On the open pampas their curiosity and anger seems greatly excited at the appearance of a person on foot; no sooner has the Gull spied him than it sweeps toward him with a rapid flight, uttering loud indignant screams that never fail to attract all of its fellows within hearing distance. These all pass and repass, hovering over the pedestrian's head, screaming all the time as if highly incensed, and finally retire, joining their voices in a kind of chorus and waving their wings upwards in a slow curious manner; but often enough, when they are almost out of sight, they suddenly wheel about and hurry back screaming, with fresh zeal, to go through the whole pretty but annoying performance again. 418. LARUS CIRRHOCEPHALUS, Vieill. (GREY-CAPPED GULL.) +Larus cirrhocephalus+, _Scl. et Salv. Nomencl._ p. 148; _iid. P. Z. S._ 1871, p. 578; _Durnford, Ibis_, 1877, p. 201 (Buenos Ayres); _Barrows, Auk_, 1884, p. 316 (Entrerios); _Saunders, P. Z. S._ 1878, p. 204. +Larus maculipennis+, _Burm. La-Plata Reise_, ii. p. 518 (Paraná). _Description._--Head (in breeding-plumage) grey, deepening in colour on the nape and throat; tail and underparts white; mantle grey (darker than in _L. maculipennis_); primaries black, with small subapical white patches on first and second, and longer ones on the outer webs of third to fifth near the base; _underwing slate-grey_; bill, legs, and feet crimson to orange-red: length 16·0 to 17·0 inches, wing 12·25. _Hab._ South Brazil, Uruguay, and La Plata, also coast of Peru. The Grey-capped Gull is found on the Rio de la Plata, and as far north as Concepcion on the Uruguay in winter, where Mr. Barrows observed it in immense flocks frequenting the "_Saladeros_."