HABITS. The Black-throated Gray or Dusky Warbler, so far as is now known, belongs to the Western and Middle Provinces, occurring certainly as far to the south as San Diego, in California, and as far to the north as Fort Steilacoom, in Washington Territory, penetrating in winter into Mexico. The most easterly localities in which it has been met with are in Arizona and New Mexico. The Smithsonian Institution has received specimens also from Columbia River, Calaveras, Cal., and Fort Defiance. This species was first obtained and described by Mr. Townsend, who found it abundant in the forests of the Columbia, where it breeds and remains until nearly winter. Its nest, which he there met with, resembles that of _Parula americana_, only it is made of the long and fibrous green moss, or _Usnea_, peculiar to that region, and is placed among the upper branches of oak-trees, suspended between two small twigs. Mr. Nuttall states that it arrives on the Columbia early in May, and from the manner in which its song was delivered at intervals, in the tops of deciduous trees, he had no doubt that they were breeding in those forests as early as May 23. This song he describes as delicate, but monotonous, uttered as it busily and intently searches every leafy bough and expanding bud for insects and their larvæ in the spreading oak, in which it utters its solitary notes. Its song is repeated at short and regular intervals, and is said by Mr. Nuttall to bear some resemblance to _t-shee-tshāy-tshaitshee_, varying the feeble sound very little, and with the concluding note somewhat slenderly and plaintively raised. Dr. Suckley speaks of this bird as moderately abundant near Fort Steilacoom, generally met with on oaks, and very much resembling _Dendroica auduboni_ in its habits. Its arrival there he gives as occurring in the first week in April, or a month earlier than stated by Nuttall. Dr. Cooper met with a pair at Puget Sound that appeared to have a nest, though he sought for it in vain. He describes its note as faint and unvaried. Dr. Coues met with this Warbler in the vicinity of Fort Whipple, Arizona. He speaks of it as common there as a spring and autumn migrant. He thinks that a few remain to breed. It arrives in that Territory about April 20, and is found until late in September. It is most common among the pine-trees, and in its general habits is stated to resemble the new species _D. graciæ_. Dr. Heermann found a few birds of this species near Sacramento, and also on the range of mountains dividing the Calaveras and the Mokelumne Rivers. During the survey by Lieutenant Williamson’s party, Dr. Heermann met with a single specimen among the mountains, near the summit of the Tejon Pass. It was in company with other small birds, migrating southward, and gleaning its food from among the topmost branches of the tallest oaks. He states that its notes closely resemble the sounds of the locust.