These birds inhabit Patagonia, migrating north to the pampas in winter, where they arrive in April. They usually go in flocks of about forty or fifty individuals, and fly rapidly, keeping very close together. On the ground, however, they are always much scattered, and are so reluctant to rise that they will allow a person to walk or ride through the flock without taking wing, each bird creeping into a little hollow in the surface or behind a tuft of grass to escape observation. During its winter sojourn on the pampas the flock always selects as a feeding-ground a patch of whitish argillaceous earth, with a scanty withered vegetation; and here when the birds crouch motionless on the ground, to which their grey plumage so closely assimilates in colour, it is most difficult to detect them. If a person stands still close to or in the midst of the flock the birds will presently betray their presence by answering each other with a variety of strange notes, resembling the cooing of Pigeons, loud taps on a hollow ground, and other mysterious sounds, which seem to come from beneath the earth. In the valley of Rio Negro I met with a few of these birds in summer, but could not find their nests. Durnford, however, who found them breeding in Chupat at the end of October, tells us that the nest is a slight depression in the ground, sometimes lined with a few blades of grass. "The eggs have a pale stone ground-colour, very thickly but finely speckled with light and dark chocolate markings; they have a polished appearance, and measure 1·3 × ·8 inch" (Ibis, 1878, p. 403). 394. THINOCORUS ORBIGNYANUS, Geoffr. et Less. (D'ORBIGNY'S SEED-SNIPE.) +Thinocorus orbignyanus+, _Burm. La-Plata Reise_, ii. p. 500; _Scl. et Salv. Nomencl._ p. 144; _Tacz. Orn. Pér._ iii. p. 281. _Description._--Above yellowish brown, streaked and marbled with black; wing-feathers blackish with lighter edgings, inner secondaries like the back; back and sides of neck grey: beneath white; throat white, surrounded by a narrow black band; breast grey, joining the grey neck, and bordered beneath by a narrow black band; bill brown, tip black; feet yellow, claws black: whole length 8·0 inches, wing 5·5, tail 3·0. _Female_: above like the male, but without the grey neck: beneath white, sides of neck and breast like the back; throat white. _Hab._ Western Peru, Bolivia, Chili, and Western Argentina. Dr. Burmeister met with examples of this Seed-Snipe, which is easily distinguishable from the preceding species by its larger size, in the high valleys of the Sierra of Uspallata, at an elevation of about 6000 feet above the sea-level. It is called "Guancho" by the natives after its peculiar call-note, which, however, sounded more like "Tulco" to Dr. Burmeister, and is often heard at night-time.