318 
Psyche 
[December 
Withycombe’s larvae all belong to the same species of Cro- 
cine Nemopterid, which should bear the name N ecrophylus 
arenarius (Roux) Schaum. 
The Crocini obviously constitute a peculiar tribe of 
Nemopteridse, with strongly marked larval and adult char- 
acters, both morphological and ethological. The adults are 
small, frail insects with a strongly produced beak-like front, 
short antennae and very long, thread-like hind wings. The 
larvae have the prothorax produced into a slender and 
elongate “neck” anteriorly but the attenuation and elonga- 
tion of this region differ considerably in different genera, 
being very great in Necrophylus, less pronounced in Nina 
and much feebler in Croce, as shown by the observations of 
Maxwell-Lefroy (1909, 1910), Ghosh (1910), and Imms 
(1911) on the Indian Croce filipennis. Withycombe (1924) 
has been able to study the first instar larva of one of the 
true Nemopteras (N. bipennis) and has shown that it has a 
very short prothorax and neck, even shorter than in ant- 
lion (Myrmeleontid) larvse. 
Ethological observations on the Crocini show that they 
are to be regarded as cavernicolous insects. The larvse of 
the species of Necrophylus and Nina, as we have seen, live 
in the dust and sand of tombs, caves and rock-cavities, and 
those of Croce filipennis are common in the dust that accu- 
mulates on the floors of disused rooms and bungalows, 
where they feed on Psocids, Lepismids, etc. The adult 
Crocini fly at dusk or, if during the day, in dark corners, 
within the confines of the caves, cavities or human dwell- 
ings. This is also true of the Spanish Josandreva sazi, which 
was found by Navas (1910) flying at dusk in the cavities 
of walls and especially in those containing sand or dust. In 
all probability the larvse of this delicate insect lives and 
hunts its prey in these accumulations. The adults of the 
genus Nemoptera, however, live in the open and may fly by 
day. At any rate I took quite a number of A. bipennis fly- 
ing or resting on the sparse vegetation of the sun-baked 
hills about Ronda, Spain (June 30, 1925), at a considerable 
distance from walls or rock-cavities. The larvse probably 
