Mr. R. Deane, of Cambridge, found this bird breeding near Lake Umbagog. Its nest was in the fork of a low spruce about three feet from the ground. The nest contained four eggs, and was made of dry grasses, spruce twigs, and rootlets. It was lined with fine black roots, being a rather coarse structure for a Warbler. The eggs were nearly spherical, averaging .62 by .51 of an inch. Their ground-color was a creamy-white, sparsely marked with a few large blotches of lilac and umber. Dendroica cærulea, BAIRD. CÆRULEAN WARBLER; WHITE-THROATED BLUE WARBLER. _Sylvia cærulea_, WILS. Am. Orn. II, 1810, 141, pl. xvii, fig. 5. _Sylvicola c._ SWAINS.; JARD.; RICH.; BON.; AUD. Orn. Biog. I, pl. xlix; NUTT. _Dendroica c._ BAIRD, Birds N. Am. 1858, 280; Rev. 191.—GUNDL. Cab. Jour. 1861, 326 (Cuba; very rare).—SAMUELS, 579. _Sylvia rara_, WILSON, II, pl. xxvii, fig. 2.—BON.; AUD. Orn. Biog. I, pl. xlix. _Sylvia azurea_, STEPH. Shaw, Zoöl. X, 1817.—BON. Am. Orn. II, 1828, pl. xxvii (♀).—AUD. Orn. Biog. I, pl. xlviii, xlix; NUTT. _Sylvia bifasciata_, SAY, Long’s Exped. I, 1823, 170. _Sylvia populorum_, VIEILL. Encyc. Méth. II, 1823, 449 (from Wilson). Other localities: _Bogota_, SCLATER, P. Z. S. 1857, 18. _Panama R. R._, LAWRENCE, Ann. N. Y. Lyc. 1861, 322. _Yucatan_, LAWR. _Veragua_, SALV. SP. CHAR. _Male._ Above bright blue, darkest on the crown, tinged with ash on the rump; middle of back, scapulars, upper tail-coverts, and sides of the crown, streaked with black. Beneath white; a collar across the breast, and streaks on the sides, dusky-blue. Lores, and a line through and behind the eye (where it is bordered above by whitish), dusky-blue; paler on the cheeks. Two white bands on the wings. All the tail-feathers except the innermost with a white patch on the inner web near the end. _Female_, greenish-blue above, brightest on the crown; beneath white, tinged with greenish-yellow, and obsoletely streaked on the sides; eyelids and a superciliary line greenish-white. Length, 4.25; wing, 2.65; tail, 1.90. HAB. Eastern United States, north to Niagara Falls; Cuba (very rare); Guatemala; Veragua, Panama, and Bogota. Not recorded from Mexico (except Yucatan), or West Indies (except Cuba). The autumnal adult plumage of both sexes is, in every respect, exactly like the spring dress. Young males in late summer are very similar to adult females, but are purer white below, and less uniform greenish-blue above, the dark stripes on sides of the crown and black centres to scapulars being quite conspicuous; the young female, at the same season, is similar in pattern to the adult, but is dull green above, without any tinge of blue, and light buffy-yellow below.