134 
MICROLEPIDOPTERA OF NEW GUINEA 
STENOMIDAE 
The view, adhered to by several authors, that the present group 
represents a subfamily of the Xyloryctidae appears to be erroneous. The 
male genital characters, in the first place, show considerable differences 
between these groups, which are especially obvious in the representatives 
of the Papuan fauna. 
Another point of difference between the Stenomidae and the Xylo- 
ryctidae is the entire absence of setae on the abdominal tergites in the 
former family, the presence of which is such a persisting characteristic in 
all the Indo-Malayan and the Papuan genera of the Xyloryctidae known 
to us. 
In our opinion the Stenomidae doubtlessly represent an independent 
group, natural and characteristic, comprising species of a moderate size, 
with a typical neuration of the hind wing, with vein 8 almost always 
sinuate, and with the upper edge of the cell curved upwards and approxi- 
mated towards, or connected with, 8 before the angle; veins 6 and 7 are 
usually stalked ; the scape of the antenna is always devoid of a pecten. In 
some of the Papuan species recorded below the under side of both the fore 
and the hind wing is covered with sparse fine hairs. 
Judging from the large number of closely related species in certain 
genera, e.g., in Stenoma, the family seems to be a relatively recent one, 
and the considerable specialisation of the male genitalia affirms this to 
some extent. It is very numerous in the New World, but is only scantily 
represented in the southern Asia. 
Most of the genera are separated on account of but slight differences 
of external structures, and are difficult of recognition. A thorough revision 
of the family based on the study of genital characters is urgently needed. 
The knowledge of these characters is very elementary at present, and 
their study will, without doubt, provide convincing data for proper 
separation of the genera. It will reveal, we are sure, that certain large 
genera — e.g., Stenoma counts over 700 species in the New World alone — 
consist of several groups, each deserving a generic rank. 
The Stenomidae of the New World are listed by Busck in the Lepidop- 
terorum Catalogues (part 67, 1935), but representatives of other countries 
are excluded from that list, without any mentioning of this tact by that 
author. 
The male genitalia of the Papuan species possess a very short tegumen 
with a broad base and a moderate uncus ending in a slender hook. Thesocii 
are absent. The gnathos forms a pending long hook. The basal parts of 
the valvae together with the vinculum form a large and robust ring, while 
the disc of the valva is reduced to relatively small appendages at the base 
of the tegumen, sometimes intricately folded and bristled. The costa is 
often armed with long crochets. The furca is shaped like a flattened rising 
