On some experiments with dragonfly larvae

During the past few years I have kept and reared a large number of dragonfly larvae of various species.The present paper is an attempt to collect together, in the form of a short narrative, the notes I have made about them concerning three points only, viz.: -longevity, resistance to starvation, and resistance to drought.The chief experiments carried out were made with (1) an unknown Libellulid larva of very peculiar structure, (2) a number of larvae of Synthemis eu&talacia Burui.I shall deal with these separately.i.The unknown Lihellidid larva.On October 10th, 1908, I dredged from tlie loose trash (consisting mainly of half-decayed vegetable matter such as eucalypt leaves) which collects in the small pools of the Heathcote Creek (Illawarra district, N.S.W.), a large number of larvse of Austrogomphus ochraceus Selys.Together with these, I found twa remarkable larvse of Libellulid form, which I am quite unable to recognise as belonging to an}' known species.They are very hard, and when touched, curl up into a half-ball, remaining motionless for a considerable time.They have very short legs, a somewhat triangular head, a broadly oval body absolutely flat on the underside, and a deeply and very irregularly indented labium.At the time I took them, I was already acquainted witli the larvae of every dragonfly occurring in the neighbourhood, except that of Synthemis Jlavoterminata Martin, so that it was not unreasonable to expect that this was the larva of that species.However, I have since taken, and bred out, the larva of S.Jlavoterminata, which is of an absolutely different type to the one BY