HAB. Adjacent borders of the United States and Mexico, from the mouth of the Rio Grande to the Valley of the Colorado, and to the Pacific coast of Southern California. Replaced at Cape St. Lucas by _C. affinis_. This species is found abundantly along the line of the Rio Grande and Gila, extending northward some distance, and everywhere conspicuous by its wren-like habits and enormous nest. [Illustration: _Campylorhynchus brunneicapillus._] HABITS. The Brown-headed Creeper is a comparatively recent addition to the fauna of the United States, but appears to be common along the southwestern borders of the United States, from the valley of the Rio Grande to San Diego, in California. In Lower California it is replaced by the _C. affinis_. It was first added to our avifauna by Mr. Lawrence in 1851, on the strength of a specimen obtained in Texas by Captain McCown. Dr. Heermann, in his paper on the Birds of California, speaks of finding it in the arid country back of Guymas, on the Gulf of California. This country, presenting only broken surfaces and a confused mass of volcanic rocks, covered by a scanty vegetation of thorny bushes and cacti, among other interesting birds, was found to contain this species in abundance. He describes it as a lively, sprightly species, uttering, at intervals, clear, loud, ringing notes. Its nest, composed of grasses and lined with feathers, was in the shape of a long purse, enormous for the size of the bird, and laid flat between the forks or on the branches of a cactus. The entrance was a covered passage, varying from six to ten inches in length. The eggs, six in number, he described as being of a delicate salmon-color, very pale, and often so thickly speckled with ash and darker salmon-colored spots as to give quite a rich cast to the whole surface of the egg. Lieutenant Couch met with these birds near Monterey. He states that they have a rich, powerful song. Of the nest he gives substantially the same description as that furnished by Dr. Heermann. The eggs are of an oblong-oval shape, slightly more pointed at one end, and are so equally and generally covered, over a white ground, with fine salmon-colored spots, as to present a uniform and almost homogeneous appearance. They vary in length from an inch to 1.02 inches, and have an average breadth of .68 of an inch. Campylorhynchus affinis, XANTUS. THE CAPE CACTUS WREN. _Campylorhynchus affinis_, XANTUS, Pr. A. N. Sc. 1859, 298 (Cape St. Lucas).—BAIRD, Pr. A. N. Sc. 1859, 303; Rev. 100.—SCL. Catal. 1861, 17, no. 108.—ELLIOT, Illust. B. N. A. I, IV.—COOPER, Orn. Cal. 1, 1870, 62.