HorLoway.—Studies in the New Zealand Hymenophyllaceae. 585 
taxads being absent. The kawhaka descends also in some localities into 
the lowlands, where it forms a very characteristic feature. The last associa- 
tion to be noted is that in which the small-growing Dacrydium Colensoi 
(the silver or Westland pine), and to a less extent D. intermedium (the yellow- 
floor and fallen logs. The story next below the canopy is composed of the 
tops of the mixed assemblage of shrubby trees, several of which have com- 
paratively large leaves, whose horizontally-spreading branches are thickly 
covered with epiphytic ferns, while some of the latter, including several 
species of Hymenophyllum, along with epiphytic orchids and species of 
Astelia, spread up the trunks of the tallest trees, and flourish even in the 
prevailing thro 
distribution of the Hymenophyllaceae, the main differentiating factor in 
their regional distribution being that of altitude, another operating more 
locally being that of the particular forest subassociation present. 
III. THe DISTRIBUTION or THE SPECIES IN WESTLAND. 
It is, of course, apparent that the study of the forest flora of any 
particular district involves the close comparison of gullies with hillsides 
and ridges, and also the detailed observation of the epiphytic flora from 
the tree-bases to the canopy, as well as the more general conyparison of 
the lowland with the upland and subalpine floras. In studying the high epi- 
phytes in Westland I have been greatly assisted by the sawmilling which is at 
work in many different localities, being thereby able to examine thoroughly 
the tops of large numbers of newly felled trees throughout the district. 
Wind-felled trees also were examined at every opportunity. With respect 
to the Hymenophyllaceae in the forests of Jamaica, Forrest Shreve (26) 
has drawn attention to the facts regarding the relative occurrence of the 
species on the mountain-slopes and ridges and in the ravines. He there 
found (ibid., bottom of p. 189), with regard to both the Hymenophyllaceae 
and the epiphytes generally, that “the trees of the upper slopes have the 
same epiphytic flora that would be found in the upper two-thirds of the 
[height of the] trees of the ravines, while the trees of ridges and peaks have 
only those that are characteristic of the uppermost third, and the mid- 
height species are restricted in these habitats to the sides of prostrate trunks 
or fallen logs." I may state briefly that the present study bears out this 
statement in a general way with regard to the more widely ranging 
members of the New Zealand Hymenophyllaceae, but that since certain 
species are confined altogether to lower altitudes and others to higher, 
