Mr. Dall, in his notes on the birds of Alaska, states that this Warbler is a rather common bird all through that territory, and gives its arrival as about the 10th of May. Its extreme southern limit is not so distinctly traced, but is at least as far as the northern portions of South America, inclusive of Cayenne and Ecuador. In all of the West Indies except Trinidad it is replaced by several closely allied species or local races. In Trinidad, Mr. E. C. Taylor states that he found this species common, and could perceive no difference from North American specimens. In Guatemala it is abundant in the winter. Dr. Coues found this Warbler abundant in Arizona, where it is a summer resident, from April 25 to the middle of September. There, as elsewhere, its preference for watercourses was noticed. Wherever found, it is always most abundant in alluvial meadows, and more rare in other localities. Dr. Samuel Cabot found this Warbler common in Central America, and Dr. Cragin, of Surinam, sent the Boston Society several specimens from Guiana. Dr. Woodhouse found it abundant in Texas and New Mexico, as did Drs. Suckley and Cooper in Washington Territory and California. It breeds over the whole area of North America, from Georgia on the southeast and from Mexico, northward. Dr. Sumichrast found it, only as a migratory bird, abundant on the plains of Mexico. The notes of Mr. Kennicott and the memoranda of Messrs. McFarlane, Ross, and Lockhart attest the extreme abundance of this species in the farthest Arctic regions. In nearly every instance the nests were placed in willows from two to five feet from the ground, and near water. In one instance Mr. Ross found the eggs of this species in the nest of _Turdus swainsoni_, which had either been deserted or the parent killed, as the eggs were in it, and would probably have been hatched by the Warbler with her own. Dr. Cooper found this Warbler very abundant in Washington Territory, and noticed their arrival in large numbers at the Straits of Fuca as early as April 8.