In this species the bill is rather long; the wings are very short, and much rounded; the tertials equal to the primaries; the secondaries rather shorter; the first quill is .65 of an inch shorter than the seventh, which is longest. The tail is short; the lateral feathers much graduated; the outer half an inch shorter than the middle. All the Mexican specimens before us have the bill stouter than those from the Rio Grande of Texas, the stripes on the head apparently better defined. The back is darker olive; the flanks brighter olive-green, not olive-gray, the wings are apparently shorter. The series is not sufficiently perfect to show other differences, if any exist. [Illustration: _Embernagra rufivirgata._] HABITS. In regard to the habits and distribution of this species we are entirely without any information, other than that it has been met with in the valley of the Rio Grande, and at various places in Mexico. Specimens were obtained at New Leon, Mexico, by Lieutenant Couch, and at Ringgold Barracks, in Texas, by Mr. J. H. Clark. The season when these birds were met with is not indicated by him. It is stated by Mr. Sumichrast that this species is found throughout both the temperate and the hot districts of the State of Vera Cruz, Mexico. He also mentions that he has found this bird in localities quite remote from each other, and belonging both to the hot and to the temperate regions. In the latter it is found to the height of at least four thousand feet. This species was met with by Mr. Boucard, during the winter months, at Plaza Vicente, in the hot lowlands of the State of Oaxaca, Mexico. SUBFAMILY PASSERELLINÆ. CHAR. Toes and claws very stout; the lateral claws reaching beyond the middle of the middle one; all very slightly curved. [Line drawing: _Passerella iliaca_. 846] Bill conical, the outlines straight; both mandibles equal; wings long, longer than the even tail or slightly rounded, reaching nearly to the middle of its exposed portion. Hind claw longer than its digit; the toe nearly as long as the middle toe; tarsus longer than the middle toe. Brown above, either uniformly so or faintly streaked; triangular spots below. This section embraces a single North American genus, chiefly characterized by the remarkable elongation of the lateral claws, as well as by the peculiar shape and large size of all the claws; the lateral, especially, are so much lengthened as to extend nearly as far as the middle. The only approach to this, as far as I recollect, among United States _Conirostres_, is in _Pipilo megalonyx_, and _Xanthocephalus icterocephalus_. GENUS PASSERELLA, SWAINSON. _Passerella_, SWAINSON, Class. Birds, II, 1837, 288. (Type, _Fringilla iliaca_, MERREM.)