128 
Psyche 
[June 
All deposited eggs were brought down to Kuching by the 
returning collectors, but for some unaccountable reason, not a 
single one hatched. Evidently the sudden change in altitude 
and temperature between the cold mountains and the hot low- 
land must be responsible for their failure to hatch. 
As already stated females of the smaller and more narrow 
type of “trilobite-larva” had also been exposed, but no males 
were ever found. The females deposited about 100 eggs each. 
In spite of the female of this type being much smaller than the 
first one its eggs, as seen on Plate IV fig 2, are curiously enough 
twice as large. 
Thus nearly two years of more or less continuous field work 
had resulted in rearing three species of “trilobite-larvae” to egg- 
producing adult females and in the capturing of several males of 
the second largest species. 
All my attempts to rear the very common, flat, leaf-like 
lowland species figured in Plate III Fig. 5, had been a failure. 
Although the larvae were kept by me in hundreds in cages not a 
single one turned into a female. When attaining their maximum 
of size they were all attacked by a whitish mould which killed 
them in great numbers. 
The only way to rear this species seems to be to build big 
cages in the forest and to keep some hundred of the largest 
ones in captivity under conditions as natural as possible until 
the females develop like the other species. The larvae feed on 
decaying old wood. This type of larva is extremely abundant 
and it would be more interesting to get its male which, for 
reasons given below, probably represents a new genus. 
IV. Neoteinic Females. 
A closer examination of the “trilobite-larvae” from Borneo 
thus reveals the interesting fact, that the “trilobite-larvae” so 
commonly met with are the female-larvae of Lycid beetles of 
various genera and that the females undergo, practically speak- 
ing, no metamorphoses at all. They attain sexual maturity as 
complete larvae and differ in their organization only by possessing 
developed ovaries and a sexual duct and opening. They are 
