The _Sericornis magnirostris_ an inhabitant of the brushes of New South Wales, both those which clothe the gullies and sides of the mountain ranges of the interior, as well as those near the coast; such as occur at Illawarra and on the banks of the Hunter, the Clarence, the Macleay and other rivers; it is never seen in the open country, and so far as I am aware, is entirely confined to New South Wales. Although it has nothing either in its form or colouring to recommend it to notice, it must always be an object of interest, from the very singular nest it constructs, and which, like that of _Sericornis citreogularis_, forms a remarkable object in the scenery of the portion of the country it inhabits. It is formed of a large loose mass of moss, and being attached to the extreme tips of the pendent branches, waves about with every wind that blows; it is very frequently constructed within reach of the hand, but is more often suspended at about ten, and sometimes as high as thirty feet from the ground; occasionally two or three are constructed together under a dense canopy of foliage, overhanging water or a deep and gloomy gully, and then present a very singular appearance. I procured several examples by shooting the branch asunder just above the nest. The nest so perfectly resembles the tufts of living moss which are attached to many of the extremities of the branches of the trees of the brushes, that it is impossible to distinguish the one from the other; and it is a question whether the bird purposely builds its nest in imitation of these hanging masses in order to elude pursuit, or whether it avails itself of the mass already formed, and by a little architectural skill converts it into a receptacle for its eggs. It would seem that the same nest is resorted to for several seasons in succession, and probably for a series of years; the entire mass consists of living moss, and the small hole left for an entrance is so skilfully concealed as scarcely to admit of detection. The breeding-season commences in August and continues until February, during which period many broods are reared. I procured a nest in September out of which flew three young birds, and others during the same month which contained eggs so recently laid that they could scarcely have been sat upon. The eggs are generally two or three in number; their ground-colour varies from bluish white to dull reddish white, with the larger end sparingly washed, freckled and streaked with dark brown; they are large for the size of the bird, being nine and a half lines long by seven lines broad. It is a very active but shy bird, keeping much among the branches of the high trees, where it gains a plentiful supply of insect food; it may, however, be easily enticed into view by imitating the squeak of its young. Its powers of song are very feeble. The sexes do not differ in external appearance, nor do the young when fully fledged offer any variation in colour from the adult.