XIV 
herbaceous (Ad. lunulatum, Nephr. dissectum) sub- 
coriaceous (Nephr. splendens and syrmaticum). 
20. Scales are of various shapes, peltate or shield- 
shape, ovate-lane, linear , &c. ; and are adpressed or closely 
adherent, deciduous or easily detached and falling off 
ferruginous, rusty-coloured ; and vary through shades of 
brown to black. They are usually found on stems, but 
may extend to under-rachis, and are largest at base of 
stem. In describing these, basal scales should first be 
noted. 
Having so far gained a general idea of these diffe- 
rent parts, the following description of a few common 
species should be compared, step by step, with living spe- 
cimens : — 
P(olypodium) (Phym.) membranaceum, Don ; rhiz- 
(ome) stout, scales ovate, spreading, membranous, lurid 
green ; stem 1 — 4 in. l.(ong), firm, erect ; fr.(ond), 1 — 3 
ft. 1., 2 — G in. broad, edge entire or repand, both ends nar- 
rowed gradually ; text, very thin, membranous ; main 
veins distinct with very copious fine areolae with free vein- 
lets between them ; sori mostly in 2 rather irreg. rows 
near main veins. 
A.(splenium) alternans Wall.(ich) ; st. tufted 2 — 4 
in. 1., clothed with linear scales ;fr. G — 8 in. 1. 1 — 1^ in. 
hr. lane, obl.(ong), cut down into numerous bluntly 
rounded lobes on each side, which reach very nearly down 
to rachis, the lower gradually growing smaller and some- 
