Upper part of head and hind neck light reddish-brown, the latter with a white spot; back light greyish-blue; quills brownish-black, edged with light greyish-blue; middle tail-feathers of the same colours, the rest black, the outer three with a broad band of white near the end; lower parts yellowish-white, the sides greyish-blue. _Male_, 4, 8. From Texas to Maryland. In the interior to Mississippi. Extremely abundant. Louisiana, Georgia, Alabama, Florida, and the Carolinas. Resident. Brown-headed Nuthatch, Sitta pusilla, Wils. Amer. Orn. v. ii. p. 105. Sitta pusilla, Bonap. Syn. p. 97. Brown-headed Nuthatch, Nutt. Man. v. i. p. 584. Brown-headed Nuthatch, Sitta pusilla, Aud. Orn. Biog. v. ii. p. 151. 250. 4. Sitta pygmæa, Vigors. Californian Nuthatch. Plate CCCCXV. Figs. 3, 4. Adult. Upper part of head and hind neck dull greyish-brown; back dull leaden-grey; quills and tail-feathers dusky, margined with light grey, the lateral two feathers on each side with a white band toward the base; lower parts brownish-white. _Adult_, 3-10/12, wing, 3-5/12. California. Californian Nuthatch, Sitta pygmæa, Aud. Orn. Biog. v. v. p. 163. FAMILY XXIV. TROCHILINÆ. HUMMINGBIRDS. Bill long, very slender, straight or arched, somewhat depressed at the base, subcylindrical, flexible, acute. Head rather large; neck of moderate length; body moderately robust. Feet very short, rather stout; tarsus extremely short; toes of moderate size; the anterior coherent at the base, and nearly of equal length, the hind toe articulated high on the tarsus; claws rather long, arched, much compressed, very acute. Plumage compact above, soft and blended beneath, often with metallic lustre; wings very long, extremely narrow, falciform, with the first quill longest, the other primaries rapidly diminishing; secondaries extremely short. Tail various, of ten feathers. Tongue very long, slender, with two flat, thin-edged terminal filaments, and extensile by means of the elongation of the hyoid bones, which curve over the head to the fore part of the forehead, and with their muscles slide in a groove, like those of the Woodpeckers. Œsophagus narrow, considerably enlarged about the middle; stomach extremely small, roundish, moderately muscular, its epithelium dense and longitudinally rugous; intestine very short and of moderate width; no cœca; cloaca globular. Trachea simple, but divided very high up on the neck, so that the bronchi are of excessive length, with a large pair of inferior laryngeal muscles. GENUS I. TROCHILUS, Linn. HUMMINGBIRD.