The Genus _Rhynchium_ comprises about six described species, handsome insects not unlike the former in general form, but with the abdomen more tapering. _Rhynchium mirabile_ measures ¾ of an inch in length; it is of a general black colour, the head marked with, and collar of thorax, yellow; and the hind margin of the abdominal segments is ringed with slender bands of orange yellow. _Rhynchium superbum_ is a smaller insect of similar form and colour, with the basal half of the abdomen black and the hind portion rich yellow. Both these species come from Queensland. The Genus _Odynerus_ contains a great number of small thickset wasps, that make clay nests of various shapes, sometimes very delicate in structure, forming a finger-shaped row of clay cells or rounded cup-shaped chambers; while some species make use of a hole in the wood or wall and simply coat it over with clay. Australia is rich in species, some of which have a very wide range. _Odynerus bicolor_, one of our commonest species, is black, with the collar of the thorax, legs, and all the abdomen except the basal segment, dull reddish yellow. _Odynerus nigro-cinctus_ is of a general dark orange yellow colour, with the head and centre of abdomen black. The closely allied species forming the Genus _Alastor_ differ slightly in the venation of the wings, but their habits are identical; about 30 species have been described from Australia, chiefly by Saussure, some of which are figured in colours in his Monograph. These wasps may be captured round water-holes in the summer months, and may sometimes be found resting upon grass stalks in the early morning. Family 20. Social or Paper-nest Wasps. VESPIDAE. These typical wasps are found all over the world, and next to the bees have probably received more attention from the casual observer than most of the other groups. Each community consists of males, females, and workers, and though the structure of their nests differs considerably in the various groups, the social economy is the same. The female first starting the nest constructs a stout stalk at the apex attached to a twig or roof, and constructs a six-sided cell from which the whole mushroom-shaped nest is built. In each little cell she deposits an egg from which the legless white grub emerges, attaches itself to the roof of the cell and hangs head downward, being fed by the mother wasp until full grown with food chiefly composed of masticated spiders, when it pupates under a silken cover spun over the apex of the cell. As soon as it emerges it sets to work to help on the nest, so that the community rapidly increases in numbers. The nest of _Polistes tasmaniensis_ sometimes measures six inches in diameter. Some confusion as to the identity of this species and _P. variabilis_ seems to exist, but from Saussure’s description, our common species appears to be _P. tasmaniensis_. [Illustration: Plate XV.--HYMENOPTERA. Family VESPIDAE.