It is very common near Buenos Ayres; but I do not recollect having seen many in Banda Oriental. It sits on the bough of a tree, and very frequently on the ombu, which is planted in front of many of the farm houses, and thence takes short flights in pursuit of insects. From the remarkable structure of its tail, the inhabitants of the country call it scissor-tail; a name very well applied from the manner in which it opens and shuts the forked feathers of its tail. Like all birds thus constructed, (of which the frigate bird offers a most striking example), it has the power of turning very shortly in its flight, at which instant it opens and shuts its tail, sometimes, as it appears, in a horizontal and sometimes in a vertical plane. When on the wing it presents in its general appearance a caricature likeness of the common house swallow (_Hirundo rustica_). The Muscivora, although unquestionably belonging to the family of Muscicapidæ manifests in its habits an evident relationship with birds of the fissirostral structure. SUB-GEN. PYROCEPHALUS, GOULD. MUSCICAPA. _Auct._ MUSCIPETA. _Cuv._ TYRANNULA. _Swain._ _Rostrum capite brevius, rectum, depressum, basi setis numerosis nigris obsessum; mandibulâ superiore emarginatâ, inferiorem obtegente; naribus rotundatis patulis. Caput subcristatum. Alæ longæ; remige prima secundum tertiamque longissimas subæquales fere æquante. Tarsi mediocres, anticè scutellati; digitis lateralibus inæqualibus, exteriore longiore. Cauda mediocris quadrata._ Mr. Gould observes, that “the males of nearly all the members of this group (which may be considered either as a distinct genus or sub-genus of Myiobius), have the crown of the head and greater part of the under surface scarlet. Four species were obtained.—_Pyrocephalus parvirostris_, (_Gould_), and _Muscicapa coronata_, (_Auct._), may be taken as types. 1. PYROCEPHALUS PARVIROSTRIS. _Gould._ PLATE VI. Le Churrinche, _Azara_. No. 177. _P. suprà fuscus; capite et subtus nitidè puniceis; rectricibus exterioribus tectricumque et secundariorum apicibus griseo-marginatis._ Long. tot. 5⁵⁄₁₂ unc.; _alæ_, 13¹⁄₁₂; _caudæ_, 2⁵⁄₁₂; _tarsi_, ⁷⁄₁₂; _rost._, ⁶⁄₁₂. [Illustration: _Birds. Pl. 6._ _Pyrocephalus parvirostris._ ] [Illustration: _Birds. Pl. 7._ _Pyrocephalus nanus._ ] Crown of the head, crest, and all the under surface, bright scarlet; the remainder of the plumage, deep brown; the outer tail-feathers on each side, and the edges of the secondaries and wing-coverts, margined with grey. Habitat, La Plata, (_October._)