Yapp . — Two Malayan ‘ Myrmecophilozts ' Ferns 223 
recognized by some of the older botanists, seem to indicate 
that a close relationship exists between the two Ferns. It 
may be pointed out, moreover, that certain other species, 
which are also ant-inhabited epiphytes of the Malayan region, 
are apparently, so far as their external features are concerned, 
actually intermediate between our two forms ; e. g. P. loma- 
rioides , Kze., and P. sarcopus , De Vriese et Teysm., possess 
the peltate scales of P. sinuosum but have pinnate fronds, 
whilst the habit of P. sarcopus and P. carnosum is almost 
precisely similar 1 . 
In fact, when the structure of these additional forms is 
more fully known, it may perhaps be possible to place them 
all (including Lecanopteris ) into a single natural group, which 
might either stand as a section of the genus Polypodium, or as 
a subdivision of the section Phymatodes . To this group the 
name ‘ Myrmecophila', adopted by Christ 2 in a rather more 
limited sense, might not inappropriately be applied. 
Some such arrangement as the following may perhaps be 
found convenient : — 
Myrmecophila. Epiphytic Ferns whose fleshy creeping 
rhizomes are traversed by a regularly arranged system of 
galleries, which are inhabited by ants. Leaves borne on 
prominent, more or less conical leaf-cushions. 
a. Rhizome covered with peltate scales. Sori sunken, but 
not borne on marginal lobes. This sub-group (which 
forms the Myrmecophila of Christ 3 * ) would contain such 
forms as P. sinuosum , P. lomarioides and P. sarcopus. 
(3. Rhizome without peltate scales. Sori sunken, and borne 
on marginal lobes, which are either reflexed upon the 
upper surface of the leaf, or twisted to one side, so that 
the sorus faces the apex of the frond. 
This would include P. carnosum and the other species of 
Blume’s genus Lecanopteris. 
1 Christ 0 9 8), p. 160, and PL XVI, Fig. 2 5^. 2 Christ (’97), p. 112. 
3 Christ includes P. imbrication , Karsten, in this group : but this differs from 
the other species in possessing black scale-hairs, and apparently also in the 
structure of the stem [Karsten (’95), p. 168]. 
