The “Green-head,” _Ectatomma metallicum_, is a common ant of medium size that lives in small communities under stones or logs, and often makes nests in the dry banks of lawns in our gardens. Though somewhat sluggish, they sting sharply if they crawl on one when resting on the grass. About 28 species and many varieties of this genus occur in Australia; one in New Zealand; and 3 in New Caledonia. The members of the Genus _Ponera_ are remarkable for their extended range; we have several species or varieties in Queensland closely allied to species from South America, Borneo, Europe, and Africa, while three are recorded from New Zealand; _Euponera lutea_, a slender pale yellow ant with the abdominal segment constricted, lives in small communities under stones or roots. It ranges from Sydney to Fremantle, round to N. Queensland. _Pachycondyla piliventris_ is a large, hairy black ant with large head and rounded body, roughened, and clothed with fine rusty down. They are generally found under stones in communities of a dozen or so, and when exposed or disturbed pretend to be dead, with their legs folded up under the body; they are common about Sydney. Six species of the Genus _Sphinctomyrmex_ are found chiefly in the North. They are somewhat rare ants; I have found two species, both small, slender, dull brownish yellow insects living under stones; _S. froggatti_ in a vineyard near Sydney; and the second, _S. hednigae_, in the New England district under large stones. * * * * * The second sub-family, DORYLINAE, comprises ants with the antennae placed close together in the front of the head, the abdomen elongated, with the first segment forming an irregular node. This group contains some very remarkable ants in Africa and America, but is only represented in Australia by two species belonging to the Genus _Ænictus_, both of which are described from specimens collected by Turner at Mackay, Queensland. * * * * * The third sub-family, MYRMICINAE, is well represented here; they are all small or medium sized ants, with the base of the abdomen formed into two small nodes, and the sting rudimentary; the pupa naked and not enclosed in a cocoon. Many of them live in very large communities. The members of the Genus _Meranoplus_ are tiny little brown ants with rounded heads and bodies, resembling some of the small wingless female Mutillid in shape and habits, for though they form irregular galleries under stones or in dry banks, they are generally found running up and down tree trunks; when touched they curl up the body and sham death. _Meranoplus oceanicus_, reddish brown, is common in N.S. Wales; _M. pubescens_ has a very wide range right round Australia. * * * * *