The typical Braconid is usually very small; many of them are no larger than some of the Chalcids. Wherever the cabbage aphis or other plant infesting insects such as caterpillars are to be found, these little wasps can be observed hovering round, waiting for an opportunity to deposit their eggs. They differ from the large ichneumons, in that while the latter only deposit a single, or at most a dozen eggs upon a victim, these often place hundreds in a large caterpillar, which, emerging when full grown, form little white oval silken cocoons on the top of the remains of their hosts, that are sometimes surrounded with a mass of white fibre exactly like cotton wool. After a plague of cut worms has passed over a paddock it is quite common to find clusters of these little cocoons attached to the grass stalks; these have been often sent to me from the country with the information that they were the eggs of the plague caterpillars or cut worms. [Illustration: =Fig. 51.=--_Ephedrus persicae_ (Froggatt). A Braconid wasp that lays its eggs on the bodies of aphids. (“Agricultural Gazette,” N.S.W.)] _Bracon limbatus_, one of our larger typical species, is found in Tasmania, and has a wide range over Australia. It measures about ½ an inch from the front of the head to the tip of the abdomen, and is of a general black colour on the upper surface, with dusky almost black wings, and a red head. The under-surface is marked with brown, with the thorax, thighs, and tibiae of the front and middle legs black; the three slender curled hair-like tails forming the ovipositor being longer than the whole insect. Eight other species of _Bracon_ are described, several of which are also recorded from New Guinea and New Zealand. Among the introduced species is _Lepolexis rapae_ of Curtis, which is parasitic upon the cabbage aphis in Europe; it can be collected in gardens about Sydney. Aphids containing these parasites are always swollen, round, and apparently dead skins through which each braconid eats its way. Five species of the Genus _Agathes_ are described; they are remarkable for their showy particoloured wings, and large size in comparison with other members of this family. Ashmead has described a tiny black species marked with yellow bred by me from the larva of a Noctuid Moth, an undetermined species of _Agrotis_, under the name of _Apanteles antipoda_; and a second larger one as _Apanteles australasiae_. In his Genus _Microbracon_ he has described a dainty little black and yellow creature that infests the larvae of our scale-eating moth (_Thalpochares coccophaga_) under the name of _Microbracon thalpocaris_. Family 10. Ruby Wasps. CHRYSIDIDAE.