150 
Psyche 
[June 
possessing sexual organs, ovaries, duct and aperture; and pass 
through no marked pupal state. The full grown larva simply 
rolls up openly for some days as does the larva when casting its 
skin, sheds the larval skin and turns into an adult female with 
the same head, simple eyes and one clawed tarsi as the larva. 
The two females bred without any complications (which as 
stated before happened to No. 1) behaved in exactly the same 
way, kept still for some days and started to deposit eggs and to 
expose the sexual opening by turning upwards the tip of the 
abdomen and secreting from the sexual aperture a drop of clear 
liquid. 
The small group of Lycids which has developed in this 
queer direction, of which the larvse up to now have been known 
as “trilobite-larvse” is confined to the Oriental region. They 
belong undoubtedly to several genera and represent the most 
degraded forms known among the non-parasitic beetles. Judging 
from the abundance of the larvae in the field, their peculiar 
regressive development seems to be a successful specialization. 
They differ also from normal Lycids by being non-carnivorous, 
with their mouthparts very much reduced, enabling them only 
to suck the juice of decaying wood. Their larvae are further 
more non-gregarious and typical jungle insects, whereas most 
Lycids are gregarious and love sunny open places. 
The group apparently reaches its maximum of size and 
variety in Borneo. Up to now six distinct forms are known 
from there, but future investigations will undoubtedly show 
that the “trilobite-larvae” are richly represented in the central 
mountain chains of Borneo, a region which, however, still falls 
outside the beaten track. 
It has long been established that the Malacoderms have to 
be placed among the more primitive forms of beetles, This 
explains partly why the members of this group which is in many 
ways undifferentiated display great plasticity in various direc- 
tions. In all four families we find steps towards higher special- 
ization mostly in retrograde direction, this applying chiefly to 
the females. In the Drilids a kind of hypermetamorphosis is 
found. Some of the Lampyrids show prothetely {vide Williams, 
Psyche, Yol. XXI. No. 4, pp. 126-129). 
