Of the lovely group of birds forming the genus _Malurus_, the present species is the oldest known, being that figured in White’s Voyage to New South Wales, under the name of Superb Warbler, a term by which the bird is still familiarly known in Australia. It is abundantly dispersed over every portion of the colony of New South Wales, and I observed it to be equally numerous on the plains of the interior to the northward; but how far its range may extend in that direction, can only be determined when those parts of the continent shall have been fully explored. I also killed specimens in South Australia, which I then believed to be identical with the present bird; but on comparison since my return, I find them to be more nearly allied to the _Malurus longicaudus_, at the same time possessing characters different from either; a further knowledge of the South Australian bird is therefore necessary, before I can determine to which it is referable, or if it may not be distinct from both. The kind of country to which the _Malurus cyaneus_ gives preference is of a wild and sterile character, thinly covered with low scrubby brushwood, especially localities of this description situated near the borders of rivers and ravines. During the months of winter it associates in small troops, of from six to eight in number, probably the brood of a single pair; it is of a very wandering disposition, and although never migrating to any great distance, is continually traversing the district in which it was bred, retiring at night-fall to roost in the accustomed haunt. At this period of the year the plumage of the sexes is so nearly alike, that a minute examination is requisite to distinguish them, and hence has risen the supposition that there was but one male to several females. The old males, however, have at all seasons the bill black, whereas the young males during the first year, and the females, have this organ always brown; the tail-feathers also, which with the primaries are only moulted once a year, are of a deeper blue in the male than in the other sex. As spring advances they separate into pairs, the male undergoing a total transformation, not only in the colour, but also in the texture of its plumage; indeed, a more astonishing change can scarcely be imagined, its plain and unassuming garb being thrown off for a few months and another assumed, which for resplendent beauty is hardly surpassed by any of the feathered race, certainly by none but the Humming-birds and Cotingas of America: nor is the change confined to the plumage alone, but extends also to its habits; in fact, its whole character and nature appear to have received a new impulse; the little creature now displaying great vivacity, proudly showing off its gorgeous attire to the utmost advantage, and pouring out its animated song unceasingly, until the female has completed her task of incubation, and the craving appetites of its newly-hatched young call forth a new