The Genus _Notonomus_ has been recently revised by Sloane (Pro. Linn. Soc. N.S.W. 1902); in this paper he enumerated 72 species, a number of them previously undescribed. These beetles are apterous, and confined to the coastal forests of Eastern Australia. Sloane says: “From the Grampians in Western Victoria, along the coast of Eastern Australia as far north as the Burnett River in Queensland, and many species are very restricted in their range.” _Notonomus australasiae_ is one of the commonest species around Sydney; it measures under ¾ of an inch in length, and is of a uniform black colour; the broad thorax is arcuate behind the head, swelling out and broadly rounded on the sides; it has a rich blue metallic tint, and a distinct medium suture; the wing covers are distinctly striated, forming broad parallel ridges. Passing over a number of more or less important genera we finish with the Genus _Bembidium_, which contains a number of small active beetles generally found along the edges of swamps. _B. ocellatum_ is a shining black beetle under ⅙ of an inch in length, with a broad head, and the thorax rounded on the hind margin. Family 3. Water Beetles. DYTISCIDAE. This group contains the first division of the Water Beetles; these have the antennae bare and filiform; short palpi and undivided eyes; the legs fringed with hairs, the front pair not longer than the hind pair, adapted for swimming. They live in the water both in the larval and beetle stage; the former are slender, elongate creatures, with a body consisting of twelve segments; the head is broad and furnished with powerful hollow jaws; they are very voracious creatures, devouring all sorts of aquatic insects, and even the smaller and weaker of their own species. When full grown they pupate in cells which they form in the soft mud. These beetles are perfectly at home in the water, and breathe by coming to the surface; turning head downwards, and with the tip of the wing covers slightly raised, they draw in a supply of air which occupies a cavity on the back, and when the elytra are closed down, the beetle can remain under water until the supply is exhausted. Many species can be easily captured in the water with a small hand-net; on a warm summer night numbers leave the water and come flying in to the lighted lamps. Many are very small, few over ½ an inch in length; they are quite as numerous in the colder waters of the globe as in the tropics, and many species have a very wide distribution. We have representatives of most of the typical genera; our species have been described by Clark (Journal of Entomology 1862), and Sharp (Trans. Dublin Soc. 1882).