The opinion generally entertained respecting the extensive dispersion of the Black-cap Titmouse, has in all probability originated from the great resemblance which it bears to the Carolina Titmouse, _Parus Carolinensis_, described at p. 341 of the second volume of this work; that species being now known to extend its spring and summer migrations as far eastward as the State of New Jersey, where it has been found breeding by my friend EDWARD HARRIS, Esq. of Moorestown. The Black-cap, on the other hand, is rarely observed farther south, and then only in winter, when it proceeds as far as beyond the middle portions of Maryland, from whence I have at that season received specimens in spirits, collected by my friend Colonel THEODORE ANDERSON of Baltimore. Westward of the Alleghanies it extends as far as Kentucky in winter, but at the approach of spring returns northward. In Pennsylvania and New Jersey some are known to breed; but as the Carolina Titmouse breeds there also, it is difficult to say which of them is the most numerous, they being so like each other that one is apt to confound them. In the State of New York it is abundant, and often rears two broods in the season; as you proceed eastward you may observe it in all places favourable to its habits; and, according to Dr RICHARDSON, it is found as far north as Lat. 65°, it being in the Fur Countries the most common bird, “a small family inhabiting almost every thicket.” None were seen by Dr TOWNSEND either on the Rocky Mountains or about the Columbia River, where, on the contrary, _Parus Carolinensis_ is abundant, as it is also in the Texas, where I found it breeding in the spring of 1837. Although bearing a considerable resemblance to the Marsh Titmouse of Europe, _P. palustris_, it differs from that species not only in colour, but more especially in its habits and notes.