusium. The furrows are rather analogous to what occurs 

 in VittarietB, only they are in a different position. The plant 

 appears to us to associate better with the JPleurogrammece. 



Ex. : D. angustissima, Brackenridge. 



(c) Veins simple, oblique, from a central costa. 



24. PLEUROGRAMMA, Blwrne, Fl. Jav. 69 () : Presl, 



Tent. Pter. 223. 



COCHMDII sp., Eaulfusg; MICBOPTEBIDIS sp., Desvaux: TSNITIDIS sp., 

 Kaulfuss; BLECHM sp., Wil Idenow ; GEAMMITIDIS sp., Auct.; MONO- 



GEAMMATIS Sp., Auct. 



Sori superficial, non-indusiate, more or less elongate near the 

 apex of the frond ; the receptacle contiguous to, or more or less 

 coalescent with the costa. Veins simple or forked from a central 

 costa, free. 



Fronds small, entire, linear, rarely ovoid. Ehizome creeping. 



Ex. : P. graminifolia, Pregl. \ P. linearis, Presl. 



P. pumila, Presl. \ P. linearifolia (Monogramma, Detv.J 



25. XIPHOPTEBIS, Kaulfuss, Serlin Jalvrl. der Ph. ; 



Id. Enum. Ml. 85. 



MICBOPTEBIDIS sp., Desvaux ; GBAMMITIBIS sp., Auct ; ACBOSTICHI sp., 

 Swartz ; ASPLBNII sp., Swartz ; GTMNOPTEBIDIS sp., Sernhardi ; POLX- 

 i-ODii sp., Mettenius. 



Sori superficial, non-indusiate, elongate on the dilated and 

 longitudinally plicate apex of the fronds; the receptacle co- 

 alescent with the costa. Veins simple from a central costa, free. 



