[Illustration 268: Nighthawk.] [Illustration: Grayish white.] [Illustration: Grayish white.] [Illustration: left hand margin.] Page 267 [Illustration 269: J. E. Seebold. NEST AND EGGS OF NIGHTHAWK.] Page 268 420c. SENNETT'S NIGHTHAWK. _Cordeiles virginianus sennetti._ Range.--A very pale species with little or no tawny; found in the Great Plains from Texas north to the Saskatchewan; winters south of the United States. 421. TEXAS NIGHTHAWK. _Chordeiles acutipennis texensis._ Range.--Mexico and Central America, breeding north to southern Utah and California. The pattern of the marking of this species is finer and more mottled with rusty than the Nighthawk. Its habits do not differ to any extent from those of the preceding species; they lay their two mottled gray eggs upon the bare ground, often on the dry sand and in arid regions where they are exposed, with no protection, to the scorching rays of the sun. The eggs vary endlessly in extent of markings, some being very pale and others very dark gray, mottled with various shades of gray, brown and lilac. Size 1.10 x .75. SWIFTS. Family MICROPODIDÆ 422. BLACK SWIFT. _Cypseloides niger borealis._ Range.--Mountain ranges from Central America north to British Columbia, locally distributed throughout its range. The plumage of this Swift is entirely sooty black, darkest above; the tail is slightly forked and is without spines; length of bird, 7 inches. Although the general habits of this species are well known, little is known of their nesting; they are seen during the breeding season about the higher ranges throughout their United States habitat, and are supposed to nest in crevices on the face of cliffs at a high altitude. [Illustration 270: 420-421.] [Illustration: Grayish white.] [Illustration: 422-424.] [Illustration: left hand margin.] Page 269 423. CHIMNEY SWIFT. _Chætura pelagica._ Range.--North America east of the Plains, breeding from central Canada, south to the Gulf coast, and wintering south of our borders. This well known species is sooty brownish black, 5.5 inches long, and has the tail feathers terminating in sharp spines. They are very abundant in all portions of their range, and may be seen on the wing at all hours of the day, but especially abundant in the early morning and toward dusk. They formerly dwelt and bred only in hollow trees, and a great many still continue to do so, as large hollow stumps are known where hundreds nest every year. The majority of the eastern Chimney Swifts now nest in old chimneys that are unused, at least during the summer; some small chimneys contain but a single pair while other large ones may have from fifty to a hundred or more nests glued to the sides. The birds are on the wing during the greater part of the day, generally not frequenting the vicinity of their nesting site, but returning toward dusk, when they may