HABITS. This species was first noticed as belonging to the North American fauna by Captain McCown, who obtained it near Ringgold Barracks in 1850. It has since been noticed at Fort Yuma and at San Diego, and obtained in greater abundance at Cape St. Lucas. It is also found in Mexico. Dr. Cooper says that it is common all winter both at San Diego and at Fort Mohave. It has been traced as far north as latitude 30° in the Sierra Nevada. Its song he describes as a harsh ditty of five parts, something like a wren’s song, with notes like those of a swallow, and also closely resembling the song of _Vireo belli_. Their scolding note is a faint mew, like that of a cat. The habits of this species appear to be not unlike those of the peculiar family to which it belongs. All its members are among our smallest birds, are almost exclusively inhabitants of woods, and resemble the _Reguli_ in their restless activity in pursuit of the smallest insects on which they feed. This bird is described as particularly active, quick in its movements, searching with great activity for its food, and preferring low trees and bushes. At times it will dart about in the air in pursuit of small insects. Mr. John Xantus found these birds to be quite abundant at Cape St. Lucas, and obtained several of their nests. They were generally built among the interlacing tendrils of a wild vine (_Antigonon leptopus_), and so closely interwoven with the smaller branches as to be inseparable. The nests, like those of all this family, are structures of great beauty and delicacy. They have a height and an external diameter of about 2¼ inches. The cavity is 1½ inches wide at the rim, and fully two inches deep. This great proportionate depth of the nest seems to be characteristic of this genus. The external portion of this nest is composed of a composite blending of various vegetable materials, fine hempen fibres of plants, strips of delicate bark from smaller shrubs, silken fragments of cocoons and downy cotton-like substance, all very closely impacted and felted together, somewhat after the manner of the Humming-Bird. The whole is very softly and warmly lined with a beautifully interwoven and silky fabric composed of the soft down of various plants. The walls of the nest, though of the softest materials, are so thick and so firmly impacted as to make it a structure remarkably firm and secure against accidents. The eggs, four in number, measure .55 of an inch in length by .45 in breadth. They are of an oblong-oval shape, their ground-color is a pale greenish-white sprinkled over the entire surface with fine dottings of purple, reddish-brown, and black. FAMILY CHAMÆADÆ.—THE GROUND-TITS.