Durnford describes the nest, found in a rush-bed, as a circular or domed structure of grass, with the aperture at the side; the eggs white. 202. SYNALLAXIS PATAGONICA (Lafr. et d'Orb.). (PATAGONIAN SPINE-TAIL.) +Synallaxis patagonica+, _Hudson, P. Z. S._ 1872, p. 544 (Rio Negro); _Scl. et Salv. Nomencl._ p. 64; _Scl. P. Z. S._ 1874, p. 24; _Durnford, Ibis_, 1877, p. 35 (Chupat). _Description._--Above greyish earthy brown; wing-feathers blackish brown, basal halves of secondaries very pale clear brown, forming a transverse band; tail blackish, edged with greyish brown; outer web of outer feather on each side pale brown; beneath cinereous, with an obscure blackish spot on the throat; belly and flanks dull buff; under wing-coverts cinnamomeous; bill and feet blackish: whole length 6·0 inches, wing 2·2, tail 2·5. _Female_ similar. _Hab._ Patagonia. This dull-coloured little bird, which is found in Patagonia and also near the Andes in the north-western provinces of the Argentine Republic, is one of those species which diverge greatly in habits from the typical _S. ruficapilla_ and its nearest allies. The body is stout, the tail, square and short, is carried vertically as in the House-Wren. The Patagonian Spine-tail is a resident in the Rio Negro district. It is a silent, shy, solitary little bird, which lives on the ground and seeks its food after the manner of the Cachalote (_Homorus_). Being small and feeble, however, it does not hunt about the roots of trees and large bushes like the larger and more powerful _Homorus_, but keeps under the diminutive scrubby plants in open sterile situations. About the roots of these wiry little bushes, only twelve to eighteen inches high, the bird searches for small insects, and when disturbed has a feeble jerky flight, which carries it to a distance of about twenty yards. It flies with great reluctance, and when approached runs swiftly away, leaving a person in doubt as to whether he has seen a mouse or a little obscure bird. The only note I have heard it utter is a faint creaking sound when alarmed or flying. 203. SYNALLAXIS HUDSONI, Scl. (HUDSON'S SPINE-TAIL.) +Synallaxis hudsoni+, _Scl. P. Z. S._ 1874, p. 25; _Durnford, Ibis_, 1877, p. 36, et 1878, p. 396 (Chupat, Central Patagonia); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 209 (Azul, Sierra de la Ventana). +Synallaxis sclateri+, _Cab. J. f. O._ 1878, p. 196.