A nest of this bird presented by Mr. Nuttall to Audubon was cylindrical in form, nine inches in length and three and a half in diameter. It was suspended from the fork of a small twig, and was composed externally of hypnum, lichens, and fibrous roots so interwoven as to present a smooth surface, with a few stems of grasses and feathers intermingled. The aperture was at the top, and did not exceed seven eighths of an inch in diameter. The diameter of the internal passage for two thirds of its length was two inches. This was lined with the cottony down of willows and a vast quantity of soft feathers. The eggs were nine in number, pure white, .56 of an inch by .44 in their measurement. Dr. Cooper found them throughout the year near San Francisco. He found one of their nests at San Diego as early as the first of March. The nest is so large, compared with the size of the birds, as to suggest the idea that the flock unite to build it. He gives the measurements as eight inches in length and three in diameter, outside; the cavity five inches long, one and a half in diameter. It was cylindrical, and suspended by one end from a low branch. When one of these birds is killed, Dr. Cooper says that the others come round it with great show of anxiety, and call plaintively until they find it will not follow them, becoming so fearless as almost to allow of their being taken by the hand. Psaltriparus minimus, var. plumbeus, BAIRD. LEAD-COLORED BUSH-TITMOUSE. _Psaltria plumbea_, BAIRD, Pr. A. N. S. VII, June, 1854, 118 (Little Colorado). _Psaltriparus plumbeus_, BAIRD, Birds N. Am. 1858, 398, pl. xxxiii, fig. 2; Review, 84.—SCLATER, Catal. 1861, 398, no. 77.—COOPER, Birds Cal. 1, 49. SP. CHAR. Tail long, feathers graduated. Above rather light olivaceous-cinereous. Top of head rather clearer; forehead, chin, and sides of head, pale smoky-brown. Beneath brownish-white, scarcely darker on the sides. Length about 4.20 inches; wing, 2.15; tail, 2.50. HAB. Southern Rocky Mountain region of United States, from mountains of West Arizona to Green River, Wyoming; west to Carson City, Nevada (RIDGWAY). This variety is very similar to the _Psaltriparus minimus_ of the west coast, which it represents in the Rocky Mountain region. It is, however, appreciably larger, the wings and tail proportionally longer. The top of the head is plumbeous, uniform with the back, instead of smoky-brown. The back is a paler ash, the under parts darker.