The STILTED FLY-CATCHERS (_Fluvicolæ_) constitute a group of South American birds differing in many particulars from the Tyrant Shrikes. The members of this group are recognisable by their large, powerful bodies, and their long wings and tail, in the former of which the first quill is only a trifle shorter than the second. They have strong legs, high tarsi, and thick, sharp claws. Their large, high, and slender beak is of a conical form, and but very slightly bent at its extremity. Their thick plumage is heavy, and is composed of small feathers, presenting but a very slight development of down. The base of the beak is covered with stiff bristles, of which from three to five of still stiffer and larger size are scattered over the region of the cheek-stripes. The Stilted Fly-catchers are frequently met with in the immediate neighbourhood of human habitations, and in such open plains as are almost entirely destitute of trees or bushes, near ponds, rivers, or even in marshy districts, everywhere subsisting upon insects, and carrying on the pursuit of their prey exactly in the same manner as the birds above described. THE YIPERU, OR YETAPA. The YIPERU, or YETAPA--Cunningham's Bush Shrike--(_Gubernates Yiperu_), a well-known member of this group, has a slender body, large wings, and very long, forked tail. Its beak is thick and broad at its base, the upper mandible considerably arched, and furnished with a strong, short hook at its extremity; the legs, though short, are powerful, the toes of moderate size, and armed with slightly-curved claws. The plumage is thick and soft, that of the wings and tail being unusually heavy. The back and under side of the body are grey, the wings and tail black, with a white patch at the shoulder, and a light red spot on the outer web of the large quills. The throat is white, separated from the grey breast by a reddish brown line, which extends as far as the eyes; the brow is of a whitish shade, the eye itself reddish brown, and the beak and feet black. The length of this species is fifteen inches, of which nine are included in the length of the exterior tail-feathers, whilst those in the centre are not more than two and a half inches long. The span of the wings is about fifteen inches. We learn from Azara that the Yetapas principally frequent such plains as are only partially covered with brushwood or trees, and fly about in small parties, seeking for their insect food upon the ground. Their cry is monotonous but penetrating. THE COCK-TAILED FLY-CATCHER.