86 Transactions. 
tree-ferns are scanty. The leaves of all the Nothofagus species are small, 
and the canopy and lower story are more open than are those of the 
heavier mixed-taxad forest. Thus under similar climatic conditions it 
would appear that whereas the atmospheric humidity of the interior of 
the heavy mixed-taxad forest is more or less consistently high up to the 
mid-epiphytie station on the trees, the same high humidity is maintained 
only up to the low epiphytic station in pure southern-beech forest. 
is comparison may be even more strikingly made with regard to 
the southern-beech forests of the larger lowland valleys in the close 
vicinity of Reefton, which lie at an altitude of from 600 ft. to 700 ft. 
Tree-ferns, except for the low-growing Alsophila Colensoi, are noticeably 
absent. The forest-floor is very open, and, except for occasional Asplenium 
at altitudes of 1,200 ft. to 1,500 ft. Here there is a close undergrowth of 
shrubs and tree-ferns. In addition to the six species mentioned above, 
the lowland T. venosum and H. scabrum and the upland H. rufescens and 
T. Colensoi are to be found commonly in gullies in their usual stations, and 
H. ferrugineum is abundant on the dripping gully-walls, while H. flabellatum 
and H. bivalve occur everywhere on banks and bases of old trees. Although 
à forested mountain-side at these altitudes is usually wetter than the 
forests of the lowlands, on account of the prevalence of the mountain mists, 
yet at Reefton this difference in the humidity will be largely compensated 
for by the fact that fogs in the lowland valleys are a frequent and 
persistent climatie feature. The very scanty distribution of the Hymeno- 
phyllaceae in the southern-beech forests must be attributed mainly, if not 
altogether, to the more open character of this type of forest as compared 
with that of the mixed and of the pure taxad forests. 
Townson (31) has published a list of plants found by him in the 
Westport district, including fourteen species of Hymenophyllum and all 
of those of Trichomanes. It is to be noted that this list includes 
the two typically northern species T. elongatum and T. humile, both of 
which seem to be absent from Westland. From Townson's brief notes 
on some of the species it is evident that here the lowland species reach a 
higher altitude than in Westland, T. reniforme being said to occur up to 
3,000 ft., and H. ferrugineum and Н. Tunbridgense up to 2,000 ft. As will 
be seen below, in the neighbourhood of Nelson, and to a still greater 
