_Description._--Above and below nearly uniform chestnut, tinged with olivaceous on the crown and throat; narrow shaft-spots on the breast-feathers whitish, forming faint lines; beak pale horn-colour; feet bluish grey: whole length 11·10 inches, wing 5·5, tail 4·0. _Female_ similar. _Hab._ North Argentina, Paraguay, and Bolivia. This large and powerful Wood-hewer is confined to the hottest portion of the Argentine Republic, and also inhabits Paraguay and Bolivia. White met with it at Oran, in the province of Salta, and writes concerning its habits:--"Common here in the dense forest, where their continued hard pecking at the lofty tree-trunks is very accentuated. Two or three at a time maintain a continued race up a magnificent clear stem as far as the branches, when they fly to the bottom of the next and do likewise." This species is nearly a foot in length, the beak being about two inches long, curved and very powerful. The tail is stiff, being used as a support in climbing, and the claws are strong and sharply hooked. The colour of the whole plumage is nearly uniformly bright rufous. 221. PICOLAPTES ANGUSTIROSTRIS (Vieill.). (NARROW-BILLED WOOD-HEWER.) +Picolaptes angustirostris+, _Scl. et Salv. Nomencl._ p. 69; _White, P. Z. S._ 1883, p. 433 (Cordova). +Lepidocolaptes atripes+, _Barrows, Auk_, 1884, p. 21 (Entrerios). _Description._--Above, head and neck blackish, with oblong whitish shaft-spots on the crown and neck; broad superciliaries white, extending nearly to the back and broken at their lower ends into shaft-spots; rest of upper surface dull brown, brighter on the rump; wing-feathers pale obscure chestnut; outer webs and broad tips of primaries blackish; tail chestnut; beneath white, clearer on the throat; sides of breast and belly thickly marked with faint blackish stripes; under wing-coverts cinnamon; bill pale horn-colour; feet grey: whole length 8·2 inches, wing 3·8, tail 2·5. _Female_ similar. _Hab._ Paraguay and Argentina. This is the only member of the genus _Picolaptes_ as yet met with within the limits of the Argentine Republic. Azara found it abundant in Paraguay, and on this account named it the Common Climber, "_Trepador comun_." In Buenos Ayres it is a summer visitant, appearing at the end of September. It is a solitary bird, never seen away from the woods, and invariably utters a loud melancholy cry when passing from one tree to another. It always alights on the trunk close to the ground, clinging to the bark in a vertical position, supported by the tail, and with head thrown far back in order to give free play to the extremely long beak. Having thus alighted, it progresses upwards by short hops, exploring the crevices in the wood for small insects, until it reaches the branches, when it flies off to the next tree. Fam. XVIII. FORMICARIIDÆ, or ANT-BIRDS.