This species is a summer visitor in Buenos Ayres, and is one of the last to arrive and first to depart of our migrants. These birds are always most abundant in plantations, preferring peach-trees, but do not associate in flocks: they are exceedingly swift and active, overflowing with life and energy, their impetuous notes and motions giving one the idea that they are always in a state of violent excitement. The male has a loud, startled chirp, also a song composed of eight or ten notes, delivered with such vehemence and rapidity, that they run into each other and sound more like a scream than a song. There is not a more clever architect than this species; and while many _Synallaxes_ are laboriously endeavouring to show how stately a mansion of sticks a little bird can erect for itself, the Screaming Finch has successfully solved the problem of how to construct the most perfect nest for lightness, strength, and symmetry with the fewest materials. It is a small, cup-shaped structure, suspended hammock-wise between two slender upright branches, and to which it is securely attached by fine hairs and webs. It is made of thin, pale-coloured, fibrous roots, ingeniously woven together--reddish or light-coloured horse-hair being sometimes substituted; and so little material is used that, standing under the tree, a person can easily count the eggs through the bottom of the nest. Its apparent frailness is, however, its best protection from the prying eyes of birds and mammals that prey on the eggs and young of small birds; for it is difficult to detect this slight structure, through which the sunshine and rain pass so freely. So light is the little basket-nest that it may be placed on the open hand and blown away with the breath like a straw; yet so strong that a man can suspend his weight from it without pulling it to pieces. The eggs are three in number, white and spotted with black, sometimes bluish-brown spots are mingled with the black. 54. PAROARIA CUCULLATA (Lath.). (CARDINAL FINCH.) +Paroaria cucullata+, _Burm. La-Plata Reise_, ii. p. 482 (Paraná, Tucuman); _Scl. et Salv. Nomencl._ p. 30; _Durnford, Ibis_, 1877, p. 171 (Buenos Ayres); _Gibson, Ibis_, 1880, p. 19 (Buenos Ayres); _White, P. Z. S._ 1882, p. 598 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 129 (Concepcion). _Description._--Above grey; wing- and tail-feathers blackish grey; head all round, crest, and throat brilliant scarlet, the scarlet extending downwards to the chest; below white, the white colour extending up the sides of the neck; nape spotted with white: total length 8·0 inches, wing 4·0, tail 3·5. _Female_ similar. _Hab._ Bolivia, Paraguay, and Argentina.