This is the commonest species of the Pigeon tribe in the Argentine country, and is known to every one as the _Torcasa_, probably a corruption of _Tortola_, Turtle-Dove. In autumn they often congregate in very large flocks, and are sometimes observed migrating, flock succeeding flock, all travelling in a northerly direction, and continuing to pass for several consecutive days. But these autumnal migrations are not witnessed every year, nor have I seen any return-migration in spring; while the usual autumn and winter movements are very irregular, and apparently depend altogether on the supply of food. When the giant thistle has covered the plains in summer incredible numbers of Torcasas appear later in the season, and usually spend the winter on the plains, congregating every evening in countless myriads wherever there are trees enough to form a suitable roosting-place. On bright warm days in August, the sweet and sorrowful sob-like song of this Dove, composed of five notes, is heard from every grove--a pleasing, soft, murmuring sound, which causes one to experience by anticipation the languid summer feeling in his veins. The nest, as in other Pigeons, is a simple platform of slender sticks; the eggs are oval, white, and two in number. The birds appear to breed by preference near a human habitation, and do so probably for the sake of the protection afforded them; for the Chimango and other birds of prey destroy their eggs and young to a large extent. One summer a Torcasa laid an egg in the nest of one of my Pigeons, built on the large horizontal branch of a tree at some distance from the dove-cote. The egg was hatched, and the young bird feared by its foster-parents; and when able to fly it took up its abode along with the other Pigeons. The following spring it began to separate itself from its companions, and would fly to the porch, and sit there cooing by the hour every day. At length it went away to the plantation, having, I believe, found a mate, and we saw no more of it. 360. METRIOPELIA MELANOPTERA (Mol.). (BLACK-WINGED DOVE.) +Metriopelia melanoptera+, _Burm. La-Plata Reise_, ii. p. 496 (Cordilleras); _Scl. et Salv. Nomencl._ p. 132. _Description._--Above pale brown; wings and tail black; bend of wing white; wing-coverts like the back: beneath pale vinaceous; bill and feet black: whole length 8·0 inches, wing 5·0, tail 3·5. _Female_ similar. _Hab._ Andes of South America. This Dove is widely diffused in Western South America from Ecuador to Chili. Dr. Burmeister tells us that it is found in the high valleys of the Cordilleras on the Argentine side, from 6000 to 12,000 feet in altitude, and along with _Phrygilus fruticeti_ is one of the birds seen at the greatest altitudes by the traveller over the passes of the Andes. One of Dr. Burmeister's specimens is in the collection of Messrs. Salvin and Godman. 361. METRIOPELIA AYMARA (Knip et Prév.). (AYMARA DOVE.)