ZXXvi. GENEBA OP PEBKB : 



Fronds simple, coriaoeo-membranaoeous, the fertile narrower. 

 Rhizome short, thick, erect. — This genus, though distinct in 

 aspect, presents no technical difference of generic value to dis- 

 tinguish it from Jjindscea, except the compound reticulation, and 

 free included branches of its veins, are admitted to be differences 

 thus important. Hence we regard the fact of such a genus being 

 proposed, and admitted, as entirely sanctioning the derivation of 

 generic characters from the venation of ferns. 



Ex, : D. panamense, Sook, 



§ Adixstem. 

 (a) Vemsfree. 

 42. ADIANTTJM. Unnaus, Gen. PI. 782. 



ADIAlf TELLUM, Pres^; APOTOMIA, P^e ; SxiraOHIA Mei MES07LBT7BXA, 



Moore MS. ; Scolofendbii sp,, Adanson ; Fiebidis Bp., Auct. 



Sort indusiate, transverse marginal, reniform oblong or 

 linear, continuous or interrupted ; the receptacles seated on the 

 under surface of the indusium, and proceeding from the apices 

 of two or more converging venules. Indasium (inverted mem- 

 branaceous marginal lobe) venulose, sporangiferous beneath on 

 the venules ; the receptacles, therefore, resupinate. Vems flabel- 

 lately forked, or forked from a medial costa, the furcations 

 repeated; venules parallel, free, continued in the fertile parts 

 into the indusium. 



Fronds coriaceous or herbaceous, simple, pinnately or pedately 



divided, or supradecompound ; pinnce often articulated, usually 



dimidiate with the costa wanting. Stipes and rachis ebeneous. 



Rhizome tufted, or short creeping. — A perfectly natural genus. 



§ Mesopleima. — Costa medial ; Bori linear, elongate, continuous. 



Ex, : A, "Wilsoni, Sooh. I A. obliquum, Willd. 



A, Phyllitidis, J, Sm. \ A. luoidum, Sw. 



§ Synechia. — Costa wanting ; sori elongp.te, continuous, 

 Ex. : A. incisum, Fr. I A. villosum, Lm. 



A, pulrerulentmn, Xi«. | A. varium, M. B. K, 



§ Adiamiellwm. — Costa wanting; Bori round or oblong. 



Ex. : A, reniforme, lAn. I A. Capillus-veneris, lAn. 



A. lunulatam, Bv/rm. A. trapeziforme, lA/a. 



A. prionopliyllum, M. B. K. \ A. concinnum, H. B. Z, 



