86 Mr. R. Shelford on 
and I would suggest that in the case of Collyris at any rate 
they function as guides for the passage of the egg through 
the aperture bored in the woody tissue of the twig. 
Species of Cicindela, to take an example, would have 
presumably no difficulty in depositing their eggs in the 
burrows excavated for their reception; the burrow is of 
sufficient diameter to admit the tip of the abdomen and 
the egg can be simply dropped before the tip of the 
abdomen is withdrawn after the operation of excavation. 
The entrance to the burrow occupied by the larva of 
Collyris emarginatus is not large enough to admit the tip 
of the abdomen of the adult female, as can be shown by 
measurements, but the two ventral spines fit into it with 
ease. Without these spines it is difficult to see how the 
female Collyris could be certain of passing her egg through 
the aperture in the wood which she has made; she would 
be liable to deposit it rather on the outer surface of the 
twig, whence it would drop to the ground, but with the 
ventral spines inserted in the aperture the egg can readily 
pass from the oviduct to the place prepared for it. 
Description of the Larva. (Plate III, figs. 1-10.) 
The largest specimen in my possession is 12 mm. in length. The 
head is typically Cicindelidan ; that is to say, it is strongly chitinised, 
swollen and concave beneath, flattened above; the mouth-parts 
are prominent and point in an upward direction. The antennz are 
short and four-jointed. There are two ocelli borne on each side of 
the head near the origin of the antenne ; the area surrounding these 
ocelli is much darker than the rest of the head and is somewhat 
inflated. The labrum is broad and transverse with a quadrangular 
projection from the middle of the front margin, flanked on each side 
by a tooth; this quadrangular projection is ridged and has a blunt 
tooth on each side. The mandibles are strong and curved, each bears 
a tooth on its inner margin at the centre; distad of this tooth the 
inner border of the mandible is grooved, proximad of it the inner 
border is sharp and trenchant. The maxille consist of a small 
cardo, a stout triangular stipes, bearing a two-jointed palp and a 
narrow ga/ea almost equal to the palp in length and furnished with 
like structures. The species of Therates that I took in Borneo were 
not, so far as I can remember, arboreal, and in these the ventral 
spines are very small indeed. The Australian genus Distypsidera is 
said to be arboreal and in this genus also the ventral spines are 
present. 
