the following year (1804). The latest period I observed them was on the 30th of May 1806, when a number of them were twittering and flying high in the air. When I missed them at Paramatta, I have sometimes met with them among the north rocks, a romantic spot about two miles to the northward of the former place.” A few stragglers remain in New South Wales during the whole of the winter, but their numbers cannot be for a moment compared with those to be observed in the summer, and which during the colder months have wended their way to a warmer and more congenial climate, where insect life is sufficiently abundant for the support of so great a multitude. I have never been able to trace this bird very far to the north; it certainly does not visit Java, nor I believe New Guinea, neither have I yet seen it from Port Essington or any part of the north coast, although it is probable that its range does extend thus far. The natural breeding-places of this bird are the deep clefts of rocks and dark caverns, but since the colonization of Australia it has in a remarkable degree imitated its European prototype, by selecting for the site of its nest, the smoky chimneys, the chambers of mills and out-houses, or the corner of a shady verandah; the nest is also similarly constructed, being open at the top, formed of mud or clay, intermingled with grass or straw to bind it firmly together, and lined first with a layer of fine grasses and then with feathers. The shape of the nest depends upon the situation in which it is built, but it generally assumes a rounded form in front. The eggs are usually four in number, of a lengthened form; the ground colour pinky white, with numerous fine spots of purplish brown, the interspaces with specks of light greyish brown, assuming in some instances the form of a zone at the larger end; they are from eight to nine lines long by six lines broad. At Swan River the breeding-season is in September and October. The food consists of small flies and other insects. Forehead, chin, throat and chest rust-red; head, back of the neck, back, scapularies, wing-coverts, rump and upper tail-coverts deep steel-blue; wings and tail blackish brown, all but the two centre feathers of the latter with an oblique mark of white on the inner web; under surface very pale brown; under tail-coverts pale brown passing into an irregular crescent-shaped mark near the extremity and tipped with white; irides dark brown; bill and legs black. The figures are those of a male and female of the natural size. [Illustration: CHELIDON ARBOREA: _Gould_. _J. Gould and H. C. Richter, del^t_ _C. Hullmandel Imp._ ] COLLOCALIA ARBOREA. Tree Martin. _Dun-rumped Swallow_, Lath. Gen. Hist., vol. vii. p. 309. _Hirundo pyrrhonota_, Lath. MSS.—Vig. and Horsf. in Linn. Trans., vol. xv. p. 190. _Hirundo nigricans_, Vieill. Ency. Méth., Part II. p. 525?