produced by the small cog-wheels of a steam-mill. The stomach is muscular, and the food consists of insects of various kinds. The sexes are alike in plumage, and may be thus described:— Head, neck, throat, sides of the chest, upper surface and tail, glossy greenish black; over each eye a narrow line of white; wings brown; wing-coverts with a small triangular spot of white at the tip; under surface pale buffy white; irides, bill and feet black. The figures are of the natural size. [Illustration: SEÏSURA INQUIETA. _J. Gould and H. C. Richter del et lith._ _Hullmandel & Walton Imp._ ] SEÏSURA INQUIETA. Restless Flycatcher. _Turdus inquietus_, Lath. Ind. Orn. Supp., p. xl. _Restless Thrush_, Lath. Gen. Syn. Supp., vol. ii. p. 181.—Shaw, Gen. Zool., vol. x. p. 263.—Lath. Gen. Hist., vol. v. p. 120. _Turdus volitans_, Lath. Ind. Orn. Supp., p. xli. _Volatile Thrush_, Lath. Gen. Syn. Supp., vol. ii. p. 183.—Shaw, Gen. Zool., vol. x. p. 290.—Lath. Gen. Hist., vol. v. p. 122. _Seïsura volitans_, Vig. and Horsf. in Linn. Trans., vol. xv. p. 250.—Swains. Class. of Birds, vol. ii. p. 256.—G. R. Gray, List of Gen. of Birds, 2nd Edit., p. 43.—Nat. Lib. Orn., vol. x., Flycatchers, pl. 12. p. 138. _Jiẗ-tee-gnut_, Aborigines of Western Australia. _The Grinder_, of the Colonists of Swan River and New South Wales. This species ranges over the whole of the southern portions of the Australian continent, and appears to be as numerous at Swan River as it is in New South Wales, where it may be said to be universally distributed, for I observed it in every part I visited, both among the brushes as well as in the more open portions of the country, in all of which it is apparently a stationary species. It is a bird possessing many peculiar and very singular habits. It not only captures its prey after the usual manner of the other Flycatchers, but it frequently sallies forth into the open glades of the forest and the cleared lands, and procures it by poising itself in the air with a remarkably quick motion of the wings, precisely after the manner of the English Kestrel (_Tinnunculus Alaudarius_), every now and then making sudden perpendicular descents to the ground to capture any insect that may attract its notice. It is while performing these singular movements that it produces the remarkable sound, which has procured for it from the colonists of New South Wales the appellation of “The Grinder.” The singular habits of this species appear to have attracted the notice of all who have paid any attention to the natural history of New South Wales: Mr. Caley observes, “It is very curious in its actions. In alighting on the stump of a tree it makes several semicircular motions, spreading out its tail at the time, and making a loud noise somewhat like that caused by a razor-grinder at work. I have seen it frequently