distributed, in both temperate and tropical regions, vary- 
ing much in size and circumscription of the fronds, and in 
the position of the sori being terminal or lateral on the 
venules, which, although common to closely allied species, 
has however, been considered by many authors sufficient 
to characterise several genera, The most obvious differen- 
tial character of species consists in some having erect 
vernation and the others decumbent, which admits of their 
being arranged in groups as follows :— 
Group 1.—Vernation erect, acaulose or subarboroid 
(Desmopobium). 
* Fronds pinnate, pinne entire or pinnatifid. 
Sp. P. hastefolia (Sw.) (v v.) ; P. elongata ( Wall.) ; P. 
Walker (Hook.) (v v.); P. Sieberiana (Kawlf.) (v ei: 
P. appendiculata ( Wall.) ; P. auriculata ( Wall.) ; Bedd, F. 
Brit. Ind., pl. 203; P. erubescens (Wall.); Bedd. F. Brit. 
Ind., pl. 213; P. Tijucana (Radd.); P. Imrayana, J. Sm, 
(Nephrodium, Hook.); P. rotundata (Willd.); P. favo- 
punctata (Kaulf.); P. rude (Kze.); P. decussata, (Linn.) 
(v v.); P. caudata (Kaulf.) 
** Fronds bi-tripinnate, multifid. 
P. drepana (Sw.) (v v.); P. platyphyllum (Hook.); P. 
rufescens ( Wall.) (v v.); P.grande(Pr.); P.ampla(H.B. K.) 
(v v.); P.spectabilis ( Kauf.) (v v.) ; P.lachnopoda (J. Sm.) 
(v v.); P. macroptera (Kaulf.) (v v.); P. macrophylla 
(Hook.) ; P. molle (Rozb.) (Polypodium Dianee, Hook.) 
Group 2.—Vernation decumbent ( Catapodium). 
P. alpestris (Hoppe) (v v.); P. flexilis (Moore) (v v.) ; 
P. brunea ( Wall.) ; P. paludosa (Bl.) ; P. divergens ( Willd.) 
(v v.); P. effusa (Sw.) (v v.) ; P. trichodes (Reinw.) (v v.) ; — 
. P.rugulosa (Labill) (v v.); P. unidentata (Hook.) (v v.); — — 
.. P. ornata (Wall.). E 
CHARACTERS OF TRIBES AND GENERA, EU — 
