Professor Verrill found this Warbler a common summer visitant in Western Maine, arriving about the second week in May, and remaining there to breed. Mr. Boardman thinks it reaches Eastern Maine about the middle of May, and is a common summer resident. I did not meet this species either in New Brunswick or Nova Scotia, nor was Dr. Bryant more fortunate, but Lieutenant Bland gives it in his manuscript list of the birds found in the neighborhood of Halifax. Mr. Ridgway informs me that this species breeds in the oak openings and among the prairie thickets of Southern Illinois. During the eight months that are not included in their season of reproduction, this species is scattered over a wide extent of territory. Their earliest appearance in the Northern States (at Plattesmouth) is April 26, and they all disappear early in September. At other times they have been met with in the Bahamas, in Mexico, Guatemala, Costa Rica, and Panama. It has not yet been detected in the West Indies. M. Boucard obtained specimens at Playa Vicente, in the hot country of Oaxaca, Mexico. In the neighborhood of Calais, Mr. Boardman informs me that this Warbler is common, and that its habits resemble those of the Black-poll Warbler more than those of any other of the genus. It always nests in bushes or in low trees, and in the vicinity of swamps. Among the memoranda furnished to the late Mr. Kennicott by Mr. Ross is one to the effect that the Chestnut-sided Warbler was observed at Lake of the Woods, May 29. How common it is at this point is not stated. Mr. C. S. Paine regards the Chestnut-sided Warbler as one of the sweetest singers that visit Vermont. He describes it as very confiding and gentle in its habits. It is chiefly found inhabiting low bushes, in the neighborhood of taller trees, and it always builds its nest in the fork of a low bush, not more than from three to five feet from the ground. He has seen many of their nests, and they have all been in similar situations. They will permit a very near approach without leaving their nests. These are constructed about the last of May. Their song continues until about the last of June. After this they are seldom heard. J. Elliot Cabot, Esq., had the good fortune to be the first of our naturalists to discover in June, 1839, the nest and eggs of this Warbler. It was fixed on the horizontal forked branch of an oak sapling, in Brookline, Mass. The female remained sitting on her nest until so closely approached as to be distinctly seen. The nest was of strips of red-cedar bark, and well lined with coarse hair, and was compact, elastic, and shallow. It contained four eggs, the ground-color of which was white, over which were distributed numerous distinct spots of umber-brown. These were of different sizes, more numerous towards the larger end.