The _Parus sibiricus_ of Europe is very similar in coloration and characters to the _P. hudsonicus_. The principal difference is seen in the cheeks, which in _sibiricus_ are pure white, this color extending along the entire side of the neck, widening behind, and extending round towards the back. In _hudsonicus_ the cheeks behind the eyes and sides of the neck are ash-gray, the white being confined to the region below or near the eye. The smoky-gray of the upper part of head and neck in _sibiricus_ is in a stronger contrast with the brighter rufescent-gray of the back, and is separated from it by an obscure, concealed, whitish dorsal half-collar, represented in _hudsonicus_ only by a dull grayish shade in the plumage. HABITS. This interesting species, one of the liveliest and most animated of its family, belongs to the northern and eastern sections of North America. It is found in the eastern and northern portions of Maine, and probably also in the northern parts of New York, Vermont, and New Hampshire. In the heavily wooded mountain-valley of Errol, in the latter State, Mr. Maynard met with this bird in the latter part of October, in company with the common _atricapillus_. In the same month he also obtained two birds in Albany, in the northwestern corner of Maine. A single specimen was taken at Concord, Massachusetts, October 29, by Mr. William Brewster. Near Calais it is resident, but not common. It is more abundant in the islands of the Bay of Fundy, where it takes the place, almost exclusively, of the _atricapillus_. The writer first met with these lively little wood-sprites in 1850, in the thick swampy woods which cover one of the small islands near Grand Menan. Their general appearance as they flitted through the woods, or rustled restlessly among the tangled débris of decaying trees and underbrush with which the forest was choked, was not unlike that of our common Black-Cap. Yet there was an indescribable something both in their cries and in their manners that at once suggested a difference of species. To my ear their cries were sharper, clearer, and a trifle harsher. There was none of that resonant jingle so full of charm in the Chickadee. Their notes, too, were more articulate, more like distinct words, and were brought out at certain times with an emphasis the effect of which was very striking. Beginning with _tschā-dēē_, the _dēē-dēē-dēē_ was reiterated with an almost incessant volubility.