Fam. VII. VIREONIDÆ, or GREENLETS. Three of the groups of the peculiar American family of Greenlets, allied to our Shrikes, have representatives within the Argentine Republic. The genera _Vireo_ and _Hylophilus_ both extend, each in the shape of one of its South-Brazilian members, into the woodlands of the Paraná; while _Cyclorhis_, another genus also widely spread over South and Central America, has two representatives within our area. One of these latter is well known in the neighbourhood of Buenos Ayres; the other is only found in the extreme north of the Republic. 21. VIREOSYLVIA CHIVI (Vieill.). (CHIVI GREENLET.) +Contramaestre gaviero+, _Azara, Apunt._ ii. p. 34. +Sylvia chivi+, _Vieill. N. D._ xi. p. 174. +Vireosylvia chivi+, _Baird, Rev. A. B._ p. 337; _Scl. et Salv. P. Z. S._ 1869, p. 160 (Buenos Ayres); _Berl. et Jher. Zeitschr. ges. Orn._ 1885, p. 115. +Vireo chivi+, _Gadow, Cat. B._ viii. p. 295. _Hab._ South America, from Colombia down to Buenos Ayres. A single specimen of this Greenlet was found in a collection made by Mr. Haslehurst near Buenos Ayres. As the species occurs in Rio Grande do Sul (_Berlepsch_) and Paraguay (_Azara_), its occasional appearance in Eastern Argentina is quite probable. Whether the bird is really distinct from the widespread _Vireo olivaceus_ seems to be a question which is not yet finally settled. Azara, describing this species, says it is one of the commonest in deep woods, where it moves about among the terminal twigs, without ever rising to the tops of the trees or flying down to the brush or the ground. It is active, and extremely restless in manner; and in searching after and taking the small insects and spiders on which it lives it climbs about the twigs, assuming every position, and frequently suspending itself, head downwards, by its feet. It has a full pleasing voice of considerable power, heard incessantly in the woods, particularly in the love-season. The nest is a slender beautiful structure, even surpassing that of the Humming-birds, constructed of thin dry leaves outside, smoothly attached to the rest with spiders' webs, while the inside is formed of fine fibres and cotton. 22. HYLOPHILUS PŒCILOTIS, Max. (BROWN-HEADED WOOD-BIRD.) +Hylophilus pœcilotis+, _Scl. et Salv. Nomencl._ p. 12; _Scl. Ibis_, 1881, p. 300; _White, P. Z. S._ 1882, p. 595 (Misiones); _Gadow, Cat. B._ viii. p. 308.