ROCK WREN. _Troglodytes obsoletus_, SAY, Long’s Exped. II, 1823, 4 (south fork of Platte).—AUD. Orn. Biog. IV, pl. ccclx.—IB. B. A. II, pl. cxvi.—NEWBERRY, P. R. R. Rep. VI, IV, 1857, 80.—HEERMANN, P. R. R. Rep. X, 1859, 41. _Salpinctes obsoletus_, CAB. Wiegmann’s Archiv, 1847, I, 323.—BAIRD, Birds N. Am. 1858, 357; Rev. 110.—SCLATER, P. Z. S. 1859, 371 (Oaxaca).—COOPER, Orn. Cal. 1, 1870, 64. _? Troglodytes latisfasciatus_, LICHT. Preis-Verzeich. 1831, no. 82. [Line drawing: _Salpinctes obsoletus._ 7157 ♂] SP. CHAR. Plumage very soft and lax. Bill about as long as the head. Upper parts brownish-gray, each feather with a central line and (except on the head) transverse bars of dusky, and a small dull brownish-white spot at the end (seen also on the tips of the secondaries). Rump, sides of the body, and posterior part of belly and under tail-coverts dull cinnamon, darker above. Rest of under parts dirty white; feathers of throat and breast with dusky central streaks. Lower tail-coverts banded broadly with black. Inner tail-feathers like the back, the others with a broad black bar near the end; the tips cinnamon; the outer on each side alternately banded with this color and black. A dull white line above and behind the eye. Iris brown. Length, 5.70; wing, 2.82; tail, 2.40. Young not marked or banded beneath. Eggs white, spotted with red. HAB. Central regions of the United States, to Mexico, east to mouth of Yellowstone River. Cape St. Lucas. Not recorded from Pacific slope. W. Arizona, Coues. Oaxaca, SCLATER. [Illustration: _Salpinctes obsoletus._]