HorrLowav.—Studies in the New Zealand Hymenophyllaceae. 589 
commonly with the two other members of this group in the tops of the 
rimu and other forest-trees, but not as a mid-epiphyte. 
On the lower parts of the ranges H. multifidum and Н. villosum occur 
commonly together both in the ies as high epiphytes, and on the spurs 
and valley-sides on the lower branches of the trees, H. sanguinolentum 
being here absent. At stil higher altitudes H. multifidum descends to 
the floor in moss, but H. villosum retains for the most part a low epiphytic 
station on the stunted trees. is difference in behaviour between the 
two species is found to hold also in other parts of New Zealand. When 
growing terrestrially H. multifidum adopts a very characteristic “ mountain 
form " (Plate 69), in which the segments of the small strictly deltoid frond 
are more or less inrolled and overlap one another, and the frond as a 
whole is decurved and lies close to the moss in which the plants are growing. 
The short segments on which the sori are borne then bend sharply upward, 
so that the sori stand erect although the frond is practically horizontal. 
This mountain form is very distinct, and is found wherever the species 
occurs on the ground at altitudes above 1,500 ft. Occasionally fronds on 
terrestrially-growing individuals of the mountain plant may be found inter- 
mediate in form between the pendulous epiphytic and the deltoid terrestrial 
form, but this seems to be always when the fronds are able to hang freely. 
This species, along with H. villosum, is found also at altitudes above the 
subalpine forest, H. multifidum in sheets on moss or damp rock-faces and 
in other specially favourable places, and H. villosum in close mats on rocks 
and boulders and in other extremely xerophytic situations, as well as epi- 
phytic on the shrubs. In sheltered gullies at lower altitudes the fronds 
of H. villosum, though generally deltoid in form and erect-growing, attain 
an extreme length of 6-9 in. and become pendulous, but in exposed situa- 
tions at higher altitudes they are exceedingly stunted and imbricated. 
which this species derives its name, is well developed, not only the rhizome 
and young fronds but also the mature fronds, which in more mesophytic 
