These Blackbirds were found by Mr. Ridgway abundant in the marshy regions of California, but they were rarely met with east of the Sierra Nevada. A few individuals were collected in Nevada in the valley of the Truckee. A few pairs were found breeding among the _tulé_ sloughs and marshes. The nests found in the Truckee Reservations were built in low bushes in wet meadows. A nest procured by Dr. Cooper from the summit of the Coast Range was built of grass and rushes, and lined with finer grass. The eggs are described as pale greenish-white, with large curving streaks and spots of dark brown, mostly at the large end. They are said to measure one inch by .75 of an inch. Eggs of this variety in my cabinet, taken in California by Dr. Heermann, are of a rounded-oval shape, nearly equally obtuse at either end, and varying in length from .90 of an inch to an inch, and in breadth from .70 to .80. Their ground-color is a light blue, fading into a bluish-white, marked only around the larger end with waving lines of dark brown, much lighter in shade than the markings of the _phœniceus_ usually are. Agelaius tricolor, BONAP. RED AND WHITE SHOULDERED BLACKBIRD. _Icterus tricolor_, “NUTTALL,” AUD. Orn. Biog. V, 1839, I, pl. ccclxxxviii.—NUTTALL, Man. I, (2d ed.,) 1840, 186. _Agelaius tricolor_, BON. List, 1838.—AUD. Syn. 1839, 141.—IB. Birds Am. IV, 1842, 27, pl. ccxiv.—HEERM. X, S, 53 (nest).—BAIRD, Birds N. Am. 1858, 530.—COOPER, Orn. Cal. 1, 1870, 265. SP. CHAR. Tail nearly even. Second and third quills longest; first a little shorter than the fourth. Bill slender, not half as high as long. _Male._ General color uniform lustrous velvet-black, with a strong silky-bluish reflection. Shoulders and lesser wing-coverts brownish-red, of much the color of venous blood; the median coverts of a well-defined and nearly pure white, with sometimes a brownish tinge. Wing, 4.90; tail, 3.70; culmen, .97; tarsus, 1.13. _Female._ General color dusky slaty-brown, faintly variegated on head also by lighter streaks; middle wing-coverts broadly and sharply bordered with pure white. An obsolete superciliary and maxillary stripe of grayish-white. Beneath grayish-white for anterior half, with narrow streaks of dusky, this color gradually prevailing posteriorly, the sides, flanks, and crissum being nearly uniform dusky. Wing, 4.25; tail, 3.20. HAB. Pacific Province of United States, from Columbia River southward, not yet found out of California and Oregon.