The Yellow-winged Locust, _Locusta danica_, is common in open forest country all over Australia, and usually makes a rustling noise as it flies up; it is too well known to need describing; with its wings closed it is a mottled, dull brown and green insect up to 2 inches in length, with a short broad head and crested thorax; when the wings are opened it shows a large patch of rich yellow banded with black. The male is often fully a third smaller than the female. It has been described under a great number of different names, but is now considered the same insect as found in the South of Europe, Africa and Asia. The Blue Mountain Locust, _Oedaleus senegalensis_, might easily be mistaken for a smaller dull coloured specimen of the last one, but the yellow tint, when present, is very slight, and the wings have the tips blackened as well as the inner band. It has a wide range over Australia, and is also found in Africa from which place it was described by Krauss. [Illustration: =Fig. 24.=--_Chortoicetes pusilla_ (Walker). The small Plague-locust of the interior of Australia. (“Agricultural Gazette,” N.S.W.)] [Illustration: =Fig. 25.=--_Chortoicetes terminifera_ (Walker). The larger Plague-locust. (“Agricultural Gazette,” N.S.W.)] The Large Coast Locust, _Acridium maculicollis_, is sometimes found in gardens; it measures 3 inches to the tip of the wings, and is greyish brown with darkly mottled elytra. _Locusta australis_ is like the Yellow-winged Locust, with more regularly mottled elytra, and clear transparent wings. The small plain Locust, _Chortoicetes pusilla_, is under 1 inch in length; the male is of a general bright yellow colour, and the female, somewhat larger, of a general greyish brown tint. It is the species that for the last few years has done so much damage to our grass and crops in the Western country. _C. terminifera_ is one-third larger, and is of a general light brown mottled colour, with the wings semitransparent, tipped with dull brown; it at times is one of our plague locusts. The Rose-winged Locust, _Hyalopteryx australis_, is one of our small but very noisy locusts, about 8 lines in length; when at rest it is light brown mottled with darker tints, the expanded hind wings are brightly shaded with rose pink and clouded with black. It is found in open grass lands, and when disturbed rises with a very shrill screech. The Red-legged Locust, _Cirphula pyrocnemis_, is a short broad insect about 1 inch long; is of a general dark brown tint, with the expanded wings dark yellowish brown: the head and thorax are roughened; the abdominal segments are dull yellow with several black bands on the sides: it is common on the open flats about Sydney in summer. The common “Great Striped Locust,” _Cyrtacanthacris exacta_, measures nearly 3 inches; it ranges all along the Eastern coast and is often seen in secluded gardens; it has a broad dorsal stripe down the centre, varying from yellow to dull green.