A nest with eggs, procured at Fort Mohave by Dr. Cooper, is in the Smithsonian Collection (No. 7,276). The egg measures .93 by .70 of an inch, is obovate in shape, being much rounded at the smaller end. Its ground-color is a dull white, without any perceptible tinge of blue,—though possibly bluish when fresh,—with heavy dots and occasional delicate, hair-like, zigzag markings of black. These markings are wholly confined to the larger end. One of the eggs has these markings much finer, consisting of minute dots, more dense, and upon the apex of the larger end. The nest is loosely built and very bulky. Its external diameter is about six inches, and its depth three. The cavity is three inches wide and two deep. It is constructed almost entirely of strips of inner bark, the coarser, ribbon-like pieces being used on the outer portion, and the finer shreds composing the lining. Externally are also a few sticks about one quarter of an inch in diameter. SECTION IV. _Crown rufous; body above, olive-green._ Pipilo chlorurus, BAIRD. GREEN-TAILED BUNTING; BLANDING’S FINCH. _Fringilla chlorura_, (TOWNSEND,) AUD. Orn. Biog. V, 1839, 336 (Young). _Zonotrichia chlorura_, GAMBEL, J. A. N. Sc. Ph. 2d Series, I, 1847, 51. _Embernagra chlorura_, BONAP. Conspectus, 1850, 483. _Fringilla blandingiana_, GAMBEL, Pr. A. N. Sc. Ph. I, April, 1843, 260. _Embernagra blandingiana_, CASSIN, Illus. I, III, 1853, 70, pl. xii. _Pipilo rufipileus_, LAFRESNAYE, Rev. Zoöl. XI, June, 1848, 176.—BP. Conspectus, 1850, 487. _Kieneria rufipileus_, BON. Comptes Rendus, XL, 1855, 356. _Pipilo chlorura_, BAIRD, Birds N. Am., 1858, 519.—HEERM. X, c, 15.—COOPER, Orn. Cal. 1, 248. SP. CHAR. Above dull grayish olive-green. Crown uniform chestnut. Forehead with superciliary stripe, and sides of the head and neck, the upper part of the breast and sides of the body, bluish-ash. Chin and upper part of throat abruptly defined white, the former margined by dusky, above which is a short white maxillary stripe. Under tail-coverts and sides of body behind brownish-yellow. Tail-feathers generally, and exterior of wings, bright olive-green, the edge and under surface of the wings bright greenish-yellow; edge of first primary white. First quill longer than eighth, fourth longest. Length, about 7 inches; wing, 3.20; tail, 3.65. HAB. Whole of the Middle Province, including the Rocky Mountains and eastern slope of the Sierra Nevada; north to beyond the 40th parallel; south to Mexico. In this species the wing is considerably rounded, the tertials considerably shorter than the primaries, and not exceeding the secondaries; the fourth quill longest, the first shorter than the sixth, the second and fifth quills considerably longer than the rest. The tail is long and considerably graduated, the outer feather half an inch shortest; the feathers broad and obtusely pointed, the corners rounded.