164 
MICROLEPIDOPTERA OP NEW GUINEA 
Choice of material 
To avoid inaccuracies as much as possible we shall limit our attention 
to the region of Central Dutch New Guinea, comprising the camps of the 
Expedition from the Idenburg River at 50 meters’ altitude up to the 
highest collecting stations at the foot of Mount Wilhelmina, and exclude 
from the following summary the records from Hollandia, from the environs 
of the Humboldt Bay, and from the Cyclops Mountains. The reasons for 
this procedure are first, that collecting in the last mentioned stations was 
more or less incidental, the material, consequently, being scanty. And 
second, because Humboldt Bay belongs to the coastal regions which form 
the thoroughfares for the dispersion of insects, where widely distributed 
and even circumtropical forms may be expected to occur; these are liabe 
to obscure the true character of the indigenous fauna. As for the Cyclops 
Mountains, these are rather remote, in their own isolation, from the region 
of the Central Mountains. 
This region which henceforward we shall indicate as „the Central 
Region” will have our special attention on the consideration that a 
collection of 580 species made there by the Expedition renders fairly 
workable material and allows of a few conclusions. 
In the following table are summarized the numbers of genera, species, 
and subspecies, arranged according to the families (Table I). 
In order to come to a better understanding of the fauna of the Central 
Region we must subject the material to further selection. 
Since of the 580 species collected in the region only twelve are known 
to occur also outside the Papuan region — as the region is circumscribed 
in the Introduction to this paper (part I, page 6) — a consideration of the 
distribution based on our knowledge ol the species is not possible , 
we are compelled to restrict our attention to the distribution of the 
genera. 
When we take into consideration the character of the genera collected, 
a further limitation appears to be necessary. 
The fauna of the Central Region is represented in the collection by 
196 genera, 112 of which are apodemic and 84 are endemic. The relation- 
ships of the endemic genera are often obscure; although superficial charac- 
ters point to certain correlations, it is our very fragmentary knowledge 
of the genital characters of many of the previously described genera — 
one of the most reliable criteria for the determination of those relationships 
which mostly prevents us from making definite statements in that 
respect. Our conclusions as to these correlations ol new ly described genera, 
as given in the systematic part of this paper — when ventured at all 
have often too tentative a nature to allow of their use for the present 
discussion. Therefore in this chapter we prefer to leave the category ol the 
endemic genera out of consideration, and to restrict ourselves to a review' 
of the apodemic genera. 
