The actions of this species are somewhat peculiar, and unlike those of most other insectivorous birds: it pries about the leafy branches of the trees, and leaps from twig to twig in the most agile manner possible, making all the while a most scrutinizing search for insects, particularly coleoptera. When the male exposes himself, as he occasionally does, on some bare twig, the rich yellow of his plumage, offering a strong contrast to the green of the surrounding foliage, renders him a conspicuous and doubtless highly attractive object to his sombre-coloured mate, who generally accompanies him. Males in colour like those represented on the accompanying Plate seldom associate together, their recluse disposition leading them not only to avoid each other’s society, but also that of all other birds. It sometimes resorts to the gardens and shrubberies of the settlers, but much less frequently than might be supposed, when we consider that the neighbouring forests are its natural place of abode. The voice of the Grey-tailed Pachycephala is a loud whistling call of a single note several times repeated, and by which the presence of the male is often detected when it would otherwise be passed by unnoticed. I was unsuccessful in my search for its nest, and the eggs are still a desideratum to my cabinet. I shot the young in various stages of plumage, and found them to differ so much that a more, than ordinarily minute description is necessary, in order that those who may not have an opportunity of seeing the bird in its native country may not be misled respecting it. Soon after leaving the nest the ground-colour of the entire plumage is grey, washed or stained as it were, both on the upper and under surface, with rusty or chestnut-red; this gradually gives place to a uniform olive-brown above and pale brown beneath, which being precisely the colouring of the adult females, the young birds in this stage and the old females are not to be distinguished from each other. The adult male has the crown of the head, lores, space beneath the eye and a broad crescent-shaped mark from the latter across the breast deep black; throat, within the black, white; back of the neck, a narrow line down each side of the chest behind the black crescent and the under surface yellow; back and wing-coverts yellowish olive; wings dark slate-colour margined with grey; tail entirely grey; under tail-coverts white, or very slightly washed with yellow; irides reddish brown; bill black; feet dark brown. The Plate represents two males and a female of the natural size, on one of the common Acacias of Van Diemen’s Land. [Illustration: PACHYCEPHALA MELANURA: _Gould_. _J. Gould and H. C. Richter del et lith._ _Hullmandel & Walton Imp._ ] PACHYCEPHALA MELANURA, _Gould_. Black-tailed Pachycephala. _Pachycephala melanura_, Gould in Proc. of Zool. Soc., Part X. p. 134.