588 Transactions. 
(b.) Н. ferrugineum and Т. venosum. (Plates 66, 76, 72.) 
These two species form a very characteristic group, which also is confined 
to the lowlands. Along with Tmesipteris and Lycopodium Billardiert var. 
gracile they occur very commonly on the stems of tree-ferns, and more 
especially upon Dicksonia squarrosa. In the heavy forest of the lowlands 
these two species are rarely to be found on other than tree-fern stems, 
but at the foot of the ranges 7. venosum occasionally occurs also on the 
bases of large forest-trees. In deep narrow ravines in the same localities 
H. ferrugineum not infrequently may be found on dripping mossy rock- 
. walls, its fronds being here actually bathed in water to a far greater extent 
than most Hymenophyllaceae naturally seek. In such stations the fronds are 
apt to become very attenuated in form, some which were measured being 
14 ft. in length and only from iin. to lin. in width. These two species 
are always low epiphytes, and are evidently strongly hygrophilous. 
T. venosum is a small delicate species, and occurs in close mats, its fronds 
endulous and overlapping. Н. ferrugineum also occurs in more or less 
Н. rarum, and Н. atum are said to occur commonly in Tasmania 
on tree-fern stems (25), and in rather drier parts of New Zealand, also. 
the two latter species frequently adopt this station along with the two 
which usually occur there. It will be noted that all these tree-fern-loving 
Hymenophyllaceae possess a filiform stipe. 
. venosum probably affords an example of reduction. The margins 
of the frond-segments are irregularly sinuate in outline, and the veins give 
rise to secondary and tertiary veinlets which end in spurious venules. 
Individuals can occasionally be found in which the pinnae are further divided, 
bearing from two to four sori. 
(c.) Н. sanguinolentum, Н. multifidum, and H. villosum. (Plates 57, 69, 58, 59.) 
is absent from the coastal forest and is properly a mountain plant, while. _ 
on the other hand, H. sanguinolentum is abundant at sea-level but does not : 
