The Guira-yetapá is a very curious little bird, with a black, white, and grey plumage and the beak of a true Tyrant; but it differs from all its congeners in having the skin of the chin, throat, and sides of the head bare of feathers, and these parts in the breeding-season are a bright orange colour. It is a feeble flier, its wings being very short, while the two outer tail-feathers are abnormally long and peculiar in form. Mr. Barrows says:--"The remarkable condition of the outer pair of tail-feathers is interesting. In the male these two feathers reach a length of nearly ten inches, the rest of the tail being about three inches in length. The vane on the _inner_ side of each is wanting for the first two inches, and then suddenly develops to a width of nearly two inches, which it maintains almost to the tip, when it gradually narrows. The vane on the _outer_ side of the shaft is only about one-quarter of an inch wide, and is folded so tightly against the shaft that it is quite inconspicuous. In the only two males of this species which I have seen flying, these long feathers seemed to be carried folded together _beneath_ the rest of the tail, and stretching out behind like a rudder or steering-oar, their vanes at right angles to the plane of the rest of the tail." Mr. Gibson gives a different account, and says the flight is singularly feeble, resembling the fluttering passage of a butterfly through the air, while the tail streams out behind. It inhabits Paraguay, Uruguay, and the eastern portion of the Argentine Republic, ranging as far south as the pampas in the neighbourhood of Patagonia. It is usually seen singly or in pairs; Azara says he saw a flock of thirty individuals, but as they were all _females_, it may be that in this species, as in _Lichenops perspicillata_, the females are sometimes gregarious, and the males always solitary. It frequents open places, such as the borders of marshes, or plains covered with tall grasses, and perches in a conspicuous place, from which it darts at passing insects like a Flycatcher. Mr. Gibson found its nest on the ground amongst herbage, and describes it as a neat structure of dried grass, containing three white eggs with a faint cream-coloured tinge. 124. CYBERNETES YETAPA (Vieill.). (YETAPA TYRANT.) +Cybernetes yetapa+, _Scl. et Salv. Nomencl._ p. 43; _White, P. Z. S._ 1882, p. 604 (Itapua, Misiones).