The species was based by Mr. Audubon on a skin brought by him from the mouth of the Yellowstone River, in 1843, in rather defective and worn plumage. This has hitherto
served as the basis of all the descriptions of the species which is justly considered one of the rarest in the North American fauna.
Habits. In regard to the habits, distribution, or general history of this very rare species, but little is known, only one specimen having been met with. This was procured by Mr. Audubon’s party to the Yellowstone River, in Dakota, on the last day of July, 1843. That it is a resident where obtained, certainly during the breeding-season, is a natural inference from the circumstances of its capture. That it may be a common bird in certain other portions of the region, immediately north of Dakota, is quite probable. Its close habits, as described by Mr. Audubon, favor its escaping notice wherever it may exist.
The specimen was met with in a wet place, overgrown closely by a kind of slender rush-like grass, from the midst of which the notes of these birds were heard, and at first mistaken for those of the Marsh Wren. A search was immediately instituted for the singers, which Mr. Bell soon ascertained could not be the Wren in question, the notes being much softer and more prolonged. Much difficulty was encountered in the endeavor to raise them from the long close grass to which they closely confined themselves, and they were several times nearly trodden on before they would take wing, almost instantaneously realighting within a few steps, and running like mice through the grass. After a while two were shot while on the wing, and proved to be adult male and female. The party found this species quite abundant in all such situations, and there seems to have been no doubt that it was breeding.
Genus PASSERCULUS, Bonap.
Passerculus, Bonap. Comp. List Birds, 1838. (Type, Fringilla savanna.)
Passerculus savanna.
7108
Gen. Char. Bill moderately conical; the lower mandible smaller; both outlines nearly straight. Tarsus about equal to the middle toe. Lateral toes about equal, their claws falling far short of the middle one. Hind toe much longer than the lateral ones, reaching as far as the middle of the middle claw; its claws moderately curved. Wings unusually long, reaching to the middle of the tail, and almost to the end of the upper coverts. The tertials nearly or quite as long as the primaries; the first primary longest. The tail is quite short, considerably shorter than the wings; as long as from the carpal joint to the end of the secondaries. It is emarginate, and slightly rounded; the feathers pointed and narrow.
The essential characters of this well-marked genus lie in the elongated wings, longer than the tail, the tertiaries equal to the primaries, the first